This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: longjmp handling vs. glibc LD_POINTER_GUARD problems
- From: Pedro Alves <pedro at codesourcery dot com>
- To: gdb-patches at sourceware dot org
- Cc: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- Date: Wed, 14 May 2008 19:16:23 +0100
- Subject: Re: longjmp handling vs. glibc LD_POINTER_GUARD problems
- References: <200805141800.m4EI0IHe006471@d12av02.megacenter.de.ibm.com>
A Wednesday 14 May 2008 19:00:18, Ulrich Weigand wrote:
> I'm now wondering how we should handle this. Should be
> implement an ad-hoc solution to retrieve the guard, which
> may break in the future if glibc changes? Should we require
> use of LD_POINTER_GUARD=0 (which switches off the pointer
> guard mechanism) to enable debugging? Am I overlooking some
> defined interface to get at the value?
No, you're not. There is none. And still
LD_POINTER_GUARD=0 doesn't help when attaching to an already
running target.
> Why are we using the get_longjmp_target mechanism instead of
> just stepping through longjmp until we see where we come out?
You tell me. :-) I had assumed there was a reason. Perhaps
to support longjumping to a different stack, but that's hardly
a portable and frequent use case. This seems to be the path
to go.
--
Pedro Alves