Hi Paul, On 2016/1/28 12:25, Kefeng Wang wrote: > Insmod locktorture with torture_type=mutex will lead to crash, > > Unable to handle kernel NULL pointer dereference at virtual address 00000008 > pgd = ffffffc0f6c10000 > [00000008] *pgd=000000013b221003, *pud=000000013b221003, > *pmd=0000000000000000a > Internal error: Oops: 94000006 [#1] PREEMPT SMP > Modules linked in: locktorture(+) torture > CPU: 2 PID: 1462 Comm: insmod Not tainted 4.4.0+ #19 > Hardware name: linux,dummy-virt (DT) > task: ffffffc0fb2b3700 ti: ffffffc0fa938000 task.ti: ffffffc0fa938000 > PC is at __torture_print_stats+0x18/0x180 [locktorture] > LR is at lock_torture_stats_print+0x68/0x110 [locktorture] > pc : [<ffffffbffc017028>] lr : [<ffffffbffc017500>] pstate: 60000145 > sp : ffffffc0fa93bb20 > [snip...] > Call trace: > [<ffffffbffc017028>] __torture_print_stats+0x18/0x180 [locktorture] > [<ffffffbffc017500>] lock_torture_stats_print+0x68/0x110 [locktorture] > [<ffffffbffc0180fc>] lock_torture_cleanup+0xc4/0x278 [locktorture] > [<ffffffbffc01d144>] lock_torture_init+0x144/0x5b0 [locktorture] > [<ffffffc000082940>] do_one_initcall+0x94/0x1a0 > [<ffffffc000141888>] do_init_module+0x60/0x1c8 > [<ffffffc00011c628>] load_module+0x1880/0x1c9c > [<ffffffc00011cc00>] SyS_finit_module+0x7c/0x88 > [<ffffffc000085cb0>] el0_svc_naked+0x24/0x28 > > Fix it by check statp in __torture_print_stats(), if it is NULL, just > create a lock-torture-statistics message with zero statistic argument.
It is keep to get the statistics printout at the end if with bad argument, what's your opinion about this version？ Thanks, Kefeng > > Cc: Josh Triplett <[email protected]> > Cc: Paul E. McKenney <[email protected]> > Signed-off-by: Kefeng Wang <[email protected]> > --- > kernel/locking/locktorture.c | 24 ++++++++++++++---------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c > index 8ef1919..7f0cf9c 100644 > --- a/kernel/locking/locktorture.c > +++ b/kernel/locking/locktorture.c > @@ -647,19 +647,23 @@ 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; > - for (i = 0; i < n_stress; i++) { > - if (statp[i].n_lock_fail) > - fail = true; > - sum += statp[i].n_lock_acquired; > - if (max < statp[i].n_lock_fail) > - max = statp[i].n_lock_fail; > - if (min > statp[i].n_lock_fail) > - min = statp[i].n_lock_fail; > + if (statp) { > + min = statp[0].n_lock_acquired; > + n_stress = write ? cxt.nrealwriters_stress : > cxt.nrealreaders_stress; > + for (i = 0; i < n_stress; i++) { > + if (statp[i].n_lock_fail) > + fail = true; > + sum += statp[i].n_lock_acquired; > + if (max < statp[i].n_lock_fail) > + max = statp[i].n_lock_fail; > + if (min > statp[i].n_lock_fail) > + min = statp[i].n_lock_fail; > + } > } > + > page += sprintf(page, > "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", > write ? "Writes" : "Reads ", >
