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Re: Subversion 1.7.0 GO / NO-GO

From: Philip Martin <philip.martin_at_wandisco.com>
Date: Thu, 22 Sep 2011 09:43:16 +0100

Mattias Engdegård <mattiase_at_bredband.net> writes:

>> Mattias Engdegård (CC'd) reports on IRC that apr_atomic_xchgptr() in
>> recent APR's is broken, and the brokenness can affect Subversion under
>> certain circumstances:
>>
>> <@danielsh> wayita: t
>> < wayita> gcc 4.0.x or older
>> < wayita> apr 1.3.x or newer
>> < wayita> x86-64 only
>> < wayita> WORKAROUND: --disable-nonportable-atomics to APR's configure
>> < wayita> OS: any unix
>> < wayita> nature of the bug: apr_atomic_xchgptr() does not
>> initialize the return value
>> < wayita> https://issues.apache.org/bugzilla/show_bug.cgi?id=51851
>> < wayita> manifests as a segfault in svn.
>
> It should be noted that this also explains the crash discussed in the
> thread at http://svn.haxx.se/dev/archive-2011-08/0157.shtml, where it
> was incorrectly guessed to be a compiler bug. (CC:ing the original
> reporter)

APR has a testsuite that includes a test for apr_atomic_xchgptr. Does
that test detect the problem?

-- 
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Received on 2011-09-22 10:43:53 CEST

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