As already done in GrapheneOS, add the __alloc_size attribute for
regular kmalloc 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: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/linux/slab.h | 50 +++++++++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 19 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index c0d46b6fa12a..b2181c176999 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -181,7 +181,7 @@ int kmem_cache_shrink(struct kmem_cache *);
/*
* Common kmalloc functions provided by all allocators
*/
-void * __must_check krealloc(const void *, size_t, gfp_t);
+void * __must_check krealloc(const void *, size_t, gfp_t) __alloc_size(2);
void kfree(const void *);
void kfree_sensitive(const void *);
size_t __ksize(const void *);
@@ -425,7 +425,7 @@ static __always_inline unsigned int __kmalloc_index(size_t size,
#define kmalloc_index(s) __kmalloc_index(s, true)
#endif /* !CONFIG_SLOB */
-void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
+void *__kmalloc(size_t size, gfp_t flags) __alloc_size(1) __assume_kmalloc_alignment __malloc;
void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
void kmem_cache_free(struct kmem_cache *, void *);
@@ -449,7 +449,8 @@ static __always_inline void kfree_bulk(size_t size, void **p)
}
#ifdef CONFIG_NUMA
-void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
+void *__kmalloc_node(size_t size, gfp_t flags, int node) __alloc_size(1)
+ __assume_kmalloc_alignment __malloc;
void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
#else
static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
@@ -574,7 +575,7 @@ static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
* Try really hard to succeed the allocation but fail
* eventually.
*/
-static __always_inline void *kmalloc(size_t size, gfp_t flags)
+static __always_inline __alloc_size(1) void *kmalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size)) {
#ifndef CONFIG_SLOB
@@ -596,7 +597,8 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags)
return __kmalloc(size, flags);
}
-static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
+static __always_inline __alloc_size(1) void *
+kmalloc_node(size_t size, gfp_t flags, int node)
{
#ifndef CONFIG_SLOB
if (__builtin_constant_p(size) &&
@@ -620,7 +622,8 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
* @size: element size.
* @flags: the type of memory to allocate (see kmalloc).
*/
-static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
+static inline __alloc_size(1, 2) void *
+kmalloc_array(size_t n, size_t size, gfp_t flags)
{
size_t bytes;
@@ -638,7 +641,7 @@ static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
* @new_size: new size of a single member of the array
* @flags: the type of memory to allocate (see kmalloc)
*/
-static __must_check inline void *
+static __must_check inline __alloc_size(2, 3) void *
krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t flags)
{
size_t bytes;
@@ -655,7 +658,8 @@ krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t flags)
* @size: element size.
* @flags: the type of memory to allocate (see kmalloc).
*/
-static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+static inline __alloc_size(1, 2) void *
+kcalloc(size_t n, size_t size, gfp_t flags)
{
return kmalloc_array(n, size, flags | __GFP_ZERO);
}
@@ -684,7 +688,8 @@ static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
return __kmalloc_node(bytes, flags, node);
}
-static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
+static inline __alloc_size(1, 2) void *
+kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
{
return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
}
@@ -716,7 +721,8 @@ static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
* @size: how many bytes of memory are required.
* @flags: the type of memory to allocate (see kmalloc).
*/
-static inline void *kzalloc(size_t size, gfp_t flags)
+static inline __alloc_size(1) void *
+kzalloc(size_t size, gfp_t flags)
{
return kmalloc(size, flags | __GFP_ZERO);
}
@@ -727,26 +733,31 @@ static inline void *kzalloc(size_t size, gfp_t flags)
* @flags: the type of memory to allocate (see kmalloc).
* @node: memory node from which to allocate
*/
-static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
+static inline __alloc_size(1) void *
+kzalloc_node(size_t size, gfp_t flags, int node)
{
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 __alloc_size(1) void *
+kvmalloc_node(size_t size, gfp_t flags, int node);
+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;
@@ -756,13 +767,14 @@ static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
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 __alloc_size(3) void *
+kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags);
extern void kvfree(const void *addr);
extern void kvfree_sensitive(const void *addr, size_t len);
--
2.30.2
