diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2023-11-20 18:47:18 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-11 01:51:47 +0100 |
| commit | f816938bff1f772ce7949e5747734be27ecf7f4d (patch) | |
| tree | 2a1786cbbe14054f26dbcb21cbe588d845e629b1 /mm/kasan | |
| parent | kasan: check object_size in kasan_complete_mode_report_info (diff) | |
| download | linux-f816938bff1f772ce7949e5747734be27ecf7f4d.tar.xz linux-f816938bff1f772ce7949e5747734be27ecf7f4d.zip | |
kasan: use stack_depot_put for tag-based modes
Make tag-based KASAN modes evict stack traces from the stack depot once
they are evicted from the stack ring.
Internally, pass STACK_DEPOT_FLAG_GET to stack_depot_save_flags (via
kasan_save_stack) to increment the refcount when saving a new entry to
stack ring and call stack_depot_put when removing an entry from stack
ring.
Link: https://lkml.kernel.org/r/b4773e5c1b0b9df6826ec0b65c1923feadfa78e5.1700502145.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/tags.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index b6c017e670d8..739ae997463d 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -97,12 +97,13 @@ static void save_stack_info(struct kmem_cache *cache, void *object, gfp_t gfp_flags, bool is_free) { unsigned long flags; - depot_stack_handle_t stack; + depot_stack_handle_t stack, old_stack; u64 pos; struct kasan_stack_ring_entry *entry; void *old_ptr; - stack = kasan_save_stack(gfp_flags, STACK_DEPOT_FLAG_CAN_ALLOC); + stack = kasan_save_stack(gfp_flags, + STACK_DEPOT_FLAG_CAN_ALLOC | STACK_DEPOT_FLAG_GET); /* * Prevent save_stack_info() from modifying stack ring @@ -121,6 +122,8 @@ next: if (!try_cmpxchg(&entry->ptr, &old_ptr, STACK_RING_BUSY_PTR)) goto next; /* Busy slot. */ + old_stack = entry->stack; + entry->size = cache->object_size; entry->pid = current->pid; entry->stack = stack; @@ -129,6 +132,9 @@ next: entry->ptr = object; read_unlock_irqrestore(&stack_ring.lock, flags); + + if (old_stack) + stack_depot_put(old_stack); } void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) |