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| author | Juntong Deng <juntong.deng@outlook.com> | 2023-11-27 22:17:31 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-11 01:51:55 +0100 |
| commit | 5d4c6ac94694096cdfb528f05a3019a1a423b3a4 (patch) | |
| tree | d50b1a98914a576fd83fc1244288a25ac926d86e /mm/kasan/report.c | |
| parent | zram: use kmap_local_page() (diff) | |
| download | linux-5d4c6ac94694096cdfb528f05a3019a1a423b3a4.tar.xz linux-5d4c6ac94694096cdfb528f05a3019a1a423b3a4.zip | |
kasan: record and report more information
Record and report more information to help us find the cause of the bug
and to help us correlate the error with other system events.
This patch adds recording and showing CPU number and timestamp at
allocation and free (controlled by CONFIG_KASAN_EXTRA_INFO). The
timestamps in the report use the same format and source as printk.
Error occurrence timestamp is already implicit in the printk log, and CPU
number is already shown by dump_stack_lvl, so there is no need to add it.
In order to record CPU number and timestamp at allocation and free,
corresponding members need to be added to the relevant data structures,
which will lead to increased memory consumption.
In Generic KASAN, members are added to struct kasan_track. Since in most
cases, alloc meta is stored in the redzone and free meta is stored in the
object or the redzone, memory consumption will not increase much.
In SW_TAGS KASAN and HW_TAGS KASAN, members are added to struct
kasan_stack_ring_entry. Memory consumption increases as the size of
struct kasan_stack_ring_entry increases (this part of the memory is
allocated by memblock), but since this is configurable, it is up to the
user to choose.
Link: https://lkml.kernel.org/r/VI1P193MB0752BD991325D10E4AB1913599BDA@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kasan/report.c')
| -rw-r--r-- | mm/kasan/report.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/mm/kasan/report.c b/mm/kasan/report.c index e77facb62900..a938237f6882 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -262,7 +262,19 @@ static void print_error_description(struct kasan_report_info *info) static void print_track(struct kasan_track *track, const char *prefix) { +#ifdef CONFIG_KASAN_EXTRA_INFO + u64 ts_nsec = track->timestamp; + unsigned long rem_usec; + + ts_nsec <<= 3; + rem_usec = do_div(ts_nsec, NSEC_PER_SEC) / 1000; + + pr_err("%s by task %u on cpu %d at %lu.%06lus:\n", + prefix, track->pid, track->cpu, + (unsigned long)ts_nsec, rem_usec); +#else pr_err("%s by task %u:\n", prefix, track->pid); +#endif /* CONFIG_KASAN_EXTRA_INFO */ if (track->stack) stack_depot_print(track->stack); else |