Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Tom H. <th...@cy...>]

In message <200...@ac...>
        Julian Seward <js...@ac...> wrote:

> Thanks so much for this info; I do indeed implement __errno_location()
> but I wasn't sure it's always getting used.  This passing of a 
> descriptor block does sound like NPTL, tho, and we're operating 
> glibc-2.3.2 in old PosixThreads mode so far.  We have confirmation
> from Nick that the errno test program fails on glibc-2.2.X, so
> something else must be broken.

The idea may have come from NPTL but the glibc 2.3.2 that RedHat
shipped as an update for RH8 comes with a version of linuxthreads
that works in the same way.

The main problem is that there isn't an errno_location function
pointer in the descriptor block - instead it uses the thread_descr
function to get the address of the thread descriptor and then expects
to find the thread's errno at a particular offset in that block.

Tom

-- 
Tom Hughes (th...@cy...)
Software Engineer, Cyberscience Corporation
http://www.cyberscience.com/