[PATCH mm 3/4] kasan: simplify saving extra info into tracks

From: andrey . konovalov
Date: Thu Dec 21 2023 - 13:36:14 EST


From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

Avoid duplicating code for saving extra info into tracks: reuse the
common function for this.

Fixes: 5d4c6ac94694 ("kasan: record and report more information")
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
mm/kasan/common.c | 12 ++++++++++--
mm/kasan/generic.c | 4 ++--
mm/kasan/kasan.h | 3 ++-
mm/kasan/tags.c | 17 +----------------
4 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index fe6c4b43ad9f..d004a0f4406c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -48,7 +48,7 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags)
return stack_depot_save_flags(entries, nr_entries, flags, depot_flags);
}

-void kasan_set_track(struct kasan_track *track, gfp_t flags)
+void kasan_set_track(struct kasan_track *track, depot_stack_handle_t stack)
{
#ifdef CONFIG_KASAN_EXTRA_INFO
u32 cpu = raw_smp_processor_id();
@@ -58,8 +58,16 @@ void kasan_set_track(struct kasan_track *track, gfp_t flags)
track->timestamp = ts_nsec >> 3;
#endif /* CONFIG_KASAN_EXTRA_INFO */
track->pid = current->pid;
- track->stack = kasan_save_stack(flags,
+ track->stack = stack;
+}
+
+void kasan_save_track(struct kasan_track *track, gfp_t flags)
+{
+ depot_stack_handle_t stack;
+
+ stack = kasan_save_stack(flags,
STACK_DEPOT_FLAG_CAN_ALLOC | STACK_DEPOT_FLAG_GET);
+ kasan_set_track(track, stack);
}

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 769e43e05d0b..11b575707b05 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -553,7 +553,7 @@ void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
stack_depot_put(alloc_meta->aux_stack[1]);
__memset(alloc_meta, 0, sizeof(*alloc_meta));

- kasan_set_track(&alloc_meta->alloc_track, flags);
+ kasan_save_track(&alloc_meta->alloc_track, flags);
}

void kasan_save_free_info(struct kmem_cache *cache, void *object)
@@ -564,7 +564,7 @@ void kasan_save_free_info(struct kmem_cache *cache, void *object)
if (!free_meta)
return;

- kasan_set_track(&free_meta->free_track, 0);
+ kasan_save_track(&free_meta->free_track, 0);
/* The object was freed and has free track set. */
*(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREETRACK;
}
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 9072ce4c1263..31fb6bb26fed 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -372,7 +372,8 @@ static inline void kasan_init_object_meta(struct kmem_cache *cache, const void *
#endif

depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags);
-void kasan_set_track(struct kasan_track *track, gfp_t flags);
+void kasan_set_track(struct kasan_track *track, depot_stack_handle_t stack);
+void kasan_save_track(struct kasan_track *track, gfp_t flags);
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);
void kasan_save_free_info(struct kmem_cache *cache, void *object);

diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index c4d14dbf27c0..d65d48b85f90 100644
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -94,17 +94,6 @@ void __init kasan_init_tags(void)
}
}

-#ifdef CONFIG_KASAN_EXTRA_INFO
-static void save_extra_info(struct kasan_stack_ring_entry *entry)
-{
- u32 cpu = raw_smp_processor_id();
- u64 ts_nsec = local_clock();
-
- entry->track.cpu = cpu;
- entry->track.timestamp = ts_nsec >> 3;
-}
-#endif /* CONFIG_KASAN_EXTRA_INFO */
-
static void save_stack_info(struct kmem_cache *cache, void *object,
gfp_t gfp_flags, bool is_free)
{
@@ -137,11 +126,7 @@ static void save_stack_info(struct kmem_cache *cache, void *object,
old_stack = entry->track.stack;

entry->size = cache->object_size;
- entry->track.pid = current->pid;
- entry->track.stack = stack;
-#ifdef CONFIG_KASAN_EXTRA_INFO
- save_extra_info(entry);
-#endif /* CONFIG_KASAN_EXTRA_INFO */
+ kasan_set_track(&entry->track, stack);
entry->is_free = is_free;

entry->ptr = object;
--
2.25.1