diff options
| author | Chunyan Zhang <zhangchunyan@iscas.ac.cn> | 2025-11-13 15:28:02 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-24 15:08:54 -0800 |
| commit | f59c0924d61aa2a2bb85936a593140f327112787 (patch) | |
| tree | 6df59a487b0199e0a769d9c87fb60a725fc40746 /fs/userfaultfd.c | |
| parent | 277a1ae3879a82a15a2e2d6741e38e31ea6487ee (diff) | |
| download | tip-f59c0924d61aa2a2bb85936a593140f327112787.tar.gz | |
mm: userfaultfd: add pgtable_supports_uffd_wp()
Some platforms can customize the PTE/PMD entry uffd-wp bit making it
unavailable even if the architecture provides the resource. This patch
adds a macro API pgtable_supports_uffd_wp() that allows architectures to
define their specific implementations to check if the uffd-wp bit is
available on which device the kernel is running.
Also this patch is removing "ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP" and
"ifdef CONFIG_PTE_MARKER_UFFD_WP" in favor of pgtable_supports_uffd_wp()
and uffd_supports_wp_marker() checks respectively that default to
IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) and
"IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) &&
IS_ENABLED(CONFIG_PTE_MARKER_UFFD_WP)" if not overridden by the
architecture, no change in behavior is expected.
Link: https://lkml.kernel.org/r/20251113072806.795029-3-zhangchunyan@iscas.ac.cn
Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Conor Dooley <conor.dooley@microchip.com>
Cc: Conor Dooley <conor@kernel.org>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 3f539aabc3b383..5a0d19dec7ba3c 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1289,9 +1289,9 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MISSING) vm_flags |= VM_UFFD_MISSING; if (uffdio_register.mode & UFFDIO_REGISTER_MODE_WP) { -#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP - goto out; -#endif + if (!pgtable_supports_uffd_wp()) + goto out; + vm_flags |= VM_UFFD_WP; } if (uffdio_register.mode & UFFDIO_REGISTER_MODE_MINOR) { @@ -1999,14 +1999,14 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx, uffdio_api.features &= ~(UFFD_FEATURE_MINOR_HUGETLBFS | UFFD_FEATURE_MINOR_SHMEM); #endif -#ifndef CONFIG_HAVE_ARCH_USERFAULTFD_WP - uffdio_api.features &= ~UFFD_FEATURE_PAGEFAULT_FLAG_WP; -#endif -#ifndef CONFIG_PTE_MARKER_UFFD_WP - uffdio_api.features &= ~UFFD_FEATURE_WP_HUGETLBFS_SHMEM; - uffdio_api.features &= ~UFFD_FEATURE_WP_UNPOPULATED; - uffdio_api.features &= ~UFFD_FEATURE_WP_ASYNC; -#endif + if (!pgtable_supports_uffd_wp()) + uffdio_api.features &= ~UFFD_FEATURE_PAGEFAULT_FLAG_WP; + + if (!uffd_supports_wp_marker()) { + uffdio_api.features &= ~UFFD_FEATURE_WP_HUGETLBFS_SHMEM; + uffdio_api.features &= ~UFFD_FEATURE_WP_UNPOPULATED; + uffdio_api.features &= ~UFFD_FEATURE_WP_ASYNC; + } ret = -EINVAL; if (features & ~uffdio_api.features) |