Re: Making getenv more multi-threading--robust?

[Andreas Jaeger <aj at suse dot com>]

On Thursday, September 13, 2012 12:11:48 Stephan Bergmann wrote:
> I stumbled over this when running the LibreOffice test suite and
> getting sporadic crashes in getenv(3).  It turns out that LibreOffice
> contains many places that call getenv (mostly to check whether to
> enable one tweak or another) at arbitrary times and from arbitrary
> threads, and apparently also contains the odd call to setenv etc. to
> modify the environment.
> 
> Though getenv is generally known to not be thread-safe, glibc already
> contains measures to make concurrent calls to setenv etc. thread-safe,
> so I wonder whether something like the attached
> 0001-Prevent-races-when-getenv-walks-__environ-while-sete.patch would
> make sense.  While this would not solve my problems with
> (cross-platform) LibreOffice, it would help prevent glibc getenv
> crashes as demonstrated by the little program in the patch's commit
> message.
> 
> Stephan

Stephan, please send patches to the libc-alpha mailing list. A patch 
would also need a proper changelog entry - for details see 
http://sourceware.org/glibc/wiki/Contribution%20checklist

In general the patch looks fine, but let's discuss this on the other 
list.

Thanks a lot for your contribution!
Andreas
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