Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1484132

Re: perf: perf_fuzzer lockup in perf_cgroup_attach

From Vince Weaver <vincent.weaver@maine.edu>
Newsgroups linux.kernel
Subject Re: perf: perf_fuzzer lockup in perf_cgroup_attach
Date 2016-09-15 14:50 +0200
Message-ID <shEh4-75Z-31@gated-at.bofh.it> (permalink)
References <shuUq-12G-5@gated-at.bofh.it> <shxyV-2Tv-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Wed, 14 Sep 2016, Stephane Eranian wrote:

> I would think there is a way to disable KASLR for this kind of testing!

yes, it's just I hadn't realized I had it enabled until I couldn't figure 
out why addr2line wasn't working.

> Which of your fuzzer scripts are you using? fast_repro99.sh?

yes.  I should probably give that script a more meaningful name, but by 
now I think it's too late for that.

I also am running with paranoid set to "0"

> 
> > The best I can tell things are getting wedged somehow in
> > perf_cgroup_switch() while interrupts are disabled.  Interrupts are never
> > getting re-enabled, causing the RCU and NMI watchdogs to trigger (and more
> > alarming things like the SATA bus resetting).
> >
> How do you get to perf_cgroup_switch() from the traces you provide below?

It was my best guess after trying to trace through the code.  It could
in theory be anywhere but it definitely seems like it is happening after
perf_cgroup_attach at some point when interrupts are disabled (possibly
ftrace too?)

It's difficult because some code gets inlined and then it's jumping to a 
function pointer.  And then mid-debug the system finally had enough and 
started making threads hang forever while I was getting close.

I've rebooted the machine I'll see if I can replicate.

Vince

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

perf: perf_fuzzer lockup in perf_cgroup_attach Vince Weaver <vincent.weaver@maine.edu> - 2016-09-15 04:50 +0200
  Re: perf: perf_fuzzer lockup in perf_cgroup_attach Stephane Eranian <eranian@google.com> - 2016-09-15 07:40 +0200
    Re: perf: perf_fuzzer lockup in perf_cgroup_attach Peter Zijlstra <peterz@infradead.org> - 2016-09-15 09:30 +0200
      Re: perf: perf_fuzzer lockup in perf_cgroup_attach Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-15 14:20 +0200
        [PATCH] scripts: add script for translating stack dump function  offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-16 16:50 +0200
          Re: [PATCH] scripts: add script for translating stack dump function offsets Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-16 20:20 +0200
            Re: [PATCH] scripts: add script for translating stack dump function  offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-16 21:20 +0200
              Re: [PATCH] scripts: add script for translating stack dump function offsets Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-16 21:30 +0200
                [PATCH v2] scripts: add script for translating stack dump function  offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-16 23:30 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-17 02:10 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-17 02:50 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-17 04:00 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-17 04:40 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-17 20:50 +0200
                [PATCH v3] scripts: add script for translating stack dump function Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-19 18:00 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump function Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-19 21:00 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump function Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-19 21:20 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump  function Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-19 21:30 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump  function Rabin Vincent <rabin@rab.in> - 2016-09-19 22:10 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump function Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-19 22:30 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump  function Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-19 23:00 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump  function Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-19 23:10 +0200
                Re: [PATCH v3] scripts: add script for translating stack dump function Linus Torvalds <torvalds@linux-foundation.org> - 2016-09-19 23:10 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Peter Zijlstra <peterz@infradead.org> - 2016-09-17 03:30 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Rabin Vincent <rabin@rab.in> - 2016-09-17 10:20 +0200
                Re: [PATCH v2] scripts: add script for translating stack dump  function offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-17 20:50 +0200
              Re: [PATCH] scripts: add script for translating stack dump function offsets Vegard Nossum <vegard.nossum@gmail.com> - 2016-09-17 11:20 +0200
                Re: [PATCH] scripts: add script for translating stack dump function  offsets Josh Poimboeuf <jpoimboe@redhat.com> - 2016-09-17 21:00 +0200
    Re: perf: perf_fuzzer lockup in perf_cgroup_attach Vince Weaver <vincent.weaver@maine.edu> - 2016-09-15 14:50 +0200
  Re: perf: perf_fuzzer lockup in perf_cgroup_attach Peter Zijlstra <peterz@infradead.org> - 2016-09-15 09:20 +0200
    Re: perf: perf_fuzzer lockup in perf_cgroup_attach Vince Weaver <vincent.weaver@maine.edu> - 2016-09-15 14:50 +0200

csiph-web