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

Agovic, Sanimir
2013-09-24T07:07:51Z

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> -----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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