public inbox for gnu-gabi@sourceware.org
 help / color / mirror / Atom feed
From: Michael Matz <matz@suse.de>
To: Florian Weimer <fweimer@redhat.com>
Cc: "H.J. Lu" <hjl.tools@gmail.com>, gnu-gabi@sourceware.org
Subject: Re: [PATCH] Make _Unwind_GetIPInfo part of the ABI
Date: Fri, 01 Jan 2016 00:00:00 -0000	[thread overview]
Message-ID: <alpine.LSU.2.20.1610211546460.5714@wotan.suse.de> (raw)
In-Reply-To: <alpine.LSU.2.20.1610211521400.5714@wotan.suse.de>

Hi,

On Fri, 21 Oct 2016, Michael Matz wrote:

> > On 10/21/2016 02:58 PM, Michael Matz wrote:
> > > +This function returns the same value as \code{\_Unwind\_GetIP}.  In
> > > +addition, the argument \code{ip\_before\_insn} must not be not null, and
> > > +\code{*ip\_before\_insn} is updated with a flag which indicates whether
> > > +the returned pointer is at or after the first not yet fully executed
> > > +instruction.
> > 
> > I think this is rather misleading.  On x86_64, the location of the IP 
> > value is the same for calls and asynchronous signals: it always points 
> > to the next instruction to be executed.
> 
> No, that's simply wrong.

Or rather, it isn't wrong, it's indeed pointing to the instruction to be 
executed next after return from handler, as always.  But that's not the 
important thing for unwinding: what you're interested in is the 
instruction that _caused_ the interruption, and for that what I said 
applies.


Ciao,
Michael.

  reply	other threads:[~2016-10-21 13:48 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-01  0:00 Florian Weimer
2016-01-01  0:00 ` Michael Matz
2016-01-01  0:00   ` Florian Weimer
2016-01-01  0:00     ` Michael Matz
2016-01-01  0:00       ` Michael Matz [this message]
2016-01-01  0:00         ` Carlos O'Donell
2016-01-01  0:00       ` Florian Weimer
2016-01-01  0:00         ` H.J. Lu
2016-01-01  0:00           ` Florian Weimer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.LSU.2.20.1610211546460.5714@wotan.suse.de \
    --to=matz@suse.de \
    --cc=fweimer@redhat.com \
    --cc=gnu-gabi@sourceware.org \
    --cc=hjl.tools@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).