From: Mark Kettenis <kettenis@chello.nl>
To: thorpej@wasabisystems.com
Cc: cagney@gnu.org, drow@false.org, gdb-patches@sources.redhat.com
Subject: Re: [rfa:NetBSD/ppc] Implement signal trampoline unwinder
Date: Wed, 03 Mar 2004 21:20:00 -0000 [thread overview]
Message-ID: <200403032120.i23LKC6P001477@elgar.kettenis.dyndns.org> (raw)
In-Reply-To: <DF705FC5-6D53-11D8-BE41-000A957650EC@wasabisystems.com> (message from Jason Thorpe on Wed, 3 Mar 2004 12:46:40 -0800)
From: Jason Thorpe <thorpej@wasabisystems.com>
Date: Wed, 3 Mar 2004 12:46:40 -0800
On Mar 3, 2004, at 12:43 PM, Andrew Cagney wrote:
> Jason, am I correct to assume that the second SC here:
>
> (gdb) x/10i $lr
> 0x7fffefdc: addi r3,r1,24
> 0x7fffefe0: li r0,295
> 0x7fffefe4: sc
This is __sigreturn14
> 0x7fffefe8: li r0,1
> 0x7fffefec: sc
and this is exit (process croaks if sigreturn failed).
Andrew,
This is the usual pattern. A sigreturn system call followed by an
exit system call. There may be several versions of the sigreturn
system call in an OS (besides __sigreturn14, NetBSD also has an older
sigreturn system call). Before the system call there may be some code
that does the call to the signal handler. If all instructions have
the same length (as is the case on SPARC, and appears to be the case
on PPC) it may be enough to check for the sigreturn system call
(i.e. li r0,295; sc).
Mark
WARNING: multiple messages have this Message-ID
From: Mark Kettenis <kettenis@chello.nl>
To: thorpej@wasabisystems.com
Cc: cagney@gnu.org, drow@false.org, gdb-patches@sources.redhat.com
Subject: Re: [rfa:NetBSD/ppc] Implement signal trampoline unwinder
Date: Fri, 19 Mar 2004 00:09:00 -0000 [thread overview]
Message-ID: <200403032120.i23LKC6P001477@elgar.kettenis.dyndns.org> (raw)
Message-ID: <20040319000900.40FzIOlkhdFjbKAX2khQy_q458qHN9SdJgJK9aN0020@z> (raw)
In-Reply-To: <DF705FC5-6D53-11D8-BE41-000A957650EC@wasabisystems.com> (message from Jason Thorpe on Wed, 3 Mar 2004 12:46:40 -0800)
From: Jason Thorpe <thorpej@wasabisystems.com>
Date: Wed, 3 Mar 2004 12:46:40 -0800
On Mar 3, 2004, at 12:43 PM, Andrew Cagney wrote:
> Jason, am I correct to assume that the second SC here:
>
> (gdb) x/10i $lr
> 0x7fffefdc: addi r3,r1,24
> 0x7fffefe0: li r0,295
> 0x7fffefe4: sc
This is __sigreturn14
> 0x7fffefe8: li r0,1
> 0x7fffefec: sc
and this is exit (process croaks if sigreturn failed).
Andrew,
This is the usual pattern. A sigreturn system call followed by an
exit system call. There may be several versions of the sigreturn
system call in an OS (besides __sigreturn14, NetBSD also has an older
sigreturn system call). Before the system call there may be some code
that does the call to the signal handler. If all instructions have
the same length (as is the case on SPARC, and appears to be the case
on PPC) it may be enough to check for the sigreturn system call
(i.e. li r0,295; sc).
Mark
next prev parent reply other threads:[~2004-03-03 21:20 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-19 0:09 Andrew Cagney
2004-03-01 1:05 ` Andrew Cagney
2004-03-01 1:26 ` Daniel Jacobowitz
2004-03-19 0:09 ` Andrew Cagney
2004-03-01 1:33 ` Andrew Cagney
2004-03-01 2:47 ` Daniel Jacobowitz
2004-03-01 9:34 ` Mark Kettenis
2004-03-19 0:09 ` Mark Kettenis
2004-03-19 0:09 ` Jason Thorpe
2004-03-02 23:29 ` Jason Thorpe
2004-03-03 20:43 ` Andrew Cagney
2004-03-03 20:46 ` Jason Thorpe
2004-03-03 21:20 ` Mark Kettenis [this message]
2004-03-19 0:09 ` Mark Kettenis
2004-03-19 0:09 ` Jason Thorpe
2004-03-19 0:09 ` Andrew Cagney
2004-03-19 0:09 ` Andrew Cagney
2004-03-03 0:18 ` Andrew Cagney
2004-03-03 15:17 ` Andrew Cagney
2004-03-19 0:09 ` Andrew Cagney
2004-03-19 0:09 ` Daniel Jacobowitz
2004-03-19 0:09 ` Daniel Jacobowitz
2004-03-19 0:09 ` Kevin Buettner
2004-03-02 22:21 ` Kevin Buettner
2004-03-19 0:09 ` Andrew Cagney
2004-03-02 22:48 ` Andrew Cagney
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