From: Paul Pluzhnikov <ppluzhnikov@google.com>
To: gdb-patches@sourceware.org, Pedro Alves <pedro@codesourcery.com>,
Ulrich Weigand <uweigand@de.ibm.com>
Subject: Re: RFC: Longjmp vs LD_POINTER_GUARD revisited
Date: Sun, 15 Nov 2009 18:30:00 -0000 [thread overview]
Message-ID: <8ac60eac0911151029i60ae1713m8ee2de5c05103d9d@mail.gmail.com> (raw)
In-Reply-To: <20091115173429.GB23483@caradoc.them.org>
On Sun, Nov 15, 2009 at 9:34 AM, Daniel Jacobowitz <drow@false.org> wrote:
> * Where the jmp_buf contents are obfuscated, as done by glibc, which
> "encrypts" them using a canary stored in the thread TCB.
FWIW, I never understood the point of this obfuscation: the program
(and any rogue code injected into it) can trivially discover the value
of canary:
call sigsetjmp
a_label:
... canary = sigjmp_buf.__jmpbuf[JB_PC] - &a_label
I think GDB could also perform such discovery, and that would allow it
work with non-debug glibc (debug glibc (I believe) is exception rather
the rule outside of {gdb,glibc,gcc} developers).
--
Paul Pluzhnikov
next prev parent reply other threads:[~2009-11-15 18:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-15 17:35 Daniel Jacobowitz
2009-11-15 18:06 ` Eli Zaretskii
2009-11-15 18:30 ` Paul Pluzhnikov [this message]
2009-11-15 22:36 ` Daniel Jacobowitz
2009-11-15 23:06 ` Paul Pluzhnikov
2009-11-16 14:37 ` Daniel Jacobowitz
2009-11-16 14:55 ` Pedro Alves
2009-11-16 14:56 ` Pedro Alves
2009-11-16 15:05 ` Pedro Alves
2009-11-16 17:50 ` Daniel Jacobowitz
2009-11-15 18:39 ` Joseph S. Myers
2009-11-15 21:52 ` Mark Kettenis
2009-11-15 22:37 ` Daniel Jacobowitz
2009-11-16 15:15 ` Frank Ch. Eigler
2009-11-16 15:40 ` Paul Pluzhnikov
2009-11-16 15:43 ` Paul Pluzhnikov
2009-11-16 16:19 ` Mark Kettenis
2009-11-16 15:59 ` Mark Kettenis
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