The patch titled
Subject: slab: add __alloc_size attributes for better bounds checking
has been added to the -mm tree. Its filename is
slab-add-__alloc_size-attributes-for-better-bounds-checking.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/slab-add-__alloc_size-attributes-for-better-bounds-checking.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/slab-add-__alloc_size-attributes-for-better-bounds-checking.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: slab: add __alloc_size attributes for better bounds checking
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.
Link: https://lkml.kernel.org/r/20210818214021.2476230-5-keescook@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
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: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Cc: Miguel Ojeda <ojeda@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/slab.h | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
--- a/include/linux/slab.h~slab-add-__alloc_size-attributes-for-better-bounds-checking
+++ a/include/linux/slab.h
@@ -181,7 +181,7 @@ int kmem_cache_shrink(struct kmem_cache
/*
* Common kmalloc functions provided by all allocators
*/
-__must_check
+__must_check __alloc_size(2)
void *krealloc(const void *objp, size_t new_size, gfp_t flags);
void kfree(const void *objp);
void kfree_sensitive(const void *objp);
@@ -426,6 +426,7 @@ static __always_inline unsigned int __km
#define kmalloc_index(s) __kmalloc_index(s, true)
#endif /* !CONFIG_SLOB */
+__alloc_size(1)
void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
void *kmem_cache_alloc(struct kmem_cache *s, gfp_t flags) __assume_kmalloc_alignment __malloc;
void kmem_cache_free(struct kmem_cache *s, void *objp);
@@ -450,6 +451,7 @@ static __always_inline void kfree_bulk(s
}
#ifdef CONFIG_NUMA
+__alloc_size(1)
void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_slab_alignment __malloc;
void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
__assume_slab_alignment __malloc;
@@ -574,6 +576,7 @@ static __always_inline void *kmalloc_lar
* Try really hard to succeed the allocation but fail
* eventually.
*/
+__alloc_size(1)
static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
if (__builtin_constant_p(size)) {
@@ -596,6 +599,7 @@ static __always_inline void *kmalloc(siz
return __kmalloc(size, flags);
}
+__alloc_size(1)
static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
#ifndef CONFIG_SLOB
@@ -620,6 +624,7 @@ static __always_inline void *kmalloc_nod
* @size: element size.
* @flags: the type of memory to allocate (see kmalloc).
*/
+__alloc_size(1, 2)
static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
{
size_t bytes;
@@ -638,7 +643,7 @@ static inline void *kmalloc_array(size_t
* @new_size: new size of a single member of the array
* @flags: the type of memory to allocate (see kmalloc)
*/
-__must_check
+__must_check __alloc_size(2, 3)
static inline void *krealloc_array(void *p, size_t new_n, size_t new_size,
gfp_t flags)
{
@@ -656,6 +661,7 @@ static inline void *krealloc_array(void
* @size: element size.
* @flags: the type of memory to allocate (see kmalloc).
*/
+__alloc_size(1, 2)
static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
{
return kmalloc_array(n, size, flags | __GFP_ZERO);
@@ -685,6 +691,7 @@ static inline void *kmalloc_array_node(s
return __kmalloc_node(bytes, flags, node);
}
+__alloc_size(1, 2)
static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
{
return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
@@ -718,6 +725,7 @@ static inline void *kmem_cache_zalloc(st
* @size: how many bytes of memory are required.
* @flags: the type of memory to allocate (see kmalloc).
*/
+__alloc_size(1)
static inline void *kzalloc(size_t size, gfp_t flags)
{
return kmalloc(size, flags | __GFP_ZERO);
@@ -729,25 +737,31 @@ static inline void *kzalloc(size_t size,
* @flags: the type of memory to allocate (see kmalloc).
* @node: memory node from which to allocate
*/
+__alloc_size(1)
static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
{
return kmalloc_node(size, flags | __GFP_ZERO, node);
}
+__alloc_size(1)
extern void *kvmalloc_node(size_t size, gfp_t flags, int node);
+__alloc_size(1)
static inline void *kvmalloc(size_t size, gfp_t flags)
{
return kvmalloc_node(size, flags, NUMA_NO_NODE);
}
+__alloc_size(1)
static inline void *kvzalloc_node(size_t size, gfp_t flags, int node)
{
return kvmalloc_node(size, flags | __GFP_ZERO, node);
}
+__alloc_size(1)
static inline void *kvzalloc(size_t size, gfp_t flags)
{
return kvmalloc(size, flags | __GFP_ZERO);
}
+__alloc_size(1, 2)
static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
{
size_t bytes;
@@ -758,11 +772,13 @@ static inline void *kvmalloc_array(size_
return kvmalloc(bytes, flags);
}
+__alloc_size(1, 2)
static inline void *kvcalloc(size_t n, size_t size, gfp_t flags)
{
return kvmalloc_array(n, size, flags | __GFP_ZERO);
}
+__alloc_size(3)
extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize,
gfp_t flags);
extern void kvfree(const void *addr);
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
compiler-attributes-add-__alloc_size-for-better-bounds-checking.patch
checkpatch-add-__alloc_size-to-known-attribute.patch
slab-clean-up-function-declarations.patch
slab-add-__alloc_size-attributes-for-better-bounds-checking.patch
mm-page_alloc-add-__alloc_size-attributes-for-better-bounds-checking.patch
percpu-add-__alloc_size-attributes-for-better-bounds-checking.patch
mm-vmalloc-add-__alloc_size-attributes-for-better-bounds-checking.patch
