From: "Mark Kettenis" <mark.kettenis@xs4all.nl>
To: "Ulrich Weigand" <uweigand@de.ibm.com>, gdb-patches@sourceware.org
Subject: Re: [rfc] Handle broken CFI for signal trampolines in libc on amd64-linux
Date: Fri, 21 Nov 2008 19:19:00 -0000 [thread overview]
Message-ID: <11706.86.86.3.213.1227267599.squirrel@webmail.xs4all.nl> (raw)
> On Fri, Nov 21, 2008 at 02:33:29AM +0100, Ulrich Weigand wrote:
> > 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.
>
> I think that one reason was the extra work of the signal handler
> sniffer. The amd64 one doesn't do much for named functions, though,
> and functions with CFI are likely to be named. I suggest asking
> Mark Kettenis's opinion.
My memory is a bit hazy on this, but I think the idea was that the signal
frame unwinder would only be used for older versions of linux/glibc that
don't provide the necessary CFI, and that newer versions would provide
correct CFI which would give the kernel/glibc people complete freedom on
how to implement signal frames. As such, I'm inclined to say "no" to your
diff.
next reply other threads:[~2008-11-21 11:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-21 19:19 Mark Kettenis [this message]
2008-11-22 23:56 ` Ulrich Weigand
-- strict thread matches above, loose matches on Subject: below --
2008-11-21 15:01 Ulrich Weigand
2008-11-21 15:16 ` Daniel Jacobowitz
2008-11-21 18:12 ` Ulrich Weigand
2008-11-21 18:47 ` Daniel Jacobowitz
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