syzbot is reporting many refcount/use-after-free bugs along with flood of
memory allocation fault injection messages. Showing timestamp of memory
allocation/free would help narrowing down kernel messages to examine.
Revive timestamp field which was removed by commit cd11016e5f5212c1
("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB").
Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Andrey Konovalov <adech.fo@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Konstantin Serebryany <kcc@xxxxxxxxxx>
Cc: Dmitry Chernenkov <dmitryc@xxxxxxxxxx>
---
mm/kasan/kasan.c | 1 +
mm/kasan/kasan.h | 1 +
mm/kasan/report.c | 3 ++-
3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 135ce28..a336834 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -457,6 +457,7 @@ 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->when = jiffies;
track->stack = save_stack(flags);
}
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index c12dcfd..0e4951b 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -77,6 +77,7 @@ struct kasan_global {
struct kasan_track {
u32 pid;
depot_stack_handle_t stack;
+ unsigned long when;
};
struct kasan_alloc_meta {
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 5c169aa..062c8ae 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -183,7 +183,8 @@ static void kasan_end_report(unsigned long *flags)
static void print_track(struct kasan_track *track, const char *prefix)
{
- pr_err("%s by task %u:\n", prefix, track->pid);
+ pr_err("%s by task %u (%lu jiffies ago):\n", prefix, track->pid,
+ jiffies - track->when);
if (track->stack) {
struct stack_trace trace;
--
1.8.3.1
