Messages in this thread | | | Date | Thu, 13 Oct 2022 15:17:37 +1000 | Subject | Re: [GIT PULL] Please pull powerpc/linux.git powerpc-6.1-1 tag | From | "Nicholas Piggin" <> |
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On Thu Oct 13, 2022 at 4:37 AM AEST, Jason A. Donenfeld wrote: > On Wed, Oct 12, 2022 at 10:48:26AM -0700, Guenter Roeck wrote: > > > I've also managed to not hit this bug a few times. When it triggers, > > > after "kprobes: kprobe jump-optimization is enabled. All kprobes are > > > optimized if possible.", there's a long hang - tens seconds before it > > > continues. When it doesn't trigger, there's no hang at that point in the > > > boot process. > > > > > > > That probably explains why my attempts to bisect the problem were > > unsuccessful. > > So I just did this: > > diff --git a/drivers/char/random.c b/drivers/char/random.c > index 2fe28eeb2f38..2d70bc09db7e 100644 > --- a/drivers/char/random.c > +++ b/drivers/char/random.c > @@ -1212,6 +1212,7 @@ static void __cold try_to_generate_entropy(void) > struct entropy_timer_state stack; > unsigned int i, num_different = 0; > unsigned long last = random_get_entropy(); > + return; > > for (i = 0; i < NUM_TRIAL_SAMPLES - 1; ++i) { > stack.entropy = random_get_entropy(); > > And then ran it, and now we get the lockup from the idle process:
Yep that rules out the random code. And really if it was calling schedule() it shouldn't be getting a softlockup anyway.
Thanks, Nick
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