[PATCH 5/5] mm/vmalloc: Add __alloc_size attributes for better bounds checking

[Kees Cook <keescook@xxxxxxxxxxxx>]

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@xxxxxxxxx>
Signed-off-by: Daniel Micay <danielmicay@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 include/linux/vmalloc.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 2644425b6dce..f4ede07e1dae 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -136,21 +136,21 @@ static inline void vmalloc_init(void)
 static inline unsigned long vmalloc_nr_pages(void) { return 0; }
 #endif
 
-extern void *vmalloc(unsigned long size);
-extern void *vzalloc(unsigned long size);
-extern void *vmalloc_user(unsigned long size);
-extern void *vmalloc_node(unsigned long size, int node);
-extern void *vzalloc_node(unsigned long size, int node);
-extern void *vmalloc_32(unsigned long size);
-extern void *vmalloc_32_user(unsigned long size);
-extern void *__vmalloc(unsigned long size, gfp_t gfp_mask);
+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);
+			const void *caller) __alloc_size(1);
 void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
-		int node, const void *caller);
-void *vmalloc_no_huge(unsigned long size);
+		int node, const void *caller) __alloc_size(1);
+void *vmalloc_no_huge(unsigned long size) __alloc_size(1);
 
 extern void vfree(const void *addr);
 extern void vfree_atomic(const void *addr);
-- 
2.30.2