RE: RFA [PATCH v3] Implement 'catch syscall' for gdbserver

["Agovic, Sanimir" <sanimir dot agovic at intel dot com>]

> -----Original Message-----
> From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-owner@sourceware.org] On Behalf
> Of Philippe Waroquiers
> Sent: Monday, September 23, 2013 09:33 PM
> To: Agovic, Sanimir
> Cc: gdb-patches@sourceware.org
> Subject: RE: RFA [PATCH v3] Implement 'catch syscall' for gdbserver
> 
> On Mon, 2013-09-23 at 11:50 +0000, Agovic, Sanimir wrote:
> > Hello Philippe,
> >
> 
> > > +  if (the_low_target.get_syscall_trapinfo == NULL)
> > > +    {
> > > +      *sysno = 0;
> > > +      *sysret = 0;
> > > +      return;
> > > +    }
> > >
> > Is it sufficient to assign sysno/sysret to 0 to indicate missing 'catch syscall'
> > functionality? Both values seem legal to me.
> The idea is that will be used in case the user forces the use of the
> QCatchSyscalls packet. So, I think it is better to return "valid" (but
> not used) values : I do not think there is a syscall nr 0.
> 
gdb -batch -ex 'set architecture i386:x86-64' -ex 'catch syscall 0'
The target architecture is assumed to be i386:x86-64
Catchpoint 1 (syscall 'read' [0])

I just wanted to make sure that we do not report any false syscalls. 
Thus I checked syscall 0 in gdb on amd64 which is mapped to 'read'.

 -Sanimir

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