[PATCH v2 7/7] mm/vmalloc: Add __alloc_size attributes for better bounds checking

Kees Cook
2021-08-18T21:40:49Z

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

Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/vmalloc.h | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 2644425b6dce..1521ba38957d 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -136,20 +136,31 @@ static inline void vmalloc_init(void)
static inline unsigned long vmalloc_nr_pages(void) { return 0; }
#endif

+__alloc_size(1)
extern void *vmalloc(unsigned long size);
+__alloc_size(1)
extern void *vzalloc(unsigned long size);
+__alloc_size(1)
extern void *vmalloc_user(unsigned long size);
+__alloc_size(1)
extern void *vmalloc_node(unsigned long size, int node);
+__alloc_size(1)
extern void *vzalloc_node(unsigned long size, int node);
+__alloc_size(1)
extern void *vmalloc_32(unsigned long size);
+__alloc_size(1)
extern void *vmalloc_32_user(unsigned long size);
+__alloc_size(1)
extern void *__vmalloc(unsigned long size, gfp_t gfp_mask);
+__alloc_size(1)
extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
unsigned long start, unsigned long end, gfp_t gfp_mask,
pgprot_t prot, unsigned long vm_flags, int node,
const void *caller);
+__alloc_size(1)
void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
int node, const void *caller);
+__alloc_size(1)
void *vmalloc_no_huge(unsigned long size);

extern void vfree(const void *addr);
--
2.30.2