Date: Fri, 15 Mar 2013 18:15:09 -0700
From: Daniel Walker <dwalker@fifo99.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: linux-kernel@vger.kernel.org
Subject: ptracing a task from core_pattern pipe
Message-ID: <20130316011508.GA11010@fifo99.com>
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Hi,

I was writing an application to ptrace a process which is dumping core
from inside the pipe application for core_pattern.

So for example you make core pattern equal to something like
"|/bin/corepipe_app" then the kernel runs that app prior to actually
killing the process that failed.

Before the pipe application runs it puts SIGKILL on the pending signal
list for the failed application. However the application can't run.

This commit,

9899d11f654474d2d54ea52ceaa2a1f4db3abd68

seems to put a damper on ptracing the application at this point.

So I wanted to see what you think of all this.. Can we add an exception
to this which would allow operations on a task which is dumping core,
but still has SIGKILL pending. The other way would be to not add SIGKILL
till after the pipe app runs.

As of right now I can PTRACE_ATTACH, but the operations all fail with
-ESRCH .

Daniel

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