14 Jun
2010
14 Jun
'10
4:06 p.m.
On Sun, 13 Jun 2010 02:31:52 +0200
Stefan Keller <stefan.keller(a)isaco.de> wrote:
Hi,
I used the shm_regex functions from lib in one of my own modules and
noticed that it is dead-locking (it hangs in FUTEX_WAIT).
The code hangs in regexec() when trying to acquire the lock. This was
a bit hard to find out as I couldn't reproduce it in a virtual
machine with some test code I wrote. It turns out this only happens if
the machine has more than one physical CPU core.
Reproducable on x86_64 with two CPU cores, glibc 2.3.6 (from Debian
Etch) and glibc 2.11.1 (from Ubuntu Jaunty).
Sorry, I meant to write Ubuntu Lucid (10.04).
Attached is a patch which does its own locking and
thus works around
this problem.
Best regards,
Stefan
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