Re: [rfc] Handle broken CFI for signal trampolines in libc on amd64-linux

["Ulrich Weigand" <uweigand@de.ibm.com>]

Daniel Jacobowitz wrote:
> On Fri, Nov 21, 2008 at 12:38:11AM +0100, Ulrich Weigand wrote:
> > Unfortunately even if I use the dwarf_signal_frame_p hook to have the
> > DWARF-2 sniffer recognize a SIGTRAMP_FRAME, it still doesn't work as
> > the __restore_rt CFI (at least in my glibc) only describes the unwind
> > effects as if it were a regular function, without taking into account
> > the restoring of registers by the sigreturn system call.
> 
> What version of glibc is this?  It was fixed two years ago this month:

Well, it's the system glibc of my openSUSE 10.2 install (based on
a 2006-10-12 glibc-2.5 snapshot), which is indeed somewhat over two
years old.  I guess I could update to a more recent distro one of
these days ...

Anyway, while it is certainly good that this is fixed, I'm still
wondering why we should rely on that when we have a hard-coded
sigtramp detector that should be working just fine under any 
circumstances.

Bye,
Ulrich


-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com