From: Bernd Schubert <bernd-schubert@web.de>
To: Andi Kleen <ak@muc.de>
Subject: Re: x86_64: 32bit emulation problems
Date: Tue, 1 Mar 2005 22:07:01 +0100
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Hello Andi,

sorry, due to some mail sending/refusing problems, I had to resend to the 
nfs-list, which prevented the answers there to be posted to the other CCs.

> It is most likely some kind of user space problem.  I would change
> it to int err = stat(dir, &buf);
> and then go through it with gdb and see what value err gets assigned.
>
> I cannot see any kernel problem.

The err value will become -1 here.

 Trond Myklebust already suggested to look at the results of errno:

On Tuesday 01 March 2005 00:43, Bernd Schubert wrote:
> On Monday 28 February 2005 23:26, you wrote:
> > Given that strace shows that both syscalls (stat64() and stat())
> > succeed, I expect the "problem" is probably just glibc setting an
> > EOVERFLOW error in the 32-bit case. That's what it is supposed to do if
> > a 64 bit value overflows the 32-bit buffers.
>
> Right, thanks.
>
> > Have you tried looking at errno?
>
> bernd@hitchcock tests>./test_stat32 /mnt/test/yp
> stat for /mnt/test/yp failed
> ernno: 75 (Value too large for defined data type)
>
> But why does stat64() on a 64-bit kernel tries to fill in larger data than
> on a 32-bit kernel and larger data also only for nfs-mount points? Hmm, I
> will tomorrow compare the tcp-packges sent by the server.

So I still think thats a kernel bug.


Thanks,
 Bernd

-- 
Bernd Schubert
Physikalisch Chemisches Institut / Theoretische Chemie
Universit?t Heidelberg
INF 229
69120 Heidelberg
e-mail: bernd.schubert@pci.uni-heidelberg.de
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