Re: [Qemu-devel] User emulation & gdb & sigsegv

[Lionel Landwerlin <lionel.landwerlin@openwide.fr>]

Le jeudi 11 décembre 2008 à 00:18 +0100, Edgar E. Iglesias a écrit :
> On Thu, Dec 11, 2008 at 12:06:53AM +0100, Lionel Landwerlin wrote:
> > Hello,
> > 
> > Currently, when using gdb connected to qemu, if a sigsegv is raised,
> > Qemu just exits.
> > 
> > How should I modify Qemu to redirect this last signal to the connected
> > gdb and print a stack trace at least ?
> > 
> > I tried to call gdb_handlesig(gdbstub.c) from
> > force_sig(linux-user/signal.c) but Qemu just crashes.
> > 
> > Any idea is welcome :)
> 
> Hello,
> 
> I've got this in my git, IIRC it helped me out in those situations.
> 
> Cheers
> 
> commit 1efa40a743e16dbe2803a8d16902bf89850e80a3
> Author: Edgar E. Iglesias <edgar.iglesias@axis.com>
> Date:   Mon Sep 29 14:14:24 2008 +0200
> 
>     Pass default handler signals to gdb aswell.
> 
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 9640923..b7d22a1 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -365,6 +365,7 @@ int queue_signal(CPUState *env, int sig, target_siginfo_t *info)
>          if (sig != TARGET_SIGCHLD &&
>              sig != TARGET_SIGURG &&
>              sig != TARGET_SIGWINCH) {
> +	    sig = gdb_handlesig(env, sig);
>              force_sig(sig);
>          } else {
>              return 0; /* indicate ignored */
> 
> 

In fact this patch just make qemu crash too.
Have you tested this patch on the current svn  ?
What cpu did you use to test it ?

Regards,



-- 
Lione Landwerlin                                         

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