diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 82522e996c76..18452e35e7b2 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -174,11 +174,13 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); +void kasan_record_aux_stack(void *ptr); #else /* CONFIG_KASAN_GENERIC */ static inline void kasan_cache_shrink(struct kmem_cache *cache) {} static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} +static inline void kasan_record_aux_stack(void *ptr) {} #endif /* CONFIG_KASAN_GENERIC */ diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index ac7198ed3197..8ce77d9ac716 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -59,6 +59,7 @@ #include #include #include +#include #include "../time/tick-internal.h" #include "tree.h" @@ -2890,6 +2891,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func) head->func = func; head->next = NULL; local_irq_save(flags); + kasan_record_aux_stack(head); rdp = this_cpu_ptr(&rcu_data); /* Add the callback to our list. */ diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 757d4074fe28..ad24666f50e4 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -40,7 +40,7 @@ #include "kasan.h" #include "../slab.h" -static inline depot_stack_handle_t save_stack(gfp_t flags) +depot_stack_handle_t kasan_save_stack(gfp_t flags) { unsigned long entries[KASAN_STACK_DEPTH]; unsigned int nr_entries; @@ -53,7 +53,7 @@ static inline depot_stack_handle_t save_stack(gfp_t flags) static inline void set_track(struct kasan_track *track, gfp_t flags) { track->pid = current->pid; - track->stack = save_stack(flags); + track->stack = kasan_save_stack(flags); } void kasan_enable_current(void) diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 098a7dbaced6..d70586393b04 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -324,3 +324,24 @@ DEFINE_ASAN_SET_SHADOW(f2); DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); + +void kasan_record_aux_stack(void *addr) +{ + struct page *page = kasan_addr_to_page(addr); + struct kmem_cache *cache; + struct kasan_alloc_meta *alloc_info; + void *object; + + if (!(page && PageSlab(page))) + return; + + cache = page->slab_cache; + object = nearest_obj(cache, page, addr); + alloc_info = get_alloc_info(cache, object); + + /* + * record the last two call_rcu() call stacks. + */ + alloc_info->aux_stack[1] = alloc_info->aux_stack[0]; + alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT); +} diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index cfade6413528..f89a195e336a 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -104,6 +104,13 @@ struct kasan_track { struct kasan_alloc_meta { struct kasan_track alloc_track; +#ifdef CONFIG_KASAN_GENERIC + /* + * call_rcu() call 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]; +#endif struct kasan_track free_track[KASAN_NR_FREE_STACKS]; #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY u8 free_pointer_tag[KASAN_NR_FREE_STACKS]; @@ -159,6 +166,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip); struct page *kasan_addr_to_page(const void *addr); +depot_stack_handle_t kasan_save_stack(gfp_t flags); + #if defined(CONFIG_KASAN_GENERIC) && \ (defined(CONFIG_SLAB) || defined(CONFIG_SLUB)) void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache); diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 51ec45407a0b..445a9d56eb13 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -106,15 +106,20 @@ static void end_report(unsigned long *flags) kasan_enable_current(); } +static void print_stack(depot_stack_handle_t stack) +{ + unsigned long *entries; + unsigned int nr_entries; + + nr_entries = stack_depot_fetch(stack, &entries); + stack_trace_print(entries, nr_entries, 0); +} + static void print_track(struct kasan_track *track, const char *prefix) { pr_err("%s by task %u:\n", prefix, track->pid); if (track->stack) { - unsigned long *entries; - unsigned int nr_entries; - - nr_entries = stack_depot_fetch(track->stack, &entries); - stack_trace_print(entries, nr_entries, 0); + print_stack(track->stack); } else { pr_err("(stack is not available)\n"); } @@ -193,6 +198,19 @@ static void describe_object(struct kmem_cache *cache, void *object, free_track = kasan_get_free_track(cache, object, tag); print_track(free_track, "Freed"); pr_err("\n"); + +#ifdef CONFIG_KASAN_GENERIC + if (alloc_info->aux_stack[0]) { + pr_err("Last call_rcu():\n"); + print_stack(alloc_info->aux_stack[0]); + pr_err("\n"); + } + if (alloc_info->aux_stack[1]) { + pr_err("Second to last call_rcu():\n"); + print_stack(alloc_info->aux_stack[1]); + pr_err("\n"); + } +#endif } describe_object_addr(cache, object, addr);