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11 daysMerge branch 'for-6.19-vsprintf-timespec64' into for-linusPetr Mladek1-1/+27
2025-11-24lib/vsprintf: Unify FORMAT_STATE_NUM handlersAndy Shevchenko1-6/+6
We have two almost identical pieces that handle FORMAT_STATE_NUM case. The differences are: - redundant {} for one-line if-else conditional - missing blank line after variable definitions - inverted conditional Unify the style of two. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20251120083140.3478507-1-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-11-19lib/vsprintf: Add specifier for printing struct timespec64Andy Shevchenko1-1/+27
A handful drivers want to print a content of the struct timespec64 in a format of %lld:%09ld. In order to make their lives easier, add the respecting specifier directly to the printf() implementation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20251113150217.3030010-2-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-11-19lib/vsprintf: Deduplicate special hex number specifier dataAndy Shevchenko1-16/+10
Two functions use the same specifier data for the special hex number. Almost the same as the field width is calculated on the size of the given type. Due to that, make a compound literal macro in order to deduplicate the rest. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20251113150313.3030700-1-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-11-12lib/vsprintf: Check pointer before dereferencing in time_and_date()Andy Shevchenko1-3/+3
The pointer may be invalid when gets to the printf(). In particular the time_and_date() dereferencing it in some cases without checking. Move the check from rtc_str() to time_and_date() to cover all cases. Fixes: 7daac5b2fdf8 ("lib/vsprintf: Print time64_t in human readable format") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20251110132118.4113976-1-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-11-03lib/vsprintf: Improve vsprintf + sprintf function commentsThorsten Blum1-4/+4
Clarify that the return values of vsprintf() and sprintf() exclude the trailing NUL character. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20251103090913.2066-2-thorsten.blum@linux.dev Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-08-04Merge tag 'printk-for-6.17' of ↵Linus Torvalds1-9/+61
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Add new "hash_pointers=[auto|always|never]" boot parameter to force the hashing even with "slab_debug" enabled - Allow to stop CPU, after losing nbcon console ownership during panic(), even without proper NMI - Allow to use the printk kthread immediately even for the 1st registered nbcon - Compiler warning removal * tag 'printk-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: nbcon: Allow reacquire during panic printk: Allow to use the printk kthread immediately even for 1st nbcon slab: Decouple slab_debug and no_hash_pointers vsprintf: Use __diag macros to disable '-Wsuggest-attribute=format' compiler-gcc.h: Introduce __diag_GCC_all
2025-08-04Merge branch 'for-6.17-hash_pointers' into for-linusPetr Mladek1-4/+57
2025-08-04Merge branch 'for-6.15-printf-attribute' into for-linusPetr Mladek1-5/+4
2025-06-09slab: Decouple slab_debug and no_hash_pointersKees Cook1-4/+57
Some system owners use slab_debug=FPZ (or similar) as a hardening option, but do not want to be forced into having kernel addresses exposed due to the implicit "no_hash_pointers" boot param setting.[1] Introduce the "hash_pointers" boot param, which defaults to "auto" (the current behavior), but also includes "always" (forcing on hashing even when "slab_debug=..." is defined), and "never". The existing "no_hash_pointers" boot param becomes an alias for "hash_pointers=never". This makes it possible to boot with "slab_debug=FPZ hash_pointers=always". Link: https://github.com/KSPP/linux/issues/368 [1] Fixes: 792702911f58 ("slub: force on no_hash_pointers when slub_debug is enabled") Co-developed-by: Sergio Perez Gonzalez <sperezglz@gmail.com> Signed-off-by: Sergio Perez Gonzalez <sperezglz@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Kees Cook <kees@kernel.org> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Acked-by: Rafael Aquini <raquini@redhat.com> Tested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20250415170232.it.467-kees@kernel.org [kees@kernel.org: Add note about hash_pointers into slab_debug kernel parameter documentation.] Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-05-28Merge tag 'drm-next-2025-05-28' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-6/+34
Pull drm updates from Dave Airlie: "As part of building up nova-core/nova-drm pieces we've brought in some rust abstractions through this tree, aux bus being the main one, with devres changes also in the driver-core tree. Along with the drm core abstractions and enough nova-core/nova-drm to use them. This is still all stub work under construction, to build the nova driver upstream. The other big NVIDIA related one is nouveau adds support for Hopper/Blackwell GPUs, this required a new GSP firmware update to 570.144, and a bunch of rework in order to support multiple fw interfaces. There is also the introduction of an asahi uapi header file as a precursor to getting the real driver in later, but to unblock userspace mesa packages while the driver is trapped behind rust enablement. Otherwise it's the usual mixture of stuff all over, amdgpu, i915/xe, and msm being the main ones, and some changes to vsprintf. new drivers: - bring in the asahi uapi header standalone - nova-drm: stub driver rust dependencies (for nova-core): - auxiliary - bus abstractions - driver registration - sample driver - devres changes from driver-core - revocable changes core: - add Apple fourcc modifiers - add virtio capset definitions - extend EXPORT_SYNC_FILE for timeline syncobjs - convert to devm_platform_ioremap_resource - refactor shmem helper page pinning - DP powerup/down link helpers - extended %p4cc in vsprintf.c to support fourcc prints - change vsprintf %p4cn to %p4chR, remove %p4cn - Add drm_file_err function - IN_FORMATS_ASYNC property - move sitronix from tiny to their own subdir rust: - add drm core infrastructure rust abstractions (device/driver, ioctl, file, gem) dma-buf: - adjust sg handling to not cache map on attach - allow setting dma-device for import - Add a helper to sort and deduplicate dma_fence arrays docs: - updated drm scheduler docs - fbdev todo update - fb rendering - actual brightness ttm: - fix delayed destroy resv object bridge: - add kunit tests - convert tc358775 to atomic - convert drivers to devm_drm_bridge_alloc - convert rk3066_hdmi to bridge driver scheduler: - add kunit tests panel: - refcount panels to improve lifetime handling - Powertip PH128800T004-ZZA01 - NLT NL13676BC25-03F, Tianma TM070JDHG34-00 - Himax HX8279/HX8279-D DDIC - Visionox G2647FB105 - Sitronix ST7571 - ZOTAC rotation quirk vkms: - allow attaching more displays i915: - xe3lpd display updates - vrr refactor - intel_display struct conversions - xe2hpd memory type identification - add link rate/count to i915_display_info - cleanup VGA plane handling - refactor HDCP GSC - fix SLPC wait boosting reference counting - add 20ms delay to engine reset - fix fence release on early probe errors xe: - SRIOV updates - BMG PCI ID update - support separate firmware for each GT - SVM fix, prelim SVM multi-device work - export fan speed - temp disable d3cold on BMG - backup VRAM in PM notifier instead of suspend/freeze - update xe_ttm_access_memory to use GPU for non-visible access - fix guc_info debugfs for VFs - use copy_from_user instead of __copy_from_user - append PCIe gen5 limitations to xe_firmware document amdgpu: - DSC cleanup - DC Scaling updates - Fused I2C-over-AUX updates - DMUB updates - Use drm_file_err in amdgpu - Enforce isolation updates - Use new dma_fence helpers - USERQ fixes - Documentation updates - SR-IOV updates - RAS updates - PSP 12 cleanups - GC 9.5 updates - SMU 13.x updates - VCN / JPEG SR-IOV updates amdkfd: - Update error messages for SDMA - Userptr updates - XNACK fixes radeon: - CIK doorbell cleanup nouveau: - add support for NVIDIA r570 GSP firmware - enable Hopper/Blackwell support nova-core: - fix task list - register definition infrastructure - move firmware into own rust module - register auxiliary device for nova-drm nova-drm: - initial driver skeleton msm: - GPU: - ACD (adaptive clock distribution) for X1-85 - drop fictional address_space_size - improve GMU HFI response time out robustness - fix crash when throttling during boot - DPU: - use single CTL path for flushing on DPU 5.x+ - improve SSPP allocation code for better sharing - Enabled SmartDMA on SM8150, SC8180X, SC8280XP, SM8550 - Added SAR2130P support - Disabled DSC support on MSM8937, MSM8917, MSM8953, SDM660 - DP: - switch to new audio helpers - better LTTPR handling - DSI: - Added support for SA8775P - Added SAR2130P support - HDMI: - Switched to use new helpers for ACR data - Fixed old standing issue of HPD not working in some cases amdxdna: - add dma-buf support - allow empty command submits renesas: - add dma-buf support - add zpos, alpha, blend support panthor: - fail properly for NO_MMAP bos - add SET_LABEL ioctl - debugfs BO dumping support imagination: - update DT bindings - support TI AM68 GPU hibmc: - improve interrupt handling and HPD support virtio: - add panic handler support rockchip: - add RK3588 support - add DP AUX bus panel support ivpu: - add heartbeat based hangcheck mediatek: - prepares support for MT8195/99 HDMIv2/DDCv2 anx7625: - improve HPD tegra: - speed up firmware loading * tag 'drm-next-2025-05-28' of https://gitlab.freedesktop.org/drm/kernel: (1627 commits) drm/nouveau/tegra: Fix error pointer vs NULL return in nvkm_device_tegra_resource_addr() drm/xe: Default auto_link_downgrade status to false drm/xe/guc: Make creation of SLPC debugfs files conditional drm/i915/display: Add check for alloc_ordered_workqueue() and alloc_workqueue() drm/i915/dp_mst: Work around Thunderbolt sink disconnect after SINK_COUNT_ESI read drm/i915/ptl: Use everywhere the correct DDI port clock select mask drm/nouveau/kms: add support for GB20x drm/dp: add option to disable zero sized address only transactions. drm/nouveau: add support for GB20x drm/nouveau/gsp: add hal for fifo.chan.doorbell_handle drm/nouveau: add support for GB10x drm/nouveau/gf100-: track chan progress with non-WFI semaphore release drm/nouveau/nv50-: separate CHANNEL_GPFIFO handling out from CHANNEL_DMA drm/nouveau: add helper functions for allocating pinned/cpu-mapped bos drm/nouveau: add support for GH100 drm/nouveau: improve handling of 64-bit BARs drm/nouveau/gv100-: switch to volta semaphore methods drm/nouveau/gsp: support deeper page tables in COPY_SERVER_RESERVED_PDES drm/nouveau/gsp: init client VMMs with NV0080_CTRL_DMA_SET_PAGE_DIRECTORY drm/nouveau/gsp: fetch level shift and PDE from BAR2 VMM ...
2025-05-16vsprintf: remove redundant and unused %pCn format specifierLuca Ceresoli1-8/+2
%pC and %pCn print the same string, and commit 900cca294425 ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks") introducing them does not clarify any intended difference. It can be assumed %pC is a default for %pCn as some other specifiers do, but not all are consistent with this policy. Moreover there is now no other suffix other than 'n', which makes a default not really useful. All users in the kernel were using %pC except for one which has been converted. So now remove %pCn and all the unnecessary extra code and documentation. Acked-by: Stephen Boyd <sboyd@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Yanteng Si <si.yanteng@linux.dev> Link: https://lore.kernel.org/r/20250311-vsprintf-pcn-v2-2-0af40fc7dee4@bootlin.com Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2025-04-29vsprintf: Use %p4chR instead of %p4cn for reading data in reversed host orderingPetr Mladek1-3/+8
The generic FourCC format always prints the data using the big endian order. It is generic because it allows to read the data using a custom ordering. The current code uses "n" for reading data in the reverse host ordering. It makes the 4 variants [hnbl] consistent with the generic printing of IPv4 addresses. Unfortunately, it creates confusion on big endian systems. For example, it shows the data &(u32)0x67503030 as %p4cn 00Pg (0x30305067) But people expect that the ordering stays the same. The network ordering is a big-endian ordering. The problem is that the semantic is not the same. The modifiers affect the output ordering of IPv4 addresses while they affect the reading order in case of FourCC code. Avoid the confusion by replacing the "n" modifier with "hR", aka reverse host ordering. It is inspired by the existing %p[mM]R printf format. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Closes: https://lore.kernel.org/r/CAMuHMdV9tX=TG7E_CrSF=2PY206tXf+_yYRuacG48EWEtJLo-Q@mail.gmail.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Aditya Garg <gargaditya08@live.com> Link: https://lore.kernel.org/r/20250428123132.578771-1-pmladek@suse.com Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
2025-04-21lib/vsprintf: Add support for generic FourCCs by extending %p4ccHector Martin1-6/+29
%p4cc is designed for DRM/V4L2 FourCCs with their specific quirks, but it's useful to be able to print generic 4-character codes formatted as an integer. Extend it to add format specifiers for printing generic 32-bit FourCCs with various endian semantics: %p4ch Host byte order %p4cn Network byte order %p4cl Little-endian %p4cb Big-endian The endianness determines how bytes are interpreted as a u32, and the FourCC is then always printed MSByte-first (this is the opposite of V4L/DRM FourCCs). This covers most practical cases, e.g. %p4cn would allow printing LSByte-first FourCCs stored in host endian order (other than the hex form being in character order, not the integer value). Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Hector Martin <marcan@marcan.st> Signed-off-by: Aditya Garg <gargaditya08@live.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/PN3PR01MB9597B01823415CB7FCD3BC27B8B52@PN3PR01MB9597.INDPRD01.PROD.OUTLOOK.COM Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
2025-04-10vsprintf: Use __diag macros to disable '-Wsuggest-attribute=format'Nathan Chancellor1-5/+4
The GCC specific warning '-Wsuggest-attribute=format' is disabled around va_format() using raw #pragma statements, which includes an '#ifndef __clang__' to avoid a warning about an unknown warning option from clang (which recognizes '#pragma GCC' for compatibility reasons): lib/vsprintf.c:1703:32: error: unknown warning group '-Wsuggest-attribute=format', ignored [-Werror,-Wunknown-warning-option] 1703 | #pragma GCC diagnostic ignored "-Wsuggest-attribute=format" | ^ While the current solution works, it is not visually appealing. The kernel already has some infrastructure that wraps these #pragma statements to give more specific control over diagnostics without needing #ifdef blocks for different compilers. Convert the existing statements over to the __diag macros. Closes: https://lore.kernel.org/r/CAHk-=wgfX9nBGE0Ap9GjhOy7Mn=RSy=rx0MvqfYFFDx31KJXqQ@mail.gmail.com Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://patch.msgid.link/20250404-vsprintf-convert-pragmas-to-__diag-v1-2-5d6c5c55b2bd@kernel.org Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-04-02Merge tag 'printk-for-6.15-2' of ↵Linus Torvalds1-2/+7
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull more printk updates from Petr Mladek: - Silence warnings about candidates for ‘gnu_print’ format attribute * tag 'printk-for-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: vsnprintf: Silence false positive GCC warning for va_format() vsnprintf: Drop unused const char fmt * in va_format() vsnprintf: Mark binary printing functions with __printf() attribute tracing: Mark binary printing functions with __printf() attribute seq_file: Mark binary printing functions with __printf() attribute seq_buf: Mark binary printing functions with __printf() attribute
2025-03-30Merge tag 'rust-6.15' of ↵Linus Torvalds1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Extract the 'pin-init' API from the 'kernel' crate and make it into a standalone crate. In order to do this, the contents are rearranged so that they can easily be kept in sync with the version maintained out-of-tree that other projects have started to use too (or plan to, like QEMU). This will reduce the maintenance burden for Benno, who will now have his own sub-tree, and will simplify future expected changes like the move to use 'syn' to simplify the implementation. - Add '#[test]'-like support based on KUnit. We already had doctests support based on KUnit, which takes the examples in our Rust documentation and runs them under KUnit. Now, we are adding the beginning of the support for "normal" tests, similar to those the '#[test]' tests in userspace Rust. For instance: #[kunit_tests(my_suite)] mod tests { #[test] fn my_test() { assert_eq!(1 + 1, 2); } } Unlike with doctests, the 'assert*!'s do not map to the KUnit assertion APIs yet. - Check Rust signatures at compile time for functions called from C by name. In particular, introduce a new '#[export]' macro that can be placed in the Rust function definition. It will ensure that the function declaration on the C side matches the signature on the Rust function: #[export] pub unsafe extern "C" fn my_function(a: u8, b: i32) -> usize { // ... } The macro essentially forces the compiler to compare the types of the actual Rust function and the 'bindgen'-processed C signature. These cases are rare so far. In the future, we may consider introducing another tool, 'cbindgen', to generate C headers automatically. Even then, having these functions explicitly marked may be a good idea anyway. - Enable the 'raw_ref_op' Rust feature: it is already stable, and allows us to use the new '&raw' syntax, avoiding a couple macros. After everyone has migrated, we will disallow the macros. - Pass the correct target to 'bindgen' on Usermode Linux. - Fix 'rusttest' build in macOS. 'kernel' crate: - New 'hrtimer' module: add support for setting up intrusive timers without allocating when starting the timer. Add support for 'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and 'Pin<&mut _>' as pointer types for use with timer callbacks. Add support for setting clock source and timer mode. - New 'dma' module: add a simple DMA coherent allocator abstraction and a test sample driver. - 'list' module: make the linked list 'Cursor' point between elements, rather than at an element, which is more convenient to us and allows for cursors to empty lists; and document it with examples of how to perform common operations with the provided methods. - 'str' module: implement a few traits for 'BStr' as well as the 'strip_prefix()' method. - 'sync' module: add 'Arc::as_ptr'. - 'alloc' module: add 'Box::into_pin'. - 'error' module: extend the 'Result' documentation, including a few examples on different ways of handling errors, a warning about using methods that may panic, and links to external documentation. 'macros' crate: - 'module' macro: add the 'authors' key to support multiple authors. The original key will be kept until everyone has migrated. Documentation: - Add error handling sections. MAINTAINERS: - Add Danilo Krummrich as reviewer of the Rust "subsystem". - Add 'RUST [PIN-INIT]' entry with Benno Lossin as maintainer. It has its own sub-tree. - Add sub-tree for 'RUST [ALLOC]'. - Add 'DMA MAPPING HELPERS DEVICE DRIVER API [RUST]' entry with Abdiel Janulgue as primary maintainer. It will go through the sub-tree of the 'RUST [ALLOC]' entry. - Add 'HIGH-RESOLUTION TIMERS [RUST]' entry with Andreas Hindborg as maintainer. It has its own sub-tree. And a few other cleanups and improvements" * tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (71 commits) rust: dma: add `Send` implementation for `CoherentAllocation` rust: macros: fix `make rusttest` build on macOS rust: block: refactor to use `&raw mut` rust: enable `raw_ref_op` feature rust: uaccess: name the correct function rust: rbtree: fix comments referring to Box instead of KBox rust: hrtimer: add maintainer entry rust: hrtimer: add clocksource selection through `ClockId` rust: hrtimer: add `HrTimerMode` rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>` rust: alloc: add `Box::into_pin` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>` rust: hrtimer: add `hrtimer::ScopedHrTimerPointer` rust: hrtimer: add `UnsafeHrTimerPointer` rust: hrtimer: allow timer restart from timer handler rust: str: implement `strip_prefix` for `BStr` rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr` rust: str: implement `Index` for `BStr` rust: str: implement `PartialEq` for `BStr` ...
2025-03-28vsnprintf: Silence false positive GCC warning for va_format()Andy Shevchenko1-0/+5
va_format() is using vsnprintf(), and GCC compiler (Debian 14.2.0-17) is not happy about this: lib/vsprintf.c:1704:9: error: function ‘va_format’ might be a candidate for ‘gnu_print ’ format attribute [-Werror=suggest-attribute=format] Fix the compilation errors (`make W=1` when CONFIG_WERROR=y, which is default) by silencing the false positive GCC warning. Suggested-by: Rasmus Villemoes <ravi@prevas.dk> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Kees Cook <kees@kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250321144822.324050-7-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-03-28vsnprintf: Drop unused const char fmt * in va_format()Andy Shevchenko1-2/+2
va_format() doesn't use original formatting string, drop that argument as it's done elsewhere in similar cases. Suggested-by: Rasmus Villemoes <ravi@prevas.dk> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Kees Cook <kees@kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250321144822.324050-6-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com>
2025-03-09print: use new #[export] macro for rust_fmt_argumentAlice Ryhl1-3/+0
This moves the rust_fmt_argument function over to use the new #[export] macro, which will verify at compile-time that the function signature matches what is in the header file. Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250303-export-macro-v3-4-41fbad85a27f@google.com [ Removed period as requested by Andy. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-09rust: fix signature of rust_fmt_argumentAlice Ryhl1-1/+1
Without this change, the rest of this series will emit the following error message: error[E0308]: `if` and `else` have incompatible types --> <linux>/rust/kernel/print.rs:22:22 | 21 | #[export] | --------- expected because of this 22 | unsafe extern "C" fn rust_fmt_argument( | ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8` | = note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}` found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}` The error may be different depending on the architecture. To fix this, change the void pointer argument to use a const pointer, and change the imports to use crate::ffi instead of core::ffi for integer types. Fixes: 787983da7718 ("vsprintf: add new `%pA` format specifier") Reviewed-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250303-export-macro-v3-1-41fbad85a27f@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-08vsprintf: add simple_strntoulDavid Disseldorp1-0/+7
cpio extraction currently does a memcpy to ensure that the archive hex fields are null terminated for simple_strtoul(). simple_strntoul() will allow us to avoid the memcpy. Signed-off-by: David Disseldorp <ddiss@suse.de> Link: https://lore.kernel.org/r/20250304061020.9815-4-ddiss@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-01-13vsnprintf: fix the number base for non-numeric formatsLinus Torvalds1-1/+2
Commit 8d4826cc8a8a ("vsnprintf: collapse the number format state into one single state") changed the format specification decoding to be a bit more straightforward but in the process ended up also resetting the number base to zero for formats that aren't clearly numerical. Now, the number base obviously doesn't matter for something like '%s', so this wasn't all that obvious. But some of our specialized pointer extension formatting (ie, things like "print out IPv6 address") did up depending on the default base-10 setting, and when they then tried to print out numbers in "base zero", things didn't work out so well. Most pointer formatting (including things like the default raw hex value conversion) didn't have this issue, because they used helpers that explicitly set the base. Reported-and-tested-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202501131352.e226f995-lkp@intel.com Fixes: 8d4826cc8a8a ("vsnprintf: collapse the number format state into one single state") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-01-06vsnprintf: fix up kerneldoc for argument name changesLinus Torvalds1-3/+3
Stephen Rothwell reports that I missed fixing up the documentation when the argument names changed in commit 938df695e98d ("vsprintf: associate the format state with the format pointer"), resulting in htmldoc warnings like lib/vsprintf.c:2760: warning: Function parameter or struct member 'fmt_str' not described in 'vsnprintf' lib/vsprintf.c:2760: warning: Excess function parameter 'fmt' description in 'vsnprintf' ... which I didn't notice because the doc build takes longer than the whole "real" kernel build for me, so I never bother (and judging by the other warnings, pretty much nobody else does either). I guess the bigger issues won't be fixed until the doc build is much faster (narrator: "That isn's in the cards") but at least linux-next finds the new cases. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 938df695e98d ("vsprintf: associate the format state with the format pointer") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: don't make the 'binary' version pack small integer argumentsLinus Torvalds1-23/+6
The strange vbin_printf / bstr_printf interface used to save one- and two-byte printf numerical arguments into their packed format. That's more than a bit strange since the argument buffer is supposed to be an array of 'u32' words, and it's also very different from how the source of the data (varargs) work - which always do the normal integer type conversions, so 'char' and 'short' are always passed as int-sized anyway. This odd packing causes extra code complexity, and it really isn't worth it, since the space savings are simply not there: it only happens for formats like '%hd' (short) and '%hhd' (char), which are very rare indeed. In fact, the only other user of this interface seems to be the bpf helper code (bpf_bprintf_prepare()), and Alexei points out that that case doesn't support those truncated integer formatting options at all in the first place. As a result, bpf_bprintf_prepare() doesn't need any changes for this, and TRACE_BPRINT uses 'vbin_printf()' -> 'bstr_printf()' for the formatting and hopefully doesn't expose the odd packing any other way (knock wood). Link: https://lore.kernel.org/all/CAADnVQJy65oOubjxM-378O3wDfhuwg8TGa9hc-cTv6NmmUSykQ@mail.gmail.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsnprintf: collapse the number format state into one single stateLinus Torvalds1-71/+66
We'll squirrel away the size of the number in 'struct fmt' instead. We have two fairly separate state structures: the 'decode state' is in 'struct fmt', while the 'printout format' is in 'printf_spec'. Both structures are small enough to pass around in registers even across function boundaries (ie two words), even on 32-bit machines. The goal here is to avoid the case statements on the format states, which generate either deep conditionals or jump tables, while also keeping the state size manageable. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsnprintf: mark the indirect width and precision cases unlikelyLinus Torvalds1-4/+4
Make the format_decode() code generation easier to look at by getting the strange and unlikely cases out of line. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsnprintf: inline skip_atoi() againLinus Torvalds1-2/+1
At some point skip_atoi() had been marked 'noinline_for_stack', but it turns out that this is now a pessimization, and not inlining it actually results in a stack frame in format decoding due to the call and thus hurts stack usage rather than helping. With the simplistic atoi function inlined, the format decoding now needs no frame at all. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: deal with format specifiers with a lookup tableLinus Torvalds1-79/+54
We did the flags as an array earlier, they had simpler rules. The final format specifiers are a bit more complex since they have more fields to deal with, and we want to handle the length modifiers at the same time. But like the flags, we're better off just making it a data-driven table rather than some case statement. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: deal with format flags with a simple lookup tableLinus Torvalds1-20/+21
Rather than a case statement, just look up the printf format flags (justification, zero-padding etc) using a small table. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: associate the format state with the format pointerLinus Torvalds1-135/+157
The vsnprintf() code is written as a state machine as it walks the format pointer, but for various historical reasons the state is oddly named and was encoded as the 'type' field in the 'struct printf_spec'. That naming came from the fact that the states used to not just encode the state of the state machine, but also the various integer types that would then be printed out. Let's make the state machine more obvious, and actually call it 'state', and associate it with the format pointer itself, rather than the 'printf_spec' that contains the currently decoded formatting specs. This also removes the bit packing from printf_spec, which makes it much easier on the compiler. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: fix calling convention for format_decode()Linus Torvalds1-20/+17
Every single caller wants to know what the next format location is, but instead the function returned the length of the processed part and so every single return statement in the format_decode() function was instead subtracting the start of the format string. The callers that that did want to know the length (in addition to the end of the format processing) already had to save off the start of the format string anyway. So this was all just doing extra processing both on the caller and callee sides. Just change the calling convention to return the end of the format processing, making everything simpler (and preparing for yet more simplification to come). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: avoid nested switch statement on same variableLinus Torvalds1-52/+47
Now that we have simplified the number format types, the top-level switch table can easily just handle all the remaining cases, and we don't need to have a case statement with a conditional on the same expression as the switch statement. We do want to fall through to the common 'number()' case, but that's trivially done by making the other case statements use 'continue' instead of 'break'. They are just looping back to the top, after all. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-23vsprintf: simplify number handlingLinus Torvalds1-102/+42
Instead of dealing with all the different special types (size_t, unsigned char, ptrdiff_t..) just deal with the size of the integer type and the sign. This avoids a lot of unnecessary case statements, and the games we play with the value of the 'SIGN' flags value Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-11-30printf: Remove unused 'bprintf'Dr. David Alan Gilbert1-23/+0
bprintf() is unused. Remove it. It was added in the commit 4370aa4aa753 ("vsprintf: add binary printf") but as far as I can see was never used, unlike the other two functions in that patch. Link: https://lore.kernel.org/20241002173147.210107-1-linux@treblig.org Reviewed-by: Andy Shevchenko <andy@kernel.org> Acked-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-28printf: Add print format (%pra) for struct rangeIra Weiny1-6/+51
The use of struct range in the CXL subsystem is growing. In particular, the addition of Dynamic Capacity devices uses struct range in a number of places which are reported in debug and error messages. To wit requiring the printing of the start/end fields in each print became cumbersome. Dan Williams mentions in [1] that it might be time to have a print specifier for struct range similar to struct resource. A few alternatives were considered including '%par', '%r', and '%pn'. %pra follows that struct range is similar to struct resource (%p[rR]) but needs to be different. Based on discussions with Petr and Andy '%pra' was chosen.[2] Andy also suggested to keep the range prints similar to struct resource though combined code. Add hex_range() to handle printing for both pointer types. Finally introduce DEFINE_RANGE() as a parallel to DEFINE_RES_*() and use it in the tests. Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: open list <linux-kernel@vger.kernel.org> Link: https://lore.kernel.org/all/663922b475e50_d54d72945b@dwillia2-xfh.jf.intel.com.notmuch/ [1] Link: https://lore.kernel.org/all/66cea3bf3332f_f937b29424@iweiny-mobl.notmuch/ [2] Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://patch.msgid.link/20241025-cxl-pra-v2-3-123a825daba2@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro1-1/+1
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-03printf: remove %pGt supportMatthew Wilcox (Oracle)1-21/+0
Patch series "Increase the number of bits available in page_type". Kent wants more than 16 bits in page_type, so I resurrected this old patch and expanded it a bit. It's a bit more efficient than our current scheme (1 4-byte insn vs 3 insns of 13 bytes total) to test a single page type. This patch (of 4): An upcoming patch will convert page type from being a bitfield to a single byte, so we will not be able to use %pG to print the page type any more. The printing of the symbolic name will be restored in that patch. Link: https://lkml.kernel.org/r/20240821173914.2270383-1-willy@infradead.org Link: https://lkml.kernel.org/r/20240821173914.2270383-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-28minmax: don't use max() in situations that want a C constant expressionLinus Torvalds1-1/+1
We only had a couple of array[] declarations, and changing them to just use 'MAX()' instead of 'max()' fixes the issue. This will allow us to simplify our min/max macros enormously, since they can now unconditionally use temporary variables to avoid using the argument values multiple times. Cc: David Laight <David.Laight@aculab.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-05-02wrapper for access to ->bd_partnoAl Viro1-1/+1
On the next step it's going to get folded into a field where flags will go. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-05-02Use bdev_is_paritition() instead of open-coding itAl Viro1-1/+1
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-12-06lib/vsprintf: Fix %pfwf when current node refcount == 0Herve Codina1-3/+8
A refcount issue can appeared in __fwnode_link_del() due to the pr_debug() call: WARNING: CPU: 0 PID: 901 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110 Call Trace: <TASK> ... of_node_get+0x1e/0x30 of_fwnode_get+0x28/0x40 fwnode_full_name_string+0x34/0x90 fwnode_string+0xdb/0x140 ... vsnprintf+0x17b/0x630 ... __fwnode_link_del+0x25/0xa0 fwnode_links_purge+0x39/0xb0 of_node_release+0xd9/0x180 ... Indeed, an fwnode (of_node) is being destroyed and so, of_node_release() is called because the of_node refcount reached 0. From of_node_release() several function calls are done and lead to a pr_debug() calls with %pfwf to print the fwnode full name. The issue is not present if we change %pfwf to %pfwP. To print the full name, %pfwf iterates over the current node and its parents and obtain/drop a reference to all nodes involved. In order to allow to print the full name (%pfwf) of a node while it is being destroyed, do not obtain/drop a reference to this current node. Fixes: a92eb7621b9f ("lib/vsprintf: Make use of fwnode API to obtain node names and separators") Cc: stable@vger.kernel.org Signed-off-by: Herve Codina <herve.codina@bootlin.com> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20231114152655.409331-1-herve.codina@bootlin.com
2023-11-01vsprintf: uninline simple_strntoull(), reorder argumentsAlexey Dobriyan1-13/+12
* uninline simple_strntoull(), gcc overinlines and this function is not performance critical * reorder arguments, so that appending INT_MAX as 4th argument generates very efficient tail call Space savings: add/remove: 1/0 grow/shrink: 0/3 up/down: 27/-179 (-152) Function old new delta simple_strntoll - 27 +27 simple_strtoull 15 10 -5 simple_strtoll 41 7 -34 vsscanf 1930 1790 -140 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/all/82a2af6e-9b6c-4a09-89d7-ca90cc1cdad1@p183/
2023-08-21lib/vsprintf: split out sprintf() and friendsAndy Shevchenko1-0/+1
Patch series "lib/vsprintf: Rework header inclusions", v3. Some patches that reduce the mess with the header inclusions related to vsprintf.c module. Each patch has its own description, and has no dependencies to each other, except the collisions over modifications of the same places. Hence the series. This patch (of 2): kernel.h is being used as a dump for all kinds of stuff for a long time. sprintf() and friends are used in many drivers without need of the full kernel.h dependency train with it. Here is the attempt on cleaning it up by splitting out sprintf() and friends. Link: https://lkml.kernel.org/r/20230814163344.17429-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20230814163344.17429-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-27Merge tag 'mm-stable-2023-04-27-15-30' of ↵Linus Torvalds1-0/+21
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...
2023-04-03lib/vsprintf: Use isodigit() for the octal number checkAndy Shevchenko1-1/+1
Use isodigit() to test the octal number instead of homegrown approach. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230327142721.48378-1-andriy.shevchenko@linux.intel.com
2023-03-28mm, printk: introduce new format %pGt for page_typeHyeonggon Yoo1-0/+21
%pGp format is used to display 'flags' field of a struct page. However, some page flags (i.e. PG_buddy, see page-flags.h for more details) are stored in page_type field. To display human-readable output of page_type, introduce %pGt format. It is important to note the meaning of bits are different in page_type. if page_type is 0xffffffff, no flags are set. Setting PG_buddy (0x00000080) flag results in a page_type of 0xffffff7f. Clearing a bit actually means setting a flag. Bits in page_type are inverted when displaying type names. Only values for which page_type_has_type() returns true are considered as page_type, to avoid confusion with mapcount values. if it returns false, only raw values are displayed and not page type names. Link: https://lkml.kernel.org/r/20230130042514.2418-3-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> [vsprintf part] Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: John Ogness <john.ogness@linutronix.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-12Merge tag 'random-6.2-rc1-for-linus' of ↵Linus Torvalds1-9/+5
git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: - Replace prandom_u32_max() and various open-coded variants of it, there is now a new family of functions that uses fast rejection sampling to choose properly uniformly random numbers within an interval: get_random_u32_below(ceil) - [0, ceil) get_random_u32_above(floor) - (floor, U32_MAX] get_random_u32_inclusive(floor, ceil) - [floor, ceil] Coccinelle was used to convert all current users of prandom_u32_max(), as well as many open-coded patterns, resulting in improvements throughout the tree. I'll have a "late" 6.1-rc1 pull for you that removes the now unused prandom_u32_max() function, just in case any other trees add a new use case of it that needs to converted. According to linux-next, there may be two trivial cases of prandom_u32_max() reintroductions that are fixable with a 's/.../.../'. So I'll have for you a final conversion patch doing that alongside the removal patch during the second week. This is a treewide change that touches many files throughout. - More consistent use of get_random_canary(). - Updates to comments, documentation, tests, headers, and simplification in configuration. - The arch_get_random*_early() abstraction was only used by arm64 and wasn't entirely useful, so this has been replaced by code that works in all relevant contexts. - The kernel will use and manage random seeds in non-volatile EFI variables, refreshing a variable with a fresh seed when the RNG is initialized. The RNG GUID namespace is then hidden from efivarfs to prevent accidental leakage. These changes are split into random.c infrastructure code used in the EFI subsystem, in this pull request, and related support inside of EFISTUB, in Ard's EFI tree. These are co-dependent for full functionality, but the order of merging doesn't matter. - Part of the infrastructure added for the EFI support is also used for an improvement to the way vsprintf initializes its siphash key, replacing an sleep loop wart. - The hardware RNG framework now always calls its correct random.c input function, add_hwgenerator_randomness(), rather than sometimes going through helpers better suited for other cases. - The add_latent_entropy() function has long been called from the fork handler, but is a no-op when the latent entropy gcc plugin isn't used, which is fine for the purposes of latent entropy. But it was missing out on the cycle counter that was also being mixed in beside the latent entropy variable. So now, if the latent entropy gcc plugin isn't enabled, add_latent_entropy() will expand to a call to add_device_randomness(NULL, 0), which adds a cycle counter, without the absent latent entropy variable. - The RNG is now reseeded from a delayed worker, rather than on demand when used. Always running from a worker allows it to make use of the CPU RNG on platforms like S390x, whose instructions are too slow to do so from interrupts. It also has the effect of adding in new inputs more frequently with more regularity, amounting to a long term transcript of random values. Plus, it helps a bit with the upcoming vDSO implementation (which isn't yet ready for 6.2). - The jitter entropy algorithm now tries to execute on many different CPUs, round-robining, in hopes of hitting even more memory latencies and other unpredictable effects. It also will mix in a cycle counter when the entropy timer fires, in addition to being mixed in from the main loop, to account more explicitly for fluctuations in that timer firing. And the state it touches is now kept within the same cache line, so that it's assured that the different execution contexts will cause latencies. * tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits) random: include <linux/once.h> in the right header random: align entropy_timer_state to cache line random: mix in cycle counter when jitter timer fires random: spread out jitter callback to different CPUs random: remove extraneous period and add a missing one in comments efi: random: refresh non-volatile random seed when RNG is initialized vsprintf: initialize siphash key using notifier random: add back async readiness notifier random: reseed in delayed work rather than on-demand random: always mix cycle counter in add_latent_entropy() hw_random: use add_hwgenerator_randomness() for early entropy random: modernize documentation comment on get_random_bytes() random: adjust comment to account for removed function random: remove early archrandom abstraction random: use random.trust_{bootloader,cpu} command line option only stackprotector: actually use get_random_canary() stackprotector: move get_random_canary() into stackprotector.h treewide: use get_random_u32_inclusive() when possible treewide: use get_random_u32_{above,below}() instead of manual loop treewide: use get_random_u32_below() instead of deprecated function ...
2022-11-22vsprintf: initialize siphash key using notifierJason A. Donenfeld1-9/+5
Rather than polling every second, use the new notifier to do this at exactly the right moment. Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-18vsprintf: replace in_irq() with in_hardirq()ye xingchen1-1/+1
Replace the obsolete and ambiguos macro in_irq() with new macro in_hardirq(). Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221011024831.322799-1-ye.xingchen@zte.com.cn
2022-10-10Merge tag 'printk-for-6.1' of ↵Linus Torvalds1-23/+28
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Initialize pointer hashing using the system workqueue. It avoids taking locks in printk()/vsprintf() code path - Misc code clean up * tag 'printk-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Mark __printk percpu data ready __ro_after_init printk: Remove bogus comment vs. boot consoles printk: Remove write only variable nr_ext_console_drivers printk: Declare log_wait properly printk: Make pr_flush() static lib/vsprintf: Initialize vsprintf's pointer hash once the random core is ready. lib/vsprintf: Remove static_branch_likely() from __ptr_to_hashval(). lib/vnsprintf: add const modifier for param 'bitmap'
2022-10-04Merge branch 'for-6.1-hash-pointer-init' into for-linusPetr Mladek1-21/+26
2022-09-29lib/vsprintf: Initialize vsprintf's pointer hash once the random core is ready.Sebastian Andrzej Siewior1-19/+27
The printk code invokes vnsprintf in order to compute the complete string before adding it into its buffer. This happens in an IRQ-off region which leads to a warning on PREEMPT_RT in the random code if the format strings contains a %p for pointer printing. This happens because the random core acquires locks which become sleeping locks on PREEMPT_RT which must not be acquired with disabled interrupts and or preemption disabled. By default the pointers are hashed which requires a random value on the first invocation (either by printk or another user which comes first. One could argue that there is no need for printk to disable interrupts during the vsprintf() invocation which would fix the just mentioned problem. However printk itself can be invoked in a context with disabled interrupts which would lead to the very same problem. Move the initialization of ptr_key into a worker and schedule it from subsys_initcall(). This happens early but after the workqueue subsystem is ready. Use get_random_bytes() to retrieve the random value if the RNG core is ready, otherwise schedule a worker in two seconds and try again. Another advantage is that it removes a lock from the vsprintf() code path. It prevents a possible deadlock when printk("%p", ptr) is called under the lock taken in get_random_bytes(). Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Petr Mladek <pmladek@suse.com> [pmladek@suse.com: Added a note about the it prevented a possible deadlock in printk().] Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220927104912.622645-3-bigeasy@linutronix.de
2022-09-29lib/vsprintf: Remove static_branch_likely() from __ptr_to_hashval().Sebastian Andrzej Siewior1-11/+8
Using static_branch_likely() to signal that ptr_key has been filled is a bit much given that it is not a fast path. Replace static_branch_likely() with bool for condition and a memory barrier for ptr_key. Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220927104912.622645-2-bigeasy@linutronix.de
2022-09-28vsprintf: add new `%pA` format specifierGary Guo1-0/+13
This patch adds a format specifier `%pA` to `vsprintf` which formats a pointer as `core::fmt::Arguments`. Doing so allows us to directly format to the internal buffer of `printf`, so we do not have to use a temporary buffer on the stack to pre-assemble the message on the Rust side. This specifier is intended only to be used from Rust and not for C, so `checkpatch.pl` is intentionally unchanged to catch any misuse. Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-08-25lib/vnsprintf: add const modifier for param 'bitmap'Jian Shen1-2/+2
There is no modification for param bitmap in function bitmap_string() and bitmap_list_string(), so add const modifier for it. Signed-off-by: Jian Shen <shenjian15@huawei.com> Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220816144557.30779-1-huangguangbin2@huawei.com
2022-06-10random: remove rng_has_arch_random()Jason A. Donenfeld1-2/+1
With arch randomness being used by every distro and enabled in defconfigs, the distinction between rng_has_arch_random() and rng_is_initialized() is now rather small. In fact, the places where they differ are now places where paranoid users and system builders really don't want arch randomness to be used, in which case we should respect that choice, or places where arch randomness is known to be broken, in which case that choice is all the more important. So this commit just removes the function and its one user. Reviewed-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-05-19random: remove mostly unused async readiness notifierJason A. Donenfeld1-44/+22
The register_random_ready_notifier() notifier is somewhat complicated, and was already recently rewritten to use notifier blocks. It is only used now by one consumer in the kernel, vsprintf.c, for which the async mechanism is really overly complex for what it actually needs. This commit removes register_random_ready_notifier() and unregister_random_ ready_notifier(), because it just adds complication with little utility, and changes vsprintf.c to just check on `!rng_is_initialized() && !rng_has_arch_random()`, which will eventually be true. Performance- wise, that code was already using a static branch, so there's basically no overhead at all to this change. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-05-19random: remove get_random_bytes_arch() and add rng_has_arch_random()Jason A. Donenfeld1-4/+3
The RNG incorporates RDRAND into its state at boot and every time it reseeds, so there's no reason for callers to use it directly. The hashing that the RNG does on it is preferable to using the bytes raw. The only current use case of get_random_bytes_arch() is vsprintf's siphash key for pointer hashing, which uses it to initialize the pointer secret earlier than usual if RDRAND is available. In order to replace this narrow use case, just expose whether RDRAND is mixed into the RNG, with a new function called rng_has_arch_random(). With that taken care of, there are no users of get_random_bytes_arch() left, so it can be removed. Later, if trust_cpu gets turned on by default (as most distros are doing), this one use of rng_has_arch_random() can probably go away as well. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-24lib/vsprintf: avoid redundant work with 0 sizeWaiman Long1-3/+5
Patch series "mm/page_owner: Extend page_owner to show memcg information", v4. While debugging the constant increase in percpu memory consumption on a system that spawned large number of containers, it was found that a lot of offline mem_cgroup structures remained in place without being freed. Further investigation indicated that those mem_cgroup structures were pinned by some pages. In order to find out what those pages are, the existing page_owner debugging tool is extended to show memory cgroup information and whether those memcgs are offline or not. With the enhanced page_owner tool, the following is a typical page that pinned the mem_cgroup structure in my test case: Page allocated via order 0, mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 162970 (podman), ts 1097761405537 ns, free_ts 1097760838089 ns PFN 1925700 type Movable Block 3761 type Movable Flags 0x17ffffc00c001c(uptodate|dirty|lru|reclaim|swapbacked|node=0|zone=2|lastcpupid=0x1fffff) prep_new_page+0xac/0xe0 get_page_from_freelist+0x1327/0x14d0 __alloc_pages+0x191/0x340 alloc_pages_vma+0x84/0x250 shmem_alloc_page+0x3f/0x90 shmem_alloc_and_acct_page+0x76/0x1c0 shmem_getpage_gfp+0x281/0x940 shmem_write_begin+0x36/0xe0 generic_perform_write+0xed/0x1d0 __generic_file_write_iter+0xdc/0x1b0 generic_file_write_iter+0x5d/0xb0 new_sync_write+0x11f/0x1b0 vfs_write+0x1ba/0x2a0 ksys_write+0x59/0xd0 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Charged to offline memcg libpod-conmon-15e4f9c758422306b73b2dd99f9d50a5ea53cbb16b4a13a2c2308a4253cc0ec8. So the page was not freed because it was part of a shmem segment. That is useful information that can help users to diagnose similar problems. With cgroup v1, /proc/cgroups can be read to find out the total number of memory cgroups (online + offline). With cgroup v2, the cgroup.stat of the root cgroup can be read to find the number of dying cgroups (most likely pinned by dying memcgs). The page_owner feature is not supposed to be enabled for production system due to its memory overhead. However, if it is suspected that dying memcgs are increasing over time, a test environment with page_owner enabled can then be set up with appropriate workload for further analysis on what may be causing the increasing number of dying memcgs. This patch (of 4): For *scnprintf(), vsnprintf() is always called even if the input size is 0. That is a waste of time, so just return 0 in this case. Note that vsnprintf() will never return -1 to indicate an error. So skipping the call to vsnprintf() when size is 0 will have no functional impact at all. Link: https://lkml.kernel.org/r/20220202203036.744010-1-longman@redhat.com Link: https://lkml.kernel.org/r/20220202203036.744010-2-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Rafael Aquini <aquini@redhat.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Ira Weiny <ira.weiny@intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23Merge tag 'printk-for-5.18' of ↵Linus Torvalds1-20/+29
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Make %pK behave the same as %p for kptr_restrict == 0 also with no_hash_pointers parameter - Ignore the default console in the device tree also when console=null or console="" is used on the command line - Document console=null and console="" behavior - Prevent a deadlock and a livelock caused by console_lock in panic() - Make console_lock available for panicking CPU - Fast query for the next to-be-used sequence number - Use the expected return values in printk.devkmsg __setup handler - Use the correct atomic operations in wake_up_klogd() irq_work handler - Avoid possible unaligned access when handling %4cc printing format * tag 'printk-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: fix return value of printk.devkmsg __setup handler vsprintf: Fix %pK with kptr_restrict == 0 printk: make suppress_panic_printk static printk: Set console_set_on_cmdline=1 when __add_preferred_console() is called with user_specified == true Docs: printk: add 'console=null|""' to admin/kernel-parameters printk: use atomic updates for klogd work printk: Drop console_sem during panic printk: Avoid livelock with heavy printk during panic printk: disable optimistic spin during panic printk: Add panic_in_progress helper vsprintf: Move space out of string literals in fourcc_string() vsprintf: Fix potential unaligned access printk: ringbuffer: Improve prb_next_seq() performance
2022-03-21Merge branch 'for-5.18-vsprintf-fourcc-fixup' into for-linusPetr Mladek1-5/+8
2022-03-12random: replace custom notifier chain with standard oneJason A. Donenfeld1-4/+6
We previously rolled our own randomness readiness notifier, which only has two users in the whole kernel. Replace this with a more standard atomic notifier block that serves the same purpose with less code. Also unexport the symbols, because no modules use it, only unconditional builtins. The only drawback is that it's possible for a notification handler returning the "stop" code to prevent further processing, but given that there are only two users, and that we're unexporting this anyway, that doesn't seem like a significant drawback for the simplification we receive here. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-24vsprintf: Fix %pK with kptr_restrict == 0Christophe Leroy1-15/+21
Although kptr_restrict is set to 0 and the kernel is booted with no_hash_pointers parameter, the content of /proc/vmallocinfo is lacking the real addresses. / # cat /proc/vmallocinfo 0x(ptrval)-0x(ptrval) 8192 load_module+0xc0c/0x2c0c pages=1 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 8192 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap 0x(ptrval)-0x(ptrval) 12288 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap ... According to the documentation for /proc/sys/kernel/, %pK is equivalent to %p when kptr_restrict is set to 0. Fixes: 5ead723a20e0 ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/107476128e59bff11a309b5bf7579a1753a41aca.1645087605.git.christophe.leroy@csgroup.eu
2022-02-10vsprintf: Move space out of string literals in fourcc_string()Andy Shevchenko1-1/+2
The literals "big-endian" and "little-endian" may be potentially occurred in other places. Dropping space allows linker to merge them by using only a single copy. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220127181233.72910-2-andriy.shevchenko@linux.intel.com
2022-02-10vsprintf: Fix potential unaligned accessAndy Shevchenko1-5/+7
The %p4cc specifier in some cases might get an unaligned pointer. Due to this we need to make copy to local variable once to avoid potential crashes on some architectures due to improper access. Fixes: af612e43de6d ("lib/vsprintf: Add support for printing V4L2 and DRM fourccs") Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220127181233.72910-1-andriy.shevchenko@linux.intel.com
2022-01-23Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linuxLinus Torvalds1-17/+7
Pull bitmap updates from Yury Norov: - introduce for_each_set_bitrange() - use find_first_*_bit() instead of find_next_*_bit() where possible - unify for_each_bit() macros * tag 'bitmap-5.17-rc1' of git://github.com/norov/linux: vsprintf: rework bitmap_list_string lib: bitmap: add performance test for bitmap_print_to_pagebuf bitmap: unify find_bit operations mm/percpu: micro-optimize pcpu_is_populated() Replace for_each_*_bit_from() with for_each_*_bit() where appropriate find: micro-optimize for_each_{set,clear}_bit() include/linux: move for_each_bit() macros from bitops.h to find.h cpumask: replace cpumask_next_* with cpumask_first_* where appropriate tools: sync tools/bitmap with mother linux all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate cpumask: use find_first_and_bit() lib: add find_first_and_bit() arch: remove GENERIC_FIND_FIRST_BIT entirely include: move find.h from asm_generic to linux bitops: move find_bit_*_le functions from le.h to find.h bitops: protect find_first_{,zero}_bit properly
2022-01-15vsprintf: rework bitmap_list_stringYury Norov1-17/+7
bitmap_list_string() is very ineffective when printing bitmaps with long ranges of set bits because it calls find_next_bit for each bit in the bitmap. We can do better by detecting ranges of set bits. In my environment, before/after is 943008/31008 ns. Signed-off-by: Yury Norov <yury.norov@gmail.com> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2021-12-06vsprintf: Use non-atomic bitmap API when applicableChristophe JAILLET1-2/+2
The 'set' bitmap is local to this function. No concurrent access to it is possible. So prefer the non-atomic '__[set|clear]_bit()' function to save a few cycles. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/1abf81a5e509d372393bd22041eed4ebc07ef9f7.1638023178.git.christophe.jaillet@wanadoo.fr
2021-11-09Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-2/+1
Merge more updates from Andrew Morton: "87 patches. Subsystems affected by this patch series: mm (pagecache and hugetlb), procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs, init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork, sysvfs, kcov, gdb, resource, selftests, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits) ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL ipc: check checkpoint_restore_ns_capable() to modify C/R proc files selftests/kselftest/runner/run_one(): allow running non-executable files virtio-mem: disallow mapping virtio-mem memory via /dev/mem kernel/resource: disallow access to exclusive system RAM regions kernel/resource: clean up and optimize iomem_is_exclusive() scripts/gdb: handle split debug for vmlinux kcov: replace local_irq_save() with a local_lock_t kcov: avoid enable+disable interrupts if !in_task() kcov: allocate per-CPU memory on the relevant node Documentation/kcov: define `ip' in the example Documentation/kcov: include types.h in the example sysv: use BUILD_BUG_ON instead of runtime check kernel/fork.c: unshare(): use swap() to make code cleaner seq_file: fix passing wrong private data seq_file: move seq_escape() to a header signal: remove duplicate include in signal.h crash_dump: remove duplicate include in crash_dump.h crash_dump: fix boolreturn.cocci warning hfs/hfsplus: use WARN_ON for sanity check ...
2021-11-09lib: uninline simple_strntoull() as wellAlexey Dobriyan1-2/+1
Codegen become bloated again after simple_strntoull() introduction add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-224 (-224) Function old new delta simple_strtoul 5 2 -3 simple_strtol 23 20 -3 simple_strtoull 119 15 -104 simple_strtoll 155 41 -114 Link: https://lkml.kernel.org/r/YVmlB9yY4lvbNKYt@localhost.localdomain Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-02Merge branch 'for-5.16-vsprintf-pgp' into for-linusPetr Mladek1-2/+10
2021-10-27lib/vsprintf.c: Amend static asserts for format specifier flagsAndy Shevchenko1-1/+2
There are couple of improvements to static asserts against the format specifier flags: - new static assert for SIGN - fix static assert for SMALL SMALL is not equal to ASCII code of white space, it equals to the bit difference between capital and small letters (however the value is the same, semantically expression means different things). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20211026140356.45610-1-andriy.shevchenko@linux.intel.com
2021-10-27vsprintf: Make %pGp print the hex valueMatthew Wilcox (Oracle)1-0/+8
All existing users of %pGp want the hex value as well as the decoded flag names. This looks awkward (passing the same parameter to printf twice), so move that functionality into the core. If we want, we can make that optional with flag arguments to %pGp in the future. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20211019142621.2810043-6-willy@infradead.org
2021-09-08Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-1/+1
Merge more updates from Andrew Morton: "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f. Subsystems affected by this patch series: mm (memory-hotplug, rmap, ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan), alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib, checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig, selftests, ipc, and scripts" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits) scripts: check_extable: fix typo in user error message mm/workingset: correct kernel-doc notations ipc: replace costly bailout check in sysvipc_find_ipc() selftests/memfd: remove unused variable Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH configs: remove the obsolete CONFIG_INPUT_POLLDEV prctl: allow to setup brk for et_dyn executables pid: cleanup the stale comment mentioning pidmap_init(). kernel/fork.c: unexport get_{mm,task}_exe_file coredump: fix memleak in dump_vma_snapshot() fs/coredump.c: log if a core dump is aborted due to changed file permissions nilfs2: use refcount_dec_and_lock() to fix potential UAF nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group nilfs2: fix NULL pointer in nilfs_##name##_attr_release nilfs2: fix memory leak in nilfs_sysfs_create_device_group trap: cleanup trap_init() init: move usermodehelper_enable() to populate_rootfs() ...
2021-09-08mm: introduce PAGEFLAGS_MASK to replace ((1UL << NR_PAGEFLAGS) - 1)Muchun Song1-1/+1
Instead of hard-coding ((1UL << NR_PAGEFLAGS) - 1) everywhere, introducing PAGEFLAGS_MASK to make the code clear to get the page flags. Link: https://lkml.kernel.org/r/20210819150712.59948-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-19isystem: ship and use stdarg.hAlexey Dobriyan1-1/+1
Ship minimal stdarg.h (1 type, 4 macros) as <linux/stdarg.h>. stdarg.h is the only userspace header commonly used in the kernel. GPL 2 version of <stdarg.h> can be extracted from http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-07-08module: add printk formats to add module build ID to stacktracesStephen Boyd1-1/+7
Let's make kernel stacktraces easier to identify by including the build ID[1] of a module if the stacktrace is printing a symbol from a module. This makes it simpler for developers to locate a kernel module's full debuginfo for a particular stacktrace. Combined with scripts/decode_stracktrace.sh, a developer can download the matching debuginfo from a debuginfod[2] server and find the exact file and line number for the functions plus offsets in a stacktrace that match the module. This is especially useful for pstore crash debugging where the kernel crashes are recorded in something like console-ramoops and the recovery kernel/modules are different or the debuginfo doesn't exist on the device due to space concerns (the debuginfo can be too large for space limited devices). Originally, I put this on the %pS format, but that was quickly rejected given that %pS is used in other places such as ftrace where build IDs aren't meaningful. There was some discussions on the list to put every module build ID into the "Modules linked in:" section of the stacktrace message but that quickly becomes very hard to read once you have more than three or four modules linked in. It also provides too much information when we don't expect each module to be traversed in a stacktrace. Having the build ID for modules that aren't important just makes things messy. Splitting it to multiple lines for each module quickly explodes the number of lines printed in an oops too, possibly wrapping the warning off the console. And finally, trying to stash away each module used in a callstack to provide the ID of each symbol printed is cumbersome and would require changes to each architecture to stash away modules and return their build IDs once unwinding has completed. Instead, we opt for the simpler approach of introducing new printk formats '%pS[R]b' for "pointer symbolic backtrace with module build ID" and '%pBb' for "pointer backtrace with module build ID" and then updating the few places in the architecture layer where the stacktrace is printed to use this new format. Before: Call trace: lkdtm_WARNING+0x28/0x30 [lkdtm] direct_entry+0x16c/0x1b4 [lkdtm] full_proxy_write+0x74/0xa4 vfs_write+0xec/0x2e8 After: Call trace: lkdtm_WARNING+0x28/0x30 [lkdtm 6c2215028606bda50de823490723dc4bc5bf46f9] direct_entry+0x16c/0x1b4 [lkdtm 6c2215028606bda50de823490723dc4bc5bf46f9] full_proxy_write+0x74/0xa4 vfs_write+0xec/0x2e8 [akpm@linux-foundation.org: fix build with CONFIG_MODULES=n, tweak code layout] [rdunlap@infradead.org: fix build when CONFIG_MODULES is not set] Link: https://lkml.kernel.org/r/20210513171510.20328-1-rdunlap@infradead.org [akpm@linux-foundation.org: make kallsyms_lookup_buildid() static] [cuibixuan@huawei.com: fix build error when CONFIG_SYSFS is disabled] Link: https://lkml.kernel.org/r/20210525105049.34804-1-cuibixuan@huawei.com Link: https://lkml.kernel.org/r/20210511003845.2429846-6-swboyd@chromium.org Link: https://fedoraproject.org/wiki/Releases/FeatureBuildId [1] Link: https://sourceware.org/elfutils/Debuginfod.html [2] Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Bixuan Cui <cuibixuan@huawei.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Evan Green <evgreen@chromium.org> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Sasha Levin <sashal@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08lib: fix spelling mistakesZhen Lei1-1/+1
Fix some spelling mistakes in comments: permanentely ==> permanently wont ==> won't remaning ==> remaining succed ==> succeed shouldnt ==> shouldn't alpha-numeric ==> alphanumeric storeing ==> storing funtion ==> function documenation ==> documentation Determin ==> Determine intepreted ==> interpreted ammount ==> amount obious ==> obvious interupts ==> interrupts occured ==> occurred asssociated ==> associated taking into acount ==> taking into account squence ==> sequence stil ==> still contiguos ==> contiguous matchs ==> matches Link: https://lkml.kernel.org/r/20210607072555.12416-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+1
Merge more updates from Andrew Morton: "190 patches. Subsystems affected by this patch series: mm (hugetlb, userfaultfd, vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock, migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap, zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc, core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs, signals, exec, kcov, selftests, compress/decompress, and ipc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) ipc/util.c: use binary search for max_idx ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock ipc: use kmalloc for msg_queue and shmid_kernel ipc sem: use kvmalloc for sem_undo allocation lib/decompressors: remove set but not used variabled 'level' selftests/vm/pkeys: exercise x86 XSAVE init state selftests/vm/pkeys: refill shadow register after implicit kernel write selftests/vm/pkeys: handle negative sys_pkey_alloc() return code selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random kcov: add __no_sanitize_coverage to fix noinstr for all architectures exec: remove checks in __register_bimfmt() x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned hfsplus: report create_date to kstat.btime hfsplus: remove unnecessary oom message nilfs2: remove redundant continue statement in a while-loop kprobes: remove duplicated strong free_insn_page in x86 and s390 init: print out unknown kernel parameters checkpatch: do not complain about positive return values starting with EPOLL checkpatch: improve the indented label test checkpatch: scripts/spdxcheck.py now requires python3 ...
2021-07-01lib: uninline simple_strtoull()Alexey Dobriyan1-0/+1
Gcc inlines simple_strtoull() too agressively. Given that all 4 signatures match, everything very efficiently calls or tailcalls into simple_strtoull(): ffffffff81da0240 <simple_strtoll>: ffffffff81da0240: 80 3f 2d cmp BYTE PTR [rdi],0x2d ffffffff81da0243: 74 05 je ffffffff81da024a <simple_strtoll+0xa> ffffffff81da0245: e9 76 ff ff ff jmp simple_strtoull ffffffff81da024a: 48 83 c7 01 add rdi,0x1 ffffffff81da024e: e8 6d ff ff ff call simple_strtoull ffffffff81da0253: 48 f7 d8 neg rax ffffffff81da0256: c3 ret Space savings (on F34-ish .config) add/remove: 0/0 grow/shrink: 1/3 up/down: 52/-313 (-261) Function old new delta vsscanf 2167 2219 +52 simple_strtoul 72 2 -70 simple_strtoll 143 23 -120 simple_strtol 143 20 -123 Link: https://lkml.kernel.org/r/YMO2zoOQk2eF34tn@localhost.localdomain Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-1/+1
Merge misc updates from Andrew Morton: "191 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab, slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap, mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization, pagealloc, and memory-failure)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits) mm,hwpoison: make get_hwpoison_page() call get_any_page() mm,hwpoison: send SIGBUS with error virutal address mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes mm/page_alloc: allow high-order pages to be stored on the per-cpu lists mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA docs: remove description of DISCONTIGMEM arch, mm: remove stale mentions of DISCONIGMEM mm: remove CONFIG_DISCONTIGMEM m68k: remove support for DISCONTIGMEM arc: remove support for DISCONTIGMEM arc: update comment about HIGHMEM implementation alpha: remove DISCONTIGMEM and NUMA mm/page_alloc: move free_the_page mm/page_alloc: fix counting of managed_pages mm/page_alloc: improve memmap_pages dbg msg mm: drop SECTION_SHIFT in code comments mm/page_alloc: introduce vm.percpu_pagelist_high_fraction mm/page_alloc: limit the number of pages on PCP lists when reclaim is active mm/page_alloc: scale the number of pages that are batch freed ...
2021-06-29Merge tag 'printk-for-5.14' of ↵Linus Torvalds1-40/+70
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Add %pt[RT]s modifier to vsprintf(). It overrides ISO 8601 separator by using ' ' (space). It produces "YYYY-mm-dd HH:MM:SS" instead of "YYYY-mm-ddTHH:MM:SS". - Correctly parse long row of numbers by sscanf() when using the field width. Add extensive sscanf() selftest. - Generalize re-entrant CPU lock that has already been used to serialize dump_stack() output. It is part of the ongoing printk rework. It will allow to remove the obsoleted printk_safe buffers and introduce atomic consoles. - Some code clean up and sparse warning fixes. * tag 'printk-for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: fix cpu lock ordering lib/dump_stack: move cpu lock to printk.c printk: Remove trailing semicolon in macros random32: Fix implicit truncation warning in prandom_seed_state() lib: test_scanf: Remove pointless use of type_min() with unsigned types selftests: lib: Add wrapper script for test_scanf lib: test_scanf: Add tests for sscanf number conversion lib: vsprintf: Fix handling of number field widths in vsscanf lib: vsprintf: scanf: Negative number must have field width > 1 usb: host: xhci-tegra: Switch to use %ptTs nilfs2: Switch to use %ptTs kdb: Switch to use %ptTs lib/vsprintf: Allow to override ISO 8601 date and time separator
2021-06-29slub: force on no_hash_pointers when slub_debug is enabledStephen Boyd1-1/+1
Obscuring the pointers that slub shows when debugging makes for some confusing slub debug messages: Padding overwritten. 0x0000000079f0674a-0x000000000d4dce17 Those addresses are hashed for kernel security reasons. If we're trying to be secure with slub_debug on the commandline we have some big problems given that we dump whole chunks of kernel memory to the kernel logs. Let's force on the no_hash_pointers commandline flag when slub_debug is on the commandline. This makes slub debug messages more meaningful and if by chance a kernel address is in some slub debug object dump we will have a better chance of figuring out what went wrong. Note that we don't use %px in the slub code because we want to reduce the number of places that %px is used in the kernel. This also nicely prints a big fat warning at kernel boot if slub_debug is on the commandline so that we know that this kernel shouldn't be used on production systems. [akpm@linux-foundation.org: fix build with CONFIG_SLUB_DEBUG=n] Link: https://lkml.kernel.org/r/20210601182202.3011020-5-swboyd@chromium.org Signed-off-by: Stephen Boyd <swboyd@chromium.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Petr Mladek <pmladek@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29Merge branch 'for-5.14-vsprintf-scanf' into for-linusPetr Mladek1-35/+53
2021-05-19lib: vsprintf: Fix handling of number field widths in vsscanfRichard Fitzgerald1-34/+48
The existing code attempted to handle numbers by doing a strto[u]l(), ignoring the field width, and then repeatedly dividing to extract the field out of the full converted value. If the string contains a run of valid digits longer than will fit in a long or long long, this would overflow and no amount of dividing can recover the correct value. This patch fixes vsscanf() to obey number field widths when parsing the number. A new _parse_integer_limit() is added that takes a limit for the number of characters to parse. The number field conversion in vsscanf is changed to use this new function. If a number starts with a radix prefix, the field width must be long enough for at last one digit after the prefix. If not, it will be handled like this: sscanf("0x4", "%1i", &i): i=0, scanning continues with the 'x' sscanf("0x4", "%2i", &i): i=0, scanning continues with the '4' This is consistent with the observed behaviour of userland sscanf. Note that this patch does NOT fix the problem of a single field value overflowing the target type. So for example: sscanf("123456789abcdef", "%x", &i); Will not produce the correct result because the value obviously overflows INT_MAX. But sscanf will report a successful conversion. Note that where a very large number is used to mean "unlimited", the value INT_MAX is used for consistency with the behaviour of vsnprintf(). Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210514161206.30821-2-rf@opensource.cirrus.com
2021-05-19lib: vsprintf: scanf: Negative number must have field width > 1Richard Fitzgerald1-1/+5
If a signed number field starts with a '-' the field width must be > 1, or unlimited, to allow at least one digit after the '-'. This patch adds a check for this. If a signed field starts with '-' and field_width == 1 the scanf will quit. It is ok for a signed number field to have a field width of 1 if it starts with a digit. In that case the single digit can be converted. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210514161206.30821-1-rf@opensource.cirrus.com
2021-05-17lib/vsprintf: Allow to override ISO 8601 date and time separatorAndy Shevchenko1-5/+17
ISO 8601 defines 'T' as a separator between date and time. Though, some ABIs use time and date with ' ' (space) separator instead. Add a flavour to the %pt specifier to override default separator. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210511153958.34527-1-andriy.shevchenko@linux.intel.com
2021-04-28Merge tag 'drm-next-2021-04-28' of git://anongit.freedesktop.org/drm/drmLinus Torvalds1-0/+39
Pull drm updates from Dave Airlie: "The usual lots of work all over the place. i915 has gotten some Alderlake work and prelim DG1 code, along with a major locking rework over the GEM code, and brings back the property of timing out long running jobs using a watchdog. amdgpu has some Alderbran support (new GPU), freesync HDMI support along with a lot other fixes. Outside of the drm, there is a new printf specifier added which should have all the correct acks/sobs: - printk fourcc modifier support added %p4cc Summary: core: - drm_crtc_commit_wait - atomic plane state helpers reworked for full state - dma-buf heaps API rework - edid: rework and improvements for displayid dp-mst: - better topology logging bridge: - Chipone ICN6211 - Lontium LT8912B - anx7625 regulator support panel: - fix lt9611 4k panels handling simple-kms: - add plane state helpers ttm: - debugfs support - removal of unused sysfs - ignore signaled moved fences - ioremap buffer according to mem caching i915: - Alderlake S enablement - Conversion to dma_resv_locking - Bring back watchdog timeout support - legacy ioctl cleanups - add GEM TDDO and RFC process - DG1 LMEM preparation work - intel_display.c refactoring - Gen9/TGL PCH combination support - eDP MSO Support - multiple PSR instance support - Link training debug updates - Disable PSR2 support on JSL/EHL - DDR5/LPDDR5 support for bw calcs - LSPCON limited to gen9/10 platforms - HSW/BDW async flip/VTd corruption workaround - SAGV watermark fixes - SNB hard hang on ring resume fix - Limit imported dma-buf size - move to use new tasklet API - refactor KBL/TGL/ADL-S display/gt steppings - refactoring legacy DP/HDMI, FB plane code out amdgpu: - uapi: add ioctl to query video capabilities - Iniital AMD Freesync HDMI support - Initial Adebaran support - 10bpc dithering improvements - DCN secure display support - Drop legacy IO BAR requirements - PCIE/S0ix/RAS/Prime/Reset fixes - Display ASSR support - SMU gfx busy queues for RV/PCO - Initial LTTPR display work amdkfd: - MMU notifier fixes - APU fixes radeon: - debugfs cleanps - fw error handling ifix - Flexible array cleanups msm: - big DSI phy/pll cleanup - sc7280 initial support - commong bandwidth scaling path - shrinker locking contention fixes - unpin/swap support for GEM objcets ast: - cursor plane handling reworked tegra: - don't register DP AUX channels before connectors zynqmp: - fix OOB struct padding memset gma500: - drop ttm and medfield support exynos: - request_irq cleanup function mediatek: - fine tune line time for EOTp - MT8192 dpi support - atomic crtc config updates - don't support HDMI connector creation mxsdb: - imx8mm support panfrost: - MMU IRQ handling rework qxl: - locking fixes - resource deallocation changes sun4i: - add alpha properties to UI/VI layers vc4: - RPi4 CEC support vmwgfx: - doc cleanups arc: - moved to drm/tiny" * tag 'drm-next-2021-04-28' of git://anongit.freedesktop.org/drm/drm: (1390 commits) drm/ttm: Don't count pages in SG BOs against pages_limit drm/ttm: fix return value check drm/bridge: lt8912b: fix incorrect handling of of_* return values drm: bridge: fix LONTIUM use of mipi_dsi_() functions drm: bridge: fix ANX7625 use of mipi_dsi_() functions drm/amdgpu: page retire over debugfs mechanism drm/radeon: Fix a missing check bug in radeon_dp_mst_detect() drm/amd/display: Fix the Wunused-function warning drm/radeon/r600: Fix variables that are not used after assignment drm/amdgpu/smu7: fix CAC setting on TOPAZ drm/amd/display: Update DCN302 SR Exit Latency drm/amdgpu: enable ras eeprom on aldebaran drm/amdgpu: RAS harvest on driver load drm/amdgpu: add ras aldebaran ras eeprom driver drm/amd/pm: increase time out value when sending msg to SMU drm/amdgpu: add DMUB outbox event IRQ source define/complete/debug flag drm/amd/pm: add the callback to get vbios bootup values for vangogh drm/radeon: Fix size overflow drm/amdgpu: Fix size overflow drm/amdgpu: move mmhub ras_func init to ip specific file ...
2021-04-27Merge branch 'for-5.13-vsprintf-pgp' into for-linusPetr Mladek1-5/+61
2021-04-23lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()Rasmus Villemoes1-2/+0
Commit 9af7706492f9 ("lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps") removed support for %pF and %pf, and correctly removed the handling of those cases in vbin_printf(). However, the corresponding cases in bstr_printf() were left behind. In the same series, %pf was re-purposed for dealing with fwnodes (3bd32d6a2ee6, "lib/vsprintf: Add %pfw conversion specifier for printing fwnode names"). So should anyone use %pf with the binary printf routines, vbin_printf() would (correctly, as it involves dereferencing the pointer) do the string formatting to the u32 array, but bstr_printf() would not copy the string from the u32 array, but instead interpret the first sizeof(void*) bytes of the formatted string as a pointer - which generally won't end well (also, all subsequent get_args would be out of sync). Fixes: 9af7706492f9 ("lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps") Cc: stable@vger.kernel.org Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210423094529.1862521-1-linux@rasmusvillemoes.dk
2021-04-07printk: clarify the documentation for plain pointer printingVlastimil Babka1-2/+5
We have several modifiers for plain pointers (%p, %px and %pK) and now also the no_hash_pointers boot parameter. The documentation should help to choose which variant to use. Importantly, we should discourage %px in favor of %p (with the new boot parameter when debugging), and stress that %pK should be only used for procfs and similar files, not dmesg buffer. This patch clarifies the documentation in that regard. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210225164639.27212-1-vbabka@suse.cz
2021-03-19vsprintf: dump full information of page flags in pGpYafang Shao1-5/+61
Currently the pGp only shows the names of page flags, rather than the full information including section, node, zone, last cpupid and kasan tag. While it is not easy to parse these information manually because there're so many flavors. Let's interpret them in pGp as well. To be compitable with the existed format of pGp, the new introduced ones also use '|' as the separator, then the user tools parsing pGp won't need to make change, suggested by Matthew. The new information is tracked onto the end of the existed one. On example of the output in mm/slub.c as follows, - Before the patch, [ 6343.396602] Slab 0x000000004382e02b objects=33 used=3 fp=0x000000009ae06ffc flags=0x17ffffc0010200(slab|head) - After the patch, [ 8448.272530] Slab 0x0000000090797883 objects=33 used=3 fp=0x00000000790f1c26 flags=0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff) The documentation and test cases are also updated. The output of the test cases as follows, [68599.816764] test_printf: loaded. [68599.819068] test_printf: all 388 tests passed [68599.830367] test_printf: unloaded. [lkp@intel.com: reported issues in the prev version in test_printf.c] Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: kernel test robot <lkp@intel.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210319101246.73513-4-laoar.shao@gmail.com
2021-03-19lib/vsprintf: do not show no_hash_pointers message multiple timesMarco Elver1-0/+3
Do not show no_hash_pointers message multiple times if the option was passed more than once (e.g. via generated command line). Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210305194206.3165917-1-elver@google.com
2021-03-16Merge tag 'drm-misc-next-2021-03-03' of ↵Dave Airlie1-0/+39
git://anongit.freedesktop.org/drm/drm-misc into drm-next drm-misc-next for 5.13: UAPI Changes: Cross-subsystem Changes: Core Changes: - %p4cc printk format modifier - atomic: introduce drm_crtc_commit_wait, rework atomic plane state helpers to take the drm_commit_state structure - dma-buf: heaps rework to return a struct dma_buf - simple-kms: Add plate state helpers - ttm: debugfs support, removal of sysfs Driver Changes: - Convert drivers to shadow plane helpers - arc: Move to drm/tiny - ast: cursor plane reworks - gma500: Remove TTM and medfield support - mxsfb: imx8mm support - panfrost: MMU IRQ handling rework - qxl: rework to better handle resources deallocation, locking - sun4i: Add alpha properties for UI and VI layers - vc4: RPi4 CEC support - vmwgfx: doc cleanup Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <maxime@cerno.tech> Link: https://patchwork.freedesktop.org/patch/msgid/20210303100600.dgnkadonzuvfnu22@gilmour
2021-02-17lib/vsprintf: Add support for printing V4L2 and DRM fourccsSakari Ailus1-0/+39
Add a printk modifier %p4cc (for pixel format) for printing V4L2 and DRM pixel formats denoted by fourccs. The fourcc encoding is the same for both so the same implementation can be used. Suggested-by: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20210216155723.17109-2-sakari.ailus@linux.intel.com
2021-02-15lib/vsprintf: no_hash_pointers prints all addresses as unhashedTimur Tabi1-2/+34
If the no_hash_pointers command line parameter is set, then printk("%p") will print pointers as unhashed, which is useful for debugging purposes. This change applies to any function that uses vsprintf, such as print_hex_dump() and seq_buf_printf(). A large warning message is displayed if this option is enabled. Unhashed pointers expose kernel addresses, which can be a security risk. Also update test_printf to skip the hashed pointer tests if the command-line option is set. Signed-off-by: Timur Tabi <timur@kernel.org> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Marco Elver <elver@google.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210214161348.369023-4-timur@kernel.org
2020-11-19lib: Fix fall-through warnings for ClangGustavo A. R. Silva1-0/+1
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple warnings by explicitly adding multiple break statements instead of letting the code fall through to the next case, and by replacing a number of /* fall through */ comments with the new pseudo-keyword macro fallthrough. Notice that Clang doesn't recognize /* Fall through */ comments as implicit fall-through markings. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-11-18Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"Nick Desaulniers1-7/+7
This reverts commit 6a9dc5fd6170 ("lib: Revert use of fallthrough pseudo-keyword in lib/") Now that we can build arch/powerpc/boot/ free of -Wimplicit-fallthrough, re-enable these fixes for lib/. Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/236 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-09-25vsprintf: use bd_partno in bdev_nameChristoph Hellwig1-2/+2
No need to go through the hd_struct to find the partition number. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-24lib: Revert use of fallthrough pseudo-keyword in lib/Gustavo A. R. Silva1-7/+7
The following build error for powerpc64 was reported by Nathan Chancellor: "$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ $ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage ... In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234, from arch/powerpc/boot/decompress.c:38: arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main': arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function) 586 | fallthrough; | ^~~~~~~~~~~ This will end up affecting distribution configurations such as Debian and OpenSUSE according to my testing. I am not sure what the solution is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure that compiler_attributes.h can be safely included." In order to avoid these sort of problems, it seems that the best solution is to use /* fall through */ comments instead of the fallthrough pseudo-keyword macro in lib/, for now. Reported-by: Nathan Chancellor <natechancellor@gmail.com> Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-7/+8
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-01lib/vsprintf: Force type of flags value for gfp_tAndy Shevchenko1-1/+1
Sparse is not happy about restricted type being assigned: lib/vsprintf.c:1940:23: warning: incorrect type in assignment (different base types) lib/vsprintf.c:1940:23: expected unsigned long [assigned] flags lib/vsprintf.c:1940:23: got restricted gfp_t [usertype] Force type of flags value to make sparse happy. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20200731180825.30575-3-andriy.shevchenko@linux.intel.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
2020-08-01lib/vsprintf: Replace custom spec to print decimals with generic oneAndy Shevchenko1-7/+1
When printing phandle via %pOFp the custom spec is used. First of all, it has a SMALL flag which makes no sense for decimal numbers. Second, we have already default spec for decimal numbers. Use the latter in the %pOFp case as well. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Rob Herring <robh@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Grant Likely <grant.likely@arm.com> Link: https://lore.kernel.org/r/20200731180825.30575-2-andriy.shevchenko@linux.intel.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
2020-08-01lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert()Andy Shevchenko1-1/+4
First of all, there is no compile time check for the SMALL to be ' ' (0x20, i.e. space). Second, for ZEROPAD the check is hidden in the code. For better maintenance replace BUILD_BUG_ON() with static_assert() for ZEROPAD and move it closer to the definition. While at it, introduce check for SMALL. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Link: https://lore.kernel.org/r/20200731180825.30575-1-andriy.shevchenko@linux.intel.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
2020-07-03Replace HTTP links with HTTPS ones: vsprintfAlexander A. Klimov1-1/+1
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20200702200536.13389-1-grandmaster@al2klimov.de
2020-06-01Merge tag 'printk-for-5.8' of ↵Linus Torvalds1-6/+33
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Benjamin Herrenschmidt solved a problem with non-matched console aliases by first checking consoles defined on the command line. It is a more conservative approach than the previous attempts. - Benjamin also made sure that the console accessible via /dev/console always has CON_CONSDEV flag. - Andy Shevchenko added the %ptT modifier for printing struct time64_t. It extends the existing %ptR handling for struct rtc_time. - Bruno Meneguele fixed /dev/kmsg error value returned by unsupported SEEK_CUR. - Tetsuo Handa removed unused pr_cont_once(). ... and a few small fixes. * tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Remove pr_cont_once() printk: handle blank console arguments passed in. kernel/printk: add kmsg SEEK_CUR handling printk: Fix a typo in comment "interator"->"iterator" usb: pulse8-cec: Switch to use %ptT ARM: bcm2835: Switch to use %ptT lib/vsprintf: Print time64_t in human readable format lib/vsprintf: update comment about simple_strto<foo>() functions printk: Correctly set CON_CONSDEV even when preferred console was not registered printk: Fix preferred console selection with multiple matches printk: Move console matching logic into a separate function printk: Convert a use of sprintf to snprintf in console_unlock
2020-06-01Merge branch 'for-5.8-printf-time64_t' into for-linusPetr Mladek1-2/+29
2020-05-20lib/vsprintf: Print time64_t in human readable formatAndy Shevchenko1-2/+29
There are users which print time and date represented by content of time64_t type in human readable format. Instead of open coding that each time introduce %ptT[dt][r] specifier. Few test cases for %ptT specifier has been added as well. Link: https://lore.kernel.org/r/20200415170046.33374-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Rewieved-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-05-19vsprintf: don't obfuscate NULL and error pointersIlya Dryomov1-0/+7
I don't see what security concern is addressed by obfuscating NULL and IS_ERR() error pointers, printed with %p/%pK. Given the number of sites where %p is used (over 10000) and the fact that NULL pointers aren't uncommon, it probably wouldn't take long for an attacker to find the hash that corresponds to 0. Although harder, the same goes for most common error values, such as -1, -2, -11, -14, etc. The NULL part actually fixes a regression: NULL pointers weren't obfuscated until commit 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid pointers") which went into 5.2. I'm tacking the IS_ERR() part on here because error pointers won't leak kernel addresses and printing them as pointers shouldn't be any different from e.g. %d with PTR_ERR_OR_ZERO(). Obfuscating them just makes debugging based on existing pr_debug and friends excruciating. Note that the "always print 0's for %pK when kptr_restrict == 2" behaviour which goes way back is left as is. Example output with the patch applied: ptr error-ptr NULL %p: 0000000001f8cc5b fffffffffffffff2 0000000000000000 %pK, kptr = 0: 0000000001f8cc5b fffffffffffffff2 0000000000000000 %px: ffff888048c04020 fffffffffffffff2 0000000000000000 %pK, kptr = 1: ffff888048c04020 fffffffffffffff2 0000000000000000 %pK, kptr = 2: 0000000000000000 0000000000000000 0000000000000000 Fixes: 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid pointers") Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-15bpf: Restrict bpf_trace_printk()'s %s usage and add %pks, %pus specifierDaniel Borkmann1-0/+12
Usage of plain %s conversion specifier in bpf_trace_printk() suffers from the very same issue as bpf_probe_read{,str}() helpers, that is, it is broken on archs with overlapping address ranges. While the helpers have been addressed through work in 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers"), we need an option for bpf_trace_printk() as well to fix it. Similarly as with the helpers, force users to make an explicit choice by adding %pks and %pus specifier to bpf_trace_printk() which will then pick the corresponding strncpy_from_unsafe*() variant to perform the access under KERNEL_DS or USER_DS. The %pk* (kernel specifier) and %pu* (user specifier) can later also be extended for other objects aside strings that are probed and printed under tracing, and reused out of other facilities like bpf_seq_printf() or BTF based type printing. Existing behavior of %s for current users is still kept working for archs where it is not broken and therefore gated through CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. For archs not having this property we fall-back to pick probing under KERNEL_DS as a sensible default. Fixes: 8d3b7dce8622 ("bpf: add support for %s specifier to bpf_trace_printk()") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Link: https://lore.kernel.org/bpf/20200515101118.6508-4-daniel@iogearbox.net
2020-02-28lib/vsprintf: update comment about simple_strto<foo>() functionsAndy Shevchenko1-4/+4
The commit 885e68e8b7b1 ("kernel.h: update comment about simple_strto<foo>() functions") updated a comment regard to simple_strto<foo>() functions, but missed similar change in the vsprintf.c module. Update comments in vsprintf.c as well for simple_strto<foo>() functions. Link: https://lore.kernel.org/r/20200221085723.42469-1-andriy.shevchenko@linux.intel.com Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-12-01rss_stat: add support to detect RSS updates of external mmJoel Fernandes (Google)1-11/+29
When a process updates the RSS of a different process, the rss_stat tracepoint appears in the context of the process doing the update. This can confuse userspace that the RSS of process doing the update is updated, while in reality a different process's RSS was updated. This issue happens in reclaim paths such as with direct reclaim or background reclaim. This patch adds more information to the tracepoint about whether the mm being updated belongs to the current process's context (curr field). We also include a hash of the mm pointer so that the process who the mm belongs to can be uniquely identified (mm_id field). Also vsprintf.c is refactored a bit to allow reuse of hashing code. [akpm@linux-foundation.org: remove unused local `str'] [joelaf@google.com: inline call to ptr_to_hashval] Link: http://lore.kernel.org/r/20191113153816.14b95acd@gandalf.local.home Link: http://lkml.kernel.org/r/20191114164622.GC233237@google.com Link: http://lkml.kernel.org/r/20191106024452.81923-1-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reported-by: Ioannis Ilkos <ilkos@google.com> Acked-by: Petr Mladek <pmladek@suse.com> [lib/vsprintf.c] Cc: Tim Murray <timmurray@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Carmen Jackson <carmenjackson@google.com> Cc: Mayank Gupta <mayankgupta@google.com> Cc: Daniel Colascione <dancol@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Minchan Kim <minchan@kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-26Merge tag 'devprop-5.5-rc1' of ↵Linus Torvalds1-37/+56
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull device properties framework updates from Rafael Wysocki: "Add support for printing fwnode names using a new conversion specifier "%pfw" (Sakari Ailus), clean up the software node and efi/apple-properties code in preparation for improved software node reference properties handling (Dmitry Torokhov) and fix the struct fwnode_operations description (Heikki Krogerus)" * tag 'devprop-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (22 commits) software node: simplify property_entry_read_string_array() software node: unify PROPERTY_ENTRY_XXX macros software node: remove property_entry_read_uNN_array functions software node: get rid of property_set_pointer() software node: clean up property_copy_string_array() software node: mark internal macros with double underscores efi/apple-properties: use PROPERTY_ENTRY_U8_ARRAY_LEN software node: introduce PROPERTY_ENTRY_XXX_ARRAY_LEN() software node: remove DEV_PROP_MAX device property: Fix the description of struct fwnode_operations lib/test_printf: Add tests for %pfw printk modifier lib/vsprintf: Add %pfw conversion specifier for printing fwnode names lib/vsprintf: OF nodes are first and foremost, struct device_nodes lib/vsprintf: Make use of fwnode API to obtain node names and separators lib/vsprintf: Add a note on re-using %pf or %pF lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %ps device property: Add a function to obtain a node's prefix device property: Add fwnode_get_name for returning the name of a node device property: Add functions for accessing node's parents device property: Move fwnode_get_parent() up ...
2019-10-17printf: add support for printing symbolic error namesRasmus Villemoes1-0/+27
It has been suggested several times to extend vsnprintf() to be able to convert the numeric value of ENOSPC to print "ENOSPC". This implements that as a %p extension: With %pe, one can do if (IS_ERR(foo)) { pr_err("Sorry, can't do that: %pe\n", foo); return PTR_ERR(foo); } instead of what is seen in quite a few places in the kernel: if (IS_ERR(foo)) { pr_err("Sorry, can't do that: %ld\n", PTR_ERR(foo)); return PTR_ERR(foo); } If the value passed to %pe is an ERR_PTR, but the library function errname() added here doesn't know about the value, the value is simply printed in decimal. If the value passed to %pe is not an ERR_PTR, we treat it as an ordinary %p and thus print the hashed value (passing non-ERR_PTR values to %pe indicates a bug in the caller, but we can't do much about that). With my embedded hat on, and because it's not very invasive to do, I've made it possible to remove this. The errname() function and associated lookup tables take up about 3K. For most, that's probably quite acceptable and a price worth paying for more readable dmesg (once this starts getting used), while for those that disable printk() it's of very little use - I don't see a procfs/sysfs/seq_printf() file reasonably making use of this - and they clearly want to squeeze vmlinux as much as possible. Hence the default y if PRINTK. The symbols to include have been found by massaging the output of find arch include -iname 'errno*.h' | xargs grep -E 'define\s*E' In the cases where some common aliasing exists (e.g. EAGAIN=EWOULDBLOCK on all platforms, EDEADLOCK=EDEADLK on most), I've moved the more popular one (in terms of 'git grep -w Efoo | wc) to the bottom so that one takes precedence. Link: http://lkml.kernel.org/r/20191015190706.15989-1-linux@rasmusvillemoes.dk To: "Jonathan Corbet" <corbet@lwn.net> To: linux-kernel@vger.kernel.org Cc: "Andy Shevchenko" <andy.shevchenko@gmail.com> Cc: "Andrew Morton" <akpm@linux-foundation.org> Cc: "Joe Perches" <joe@perches.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Uwe Kleine-König <uwe@kleine-koenig.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [andy.shevchenko@gmail.com: use abs()] Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-11lib/vsprintf: Add %pfw conversion specifier for printing fwnode namesSakari Ailus1-0/+36
Add support for %pfw conversion specifier (with "f" and "P" modifiers) to support printing full path of the node, including its name ("f") and only the node's name ("P") in the printk family of functions. The two flags have equivalent functionality to existing %pOF with the same two modifiers ("f" and "P") on OF based systems. The ability to do the same on ACPI based systems is added by this patch. On ACPI based systems the resulting strings look like \_SB.PCI0.CIO2.port@1.endpoint@0 where the nodes are separated by a dot (".") and the first three are ACPI device nodes and the latter two ACPI data nodes. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11lib/vsprintf: OF nodes are first and foremost, struct device_nodesSakari Ailus1-12/+4
Factor out static kobject_string() function that simply calls device_node_string(), and thus remove references to kobjects (as these are struct device_node). Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11lib/vsprintf: Make use of fwnode API to obtain node names and separatorsSakari Ailus1-22/+17
Instead of implementing our own means of discovering parent nodes, node names or counting how many parents a node has, use the newly added functions in the fwnode API to obtain that information. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11lib/vsprintf: Add a note on re-using %pf or %pFSakari Ailus1-0/+2
Add a note warning of re-use of obsolete %pf or %pF extensions. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-11lib/vsprintf: Remove support for %pF and %pf in favour of %pS and %psSakari Ailus1-8/+2
%pS and %ps are now the preferred conversion specifiers to print function names. The functionality is equivalent; remove the old, deprecated %pF and %pf support. Depends-on: commit 2d44d165e939 ("scsi: lpfc: Convert existing %pf users to %ps") Depends-on: commit b295c3e39c13 ("tools lib traceevent: Convert remaining %p[fF] users to %p[sS]") Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-08-15vsprintf: Prevent crash when dereferencing invalid pointers for %pDJia He1-3/+10
Commit 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid pointers") prevents most crash except for %pD. There is an additional pointer dereferencing before dentry_name. At least, vma->file can be NULL and be passed to printk %pD in print_bad_pte, which can cause crash. This patch fixes it with introducing a new file_dentry_name. Link: http://lkml.kernel.org/r/20190809012457.56685-1-justin.he@arm.com Fixes: 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid pointers") To: Geert Uytterhoeven <geert+renesas@glider.be> To: Thomas Gleixner <tglx@linutronix.de> To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: linux-kernel@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Cc: Shuah Khan <shuah@kernel.org> Cc: "Tobin C. Harding" <tobin@kernel.org> Signed-off-by: Jia He <justin.he@arm.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-07-09Merge tag 'printk-for-5.3' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - distinguish different legacy clocks again - small clean up * tag 'printk-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Reinstate printing of legacy clock IDs vsprintf: fix data type of variable in string_nocheck()
2019-07-04lib/vsprintf: Reinstate printing of legacy clock IDsGeert Uytterhoeven1-1/+1
When using the legacy clock framework, clock pointers are no longer printed as IDs, as the !CONFIG_COMMON_CLK case was accidentally considered an error case. Fix this by reverting to the old behavior, which allows to distinguish clocks by ID, as the legacy clock framework does not store names with clocks. Fixes: 0b74d4d763fd4ee9 ("vsprintf: Consolidate handling of unknown pointer specifiers") Link: http://lkml.kernel.org/r/20190701140009.23683-1-geert+renesas@glider.be Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-06-12vsprintf: fix data type of variable in string_nocheck()Youngmin Nam1-1/+1
This patch fixes data type of precision with int. The precision is declared as signed int in struct printf_spec. Link: http://lkml.kernel.org/r/040301d51f60$b4959100$1dc0b300$@samsung.com To: <andriy.shevchenko@linux.intel.com> To: <geert+renesas@glider.be> To: <rostedt@goodmis.org> To: <me@tobin.cc> Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-10vsprintf: Do not break early boot with probing addressesPetr Mladek1-7/+4
The commit 3e5903eb9cff70730 ("vsprintf: Prevent crash when dereferencing invalid pointers") broke boot on several architectures. The common pattern is that probe_kernel_read() is not working during early boot because userspace access framework is not ready. It is a generic problem. We have to avoid any complex external functions in vsprintf() code, especially in the common path. They might break printk() easily and are hard to debug. Replace probe_kernel_read() with some simple checks for obvious problems. Details: 1. Report on Power: Kernel crashes very early during boot with with CONFIG_PPC_KUAP and CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG The problem is the combination of some new code called via printk(), check_pointer() which calls probe_kernel_read(). That then calls allow_user_access() (PPC_KUAP) and that uses mmu_has_feature() too early (before we've patched features). With the JUMP_LABEL debug enabled that causes us to call printk() & dump_stack() and we end up recursing and overflowing the stack. Because it happens so early you don't get any output, just an apparently dead system. The stack trace (which you don't see) is something like: ... dump_stack+0xdc probe_kernel_read+0x1a4 check_pointer+0x58 string+0x3c vsnprintf+0x1bc vscnprintf+0x20 printk_safe_log_store+0x7c printk+0x40 dump_stack_print_info+0xbc dump_stack+0x8 probe_kernel_read+0x1a4 probe_kernel_read+0x19c check_pointer+0x58 string+0x3c vsnprintf+0x1bc vscnprintf+0x20 vprintk_store+0x6c vprintk_emit+0xec vprintk_func+0xd4 printk+0x40 cpufeatures_process_feature+0xc8 scan_cpufeatures_subnodes+0x380 of_scan_flat_dt_subnodes+0xb4 dt_cpu_ftrs_scan_callback+0x158 of_scan_flat_dt+0xf0 dt_cpu_ftrs_scan+0x3c early_init_devtree+0x360 early_setup+0x9c 2. Report on s390: vsnprintf invocations, are broken on s390. For example, the early boot output now looks like this where the first (efault) should be the linux_banner: [ 0.099985] (efault) [ 0.099985] setup: Linux is running as a z/VM guest operating system in 64-bit mode [ 0.100066] setup: The maximum memory size is 8192MB [ 0.100070] cma: Reserved 4 MiB at (efault) [ 0.100100] numa: NUMA mode: (efault) The reason for this, is that the code assumes that probe_kernel_address() works very early. This however is not true on at least s390. Uaccess on KERNEL_DS works only after page tables have been setup on s390, which happens with setup_arch()->paging_init(). Any probe_kernel_address() invocation before that will return -EFAULT. Fixes: 3e5903eb9cff70730 ("vsprintf: Prevent crash when dereferencing invalid pointers") Link: http://lkml.kernel.org/r/20190510084213.22149-1-pmladek@suse.com Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Michal Hocko <mhocko@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Russell Currey <ruscur@russell.cc> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stephen Rothwell <sfr@ozlabs.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-arch@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-29lib/vsprintf: Make function pointer_string staticYueHaibing1-2/+3
Fix sparse warning: lib/vsprintf.c:673:6: warning: symbol 'pointer_string' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20190426164630.22104-1-yuehaibing@huawei.com To: <sergey.senozhatsky@gmail.com> To: <andriy.shevchenko@linux.intel.com> To: <geert+renesas@glider.be> To: <rostedt@goodmis.org> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Limit the length of inlined error messagesPetr Mladek1-12/+27
The inlined error messages must be used carefully because they need to fit into the given buffer. Handle them using a custom wrapper that makes people aware of the problem. Also define a reasonable hard limit to avoid a completely insane usage. Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Link: http://lkml.kernel.org/r/20190417115350.20479-11-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Avoid confusion between invalid address and valuePetr Mladek1-1/+1
We are able to detect invalid values handled by %p[iI] printk specifier. The current error message is "invalid address". It might cause confusion against "(efault)" reported by the generic valid_pointer_address() check. Let's unify the style and use the more appropriate error code description "(einval)". Link: http://lkml.kernel.org/r/20190417115350.20479-10-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Prevent crash when dereferencing invalid pointersPetr Mladek1-35/+101
We already prevent crash when dereferencing some obviously broken pointers. But the handling is not consistent. Sometimes we print "(null)" only for pure NULL pointer, sometimes for pointers in the first page and sometimes also for pointers in the last page (error codes). Note that printk() call this code under logbuf_lock. Any recursive printks are redirected to the printk_safe implementation and the messages are stored into per-CPU buffers. These buffers might be eventually flushed in printk_safe_flush_on_panic() but it is not guaranteed. This patch adds a check using probe_kernel_read(). It is not a full-proof test. But it should help to see the error message in 99% situations where the kernel would silently crash otherwise. Also it makes the error handling unified for "%s" and the many %p* specifiers that need to read the data from a given address. We print: + (null) when accessing data on pure pure NULL address + (efault) when accessing data on an invalid address It does not affect the %p* specifiers that just print the given address in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p. Note that we print (efault) from security reasons. In fact, the real address can be seen only by %px or eventually %pK. Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Consolidate handling of unknown pointer specifiersPetr Mladek1-11/+17
There are few printk formats that make sense only with two or more specifiers. Also some specifiers make sense only when a kernel feature is enabled. The handling of unknown specifiers is inconsistent and not helpful. Using WARN() looks like an overkill for this type of error. pr_warn() is not good either. It would by handled via printk_safe buffer and it might be hard to match it with the problematic string. A reasonable compromise seems to be writing the unknown format specifier into the original string with a question mark, for example (%pC?). It should be self-explaining enough. Note that it is in brackets to follow the (null) style. Note that it introduces a warning about that test_hashed() function is unused. It is going to be used again by a later patch. Link: http://lkml.kernel.org/r/20190417115350.20479-8-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Factor out %pO handler as kobject_string()Petr Mladek1-5/+12
Move code from the long pointer() function. We are going to improve error handling that will make it even more complicated. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-7-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Factor out %pV handler as va_format()Petr Mladek1-9/+12
Move the code from the long pointer() function. We are going to improve error handling that will make it more complicated. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-6-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Factor out %p[iI] handler as ip_addr_string()Petr Mladek1-22/+30
Move the non-trivial code from the long pointer() function. We are going to improve error handling that will make it even more complicated. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-5-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Do not check address of well-known stringsPetr Mladek1-37/+44
We are going to check the address using probe_kernel_address(). It will be more expensive and it does not make sense for well known address. This patch splits the string() function. The variant without the check is then used on locations that handle string constants or strings defined as local variables. This patch does not change the existing behavior. Link: http://lkml.kernel.org/r/20190417115350.20479-4-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
2019-04-26vsprintf: Consistent %pK handling for kptr_restrict == 0Petr Mladek1-4/+2
restricted_pointer() pretends that it prints the address when kptr_restrict is set to zero. But it is never called in this situation. Instead, pointer() falls back to ptr_to_id() and hashes the pointer. This patch removes the potential confusion. klp_restrict is checked only in restricted_pointer(). It actually fixes a small race when the address might get printed unhashed: CPU0 CPU1 pointer() if (!kptr_restrict) /* for example set to 2 */ restricted_pointer() /* echo 0 >/proc/sys/kernel/kptr_restrict */ proc_dointvec_minmax_sysadmin() klpr_restrict = 0; switch(kptr_restrict) case 0: break: number() Fixes: ef0010a30935de4e0211 ("vsprintf: don't use 'restricted_pointer()' when not restricting") Link: http://lkml.kernel.org/r/20190417115350.20479-3-pmladek@suse.com To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-26vsprintf: Shuffle restricted_pointer()Petr Mladek1-49/+49
This is just a preparation step for further changes. The patch does not change the code. Link: http://lkml.kernel.org/r/20190417115350.20479-2-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-03-09Merge tag 'printk-for-5.1' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Allow to sort mixed lines by an extra information about the caller - Remove no longer used LOG_PREFIX. - Some clean up and documentation update. * tag 'printk-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk/docs: Add extra integer types to printk-formats printk: Remove no longer used LOG_PREFIX. lib/vsprintf: Remove %pCr remnant in comment printk: Pass caller information to log_store(). printk: Add caller information to printk() output.
2019-03-07lib/vsprintf.c: move sizeof(struct printf_spec) next to its definitionRasmus Villemoes1-2/+3
At the time of commit d048419311ff ("lib/vsprintf.c: expand field_width to 24 bits"), there was no compiletime_assert/BUILD_BUG/.... variant that could be used outside function scope. Now we have static_assert(), so move the assertion next to the definition instead of hiding it in some arbitrary function. Also add the appropriate #include to avoid relying on build_bug.h being pulled in via some arbitrary chain of includes. Link: http://lkml.kernel.org/r/20190208203015.29702-2-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-28lib/vsprintf: Remove %pCr remnant in commentGeert Uytterhoeven1-1/+0
Support for "%pCr" was removed, but a reference in a comment was forgotten. Fixes: 666902e42fd8344b ("lib/vsprintf: Remove atomic-unsafe support for %pCr") Link: http://lkml.kernel.org/r/20190228105315.744-1-geert+renesas@glider.be To: Andy Shevchenko <andriy.shevchenko@linux.intel.com> To: Andrew Morton <akpm@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-12-10lib/vsprintf: Print time and date in human readable format via %ptAndy Shevchenko1-0/+100
There are users which print time and date represented by content of struct rtc_time in human readable format. Instead of open coding that each time introduce %ptR[dt][r] specifier. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-10-26Merge tag 'devicetree-for-4.20' of ↵Linus Torvalds1-1/+6
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull Devicetree updates from Rob Herring: "A bit bigger than normal as I've been busy this cycle. There's a few things with dependencies and a few things subsystem maintainers didn't pick up, so I'm taking them thru my tree. The fixes from Johan didn't get into linux-next, but they've been waiting for some time now and they are what's left of what subsystem maintainers didn't pick up. Summary: - Sync dtc with upstream version v1.4.7-14-gc86da84d30e4 - Work to get rid of direct accesses to struct device_node name and type pointers in preparation for removing them. New helpers for parsing DT cpu nodes and conversions to use the helpers. printk conversions to %pOFn for printing DT node names. Most went thru subystem trees, so this is the remainder. - Fixes to DT child node lookups to actually be restricted to child nodes instead of treewide. - Refactoring of dtb targets out of arch code. This makes the support more uniform and enables building all dtbs on c6x, microblaze, and powerpc. - Various DT binding updates for Renesas r8a7744 SoC - Vendor prefixes for Facebook, OLPC - Restructuring of some ARM binding docs moving some peripheral bindings out of board/SoC binding files - New "secure-chosen" binding for secure world settings on ARM - Dual licensing of 2 DT IRQ binding headers" * tag 'devicetree-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (78 commits) ARM: dt: relicense two DT binding IRQ headers power: supply: twl4030-charger: fix OF sibling-node lookup NFC: nfcmrvl_uart: fix OF child-node lookup net: stmmac: dwmac-sun8i: fix OF child-node lookup net: bcmgenet: fix OF child-node lookup drm/msm: fix OF child-node lookup drm/mediatek: fix OF sibling-node lookup of: Add missing exports of node name compare functions dt-bindings: Add OLPC vendor prefix dt-bindings: misc: bk4: Add device tree binding for Liebherr's BK4 SPI bus dt-bindings: thermal: samsung: Add SPDX license identifier dt-bindings: clock: samsung: Add SPDX license identifiers dt-bindings: timer: ostm: Add R7S9210 support dt-bindings: phy: rcar-gen2: Add r8a7744 support dt-bindings: can: rcar_can: Add r8a7744 support dt-bindings: timer: renesas, cmt: Document r8a7744 CMT support dt-bindings: watchdog: renesas-wdt: Document r8a7744 support dt-bindings: thermal: rcar: Add device tree support for r8a7744 Documentation: dt: Add binding for /secure-chosen/stdout-path dt-bindings: arm: zte: Move sysctrl bindings to their own doc ...
2018-10-25Merge tag 'printk-for-4.20' of ↵Linus Torvalds1-108/+108
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Fix two more locations where printf formatting leaked pointers - Better log_buf_len parameter handling - Add prefix to messages from printk code - Do not miss messages on other consoles when the log is replayed on a new one - Reduce race between console registration and panic() when the log might get replayed on all consoles - Some cont buffer code clean up - Call console only when there is something to do (log vs cont buffer) * tag 'printk-for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Hash printed address for netdev bits fallback lib/vsprintf: Hash legacy clock addresses lib/vsprintf: Prepare for more general use of ptr_to_id() lib/vsprintf: Make ptr argument conts in ptr_to_id() printk: fix integer overflow in setup_log_buf() printk: do not preliminary split up cont buffer printk: lock/unlock console only for new logbuf entries printk: keep kernel cont support always enabled printk: Give error on attempt to set log buffer length to over 2G printk: Add KBUILD_MODNAME and remove a redundant print prefix printk: Correct wrong casting printk: Fix panic caused by passing log_buf_len to command line printk: CON_PRINTBUFFER console registration is a bit racy printk: Do not miss new messages when replaying the log
2018-10-24Merge tag 'docs-4.20' of git://git.lwn.net/linuxLinus Torvalds1-11/+9
Pull documentation updates from Jonathan Corbet: "This is a fairly typical cycle for documentation. There's some welcome readability improvements for the formatted output, some LICENSES updates including the addition of the ISC license, the removal of the unloved and unmaintained 00-INDEX files, the deprecated APIs document from Kees, more MM docs from Mike Rapoport, and the usual pile of typo fixes and corrections" * tag 'docs-4.20' of git://git.lwn.net/linux: (41 commits) docs: Fix typos in histogram.rst docs: Introduce deprecated APIs list kernel-doc: fix declaration type determination doc: fix a typo in adding-syscalls.rst docs/admin-guide: memory-hotplug: remove table of contents doc: printk-formats: Remove bogus kobject references for device nodes Documentation: preempt-locking: Use better example dm flakey: Document "error_writes" feature docs/completion.txt: Fix a couple of punctuation nits LICENSES: Add ISC license text LICENSES: Add note to CDDL-1.0 license that it should not be used docs/core-api: memory-hotplug: add some details about locking internals docs/core-api: rename memory-hotplug-notifier to memory-hotplug docs: improve readability for people with poorer eyesight yama: clarify ptrace_scope=2 in Yama documentation docs/vm: split memory hotplug notifier description to Documentation/core-api docs: move memory hotplug description into admin-guide/mm doc: Fix acronym "FEKEK" in ecryptfs docs: fix some broken documentation references iommu: Fix passthrough option documentation ...
2018-10-12doc: printk-formats: Remove bogus kobject references for device nodesGeert Uytterhoeven1-11/+9
When converting from text to rst, the kobjects section and its sole subsection about device tree nodes were coalesced into a single section, yielding an inconsistent result. Remove all references to kobjects, as 1. Device tree object pointers are not compatible to kobject pointers (the former may embed the latter, though), and 2. there are no printk formats defined for kobject types. Update the vsprintf() source code comments to match the above. Fixes: b3ed23213eab1e08 ("doc: convert printk-formats.txt to rst") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-10-12lib/vsprintf: Hash printed address for netdev bits fallbackGeert Uytterhoeven1-5/+4
The handler for "%pN" falls back to printing the raw pointer value when using a different format than the (sole supported) special format "%pNF", potentially leaking sensitive information regarding the kernel layout in memory. Avoid this leak by printing the hashed address instead. Note that there are no in-tree users of the fallback. Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Link: http://lkml.kernel.org/r/20181011084249.4520-4-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-12lib/vsprintf: Hash legacy clock addressesGeert Uytterhoeven1-1/+1
On platforms using the Common Clock Framework, "%pC" prints the clock's name. On legacy platforms, it prints the unhashed clock's address, potentially leaking sensitive information regarding the kernel layout in memory. Avoid this leak by printing the hashed address instead. To distinguish between clocks, a 32-bit unique identifier is as good as an actual pointer value. Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Link: http://lkml.kernel.org/r/20181011084249.4520-3-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-12lib/vsprintf: Prepare for more general use of ptr_to_id()Geert Uytterhoeven1-103/+103
Move the function and its dependencies up so it can be called from special pointer type formatting routines. Link: http://lkml.kernel.org/r/20181011084249.4520-2-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [pmladek@suse.com: Split into separate patch] Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-12lib/vsprintf: Make ptr argument conts in ptr_to_id()Geert Uytterhoeven1-1/+2
Make the ptr argument const to avoid adding casts in future callers. Link: http://lkml.kernel.org/r/20181011084249.4520-2-geert+renesas@glider.be To: "Tobin C . Harding" <me@tobin.cc> To: Andrew Morton <akpm@linux-foundation.org> To: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> [pmladek@suse.com: split into separate patch] Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-10-05vsprintf: Fix off-by-one bug in bstr_printf() processing dereferenced pointersSteven Rostedt (VMware)1-1/+1
The functions vbin_printf() and bstr_printf() are used by trace_printk() to try to keep the overhead down during printing. trace_printk() uses vbin_printf() at the time of execution, as it only scans the fmt string to record the printf values into the buffer, and then uses vbin_printf() to do the conversions to print the string based on the format and the saved values in the buffer. This is an issue for dereferenced pointers, as before commit 841a915d20c7b, the processing of the pointer could happen some time after the pointer value was recorded (reading the trace buffer). This means the processing of the value at a later time could show different results, or even crash the system, if the pointer no longer existed. Commit 841a915d20c7b addressed this by processing dereferenced pointers at the time of execution and save the result in the ring buffer as a string. The bstr_printf() would then treat these pointers as normal strings, and print the value. But there was an off-by-one bug here, where after processing the argument, it move the pointer only "strlen(arg)" which made the arg pointer not point to the next argument in the ring buffer, but instead point to the nul character of the last argument. This causes any values after a dereferenced pointer to be corrupted. Cc: stable@vger.kernel.org Fixes: 841a915d20c7b ("vsprintf: Do not have bprintf dereference pointers") Reported-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-09-07vsprintf: print OF node name using full_nameRob Herring1-1/+6
In preparation to remove the node name pointer from struct device_node, convert the node name print to get the node name from the full name. Reviewed-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-08-15Merge tag 'random_for_linus' of ↵Linus Torvalds1-1/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random updates from Ted Ts'o: "Some changes to trust cpu-based hwrng (such as RDRAND) for initializing hashed pointers and (optionally, controlled by a config option) to initialize the CRNG to avoid boot hangs" * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: Make crng state queryable random: remove preempt disabled region random: add a config option to trust the CPU's hwrng vsprintf: Add command line option debug_boot_weak_hash vsprintf: Use hw RNG for ptr_key random: Return nbytes filled from hw RNG random: Fix whitespace pre random-bytes work
2018-08-07lib/vsprintf: Do not handle %pO[^F] as %pxBart Van Assche1-0/+1
This patch avoids that gcc reports the following when building with W=1: lib/vsprintf.c:1941:3: warning: this statement may fall through [-Wimplicit-fallthrough=] switch (fmt[1]) { ^~~~~~ Fixes: 7b1924a1d930eb2 ("vsprintf: add printk specifier %px") Link: http://lkml.kernel.org/r/20180806223421.11995-1-bart.vanassche@wdc.com Cc: linux-kernel@vger.kernel.org Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Joe Perches <joe@perches.com> Cc: Rob Herring <robh@kernel.org> Cc: v4.15+ <stable@vger.kernel.org> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-07-17vsprintf: Add command line option debug_boot_weak_hashTobin C. Harding1-0/+17
Currently printing [hashed] pointers requires enough entropy to be available. Early in the boot sequence this may not be the case resulting in a dummy string '(____ptrval____)' being printed. This makes debugging the early boot sequence difficult. We can relax the requirement to use cryptographically secure hashing during debugging. This enables debugging while keeping development/production kernel behaviour the same. If new command line option debug_boot_weak_hash is enabled use cryptographically insecure hashing and hash pointer value immediately. Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tobin C. Harding <me@tobin.cc> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-07-17vsprintf: Use hw RNG for ptr_keyTobin C. Harding1-1/+9
Currently we must wait for enough entropy to become available before hashed pointers can be printed. We can remove this wait by using the hw RNG if available. Use hw RNG to get keying material. Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tobin C. Harding <me@tobin.cc> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-06-06Merge tag 'printk-for-4.18' of ↵Linus Torvalds1-80/+53
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Help userspace log daemons to catch up with a flood of messages. They will get woken after each message even if the console is far behind and handled by another process. - Flush printk safe buffers safely even when panic() happens in the normal context. - Fix possible va_list reuse when race happened in printk_safe(). - Remove %pCr printf format to prevent sleeping in the atomic context. - Misc vsprintf code cleanup. * tag 'printk-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk: drop in_nmi check from printk_safe_flush_on_panic() lib/vsprintf: Remove atomic-unsafe support for %pCr serial: sh-sci: Stop using printk format %pCr thermal: bcm2835: Stop using printk format %pCr clk: renesas: cpg-mssr: Stop using printk format %pCr printk: fix possible reuse of va_list variable printk: wake up klogd in vprintk_emit vsprintf: Tweak pF/pf comment lib/vsprintf: Mark expected switch fall-through lib/vsprintf: Replace space with '_' before crng is ready lib/vsprintf: Deduplicate pointer_string() lib/vsprintf: Move pointer_string() upper lib/vsprintf: Make flag_spec global lib/vsprintf: Make strspec global lib/vsprintf: Make dec_spec global lib/test_printf: Mark big constant with UL
2018-06-05Merge branch 'for-4.18-vsprintf-pcr-removal' into for-4.18Petr Mladek1-3/+0
2018-06-05lib/vsprintf: Remove atomic-unsafe support for %pCrGeert Uytterhoeven1-3/+0
"%pCr" formats the current rate of a clock, and calls clk_get_rate(). The latter obtains a mutex, hence it must not be called from atomic context. Remove support for this rarely-used format, as vsprintf() (and e.g. printk()) must be callable from any context. Any remaining out-of-tree users will start seeing the clock's name printed instead of its rate. Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com> Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks") Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be To: Jia-Ju Bai <baijiaju1990@gmail.com> To: Jonathan Corbet <corbet@lwn.net> To: Michael Turquette <mturquette@baylibre.com> To: Stephen Boyd <sboyd@kernel.org> To: Zhang Rui <rui.zhang@intel.com> To: Eduardo Valentin <edubezval@gmail.com> To: Eric Anholt <eric@anholt.net> To: Stefan Wahren <stefan.wahren@i2se.com> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-doc@vger.kernel.org Cc: linux-clk@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-05-16vsprintf: Replace memory barrier with static_key for random_ptr_key updateSteven Rostedt (VMware)1-11/+15
Reviewing Tobin's patches for getting pointers out early before entropy has been established, I noticed that there's a lone smp_mb() in the code. As with most lone memory barriers, this one appears to be incorrectly used. We currently basically have this: get_random_bytes(&ptr_key, sizeof(ptr_key)); /* * have_filled_random_ptr_key==true is dependent on get_random_bytes(). * ptr_to_id() needs to see have_filled_random_ptr_key==true * after get_random_bytes() returns. */ smp_mb(); WRITE_ONCE(have_filled_random_ptr_key, true); And later we have: if (unlikely(!have_filled_random_ptr_key)) return string(buf, end, "(ptrval)", spec); /* Missing memory barrier here. */ hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); As the CPU can perform speculative loads, we could have a situation with the following: CPU0 CPU1 ---- ---- load ptr_key = 0 store ptr_key = random smp_mb() store have_filled_random_ptr_key load have_filled_random_ptr_key = true BAD BAD BAD! (you're so bad!) Because nothing prevents CPU1 from loading ptr_key before loading have_filled_random_ptr_key. But this race is very unlikely, but we can't keep an incorrect smp_mb() in place. Instead, replace the have_filled_random_ptr_key with a static_branch not_filled_random_ptr_key, that is initialized to true and changed to false when we get enough entropy. If the update happens in early boot, the static_key is updated immediately, otherwise it will have to wait till entropy is filled and this happens in an interrupt handler which can't enable a static_key, as that requires a preemptible context. In that case, a work_queue is used to enable it, as entropy already took too long to establish in the first place waiting a little more shouldn't hurt anything. The benefit of using the static key is that the unlikely branch in vsprintf() now becomes a nop. Link: http://lkml.kernel.org/r/20180515100558.21df515e@gandalf.local.home Cc: stable@vger.kernel.org Fixes: ad67b74d2469d ("printk: hash addresses printed with %p") Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-04-18vsprintf: Tweak pF/pf commentSergey Senozhatsky1-8/+4
Reflect changes that have happened to pf/pF (deprecation) specifiers in pointer() comment section. Link: http://lkml.kernel.org/r/20180414030005.25831-1-sergey.senozhatsky@gmail.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11proc: add seq_put_decimal_ull_width to speed up /proc/pid/smapsAndrei Vagin1-4/+14
seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a specified minimal field width. It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it works much faster. == test_smaps.py num = 0 with open("/proc/1/smaps") as f: for x in xrange(10000): data = f.read() f.seek(0, 0) == == Before patch == $ time python test_smaps.py real 0m4.593s user 0m0.398s sys 0m4.158s == After patch == $ time python test_smaps.py real 0m3.828s user 0m0.413s sys 0m3.408s $ perf -g record python test_smaps.py == Before patch == - 79.01% 3.36% python [kernel.kallsyms] [k] show_smap.isra.33 - 75.65% show_smap.isra.33 + 48.85% seq_printf + 15.75% __walk_page_range + 9.70% show_map_vma.isra.23 0.61% seq_puts == After patch == - 75.51% 4.62% python [kernel.kallsyms] [k] show_smap.isra.33 - 70.88% show_smap.isra.33 + 24.82% seq_put_decimal_ull_w + 19.78% __walk_page_range + 12.74% seq_printf + 11.08% show_map_vma.isra.23 + 1.68% seq_puts [akpm@linux-foundation.org: fix drivers/of/unittest.c build] Link: http://lkml.kernel.org/r/20180212074931.7227-1-avagin@openvz.org Signed-off-by: Andrei Vagin <avagin@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11lib/vsprintf: Mark expected switch fall-throughAndy Shevchenko1-0/+3
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Link: http://lkml.kernel.org/r/20180216210711.79901-9-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Replace space with '_' before crng is readyShunyong Yang1-1/+2
Before crng is ready, output of "%p" composes of "(ptrval)" and left padding spaces for alignment as no random address can be generated. This seems a little strange when default string width is larger than strlen("(ptrval)"). For example, when irq domain names are built with "%p", the nodes under /sys/kernel/debug/irq/domains like this on AArch64 system, [root@y irq]# ls domains/ default irqchip@ (ptrval)-2 irqchip@ (ptrval)-4 \_SB_.TCS0.QIC1 \_SB_.TCS0.QIC3 irqchip@ (ptrval) irqchip@ (ptrval)-3 \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2 The name "irqchip@ (ptrval)-2" is not so readable in console output. This patch replaces space with readable "_" when output needs padding. Following is the output after applying the patch, [root@y domains]# ls default irqchip@(____ptrval____)-2 irqchip@(____ptrval____)-4 \_SB_.TCS0.QIC1 \_SB_.TCS0.QIC3 irqchip@(____ptrval____) irqchip@(____ptrval____)-3 \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2 There is same problem in some subsystem's dmesg output. Moreover, someone may call "%p" in a similar case. In addition, the timing of crng initialization done may vary on different system. So, the change is made in vsprintf.c. Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Link: http://lkml.kernel.org/r/20180216210711.79901-7-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Cc: Joey Zheng <yu.zheng@hxt-semitech.com> Signed-off-by: Shunyong Yang <shunyong.yang@hxt-semitech.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Deduplicate pointer_string()Andy Shevchenko1-20/+7
There is an exact code at the end of ptr_to_id(). Replace it by calling pointer_string() directly. This is followup to the commit ad67b74d2469 ("printk: hash addresses printed with %p"). Cc: Tobin C. Harding <me@tobin.cc> Link: http://lkml.kernel.org/r/20180216210711.79901-6-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Move pointer_string() upperAndy Shevchenko1-14/+14
As preparatory patch to further clean up. No functional change. Link: http://lkml.kernel.org/r/20180216210711.79901-5-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Make flag_spec globalAndy Shevchenko1-13/+8
There are places where default specification to print flags as number is in use. Make it global and convert existing users. Link: http://lkml.kernel.org/r/20180216210711.79901-4-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Make strspec globalAndy Shevchenko1-12/+9
There are places where default specification to print strings is in use. Make it global and convert existing users. Link: http://lkml.kernel.org/r/20180216210711.79901-3-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-11lib/vsprintf: Make dec_spec globalAndy Shevchenko1-12/+9
There are places where default specification to print decimal numbers is in use. Make it global and convert existing users. Link: http://lkml.kernel.org/r/20180216210711.79901-2-andriy.shevchenko@linux.intel.com To: "Tobin C . Harding" <me@tobin.cc> To: linux@rasmusvillemoes.dk To: Joe Perches <joe@perches.com> To: linux-kernel@vger.kernel.org To: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-04-06vsprintf: Do not preprocess non-dereferenced pointers for bprintf (%px and %pK)Steven Rostedt (VMware)1-0/+4
Commit 841a915d20c7b2 ("printf: Do not have bprintf dereference pointers") would preprocess various pointers that are dereferenced in the bprintf() because the recording and printing are done at two different times. Some pointers stayed dereferenced in the ring buffer because user space could handle them (namely "%pS" and friends). Pointers that are not dereferenced should not be processed immediately but instead just saved directly. Cc: stable@vger.kernel.org Fixes: 841a915d20c7b2 ("printf: Do not have bprintf dereference pointers") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-02-08vsprintf: avoid misleading "(null)" for %pxAdam Borowski1-1/+1
Like %pK already does, print "00000000" instead. This confused people -- the convention is that "(null)" means you tried to dereference a null pointer as opposed to printing the address. Link: http://lkml.kernel.org/r/20180204174521.21383-1-kilobyte@angband.pl To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> To: Steven Rostedt <rostedt@goodmis.org> To: linux-kernel@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: "Roberts, William C" <william.c.roberts@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-02-01Merge branch 'for-linus' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk updates from Petr Mladek: - Add a console_msg_format command line option: The value "default" keeps the old "[time stamp] text\n" format. The value "syslog" allows to see the syslog-like "<log level>[timestamp] text" format. This feature was requested by people doing regression tests, for example, 0day robot. They want to have both filtered and full logs at hands. - Reduce the risk of softlockup: Pass the console owner in a busy loop. This is a new approach to the old problem. It was first proposed by Steven Rostedt on Kernel Summit 2017. It marks a context in which the console_lock owner calls console drivers and could not sleep. On the other side, printk() callers could detect this state and use a busy wait instead of a simple console_trylock(). Finally, the console_lock owner checks if there is a busy waiter at the end of the special context and eventually passes the console_lock to the waiter. The hand-off works surprisingly well and helps in many situations. Well, there is still a possibility of the softlockup, for example, when the flood of messages stops and the last owner still has too much to flush. There is increasing number of people having problems with printk-related softlockups. We might eventually need to get better solution. Anyway, this looks like a good start and promising direction. - Do not allow to schedule in console_unlock() called from printk(): This reverts an older controversial commit. The reschedule helped to avoid softlockups. But it also slowed down the console output. This patch is obsoleted by the new console waiter logic described above. In fact, the reschedule made the hand-off less effective. - Deprecate "%pf" and "%pF" format specifier: It was needed on ia64, ppc64 and parisc64 to dereference function descriptors and show the real function address. It is done transparently by "%ps" and "pS" format specifier now. Sergey Senozhatsky found that all the function descriptors were in a special elf section and could be easily detected. - Remove printk_symbol() API: It has been obsoleted by "%pS" format specifier, and this change helped to remove few continuous lines and a less intuitive old API. - Remove redundant memsets: Sergey removed unnecessary memset when processing printk.devkmsg command line option. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits) printk: drop redundant devkmsg_log_str memsets printk: Never set console_may_schedule in console_trylock() printk: Hide console waiter logic into helpers printk: Add console owner and waiter logic to load balance console writes kallsyms: remove print_symbol() function checkpatch: add pF/pf deprecation warning symbol lookup: introduce dereference_symbol_descriptor() parisc64: Add .opd based function descriptor dereference powerpc64: Add .opd based function descriptor dereference ia64: Add .opd based function descriptor dereference sections: split dereference_function_descriptor() openrisc: Fix conflicting types for _exext and _stext lib: do not use print_symbol() irq debug: do not use print_symbol() sysfs: do not use print_symbol() drivers: do not use print_symbol() x86: do not use print_symbol() unicore32: do not use print_symbol() sh: do not use print_symbol() mn10300: do not use print_symbol() ...
2018-02-01Merge tag 'trace-v4.16' of ↵Linus Torvalds1-13/+69
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "There's not much changes for the tracing system this release. Mostly small clean ups and fixes. The biggest change is to how bprintf works. bprintf is used by trace_printk() to just save the format and args of a printf call, and the formatting is done when the trace buffer is read. This is done to keep the formatting out of the fast path (this was recommended by you). The issue is when arguments are de-referenced. If a pointer is saved, and the format has something like "%*pbl", when the buffer is read, it will de-reference the argument then. The problem is if the data no longer exists. This can cause the kernel to oops. The fix for this was to make these de-reference pointes do the formatting at the time it is called (the fast path), as this guarantees that the data exists (and doesn't change later)" * tag 'trace-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: vsprintf: Do not have bprintf dereference pointers ftrace: Mark function tracer test functions noinline/noclone trace_uprobe: Display correct offset in uprobe_events tracing: Make sure the parsed string always terminates with '\0' tracing: Clear parser->idx if only spaces are read tracing: Detect the string nul character when parsing user input string
2018-01-23vsprintf: Do not have bprintf dereference pointersSteven Rostedt (VMware)1-13/+69
When trace_printk() was introduced, it was discussed that making it be as low overhead as possible, that the processing of the format string should be delayed until it is read. That is, a "trace_printk()" should not convert the %d into numbers and so on, but instead, save the fmt string and all the args in the buffer at the time of recording. When the trace_printk() data is read, it would then parse the format string and do the conversions of the saved arguments in the tracing buffer. The code to perform this was added to vsprintf where vbin_printf() would save the arguments of a specified format string in a buffer, then bstr_printf() could be used to convert the buffer with the same format string into the final output, as if vsprintf() was called in one go. The issue arises when dereferenced pointers are used. The problem is that something like %*pbl which reads a bitmask, will save the pointer to the bitmask in the buffer. Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. Obviously the value of that pointer could have changed since the time it was recorded to the time the buffer is read. Worse yet, the bitmask could be unmapped, and the reading of the trace buffer could actually cause a kernel oops. Another problem is that user space tools such as perf and trace-cmd do not have access to the contents of these pointers, and they become useless when the tracing buffer is extracted. Instead of having vbin_printf() simply save the pointer in the buffer for later processing, have it perform the formatting at the time bin_printf() is called. This will fix the issue of dereferencing pointers at a later time, and has the extra benefit of having user space tools understand these values. Since perf and trace-cmd already can handle %p[sSfF] via saving kallsyms, their pointers are saved and not processed during vbin_printf(). If they were converted, it would break perf and trace-cmd, as they would not know how to deal with the conversion. Link: http://lkml.kernel.org/r/20171228204025.14a71d8f@gandalf.local.home Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-09symbol lookup: introduce dereference_symbol_descriptor()Sergey Senozhatsky1-3/+2
dereference_symbol_descriptor() invokes appropriate ARCH specific function descriptor dereference callbacks: - dereference_kernel_function_descriptor() if the pointer is a kernel symbol; - dereference_module_function_descriptor() if the pointer is a module symbol. This is the last step needed to make '%pS/%ps' smart enough to handle function descriptor dereference on affected ARCHs and to retire '%pF/%pf'. To refresh it: Some architectures (ia64, ppc64, parisc64) use an indirect pointer for C function pointers - the function pointer points to a function descriptor and we need to dereference it to get the actual function pointer. Function descriptors live in .opd elf section and all affected ARCHs (ia64, ppc64, parisc64) handle it properly for kernel and modules. So we, technically, can decide if the dereference is needed by simply looking at the pointer: if it belongs to .opd section then we need to dereference it. The kernel and modules have their own .opd sections, obviously, that's why we need to split dereference_function_descriptor() and use separate kernel and module dereference arch callbacks. Link: http://lkml.kernel.org/r/20171206043649.GB15885@jagdpanzerIV Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: James Bottomley <jejb@parisc-linux.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Tony Luck <tony.luck@intel.com> #ia64 Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc Tested-by: Helge Deller <deller@gmx.de> #parisc64 Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-12-21vsprintf: Fix a dangling documentation referenceJonathan Corbet1-1/+1
A reference to printk-formats.txt didn't get updated when the file moved; fix that. Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-12-21doc: convert printk-formats.txt to rstTobin C. Harding1-1/+2
Documentation/printk-formats.txt is a candidate for conversion to ReStructuredText format. Some effort has already been made to do this conversion even thought the suffix is currently .txt Changes required to complete conversion - Move printk-formats.txt to core-api/printk-formats.rst - Add entry to Documentation/core-api/index.rst - Remove entry from Documentation/00-INDEX - Fix minor grammatical errors. - Order heading adornments as suggested by rst docs. - Use 'Passed by reference' uniformly. - Update pointer documentation around %px specifier. - Fix erroneous double backticks (to commas). - Remove extraneous double backticks (suggested by Jonathan Corbet). - Simplify documentation for kobject. Signed-off-by: Tobin C. Harding <me@tobin.cc> [jc: downcased "kernel"] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-11-29vsprintf: don't use 'restricted_pointer()' when not restrictingLinus Torvalds1-0/+2
Instead, just fall back on the new '%p' behavior which hashes the pointer. Otherwise, '%pK' - that was intended to mark a pointer as restricted - just ends up leaking pointers that a normal '%p' wouldn't leak. Which just make the whole thing pointless. I suspect we should actually get rid of '%pK' entirely, and make it just work as '%p' regardless, but this is the minimal obvious fix. People who actually use 'kptr_restrict' should weigh in on which behavior they want. Cc: Tobin Harding <me@tobin.cc> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29vsprintf: add printk specifier %pxTobin C. Harding1-0/+18
printk specifier %p now hashes all addresses before printing. Sometimes we need to see the actual unmodified address. This can be achieved using %lx but then we face the risk that if in future we want to change the way the Kernel handles printing of pointers we will have to grep through the already existent 50 000 %lx call sites. Let's add specifier %px as a clear, opt-in, way to print a pointer and maintain some level of isolation from all the other hex integer output within the Kernel. Add printk specifier %px to print the actual unmodified address. Signed-off-by: Tobin C. Harding <me@tobin.cc>
2017-11-29printk: hash addresses printed with %pTobin C. Harding1-7/+74
Currently there exist approximately 14 000 places in the kernel where addresses are being printed using an unadorned %p. This potentially leaks sensitive information regarding the Kernel layout in memory. Many of these calls are stale, instead of fixing every call lets hash the address by default before printing. This will of course break some users, forcing code printing needed addresses to be updated. Code that _really_ needs the address will soon be able to use the new printk specifier %px to print the address. For what it's worth, usage of unadorned %p can be broken down as follows (thanks to Joe Perches). $ git grep -E '%p[^A-Za-z0-9]' | cut -f1 -d"/" | sort | uniq -c 1084 arch 20 block 10 crypto 32 Documentation 8121 drivers 1221 fs 143 include 101 kernel 69 lib 100 mm 1510 net 40 samples 7 scripts 11 security 166 sound 152 tools 2 virt Add function ptr_to_id() to map an address to a 32 bit unique identifier. Hash any unadorned usage of specifier %p and any malformed specifiers. Signed-off-by: Tobin C. Harding <me@tobin.cc>
2017-11-29vsprintf: refactor %pK code out of pointer()Tobin C. Harding1-43/+54
Currently code to handle %pK is all within the switch statement in pointer(). This is the wrong level of abstraction. Each of the other switch clauses call a helper function, pK should do the same. Refactor code out of pointer() to new function restricted_pointer(). Signed-off-by: Tobin C. Harding <me@tobin.cc>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland1-2/+2
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-07Merge tag 'devicetree-for-4.13' of ↵Linus Torvalds1-0/+136
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull DeviceTree updates from Rob Herring: - vsprintf format specifier %pOF for device_node's. This will enable us to stop storing the full node names. Conversion of users will happen next cycle. - Update documentation to point to DT specification instead of ePAPR. - Split out graph and property functions to a separate file. - New of-graph functions for ALSA - Add vendor prefixes for RISC-V, Linksys, iWave Systems, Roofull, Itead, and BananaPi. - Improve dtx_diff utility filename printing. * tag 'devicetree-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (32 commits) of: document /sys/firmware/fdt dt-bindings: Add RISC-V vendor prefix vsprintf: Add %p extension "%pOF" for device tree of: find_node_by_full_name rewrite to compare each level of: use kbasename instead of open coding dt-bindings: thermal: add file extension to brcm,ns-thermal of: update ePAPR references to point to Devicetree Specification scripts/dtc: dtx_diff - Show real file names in diff header of: detect invalid phandle in overlay of: be consistent in form of file mode of: make __of_attach_node() static of: address.c header comment typo of: fdt.c header comment typo of: make of_fdt_is_compatible() static dt-bindings: display-timing.txt convert non-ascii characters to ascii Documentation: remove overlay-notes reference to non-existent file dt-bindings: usb: exynos-usb: Add missing required VDD properties dt-bindings: Add vendor prefix for Linksys MAINTAINERS: add device tree ABI documentation file of: Add vendor prefix for iWave Systems Technologies Pvt. Ltd ...
2017-06-27vsprintf: Add %p extension "%pOF" for device treePantelis Antoniou1-0/+136
90% of the usage of device node's full_name is printing it out in a kernel message. However, storing the full path for every node is wasteful and redundant. With a custom format specifier, we can generate the full path at run-time and eventually remove the full path from every node. For instance typical use is: pr_info("Frobbing node %s\n", node->full_name); Which can be written now as: pr_info("Frobbing node %pOF\n", node); '%pO' is the base specifier to represent kobjects with '%pOF' representing struct device_node. Currently, struct device_node is the only supported type of kobject. More fine-grained control of formatting includes printing the name, flags, path-spec name and others, explained in the documentation entry. Originally written by Pantelis, but pretty much rewrote the core function using existing string/number functions. The 2 passes were unnecessary and have been removed. Also, updated the checkpatch.pl check. The unittest code was written by Grant Likely. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-06-05uuid: rename uuid typesChristoph Hellwig1-2/+2
Our "little endian" UUID really is a Wintel GUID, so rename it and its helpers such (guid_t). The big endian UUID is the only true one, so give it the name uuid_t. The uuid_le and uuid_be names are retained for now, but will hopefully go away soon. The exception to that are the _cmp helpers that will be replaced by better primitives ASAP and thus don't get the new names. Also the _to_bin helpers are named to match the better named uuid_parse routine in userspace. Also remove the existing typedef in XFS that's now been superceeded by the generic type name. Signed-off-by: Christoph Hellwig <hch@lst.de> [andy: also update the UUID_LE/UUID_BE macros including fallout] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-08checkpatch: add ability to find bad uses of vsprintf %p<foo> extensionsJoe Perches1-0/+3
%pK was at least once misused at %pk in an out-of-tree module. This lead to some security concerns. Add the ability to track single and multiple line statements for misuses of %p<foo>. [akpm@linux-foundation.org: add helpful comment into lib/vsprintf.c] [akpm@linux-foundation.org: text tweak] Link: http://lkml.kernel.org/r/163a690510e636a23187c0dc9caa09ddac6d4cde.1488228427.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: William Roberts <william.c.roberts@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-02kernel-api.rst: fix output of the vsnprintf() documentationmchehab@s-opensource.com1-3/+3
The vsnprintf() kernel-doc comment uses % character with a special meaning other than escaping a constant. As ReST already defines ``literal`` as an escape sequence, let's make kernel-doc handle it, and use it at lib/vsprintf.c. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-02-27lib/vsprintf.c: remove %Z supportAlexey Dobriyan1-4/+4
Now that %z is standartised in C99 there is no reason to support %Z. Unlike %L it doesn't even make format strings smaller. Use BUILD_BUG_ON in a couple ATM drivers. In case anyone didn't notice lib/vsprintf.o is about half of SLUB which is in my opinion is quite an achievement. Hopefully this patch inspires someone else to trim vsprintf.c more. Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20lib/uuid.c: introduce a few more generic helpersAndy Shevchenko1-5/+4
There are new helpers in this patch: uuid_is_valid checks if a UUID is valid uuid_be_to_bin converts from string to binary (big endian) uuid_le_to_bin converts from string to binary (little endian) They will be used in future, i.e. in the following patches in the series. This also moves the indices arrays to lib/uuid.c to be shared accross modules. [andriy.shevchenko@linux.intel.com: fix typo] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20lib/vsprintf: simplify UUID printingAndy Shevchenko1-8/+4
There are few functions here and there along with type definitions that provide UUID API. This series consolidates everything under one hood and converts current users. This has been tested for a while internally, however it doesn't mean we covered all possible cases (especially accuracy of UUID constants after conversion). So, please test this as much as you can and provide your tag. We appreciate the effort. The ACPI conversion is postponed for now to sort more generic things out first. This patch (of 9): Since we have hex_byte_pack_upper() we may use it directly and avoid second loop. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-17sscanf: implement basic character setsJessica Yu1-1/+58
Implement basic character sets for the '%[' conversion specifier. The '%[' conversion specifier matches a nonempty sequence of characters from the specified set of accepted (or with '^', rejected) characters between the brackets. The substring matched is to be made up of characters in (or not in) the set. This is useful for matching substrings that are delimited by something other than spaces. This implementation differs from its glibc counterpart in the following ways: (1) No support for character ranges (e.g., 'a-z' or '0-9') (2) The hyphen '-' is not a special character (3) The closing bracket ']' cannot be matched (4) No support (yet) for discarding matching input ('%*[') The bitmap code is largely based upon sample code which was provided by Rasmus. The motivation for adding character set support to sscanf originally stemmed from the kernel livepatching project. An ongoing patchset utilizes new livepatch Elf symbol and section names to store important metadata livepatch needs to properly apply its patches. Such metadata is stored in these section and symbol names as substrings delimited by periods '.' and commas ','. For example, a livepatch symbol name might look like this: .klp.sym.vmlinux.printk,0 However, sscanf currently can only extract "substrings" delimited by whitespace using the "%s" specifier. Thus for the above symbol name, one cannot not use sscanf() to extract substrings "vmlinux" or "printk", for example. A number of discussions on the livepatch mailing list dealing with string parsing code for extracting these '.' and ',' delimited substrings eventually led to the conclusion that such code would be completely unnecessary if the kernel sscanf() supported character sets. Thus only a single sscanf() call would be necessary to extract these substrings. In addition, such an addition to sscanf() could benefit other areas of the kernel that might have a similar need in the future. [akpm@linux-foundation.org: 80-col tweaks] Signed-off-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15mm, printk: introduce new format string for flagsVlastimil Babka1-0/+75
In mm we use several kinds of flags bitfields that are sometimes printed for debugging purposes, or exported to userspace via sysfs. To make them easier to interpret independently on kernel version and config, we want to dump also the symbolic flag names. So far this has been done with repeated calls to pr_cont(), which is unreliable on SMP, and not usable for e.g. sysfs export. To get a more reliable and universal solution, this patch extends printk() format string for pointers to handle the page flags (%pGp), gfp_flags (%pGg) and vma flags (%pGv). Existing users of dump_flag_names() are converted and simplified. It would be possible to pass flags by value instead of pointer, but the %p format string for pointers already has extensions for various kernel structures, so it's a good fit, and the extra indirection in a non-critical path is negligible. [linux@rasmusvillemoes.dk: lots of good implementation suggestions] Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-11vsprintf: kptr_restrict is okay in IRQ when 2Jason A. Donenfeld1-13/+13
The kptr_restrict flag, when set to 1, only prints the kernel address when the user has CAP_SYSLOG. When it is set to 2, the kernel address is always printed as zero. When set to 1, this needs to check whether or not we're in IRQ. However, when set to 2, this check is unneccessary, and produces confusing results in dmesg. Thus, only make sure we're not in IRQ when mode 1 is used, but not mode 2. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf: factor out %pN[F] handler as netdev_bits()Andy Shevchenko1-9/+16
Move switch case to the netdev_features_string() and rename it to netdev_bits(). In the future we can extend it as needed. Here we replace the fallback of %pN from '%p' with possible flags to sticter '0x%p' without any flags variation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf: refactor duplicate code to special_hex_number()Andy Shevchenko1-26/+27
special_hex_number() is a helper to print a fixed size type in a hex format with '0x' prefix, zero padding, and small letters. In the module we have already several copies of such code. Consolidate them under special_hex_number() helper. There are couple of differences though. It seems nobody cared about the output in case of CONFIG_KALLSYMS=n, when printing symbol address, because the asked field width is not enough to care last 2 characters in the string represantation of the pointer. Fixed here. The %pNF specifier used to be allowed with a specific field width, though there is neither any user of it nor mention the possibility in the documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf.c: warn about too large precisions and field widthsRasmus Villemoes1-4/+24
The field width is overloaded to pass some extra information for some %p extensions (e.g. #bits for %pb). But we might silently truncate the passed value when we stash it in struct printf_spec (see e.g. "lib/vsprintf.c: expand field_width to 24 bits"). Hopefully 23 value bits should now be enough for everybody, but if not, let's make some noise. Do the same for the precision. In both cases, clamping seems more sensible than truncating. While, according to POSIX, "A negative precision is taken as if the precision were omitted.", the kernel's printf has always treated that case as if the precision was 0, so we use that as lower bound. For the field width, the smallest representable value is actually -(1<<23), but a negative field width means 'set the LEFT flag and use the absolute value', so we want the absolute value to fit. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: Maurizio Lombardi <mlombard@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf.c: help gcc make number() smallerRasmus Villemoes1-12/+14
One consequence of the reorganization of struct printf_spec to make field_width 24 bits was that number() gained about 180 bytes. Since spec is never passed to other functions, we can help gcc make number() lose most of that extra weight by using local variables for the field width and precision. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: Maurizio Lombardi <mlombard@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf.c: expand field_width to 24 bitsRasmus Villemoes1-20/+22
Maurizio Lombardi reported a problem [1] with the %pb extension: It doesn't work for sufficiently large bitmaps, since the size is stashed in the field_width field of the struct printf_spec, which is currently an s16. Concretely, this manifested itself in /sys/bus/pseudo/drivers/scsi_debug/map being empty, since the bitmap printer got a size of 0, which is the 16 bit truncation of the actual bitmap size. We do want to keep struct printf_spec at 8 bytes so that it can cheaply be passed by value. The qualifier field is only used for internal bookkeeping in format_decode, so we might as well use a local variable for that. This gives us an additional 8 bits, which we can then use for the field width. To stay in 8 bytes, we need to do a little rearranging and make the type member a bitfield as well. For consistency, change all the members to bit fields. gcc doesn't generate much worse code with these changes (in fact, bloat-o-meter says we save 300 bytes - which I think is a little surprising). I didn't find a BUILD_BUG/compiletime_assertion/... which would work outside function context, so for now I just open-coded it. [1] http://thread.gmane.org/gmane.linux.kernel/2034835 [akpm@linux-foundation.org: avoid open-coded BUILD_BUG_ON] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reported-by: Maurizio Lombardi <mlombard@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf.c: eliminate potential race in string()Rasmus Villemoes1-19/+9
If the string corresponding to a %s specifier can change under us, we might end up copying a \0 byte to the output buffer. There might be callers who expect the output buffer to contain a genuine C string whose length is exactly the snprintf return value (assuming truncation hasn't happened or has been checked for). We can avoid this by only passing over the source string once, stopping the first time we meet a nul byte (or when we reach the given precision), and then letting widen_string() handle left/right space padding. As a small bonus, this code reuse also makes the generated code slightly smaller. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: Maurizio Lombardi <mlombard@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf.c: move string() below widen_string()Rasmus Villemoes1-31/+31
This is pure code movement, making sure the widen_string() helper is defined before the string() function. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: Maurizio Lombardi <mlombard@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16lib/vsprintf.c: pull out padding code from dentry_name()Rasmus Villemoes1-15/+31
Pull out the logic in dentry_name() which handles field width space padding, in preparation for reusing it from string(). Rename the widen() helper to move_right(), since it is used for handling the !(flags & LEFT) case. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joe Perches <joe@perches.com> Cc: Kees Cook <keescook@chromium.org> Cc: Maurizio Lombardi <mlombard@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>