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From: ebiederm@xmission.com (Eric W. Biederman)
To: Tycho Andersen <tycho@tycho.ws>
Cc: Kees Cook <keescook@chromium.org>,
	Oleg Nesterov <oleg@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: siginfo pid not populated from ptrace?
Date: Mon, 12 Nov 2018 12:30:25 -0600	[thread overview]
Message-ID: <87efbqi1xa.fsf@xmission.com> (raw)
In-Reply-To: <20181112171144.GI3645@cisco> (Tycho Andersen's message of "Mon, 12 Nov 2018 10:11:44 -0700")

Tycho Andersen <tycho@tycho.ws> writes:

> Hi Oleg,
>
> I've been running some tests on my seccomp series, and in one of the
> tests on v4.20-rc2, I noticed,
>
> [ RUN      ] global.syscall_restart
> seccomp_bpf.c:2784:global.syscall_restart:Expected getpid() (1492) == info._sifields._kill.si_pid (0)
> global.syscall_restart: Test failed at step #22
>
> which seems unrelated to my series (the kernel was stock v4.20 with my
> patches on top).
>
> I've been running a lot of tests, and only seen this once, so it seems
> like a fairly rare race. I tried to look through the code but didn't
> see anything obvious. Thoughts?

My guess would be pid namespaces, or stopping for a signal other than
SIGSTOP.

If you can get this to reproduce at all it would be interesting to see
si_signo and si_code.  So that we can see just which signal is in info,
and how it should be decoded. 

I see this test at line 2736 in 4.20-rc1 so there are almost 50 lines of
change in your version of seccomp_bpf.c.  So I hope I am reading the
proper test.

Eric

  reply	other threads:[~2018-11-12 18:30 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-12 17:11 Tycho Andersen
2018-11-12 18:30 ` Eric W. Biederman [this message]
2018-11-12 18:55   ` Tycho Andersen
2018-11-12 19:22     ` Eric W. Biederman
2018-11-12 19:24     ` Tycho Andersen
2018-11-27 23:21       ` Tycho Andersen
2018-11-28  0:38         ` Kees Cook
2018-11-28  1:17           ` Kees Cook
2018-11-28  4:44             ` Eric W. Biederman
2018-11-29 21:17               ` Kees Cook
2018-11-29 23:22                 ` Tycho Andersen
2018-12-01 15:04                 ` Eric W. Biederman
2018-12-06  1:00                   ` Kees Cook
2018-12-06 14:40                     ` Eric W. Biederman
2018-12-06 18:48                       ` Linus Torvalds
2018-12-06 19:20                         ` Tycho Andersen
2018-12-06 21:11                           ` Eric W. Biederman
2018-12-06 21:34                             ` Kees Cook
2018-12-06 22:43                               ` Eric W. Biederman
2018-12-06 22:55                                 ` Kees Cook
2018-12-10 15:37                             ` Oleg Nesterov
2018-12-10 15:44                               ` Tycho Andersen
2018-12-10 17:36                               ` Eric W. Biederman
2018-12-10 14:57                           ` Oleg Nesterov

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