diff options
| author | Yongxin Liu <yongxin.liu@windriver.com> | 2025-12-10 08:02:20 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-12-10 08:44:34 +0100 |
| commit | c8161e5304abb26e6c0bec6efc947992500fa6c5 (patch) | |
| tree | d27958ca77eb3391054d8ad3203cd2662e39e896 | |
| parent | 5288176a541215ba48d38fb74bb619e64d4d9bab (diff) | |
| download | tip-x86/urgent.tar.gz | |
x86/fpu: Fix FPU state core dump truncation on CPUs with no extended xfeaturesx86/urgent
Zero can be a valid value of num_records. For example, on Intel Atom x6425RE,
only x87 and SSE are supported (features 0, 1), and fpu_user_cfg.max_features
is 3. The for_each_extended_xfeature() loop only iterates feature 2, which is
not enabled, so num_records = 0. This is valid and should not cause core dump
failure.
The issue is that dump_xsave_layout_desc() returns 0 for both genuine errors
(dump_emit() failure) and valid cases (no extended features). Use negative
return values for errors and only abort on genuine failures.
Fixes: ba386777a30b ("x86/elf: Add a new FPU buffer layout info to x86 core files")
Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20251210000219.4094353-2-yongxin.liu@windriver.com
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 48113c5193aa3c..76153dfb58c9d0 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1946,7 +1946,7 @@ static int dump_xsave_layout_desc(struct coredump_params *cprm) }; if (!dump_emit(cprm, &xc, sizeof(xc))) - return 0; + return -1; num_records++; } @@ -1984,7 +1984,7 @@ int elf_coredump_extra_notes_write(struct coredump_params *cprm) return 1; num_records = dump_xsave_layout_desc(cprm); - if (!num_records) + if (num_records < 0) return 1; /* Total size should be equal to the number of records */ |