If nwriters_stress=0 is passed to the lock torture test it will panic in: Internal error: Oops: 96000005 [#1] SMP ... [<ffff000000b7022c>] __torture_print_stats+0x2c/0x1c8 [locktorture] [<ffff000000b7070c>] lock_torture_stats_print+0x74/0x120 [locktorture] [<ffff000000b707f8>] lock_torture_stats+0x40/0xa8 [locktorture] [<ffff0000080f3570>] kthread+0x108/0x138 [<ffff000008084b90>] ret_from_fork+0x10/0x18
This is caused by the deference to a null statp. Fix that by checking the n_stress for non zero count before referencing statp. Signed-off-by: Jeremy Linton <[email protected]> --- kernel/locking/locktorture.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index f24582d4dad3..8229ba7147e5 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -716,10 +716,14 @@ static void __torture_print_stats(char *page, bool fail = 0; int i, n_stress; long max = 0; - long min = statp[0].n_lock_acquired; + long min = 0; long long sum = 0; n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; + + if (n_stress) + min = statp[0].n_lock_acquired; + for (i = 0; i < n_stress; i++) { if (statp[i].n_lock_fail) fail = true; -- 2.13.5
