Re: [rfa] Attach vsyscall support for GNU/Linux

Mark Kettenis
2004-10-24T20:55:07Z

Date: Sun, 24 Oct 2004 14:53:45 -0400
From: Daniel Jacobowitz <drow@false.org>

This patch, based on a patch Andrew posted earlier this year, connects
vsyscall support to the inferior_created observer.

As before, I have adjusted the i386-linux sigtramp code to recognize
the names of the kernel trampolines (both of them this time - I forgot
the RT case when I first did this). And I have adjusted the i386
target to recognize signal trampolines before searching for DWARF-2
unwind information, as previously discussed. Other architectures which
now have a vsyscall DSO may need to make the same change.

I still don't get it. What exactly was the purpose of adding the
vsyscall DSO if we're not using the DWARF CFI it contains. Can't the
people who dreamt up this wonderful mechanism fix their implementation
such that it doesn't contain any useless DWARF CFI? I'm a bit
reluctant to approve this since it'll probably mean that it never get
fixed properly :-(.

But there's another reason why I'm against this patch. It changes the
order of the unwinders for all the other i386 targets too. Please
find a way to do this such that it affect Linux only.

Sorry, I didn't realize this before...

Mark