| Message ID | 20220929081642.1932200-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Headers | show |
| Series | compiler_types.h: Test for __alloc_size__ again | expand |
On 9/29/22 10:16, Kees Cook wrote: > 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, > and restore the #ifdef in compiler_types.h. > > Cc: Vlastimil Babka <vbabka@suse.cz> > Cc: Miguel Ojeda <ojeda@kernel.org> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Yonghong Song <yhs@fb.com> > Cc: Hao Luo <haoluo@google.com> > Cc: Marco Elver <elver@google.com> > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> > Link: https://lore.kernel.org/lkml/CAMuHMdXK+UN1YVZm9DenuXAM8hZRUZJwp=SXsueP7sWiVU3a9A@mail.gmail.com > Fixes: 63caa04ec60583b1 ("slab: Remove __malloc attribute from realloc functions") > Signed-off-by: Kees Cook <keescook@chromium.org> Thanks, I decided to late squash it so we don't needlessly cause issues for people doing bisections with gcc-8 later. > --- > I swear I sent this earlier today, but I don't see it on lore still. Resending, > so apologies if this is a duplicate. > --- > include/linux/compiler_attributes.h | 3 ++- > include/linux/compiler_types.h | 9 +++++++-- > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h > index 465be5f072ff..55fbb6091ecf 100644 > --- a/include/linux/compiler_attributes.h > +++ b/include/linux/compiler_attributes.h > @@ -65,7 +65,8 @@ > > /* > * 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 > diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h > index f141a6f6b9f6..0717534f8364 100644 > --- a/include/linux/compiler_types.h > +++ b/include/linux/compiler_types.h > @@ -275,8 +275,13 @@ struct ftrace_likely_data { > * be performing a _reallocation_, as that may alias the existing pointer. > * For these, use __realloc_size(). > */ > -#define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc > -#define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) > +#ifdef __alloc_size__ > +# define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc > +# define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) > +#else > +# define __alloc_size(x, ...) __malloc > +# define __realloc_size(x, ...) > +#endif > > #ifndef asm_volatile_goto > #define asm_volatile_goto(x...) asm goto(x)
On Thu, Sep 29, 2022 at 11:14:47AM +0200, Vlastimil Babka wrote: > On 9/29/22 10:16, Kees Cook wrote: > > 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, > > and restore the #ifdef in compiler_types.h. > > > > Cc: Vlastimil Babka <vbabka@suse.cz> > > Cc: Miguel Ojeda <ojeda@kernel.org> > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Yonghong Song <yhs@fb.com> > > Cc: Hao Luo <haoluo@google.com> > > Cc: Marco Elver <elver@google.com> > > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> > > Link: https://lore.kernel.org/lkml/CAMuHMdXK+UN1YVZm9DenuXAM8hZRUZJwp=SXsueP7sWiVU3a9A@mail.gmail.com > > Fixes: 63caa04ec60583b1 ("slab: Remove __malloc attribute from realloc functions") > > Signed-off-by: Kees Cook <keescook@chromium.org> > > Thanks, I decided to late squash it so we don't needlessly cause issues for > people doing bisections with gcc-8 later. Sounds good to me; thanks!
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index 465be5f072ff..55fbb6091ecf 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -65,7 +65,8 @@ /* * 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 diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index f141a6f6b9f6..0717534f8364 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -275,8 +275,13 @@ struct ftrace_likely_data { * be performing a _reallocation_, as that may alias the existing pointer. * For these, use __realloc_size(). */ -#define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc -#define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) +#ifdef __alloc_size__ +# define __alloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) __malloc +# define __realloc_size(x, ...) __alloc_size__(x, ## __VA_ARGS__) +#else +# define __alloc_size(x, ...) __malloc +# define __realloc_size(x, ...) +#endif #ifndef asm_volatile_goto #define asm_volatile_goto(x...) asm goto(x)
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, and restore the #ifdef in compiler_types.h. Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yonghong Song <yhs@fb.com> Cc: Hao Luo <haoluo@google.com> Cc: Marco Elver <elver@google.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/lkml/CAMuHMdXK+UN1YVZm9DenuXAM8hZRUZJwp=SXsueP7sWiVU3a9A@mail.gmail.com Fixes: 63caa04ec60583b1 ("slab: Remove __malloc attribute from realloc functions") Signed-off-by: Kees Cook <keescook@chromium.org> --- I swear I sent this earlier today, but I don't see it on lore still. Resending, so apologies if this is a duplicate. --- include/linux/compiler_attributes.h | 3 ++- include/linux/compiler_types.h | 9 +++++++-- 2 files changed, 9 insertions(+), 3 deletions(-)