summaryrefslogtreecommitdiff
path: root/mm/slab.c
diff options
context:
space:
mode:
authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-10-04 16:45:56 +0300
committerVlastimil Babka <vbabka@suse.cz>2022-01-06 14:25:51 +0300
commit0b3eb091d5759479d44cb793fad2c51ea06bdcec (patch)
tree00a317cba0a53dc099678ebb16dcec3a4be41539 /mm/slab.c
parent7213230af5e1e83ff010b3448260b9d3f95dd036 (diff)
downloadlinux-0b3eb091d5759479d44cb793fad2c51ea06bdcec.tar.xz
mm: Convert check_heap_object() to use struct slab
Ensure that we're not seeing a tail page inside __check_heap_object() by converting to a slab instead of a page. Take the opportunity to mark the slab as const since we're not modifying it. Also move the declaration of __check_heap_object() to mm/slab.h so it's not available to the wider kernel. [ vbabka@suse.cz: in check_heap_object() only convert to struct slab for actual PageSlab pages; use folio as intermediate step instead of page ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com>
Diffstat (limited to 'mm/slab.c')
-rw-r--r--mm/slab.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 44bc1fcd1393..38fcd3f496df 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -372,8 +372,8 @@ static void **dbg_userword(struct kmem_cache *cachep, void *objp)
static int slab_max_order = SLAB_MAX_ORDER_LO;
static bool slab_max_order_set __initdata;
-static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
- unsigned int idx)
+static inline void *index_to_obj(struct kmem_cache *cache,
+ const struct page *page, unsigned int idx)
{
return page->s_mem + cache->size * idx;
}
@@ -4166,8 +4166,8 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
* Returns NULL if check passes, otherwise const char * to name of cache
* to indicate an error.
*/
-void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
- bool to_user)
+void __check_heap_object(const void *ptr, unsigned long n,
+ const struct slab *slab, bool to_user)
{
struct kmem_cache *cachep;
unsigned int objnr;
@@ -4176,15 +4176,15 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
ptr = kasan_reset_tag(ptr);
/* Find and validate object. */
- cachep = page->slab_cache;
- objnr = obj_to_index(cachep, page, (void *)ptr);
+ cachep = slab->slab_cache;
+ objnr = obj_to_index(cachep, slab_page(slab), (void *)ptr);
BUG_ON(objnr >= cachep->num);
/* Find offset within object. */
if (is_kfence_address(ptr))
offset = ptr - kfence_object_start(ptr);
else
- offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep);
+ offset = ptr - index_to_obj(cachep, slab_page(slab), objnr) - obj_offset(cachep);
/* Allow address range falling entirely within usercopy region. */
if (offset >= cachep->useroffset &&