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From: Mike Cardwell <linux-kernel@lists.grepular.com>
To: linux-kernel@vger.kernel.org
Subject: Procfs race condition bug
Date: Fri, 20 Jul 2012 19:12:02 +0100	[thread overview]
Message-ID: <50099F72.8020901@lists.grepular.com> (raw)

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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/
OpenPGP Key    35BC AF1D 3AA2 1F84 3DC3  B0CF 70A5 F512 0018 461F
XMPP OTR Key   8924 B06A 7917 AAF3 DBB1  BF1B 295C 3C78 3EF1 46B4


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             reply	other threads:[~2012-07-20 18:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-20 18:12 Mike Cardwell [this message]
  -- strict thread matches above, loose matches on Subject: below --
2014-07-04 10:13 Procfs race condition bug Mike Cardwell
2014-07-09 12:17 Alexey Dobriyan
2014-07-09 12:20 ` Alexey Dobriyan
2014-07-10  4:40   ` Eric W. Biederman

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