diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-07-25 19:51:10 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-03 11:24:21 +0200 |
| commit | db454f8ab4b694eaf6a23b97479aa4b42c38e6e3 (patch) | |
| tree | 171b04df7e3266fb59fd6dc117d7ae07440c3caf /kernel/locking | |
| parent | 66e1e18133c43e0cfff609054aa64ad0652371fa (diff) | |
locking/lockdep: Fix overflow in presentation of average lock-time
[ Upstream commit a7ef9b28aa8d72a1656fa6f0a01bbd1493886317 ]
Though the number of lock-acquisitions is tracked as unsigned long, this
is passed as the divisor to div_s64() which interprets it as a s32,
giving nonsense values with more than 2 billion acquisitons. E.g.
acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
-------------------------------------------------------------------------
2350439395 0.07 353.38 649647067.36 0.-32
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200725185110.11588-1-chris@chris-wilson.co.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep_proc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 6fcc4650f0c4..53cc3bb7025a 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -394,7 +394,7 @@ static void seq_lock_time(struct seq_file *m, struct lock_time *lt) seq_time(m, lt->min); seq_time(m, lt->max); seq_time(m, lt->total); - seq_time(m, lt->nr ? div_s64(lt->total, lt->nr) : 0); + seq_time(m, lt->nr ? div64_u64(lt->total, lt->nr) : 0); } static void seq_stats(struct seq_file *m, struct lock_stat_data *data) |