linux-kernel - Procfs race condition bug

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Message-ID: <50099F72.8020901@lists.grepular.com>
Date:	Fri, 20 Jul 2012 19:12:02 +0100
From:	Mike Cardwell <linux-kernel@...ts.grepular.com>
To:	linux-kernel@...r.kernel.org
Subject: Procfs race condition bug

I *think* I've uncovered a race condition bug in procfs. If I attempt to
open a file in /proc/net, eg "/proc/net/tcp" it works fine, but if I
spawn a POSIX thread and attempt to do it from there, it *usually* fails
with a "No such file or directory", but some times succeeds. If I do a
system call inside the thread to look up the thread ID and then open
"/proc/THREADID/net/tcp" instead, it works fine.

There are more details and  some example code so you can replicate the
problem on a stack overflow question I asked earlier today here:
http://stackoverflow.com/questions/11580020/opening-proc-net-tcp-in-c-from-a-posix-thread-fails-most-of-the-time

This is the first time I have attempted to report a (suspected) Linux
kernel bug, so I apologise if I have made any mistakes. I am not
subscribed to the list, so please Cc me in on any responses.

Regards,

-- 
Mike Cardwell  https://grepular.com/     http://cardwellit.com/
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