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| author | Kees Cook <keescook@chromium.org> | 2022-09-23 23:28:07 +0300 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2022-09-29 12:05:57 +0300 |
| commit | 9ed9cac1850a2a55674b4a17100c50b46f645921 (patch) | |
| tree | 4b971acef7344c8d2910c0a25032635ce8e83c0f /include/linux/compiler_attributes.h | |
| parent | e45cc288724f0cfd497bb5920bcfa60caa335729 (diff) | |
| download | linux-9ed9cac1850a2a55674b4a17100c50b46f645921.tar.xz | |
slab: Remove __malloc attribute from realloc functions
The __malloc attribute should not be applied to "realloc" functions, as
the returned pointer may alias the storage of the prior pointer. Instead
of splitting __malloc from __alloc_size, which would be a huge amount of
churn, just create __realloc_size for the few cases where it is needed.
Thanks to Geert Uytterhoeven <geert@linux-m68k.org> for reporting build
failures with gcc-8 in earlier version which tried to remove the #ifdef.
While the "alloc_size" attribute is available on all GCC versions, I
forgot that it gets disabled explicitly by the kernel in GCC < 9.1 due
to misbehaviors. Add a note to the compiler_attributes.h entry for it.
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: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'include/linux/compiler_attributes.h')
| -rw-r--r-- | include/linux/compiler_attributes.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 445e80517cab..96a4ed11b4be 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -35,7 +35,8 @@ /* * Note: do not use this directly. Instead, use __alloc_size() since it is conditionally - * available and includes other attributes. + * available and includes other attributes. For GCC < 9.1, __alloc_size__ gets undefined + * in compiler-gcc.h, due to misbehaviors. * * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-alloc_005fsize-function-attribute * clang: https://clang.llvm.org/docs/AttributeReference.html#alloc-size |