_IO_check_libio miscompiled on mips64el

[Florian Weimer]

On 06/04/2016 03:39 PM, Aurelien Jarno wrote:
> Hi all,
>
> The problem I report here looks like a GCC issue, but given it affects
> the GNU libc, I am also asking for help here. I have found that the
> function _IO_check_libio in libio/oldstdfiles.c is not compiled
> correctly on mips64el-linux-gnuabi64 when using GCC >= 4.9. The
> _IO_stdin_ symbol appears in the .data.rel.local section while I think
> it should be in the data.rel section just like  _IO_stdout_ and
> _IO_stderr_. This causes, among other things, lua to fail to work
> correctly.

_IO_check_libio should do nothing at all because _IO_stdin_used is 
defined in all current binaries.  If the definitions in oldstdfiles.c 
make *any* difference, this is (perhaps another) bug.

Does this mechanism work in previous GCC versions, i.e. _IO_stdin_used 
is defined there?

Thanks,
Florian