[036/262] mm/kvmalloc: 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/kvmalloc: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for regular
kvmalloc 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]>
Reviewed-by: Nick Desaulniers <[e-mail]>
Cc: Christoph Lameter <[e-mail]>
Cc: Pekka Enberg <[e-mail]>
Cc: David Rientjes <[e-mail]>
Cc: Joonsoo Kim <[e-mail]>
Cc: Vlastimil Babka <[e-mail]>
Cc: Andy Whitcroft <[e-mail]>
Cc: Dennis Zhou <[e-mail]>
Cc: Dwaipayan Ray <[e-mail]>
Cc: Joe Perches <[e-mail]>
Cc: Lukas Bulwahn <[e-mail]>
Cc: Miguel Ojeda <[e-mail]>
Cc: Nathan Chancellor <[e-mail]>
Cc: Tejun Heo <[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/slab.h |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Patch

--- a/include/linux/slab.h~mm-kvmalloc-add-__alloc_size-attributes-for-better-bounds-checking
+++ a/include/linux/slab.h
@@ -737,21 +737,21 @@  static inline __alloc_size(1) void *kzal
 	return kmalloc_node(size, flags | __GFP_ZERO, node);
 }
 
-extern void *kvmalloc_node(size_t size, gfp_t flags, int node);
-static inline void *kvmalloc(size_t size, gfp_t flags)
+extern void *kvmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1);
+static inline __alloc_size(1) void *kvmalloc(size_t size, gfp_t flags)
 {
 	return kvmalloc_node(size, flags, NUMA_NO_NODE);
 }
-static inline void *kvzalloc_node(size_t size, gfp_t flags, int node)
+static inline __alloc_size(1) void *kvzalloc_node(size_t size, gfp_t flags, int node)
 {
 	return kvmalloc_node(size, flags | __GFP_ZERO, node);
 }
-static inline void *kvzalloc(size_t size, gfp_t flags)
+static inline __alloc_size(1) void *kvzalloc(size_t size, gfp_t flags)
 {
 	return kvmalloc(size, flags | __GFP_ZERO);
 }
 
-static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
+static inline __alloc_size(1, 2) void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
 {
 	size_t bytes;
 
@@ -761,13 +761,13 @@  static inline void *kvmalloc_array(size_
 	return kvmalloc(bytes, flags);
 }
 
-static inline void *kvcalloc(size_t n, size_t size, gfp_t flags)
+static inline __alloc_size(1, 2) void *kvcalloc(size_t n, size_t size, gfp_t flags)
 {
 	return kvmalloc_array(n, size, flags | __GFP_ZERO);
 }
 
-extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize,
-		gfp_t flags);
+extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags)
+		      __alloc_size(3);
 extern void kvfree(const void *addr);
 extern void kvfree_sensitive(const void *addr, size_t len);