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| author |   Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-10-04 14:45:56 +0100 |
|---|---|---|
| committer |   Vlastimil Babka <vbabka@suse.cz> | 2022-01-06 12:25:51 +0100 |
| commit | 0b3eb091d5759479d44cb793fad2c51ea06bdcec (patch) | |
| tree | 00a317cba0a53dc099678ebb16dcec3a4be41539 /mm/slab.c | |
| parent | mm: Use struct slab in kmem_obj_info() (diff) | |
| download | linux-dev-0b3eb091d5759479d44cb793fad2c51ea06bdcec.tar.xz linux-dev-0b3eb091d5759479d44cb793fad2c51ea06bdcec.zip | |
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.c | 14 |
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 && |