Re: RFC: %ebp-based backtrace patch

Mark Kettenis
2009-12-27T21:37:34Z

> Date: Sun, 27 Dec 2009 11:59:16 -0500
> From: Daniel Jacobowitz <drow@false.org>
>
> On Wed, Jul 08, 2009 at 08:53:30AM -0400, Daniel Jacobowitz wrote:
> > On Wed, Jul 08, 2009 at 11:01:16AM +0200, Mark Kettenis wrote:
> > > Before comitting this diff, I ran the testsuite, and noticed a
> > > regression. The problem is that if you do a function call through a
> > > null-function-pointer or an otherwise corrupt function pointer, and
> > > get a SIGSEGV, the backtrace no longer shows the frame that did the
> > > function call.
> > >
> > > Until we come up with a way to fix this issue, I'm not going to commit
> > > the diff.
> >
> > Hmm. if (target_read_memory (pc, buf, 1)) ? That's how a similar
> > issue is handled on ARM, in arm_stub_unwind_sniffer.
>
> Hi Mark,
>
> I was looking through Ubuntu's local GDB patches and noticed this one
> is still outstanding. Will the above work? I can test and
> (hopefully) commit it, if you'd like.

Sorry, but I don't see how this would solve things. Do you have a
diff for me to look at?