* [PATCH v2 1/3] kasan: clean up comments in internal kasan.h @ 2022-05-09 15:51 andrey.konovalov 2022-05-09 15:51 ` [PATCH v2 2/3] kasan: use tabs to align shadow values andrey.konovalov 2022-05-09 15:51 ` [PATCH v2 3/3] kasan: give better names to " andrey.konovalov 0 siblings, 2 replies; 3+ messages in thread From: andrey.konovalov @ 2022-05-09 15:51 UTC (permalink / raw) To: Marco Elver, Alexander Potapenko Cc: Andrey Konovalov, Dmitry Vyukov, Andrey Ryabinin, kasan-dev, Andrew Morton, linux-mm, linux-kernel, Andrey Konovalov From: Andrey Konovalov <andreyknvl@google.com> Clean up comments in mm/kasan/kasan.h: clarify, unify styles, fix punctuation, etc. Reviewed-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- mm/kasan/kasan.h | 74 +++++++++++++++++++++--------------------------- 1 file changed, 33 insertions(+), 41 deletions(-) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index b01b4bbe0409..fed4f7a00d33 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -42,6 +42,7 @@ static inline bool kasan_sync_fault_possible(void) { return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM; } + #else static inline bool kasan_stack_collection_enabled(void) @@ -73,47 +74,41 @@ static inline bool kasan_sync_fault_possible(void) #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT) #ifdef CONFIG_KASAN_GENERIC -#define KASAN_FREE_PAGE 0xFF /* page was freed */ -#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ -#define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */ -#define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */ -#define KASAN_VMALLOC_INVALID 0xF8 /* unallocated space in vmapped page */ +#define KASAN_FREE_PAGE 0xFF /* freed page */ +#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */ +#define KASAN_KMALLOC_REDZONE 0xFC /* redzone for slab object */ +#define KASAN_KMALLOC_FREE 0xFB /* freed slab object */ +#define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */ #else #define KASAN_FREE_PAGE KASAN_TAG_INVALID #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID #define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID #define KASAN_KMALLOC_FREE KASAN_TAG_INVALID -#define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only for SW_TAGS */ +#define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */ #endif #ifdef CONFIG_KASAN_GENERIC -#define KASAN_KMALLOC_FREETRACK 0xFA /* object was freed and has free track set */ +#define KASAN_KMALLOC_FREETRACK 0xFA /* freed slab object with free track */ #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ -/* - * Stack redzone shadow values - * (Those are compiler's ABI, don't change them) - */ +/* Stack redzone shadow values. Compiler ABI, do not change. */ #define KASAN_STACK_LEFT 0xF1 #define KASAN_STACK_MID 0xF2 #define KASAN_STACK_RIGHT 0xF3 #define KASAN_STACK_PARTIAL 0xF4 -/* - * alloca redzone shadow values - */ +/* alloca redzone shadow values. */ #define KASAN_ALLOCA_LEFT 0xCA #define KASAN_ALLOCA_RIGHT 0xCB +/* alloca redzone size. Compiler ABI, do not change. */ #define KASAN_ALLOCA_REDZONE_SIZE 32 -/* - * Stack frame marker (compiler ABI). - */ +/* Stack frame marker. Compiler ABI, do not change. */ #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3 -/* Don't break randconfig/all*config builds */ +/* Dummy value to avoid breaking randconfig/all*config builds. */ #ifndef KASAN_ABI_VERSION #define KASAN_ABI_VERSION 1 #endif @@ -141,21 +136,21 @@ struct kasan_report_info { unsigned long ip; }; -/* The layout of struct dictated by compiler */ +/* Do not change the struct layout: compiler ABI. */ struct kasan_source_location { const char *filename; int line_no; int column_no; }; -/* The layout of struct dictated by compiler */ +/* Do not change the struct layout: compiler ABI. */ struct kasan_global { const void *beg; /* Address of the beginning of the global variable. */ size_t size; /* Size of the global variable. */ - size_t size_with_redzone; /* Size of the variable + size of the red zone. 32 bytes aligned */ + size_t size_with_redzone; /* Size of the variable + size of the redzone. 32 bytes aligned. */ const void *name; const void *module_name; /* Name of the module where the global variable is declared. */ - unsigned long has_dynamic_init; /* This needed for C++ */ + unsigned long has_dynamic_init; /* This is needed for C++. */ #if KASAN_ABI_VERSION >= 4 struct kasan_source_location *location; #endif @@ -164,9 +159,7 @@ struct kasan_global { #endif }; -/** - * Structures to keep alloc and free tracks * - */ +/* Structures for keeping alloc and free tracks. */ #define KASAN_STACK_DEPTH 64 @@ -183,11 +176,8 @@ struct kasan_track { struct kasan_alloc_meta { struct kasan_track alloc_track; + /* Generic mode stores free track in kasan_free_meta. */ #ifdef CONFIG_KASAN_GENERIC - /* - * The auxiliary stack is stored into struct kasan_alloc_meta. - * The free stack is stored into struct kasan_free_meta. - */ depot_stack_handle_t aux_stack[2]; #else struct kasan_track free_track[KASAN_NR_FREE_STACKS]; @@ -203,18 +193,18 @@ struct qlist_node { }; /* - * Generic mode either stores free meta in the object itself or in the redzone - * after the object. In the former case free meta offset is 0, in the latter - * case it has some sane value smaller than INT_MAX. Use INT_MAX as free meta - * offset when free meta isn't present. + * Free meta is stored either in the object itself or in the redzone after the + * object. In the former case, free meta offset is 0. In the latter case, the + * offset is between 0 and INT_MAX. INT_MAX marks that free meta is not present. */ #define KASAN_NO_FREE_META INT_MAX +/* + * Free meta is only used by Generic mode while the object is in quarantine. + * After that, slab allocator stores the freelist pointer in the object. + */ struct kasan_free_meta { #ifdef CONFIG_KASAN_GENERIC - /* This field is used while the object is in the quarantine. - * Otherwise it might be used for the allocator freelist. - */ struct qlist_node quarantine_link; struct kasan_track free_track; #endif @@ -417,9 +407,10 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init) return; /* * Explicitly initialize the memory with the precise object size to - * avoid overwriting the SLAB redzone. This disables initialization in - * the arch code and may thus lead to performance penalty. The penalty - * is accepted since SLAB redzones aren't enabled in production builds. + * avoid overwriting the slab redzone. This disables initialization in + * the arch code and may thus lead to performance penalty. This penalty + * does not affect production builds, as slab redzones are not enabled + * there. */ if (__slub_debug_enabled() && init && ((unsigned long)size & KASAN_GRANULE_MASK)) { @@ -503,8 +494,9 @@ void kasan_restore_multi_shot(bool enabled); /* * Exported functions for interfaces called from assembly or from generated - * code. Declarations here to avoid warning about missing declarations. + * code. Declared here to avoid warnings about missing declarations. */ + asmlinkage void kasan_unpoison_task_stack_below(const void *watermark); void __asan_register_globals(struct kasan_global *globals, size_t size); void __asan_unregister_globals(struct kasan_global *globals, size_t size); @@ -573,4 +565,4 @@ void __hwasan_storeN_noabort(unsigned long addr, size_t size); void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size); -#endif +#endif /* __MM_KASAN_KASAN_H */ -- 2.25.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 2/3] kasan: use tabs to align shadow values 2022-05-09 15:51 [PATCH v2 1/3] kasan: clean up comments in internal kasan.h andrey.konovalov @ 2022-05-09 15:51 ` andrey.konovalov 2022-05-09 15:51 ` [PATCH v2 3/3] kasan: give better names to " andrey.konovalov 1 sibling, 0 replies; 3+ messages in thread From: andrey.konovalov @ 2022-05-09 15:51 UTC (permalink / raw) To: Marco Elver, Alexander Potapenko Cc: Andrey Konovalov, Dmitry Vyukov, Andrey Ryabinin, kasan-dev, Andrew Morton, linux-mm, linux-kernel, Andrey Konovalov From: Andrey Konovalov <andreyknvl@google.com> Consistently use tabs instead of spaces to shadow value definitions. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- mm/kasan/kasan.h | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index fed4f7a00d33..a60ed636e899 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -74,29 +74,29 @@ static inline bool kasan_sync_fault_possible(void) #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT) #ifdef CONFIG_KASAN_GENERIC -#define KASAN_FREE_PAGE 0xFF /* freed page */ -#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */ -#define KASAN_KMALLOC_REDZONE 0xFC /* redzone for slab object */ -#define KASAN_KMALLOC_FREE 0xFB /* freed slab object */ -#define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */ +#define KASAN_FREE_PAGE 0xFF /* freed page */ +#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */ +#define KASAN_KMALLOC_REDZONE 0xFC /* redzone for slab object */ +#define KASAN_KMALLOC_FREE 0xFB /* freed slab object */ +#define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */ #else -#define KASAN_FREE_PAGE KASAN_TAG_INVALID -#define KASAN_PAGE_REDZONE KASAN_TAG_INVALID -#define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID -#define KASAN_KMALLOC_FREE KASAN_TAG_INVALID -#define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */ +#define KASAN_FREE_PAGE KASAN_TAG_INVALID +#define KASAN_PAGE_REDZONE KASAN_TAG_INVALID +#define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID +#define KASAN_KMALLOC_FREE KASAN_TAG_INVALID +#define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */ #endif #ifdef CONFIG_KASAN_GENERIC -#define KASAN_KMALLOC_FREETRACK 0xFA /* freed slab object with free track */ -#define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ +#define KASAN_KMALLOC_FREETRACK 0xFA /* freed slab object with free track */ +#define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ /* Stack redzone shadow values. Compiler ABI, do not change. */ -#define KASAN_STACK_LEFT 0xF1 -#define KASAN_STACK_MID 0xF2 -#define KASAN_STACK_RIGHT 0xF3 -#define KASAN_STACK_PARTIAL 0xF4 +#define KASAN_STACK_LEFT 0xF1 +#define KASAN_STACK_MID 0xF2 +#define KASAN_STACK_RIGHT 0xF3 +#define KASAN_STACK_PARTIAL 0xF4 /* alloca redzone shadow values. */ #define KASAN_ALLOCA_LEFT 0xCA -- 2.25.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 3/3] kasan: give better names to shadow values 2022-05-09 15:51 [PATCH v2 1/3] kasan: clean up comments in internal kasan.h andrey.konovalov 2022-05-09 15:51 ` [PATCH v2 2/3] kasan: use tabs to align shadow values andrey.konovalov @ 2022-05-09 15:51 ` andrey.konovalov 1 sibling, 0 replies; 3+ messages in thread From: andrey.konovalov @ 2022-05-09 15:51 UTC (permalink / raw) To: Marco Elver, Alexander Potapenko Cc: Andrey Konovalov, Dmitry Vyukov, Andrey Ryabinin, kasan-dev, Andrew Morton, linux-mm, linux-kernel, Andrey Konovalov From: Andrey Konovalov <andreyknvl@google.com> Rename KASAN_KMALLOC_* shadow values to KASAN_SLAB_*, as they are used for all slab allocations, not only for kmalloc. Also rename KASAN_FREE_PAGE to KASAN_PAGE_FREE to be consistent with KASAN_PAGE_REDZONE and KASAN_SLAB_FREE. Reviewed-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- mm/kasan/common.c | 12 ++++++------ mm/kasan/generic.c | 6 +++--- mm/kasan/kasan.h | 14 +++++++------- mm/kasan/quarantine.c | 2 +- mm/kasan/report_generic.c | 8 ++++---- 5 files changed, 21 insertions(+), 21 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index d9079ec11f31..c40c0e7b3b5f 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -117,7 +117,7 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init) { if (likely(!PageHighMem(page))) kasan_poison(page_address(page), PAGE_SIZE << order, - KASAN_FREE_PAGE, init); + KASAN_PAGE_FREE, init); } /* @@ -254,7 +254,7 @@ void __kasan_poison_slab(struct slab *slab) for (i = 0; i < compound_nr(page); i++) page_kasan_tag_reset(page + i); kasan_poison(page_address(page), page_size(page), - KASAN_KMALLOC_REDZONE, false); + KASAN_SLAB_REDZONE, false); } void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object) @@ -265,7 +265,7 @@ void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object) void __kasan_poison_object_data(struct kmem_cache *cache, void *object) { kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE), - KASAN_KMALLOC_REDZONE, false); + KASAN_SLAB_REDZONE, false); } /* @@ -357,7 +357,7 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object, } kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE), - KASAN_KMALLOC_FREE, init); + KASAN_SLAB_FREE, init); if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine)) return false; @@ -414,7 +414,7 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip) if (unlikely(!folio_test_slab(folio))) { if (____kasan_kfree_large(ptr, ip)) return; - kasan_poison(ptr, folio_size(folio), KASAN_FREE_PAGE, false); + kasan_poison(ptr, folio_size(folio), KASAN_PAGE_FREE, false); } else { struct slab *slab = folio_slab(folio); @@ -505,7 +505,7 @@ static inline void *____kasan_kmalloc(struct kmem_cache *cache, redzone_end = round_up((unsigned long)(object + cache->object_size), KASAN_GRANULE_SIZE); kasan_poison((void *)redzone_start, redzone_end - redzone_start, - KASAN_KMALLOC_REDZONE, false); + KASAN_SLAB_REDZONE, false); /* * Save alloc info (if possible) for kmalloc() allocations. diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index a25ad4090615..437fcc7e77cf 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -369,14 +369,14 @@ void kasan_set_free_info(struct kmem_cache *cache, kasan_set_track(&free_meta->free_track, GFP_NOWAIT); /* The object was freed and has free track set. */ - *(u8 *)kasan_mem_to_shadow(object) = KASAN_KMALLOC_FREETRACK; + *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREETRACK; } struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, void *object, u8 tag) { - if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_KMALLOC_FREETRACK) + if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_SLAB_FREETRACK) return NULL; - /* Free meta must be present with KASAN_KMALLOC_FREETRACK. */ + /* Free meta must be present with KASAN_SLAB_FREETRACK. */ return &kasan_get_free_meta(cache, object)->free_track; } diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index a60ed636e899..610d60d6e5b8 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -74,22 +74,22 @@ static inline bool kasan_sync_fault_possible(void) #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT) #ifdef CONFIG_KASAN_GENERIC -#define KASAN_FREE_PAGE 0xFF /* freed page */ +#define KASAN_PAGE_FREE 0xFF /* freed page */ #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */ -#define KASAN_KMALLOC_REDZONE 0xFC /* redzone for slab object */ -#define KASAN_KMALLOC_FREE 0xFB /* freed slab object */ +#define KASAN_SLAB_REDZONE 0xFC /* redzone for slab object */ +#define KASAN_SLAB_FREE 0xFB /* freed slab object */ #define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */ #else -#define KASAN_FREE_PAGE KASAN_TAG_INVALID +#define KASAN_PAGE_FREE KASAN_TAG_INVALID #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID -#define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID -#define KASAN_KMALLOC_FREE KASAN_TAG_INVALID +#define KASAN_SLAB_REDZONE KASAN_TAG_INVALID +#define KASAN_SLAB_FREE KASAN_TAG_INVALID #define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */ #endif #ifdef CONFIG_KASAN_GENERIC -#define KASAN_KMALLOC_FREETRACK 0xFA /* freed slab object with free track */ +#define KASAN_SLAB_FREETRACK 0xFA /* freed slab object with free track */ #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ /* Stack redzone shadow values. Compiler ABI, do not change. */ diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 0a9def8ce5e8..fac4befb9ef2 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -152,7 +152,7 @@ static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) * As the object now gets freed from the quarantine, assume that its * free track is no longer valid. */ - *(u8 *)kasan_mem_to_shadow(object) = KASAN_KMALLOC_FREE; + *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREE; ___cache_free(cache, object, _THIS_IP_); diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c index efc5e79a103f..6689fb9a919b 100644 --- a/mm/kasan/report_generic.c +++ b/mm/kasan/report_generic.c @@ -66,7 +66,7 @@ static const char *get_shadow_bug_type(struct kasan_report_info *info) bug_type = "out-of-bounds"; break; case KASAN_PAGE_REDZONE: - case KASAN_KMALLOC_REDZONE: + case KASAN_SLAB_REDZONE: bug_type = "slab-out-of-bounds"; break; case KASAN_GLOBAL_REDZONE: @@ -78,9 +78,9 @@ static const char *get_shadow_bug_type(struct kasan_report_info *info) case KASAN_STACK_PARTIAL: bug_type = "stack-out-of-bounds"; break; - case KASAN_FREE_PAGE: - case KASAN_KMALLOC_FREE: - case KASAN_KMALLOC_FREETRACK: + case KASAN_PAGE_FREE: + case KASAN_SLAB_FREE: + case KASAN_SLAB_FREETRACK: bug_type = "use-after-free"; break; case KASAN_ALLOCA_LEFT: -- 2.25.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-05-09 15:51 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-05-09 15:51 [PATCH v2 1/3] kasan: clean up comments in internal kasan.h andrey.konovalov 2022-05-09 15:51 ` [PATCH v2 2/3] kasan: use tabs to align shadow values andrey.konovalov 2022-05-09 15:51 ` [PATCH v2 3/3] kasan: give better names to " andrey.konovalov
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).