History

mm/kasan: Convert to struct folio and struct slab

KASAN accesses some slab related struct page fields so we need to convert it to struct slab. Some places are a bit simplified thanks to kasan_addr_to_slab() encapsulating the PageSlab flag check through virt_to_slab(). When resolving object address to either a real slab or a large kmalloc, use struct folio as the intermediate type for testing the slab flag to avoid unnecessary implicit compound_head(). [ vbabka@suse.cz: use struct folio, adjust to differences in previous patches ]

Matthew Wilcox (Oracle) committed 5 years ago

Commit 6e48a961 parent 50757019 files · +42 −28Browse files

Unified · Split

9 files
  1. include/linux/kasan.h +5 −4
  2. mm/kasan/common.c +13 −10
  3. mm/kasan/generic.c +4 −4
  4. mm/kasan/kasan.h +1 −0
  5. mm/kasan/quarantine.c +1 −1
  6. mm/kasan/report.c +11 −2
  7. mm/kasan/report_tags.c +5 −5
  8. mm/slab.c +1 −1
  9. mm/slub.c +1 −1
include/linux/kasan.h+5−4
@@ -9,6 +9,7 @@ · 8 unmodified lines
99
1010 struct kmem_cache;
1111 struct page;
12+struct slab;
1213 struct vm_struct;
1314 struct task_struct;
1415
@@ -193,11 +194,11 @@ static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache) · 178 unmodified lines
193194 return 0;
194195 }
195196
196−void __kasan_poison_slab(struct page *page);
197−static __always_inline void kasan_poison_slab(struct page *page)
197+void __kasan_poison_slab(struct slab *slab);
198+static __always_inline void kasan_poison_slab(struct slab *slab)
198199 {
199200 if (kasan_enabled())
200− __kasan_poison_slab(page);
201+ __kasan_poison_slab(slab);
201202 }
202203
203204 void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
@@ -322,7 +323,7 @@ static inline void kasan_cache_create(struct kmem_cache *cache, · 118 unmodified lines
322323 slab_flags_t *flags) {}
323324 static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
324325 static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
325−static inline void kasan_poison_slab(struct page *page) {}
326+static inline void kasan_poison_slab(struct slab *slab) {}
326327 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
327328 void *object) {}
328329 static inline void kasan_poison_object_data(struct kmem_cache *cache,
mm/kasan/common.c+13−10
@@ -247,8 +247,9 @@ struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache, · 246 unmodified lines
247247 }
248248 #endif
249249
250−void __kasan_poison_slab(struct page *page)
250+void __kasan_poison_slab(struct slab *slab)
251251 {
252+ struct page *page = slab_page(slab);
252253 unsigned long i;
253254
254255 for (i = 0; i < compound_nr(page); i++)
@@ -401,9 +402,9 @@ void __kasan_kfree_large(void *ptr, unsigned long ip) · 146 unmodified lines
401402
402403 void __kasan_slab_free_mempool(void *ptr, unsigned long ip)
403404 {
404− struct page *page;
405+ struct folio *folio;
405406
406− page = virt_to_head_page(ptr);
407+ folio = virt_to_folio(ptr);
407408
408409 /*
409410 * Even though this function is only called for kmem_cache_alloc and
@@ -411,12 +412,14 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip) · 1 unmodified line
411412 * !PageSlab() when the size provided to kmalloc is larger than
412413 * KMALLOC_MAX_SIZE, and kmalloc falls back onto page_alloc.
413414 */
414− if (unlikely(!PageSlab(page))) {
415+ if (unlikely(!folio_test_slab(folio))) {
415416 if (____kasan_kfree_large(ptr, ip))
416417 return;
417− kasan_poison(ptr, page_size(page), KASAN_FREE_PAGE, false);
418+ kasan_poison(ptr, folio_size(folio), KASAN_FREE_PAGE, false);
418419 } else {
419− ____kasan_slab_free(page->slab_cache, ptr, ip, false, false);
420+ struct slab *slab = folio_slab(folio);
421+
422+ ____kasan_slab_free(slab->slab_cache, ptr, ip, false, false);
420423 }
421424 }
422425
@@ -560,7 +563,7 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, · 137 unmodified lines
560563
561564 void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flags)
562565 {
563− struct page *page;
566+ struct slab *slab;
564567
565568 if (unlikely(object == ZERO_SIZE_PTR))
566569 return (void *)object;
@@ -572,13 +575,13 @@ void * __must_check __kasan_krealloc(const void *object, size_t size, gfp_t flag · 5 unmodified lines
572575 */
573576 kasan_unpoison(object, size, false);
574577
575− page = virt_to_head_page(object);
578+ slab = virt_to_slab(object);
576579
577580 /* Piggy-back on kmalloc() instrumentation to poison the redzone. */
578− if (unlikely(!PageSlab(page)))
581+ if (unlikely(!slab))
579582 return __kasan_kmalloc_large(object, size, flags);
580583 else
581− return ____kasan_kmalloc(page->slab_cache, object, size, flags);
584+ return ____kasan_kmalloc(slab->slab_cache, object, size, flags);
582585 }
583586
584587 bool __kasan_check_byte(const void *address, unsigned long ip)
mm/kasan/generic.c+4−4
@@ -330,16 +330,16 @@ DEFINE_ASAN_SET_SHADOW(f8); · 329 unmodified lines
330330
331331 static void __kasan_record_aux_stack(void *addr, bool can_alloc)
332332 {
333− struct page *page = kasan_addr_to_page(addr);
333+ struct slab *slab = kasan_addr_to_slab(addr);
334334 struct kmem_cache *cache;
335335 struct kasan_alloc_meta *alloc_meta;
336336 void *object;
337337
338− if (is_kfence_address(addr) || !(page && PageSlab(page)))
338+ if (is_kfence_address(addr) || !slab)
339339 return;
340340
341− cache = page->slab_cache;
342− object = nearest_obj(cache, page_slab(page), addr);
341+ cache = slab->slab_cache;
342+ object = nearest_obj(cache, slab, addr);
343343 alloc_meta = kasan_get_alloc_meta(cache, object);
344344 if (!alloc_meta)
345345 return;
mm/kasan/kasan.h+1−0
@@ -265,6 +265,7 @@ bool kasan_report(unsigned long addr, size_t size, · 264 unmodified lines
265265 void kasan_report_invalid_free(void *object, unsigned long ip);
266266
267267 struct page *kasan_addr_to_page(const void *addr);
268+struct slab *kasan_addr_to_slab(const void *addr);
268269
269270 depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
270271 void kasan_set_track(struct kasan_track *track, gfp_t flags);
mm/kasan/quarantine.c+1−1
@@ -117,7 +117,7 @@ static unsigned long quarantine_batch_size; · 116 unmodified lines
117117
118118 static struct kmem_cache *qlink_to_cache(struct qlist_node *qlink)
119119 {
120− return virt_to_head_page(qlink)->slab_cache;
120+ return virt_to_slab(qlink)->slab_cache;
121121 }
122122
123123 static void *qlink_to_object(struct qlist_node *qlink, struct kmem_cache *cache)
mm/kasan/report.c+11−2
@@ -150,6 +150,14 @@ struct page *kasan_addr_to_page(const void *addr) · 149 unmodified lines
150150 return NULL;
151151 }
152152
153+struct slab *kasan_addr_to_slab(const void *addr)
154+{
155+ if ((addr >= (void *)PAGE_OFFSET) &&
156+ (addr < high_memory))
157+ return virt_to_slab(addr);
158+ return NULL;
159+}
160+
153161 static void describe_object_addr(struct kmem_cache *cache, void *object,
154162 const void *addr)
155163 {
@@ -248,8 +256,9 @@ static void print_address_description(void *addr, u8 tag) · 92 unmodified lines
248256 pr_err("\n");
249257
250258 if (page && PageSlab(page)) {
251− struct kmem_cache *cache = page->slab_cache;
252− void *object = nearest_obj(cache, page_slab(page), addr);
259+ struct slab *slab = page_slab(page);
260+ struct kmem_cache *cache = slab->slab_cache;
261+ void *object = nearest_obj(cache, slab, addr);
253262
254263 describe_object(cache, object, addr, tag);
255264 }
mm/kasan/report_tags.c+5−5
@@ -12,7 +12,7 @@ const char *kasan_get_bug_type(struct kasan_access_info *info) · 11 unmodified lines
1212 #ifdef CONFIG_KASAN_TAGS_IDENTIFY
1313 struct kasan_alloc_meta *alloc_meta;
1414 struct kmem_cache *cache;
15− struct page *page;
15+ struct slab *slab;
1616 const void *addr;
1717 void *object;
1818 u8 tag;
@@ -20,10 +20,10 @@ const char *kasan_get_bug_type(struct kasan_access_info *info) · 1 unmodified line
2020
2121 tag = get_tag(info->access_addr);
2222 addr = kasan_reset_tag(info->access_addr);
23− page = kasan_addr_to_page(addr);
24− if (page && PageSlab(page)) {
25− cache = page->slab_cache;
26− object = nearest_obj(cache, page_slab(page), (void *)addr);
23+ slab = kasan_addr_to_slab(addr);
24+ if (slab) {
25+ cache = slab->slab_cache;
26+ object = nearest_obj(cache, slab, (void *)addr);
2727 alloc_meta = kasan_get_alloc_meta(cache, object);
2828
2929 if (alloc_meta) {
mm/slab.c+1−1
@@ -2604,7 +2604,7 @@ static struct slab *cache_grow_begin(struct kmem_cache *cachep, · 2603 unmodified lines
26042604 * page_address() in the latter returns a non-tagged pointer,
26052605 * as it should be for slab pages.
26062606 */
2607− kasan_poison_slab(slab_page(slab));
2607+ kasan_poison_slab(slab);
26082608
26092609 /* Get slab management. */
26102610 freelist = alloc_slabmgmt(cachep, slab, offset,
mm/slub.c+1−1
@@ -1961,7 +1961,7 @@ static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) · 1960 unmodified lines
19611961
19621962 slab->slab_cache = s;
19631963
1964− kasan_poison_slab(slab_page(slab));
1964+ kasan_poison_slab(slab);
19651965
19661966 start = slab_address(slab);
19671967

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