Messages in this thread | | | Date | Tue, 8 Sep 2020 19:58:08 +0200 | From | peterz@infradea ... | Subject | Re: [PATCH -next] fork: silence a false postive warning in __mmdrop |
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On Tue, Sep 08, 2020 at 12:50:44PM -0400, Qian Cai wrote: > > No, you're talking nonsense. We must not free @mm when > > 'current->active_mm == mm', never. > > Yes, you are right. It still trigger this below on powerpc with today's > linux-next by fuzzing for a while (saw a few times on recent linux-next before > as well but so far mostly reproducible on powerpc here). Any idea?
If you can reliably reproduce this, the next thing is to trace mm_count and figure out where it goes side-ways. I suppose we're looking for an 'extra' decrement.
Mark tried this for a while but gave up because he couldn't reliably reproduce.
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