[PATCH v4] Implement 'catch syscall' for gdbserver

[Yao Qi]

Josh Stone <jistone@redhat.com> writes:

> Well, sure, but I have no idea where that somewhere else could be.
>
> Note these architectures do work for other syscall returns.  It's just
> that execve is a bit special by switching the whole process out.

I talked with a kernel people, looks GDB can't fetch the syscall number
on execve exit.

>
> I suppose we could try to save the number on syscall entry, and just
> report that again when it returns.  But it's not 100% sure that we'll

Yes, that is what I am thinking too.

> see every entry first.  For instance, one could 'catch execve' first,
> which will continue until PTRACE_EVENT_EXEC mid-syscall, then turn on
> 'catch syscall' and see what returns.
> (This is similar to what test_catch_syscall_mid_vfork checks.)

Yeah, we can't guarantee syscall enter comes into first.  I doubt
'lp->syscall_state' is confused in this case too, no?

-- 
Yao (齐尧)