From: Jiri Olsa <jolsa@redhat.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Namhyung Kim <namhyung@kernel.org>,
luca abeni <luca.abeni@santannapisa.it>,
Thomas Gleixner <tglx@linutronix.de>,
Oleg Nesterov <oleg@redhat.com>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: perf_event_open+clone = unkillable process
Date: Sun, 3 Feb 2019 16:21:13 +0100 [thread overview]
Message-ID: <20190203152113.GA11794@krava> (raw)
In-Reply-To: <20190202183013.GA10522@krava>
On Sat, Feb 02, 2019 at 07:30:45PM +0100, Jiri Olsa wrote:
> On Fri, Feb 01, 2019 at 06:06:03PM +0100, Dmitry Vyukov wrote:
> > On Fri, Feb 1, 2019 at 5:48 PM Dmitry Vyukov <dvyukov@google.com> wrote:
> > >
> > > Hello,
> > >
> > > The following program creates an unkillable process that eats CPU.
> > > /proc/pid/stack is empty, I am not sure what other info I can provide.
> > >
> > > Tested is on upstream commit 4aa9fc2a435abe95a1e8d7f8c7b3d6356514b37a.
> > > Config is attached.
> >
> > Looking through other reproducers that create unkillable processes, I
> > think I found a much simpler reproducer (below). It's single threaded
> > and just setups SIGBUS handler and does timer_create+timer_settime to
> > send repeated SIGBUS. The resulting process can't be killed with
> > SIGKILL.
> > +Thomas for timers.
>
> nice, I managed to kill it by strace ;-)
>
> [jolsa@krava perf]$ strace -p 10725
> strace: Process 10725 attached
> --- stopped by SIGBUS ---
> --- stopped by SIGBUS ---
> --- stopped by SIGBUS ---
> --- stopped by SIGBUS ---
> +++ killed by SIGINT +++
fyi I can no longer reproduce the kill via strace.. not sure
what was different
jirka
next prev parent reply other threads:[~2019-02-03 15:21 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-01 16:48 perf_event_open+clone = unkillable process Dmitry Vyukov
2019-02-01 17:06 ` Dmitry Vyukov
2019-02-02 18:30 ` Jiri Olsa
2019-02-03 15:21 ` Jiri Olsa [this message]
2019-02-04 9:27 ` Thomas Gleixner
2019-02-04 9:38 ` Dmitry Vyukov
2019-02-04 17:38 ` Thomas Gleixner
2019-02-05 3:00 ` Eric W. Biederman
2019-02-05 4:27 ` Eric W. Biederman
2019-02-05 6:07 ` Eric W. Biederman
2019-02-05 15:26 ` [RFC][PATCH] signal: Store pending signal exit in tsk.jobctl not in tsk.pending Eric W. Biederman
2019-02-06 12:09 ` Dmitry Vyukov
2019-02-06 21:47 ` Eric W. Biederman
2019-02-06 18:07 ` Oleg Nesterov
2019-02-06 22:25 ` Eric W. Biederman
2019-02-07 6:42 ` [PATCH 0/2]: Fixing unkillable processes caused by SIGHUP timers Eric W. Biederman
2019-02-07 6:43 ` [PATCH 1/2] signal: Always notice exiting tasks Eric W. Biederman
2019-02-11 14:13 ` Oleg Nesterov
2019-02-12 0:42 ` Eric W. Biederman
2019-02-12 8:18 ` Eric W. Biederman
2019-02-12 16:50 ` Oleg Nesterov
2019-02-13 3:58 ` Eric W. Biederman
2019-02-13 4:09 ` [PATCH] signal: Restore the stop PTRACE_EVENT_EXIT Eric W. Biederman
2019-02-13 13:55 ` Oleg Nesterov
2019-02-13 14:38 ` Oleg Nesterov
2019-02-13 14:58 ` Eric W. Biederman
2019-02-07 6:44 ` [PATCH 2/2] signal: Better detection of synchronous signals Eric W. Biederman
2019-02-11 15:18 ` Oleg Nesterov
2019-02-12 0:01 ` Eric W. Biederman
2019-02-12 17:21 ` Oleg Nesterov
2019-02-07 11:46 ` [PATCH 0/2]: Fixing unkillable processes caused by SIGHUP timers Dmitry Vyukov
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