Re: [PATCH] tilegx: provide a setxid.h to handle negative uids

[Chris Metcalf <cmetcalf at tilera dot com>]

On 5/17/2012 7:20 PM, Joseph S. Myers wrote:
> On Thu, 17 May 2012, Chris Metcalf wrote:
>
>> We observed a bug where setreuid(-1, -1) was becoming
>> setreuid(4294967295, 4294967295) instead, and therefore failing,
>> instead of doing nothing and returning success.
> For MIPS there was such an issue but it was concluded that it was a kernel 
> bug and the kernel should properly extend syscall arguments passed from 
> userspace; see the references in bug 4459.  Is tilegx doing things 
> differently from that?

Thanks for the pointer.  Some searching around tracked it down the
SYSCALL_WRAPPERS config option, which I've now enabled for tilegx, and
which appears to do exactly the right thing in terms of handling sub-word
size arguments.  I'll see if I can push it to 3.4 and to -stable.

-- 
Chris Metcalf, Tilera Corp.
http://www.tilera.com