[patch 7/9] mm/page_alloc: add __alloc_size attributes for better bounds checking

From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, apw@canonical.com, cl@linux.com,
	danielmicay@gmail.com, dennis@kernel.org,
	dwaipayanray1@gmail.com, iamjoonsoo.kim@lge.com, joe@perches.com,
	keescook@chromium.org, linux-mm@kvack.org,
	lukas.bulwahn@gmail.com, mm-commits@vger.kernel.org,
	nathan@kernel.org, ndesaulniers@google.com, ojeda@kernel.org,
	penberg@kernel.org, rientjes@google.com, tj@kernel.org,
	torvalds@linux-foundation.org, vbabka@suse.cz
Subject: [patch 7/9] mm/page_alloc: add __alloc_size attributes for better bounds checking
Date: Thu, 09 Sep 2021 20:10:40 -0700	[thread overview]
Message-ID: <20210910031040.tyehRLbzL%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210909200948.090d4e213ca34b5ad1325a7e@linux-foundation.org>

From: Kees Cook <keescook@chromium.org>
Subject: mm/page_alloc: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for
appropriate page allocator interfaces, to provide additional hinting for
better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other compiler
optimizations.

Link: https://lkml.kernel.org/r/20210818214021.2476230-6-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/gfp.h |    2 ++
 1 file changed, 2 insertions(+)

--- a/include/linux/gfp.h~mm-page_alloc-add-__alloc_size-attributes-for-better-bounds-checking
+++ a/include/linux/gfp.h
@@ -608,8 +608,10 @@ static inline struct page *alloc_pages(g
 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 
+__alloc_size(1)
 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 void free_pages_exact(void *virt, size_t size);
+__alloc_size(1)
 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
 
 #define __get_free_page(gfp_mask) \
_
