[038/262] mm/page_alloc: add __alloc_size attributes for better bounds checking

Commit Message

Andrew Morton Nov. 5, 2021, 8:36 p.m. UTC

From: Kees Cook <[e-mail]>
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/[e-mail]
Signed-off-by: Kees Cook <[e-mail]>
Co-developed-by: Daniel Micay <[e-mail]>
Signed-off-by: Daniel Micay <[e-mail]>
Cc: Andy Whitcroft <[e-mail]>
Cc: Christoph Lameter <[e-mail]>
Cc: David Rientjes <[e-mail]>
Cc: Dennis Zhou <[e-mail]>
Cc: Dwaipayan Ray <[e-mail]>
Cc: Joe Perches <[e-mail]>
Cc: Joonsoo Kim <[e-mail]>
Cc: Lukas Bulwahn <[e-mail]>
Cc: Miguel Ojeda <[e-mail]>
Cc: Nathan Chancellor <[e-mail]>
Cc: Nick Desaulniers <[e-mail]>
Cc: Pekka Enberg <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Cc: Vlastimil Babka <[e-mail]>
Cc: Alexandre Bounine <[e-mail]>
Cc: Gustavo A. R. Silva <[e-mail]>
Cc: Ira Weiny <[e-mail]>
Cc: Jing Xiangfeng <[e-mail]>
Cc: John Hubbard <[e-mail]>
Cc: kernel test robot <[e-mail]>
Cc: Matt Porter <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Souptick Joarder <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 include/linux/gfp.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

--- a/include/linux/gfp.h~mm-page_alloc-add-__alloc_size-attributes-for-better-bounds-checking
+++ a/include/linux/gfp.h
@@ -608,9 +608,9 @@  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);
 
-void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
+void *alloc_pages_exact(size_t size, gfp_t gfp_mask) __alloc_size(1);
 void free_pages_exact(void *virt, size_t size);
-void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
+__meminit void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) __alloc_size(1);
 
 #define __get_free_page(gfp_mask) \
 		__get_free_pages((gfp_mask), 0)