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From: Philippe Waroquiers <philippe.waroquiers@skynet.be>
To: Pedro Alves <palves@redhat.com>
Cc: Sergio Durigan Junior <sergiodj@redhat.com>, gdb-patches@sourceware.org
Subject: Re: Always run the PTRACE_O_TRACESYSGOOD tests even if PTRACE_O_TRACEFORK is not supported. (was: Re: RFA [PATCH v4] Implement 'catch syscall' for gdbserver)
Date: Wed, 02 Oct 2013 22:08:00 -0000	[thread overview]
Message-ID: <1380751722.2227.37.camel@soleil> (raw)
In-Reply-To: <524C76D4.1010301@redhat.com>

On Wed, 2013-10-02 at 20:41 +0100, Pedro Alves wrote:
> On 09/29/2013 04:04 PM, Philippe Waroquiers wrote:
> 
> > Index: common/linux-ptrace.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/common/linux-ptrace.c,v
> > retrieving revision 1.12
> > diff -u -p -r1.12 linux-ptrace.c
> > --- common/linux-ptrace.c	28 Aug 2013 14:09:31 -0000	1.12
> > +++ common/linux-ptrace.c	29 Sep 2013 14:20:29 -0000
> > @@ -361,16 +361,18 @@ linux_check_ptrace_features (void)
> >        return;
> >      }
> >  
> > -#ifdef GDBSERVER
> > -  /* gdbserver does not support PTRACE_O_TRACESYSGOOD or
> > -     PTRACE_O_TRACEVFORKDONE yet.  */
> > -#else
> > -  /* Check if the target supports PTRACE_O_TRACESYSGOOD.  */
> > +  /* Check if the target supports PTRACE_O_TRACESYSGOOD.
> > +     We keep PTRACE_O_TRACEFORK option activated as a fork
> > +     event notification is expected after my_waitpid below.  */
> >    ret = ptrace (PTRACE_SETOPTIONS, child_pid, (PTRACE_TYPE_ARG3) 0,
> > -		(PTRACE_TYPE_ARG4) PTRACE_O_TRACESYSGOOD);
> > +		(PTRACE_TYPE_ARG4) (PTRACE_O_TRACEFORK
> > +				    | PTRACE_O_TRACESYSGOOD));
> 
> This coupling looks unfortunate.  Actually why wasn't this a
> problem for the native target, even without GDBserver in the picture?
> It just looks like a bug fix?  
Yes I think there is already a similar coupling problem in the
native code:
if PTRACE_O_TRACESYSGOOD is supported but PTRACE_O_TRACEVFORKDONE
is not, then the PTRACE_O_TRACESYSGOOD verification has removed
the flag PTRACE_O_TRACEFORK and so the following my_waitpid will
fail.

The patch you give looks to solve all that.

Philippe



  reply	other threads:[~2013-10-02 22:08 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-21 20:55 RFA [PATCH v3] Implement 'catch syscall' for gdbserver Philippe Waroquiers
2013-09-21 21:03 ` Eli Zaretskii
2013-09-23 11:51 ` Agovic, Sanimir
2013-09-23 19:32   ` Philippe Waroquiers
2013-09-24  7:07     ` Agovic, Sanimir
2013-09-25 16:55       ` Sergio Durigan Junior
2013-09-25 22:55         ` Philippe Waroquiers
2013-09-27 13:25 ` [COMMIT PATCH] remote.c: Remove unnecessary fields from 'struct stop_reply'. (was: Re: RFA [PATCH v3] Implement 'catch syscall' for gdbserver) Pedro Alves
2013-09-27 19:30 ` RFA [PATCH v3] Implement 'catch syscall' for gdbserver Pedro Alves
2013-09-27 20:13   ` Philippe Waroquiers
2013-09-27 20:55 ` Sergio Durigan Junior
2013-09-29 15:04   ` RFA [PATCH v4] Implement 'catch syscall' for gdbserver (was Re: RFA [PATCH v3] Implement 'catch syscall' for gdbserver) Philippe Waroquiers
2013-10-01  5:16     ` Sergio Durigan Junior
2013-10-02 21:02       ` Sergio Durigan Junior
2013-10-02 19:41     ` Always run the PTRACE_O_TRACESYSGOOD tests even if PTRACE_O_TRACEFORK is not supported. (was: Re: RFA [PATCH v4] " Pedro Alves
2013-10-02 22:08       ` Philippe Waroquiers [this message]
2013-10-03 10:16         ` Always run the PTRACE_O_TRACESYSGOOD tests even if PTRACE_O_TRACEFORK is not supported Pedro Alves
2013-10-03 18:40     ` RFA [PATCH v4] Implement 'catch syscall' for gdbserver (was Re: RFA [PATCH v3] Implement 'catch syscall' for gdbserver) Pedro Alves
2013-10-03 19:53       ` Tom Tromey
2013-10-04 17:41         ` Pedro Alves
2013-10-03 22:02       ` Philippe Waroquiers
2013-10-04 17:29         ` Pedro Alves
2013-10-05  9:15           ` Pedro Alves
2013-10-09 21:54             ` Philippe Waroquiers
2013-10-09 22:05               ` Sergio Durigan Junior
2013-10-09 22:09                 ` Philippe Waroquiers
2013-10-04  4:22     ` Luis Machado
2013-10-04 17:40       ` Pedro Alves
2013-10-04 18:55         ` Stan Shebs
2013-10-07 19:07           ` Pedro Alves

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