[sr-dev] shm_regex deadlock

[Henning Westerholt]

On Sunday 13 June 2010, Stefan Keller wrote:
> 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).
> Attached is a patch which does its own locking and thus works around
> this problem.

Hi Stefan,

thank you for the patch, it looks fine to me on a first sight. The library in 
question is not used in any of the existing modules, so i think it should be 
pretty save. Miklos, its ok when i apply it, or do you maybe want to refine it 
a bit?

Regards,

Henning