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From: "Ulrich Weigand" <>
Subject: Re: sizeof (siginfo_t) problem
Date: Mon, 14 Jul 2003 20:31:34 +0200	[thread overview]
Message-ID: <> (raw)

Jakub Jelinek wrote:

>I have noticed this on s390x in a different place:
>MD_FALLBACK_FRAME_STATE_FOR in gcc, in order to unwind through
>signal frames, needs to locate ucontext, and looking at
>stack pointer + 8 + sizeof(siginfo_t) (which works on s390 32-bit)
>did not work at all, everything was shifted by 8 bytes.

The MD_FALLBACK_FRAME_STATE_FOR macro does not use sizeof(siginfo_t)
at all, but hardcodes 128.  (This has always been the case, and was
done to avoid the need to include signal.h.)  This is still broken
with the current kernel behaviour, though.

It is strange that I didn't notice the problem earlier; apparently
most of the places where unwinding through signal frames is required
use non-RT frames ...

>This though means that the kernel siginfo_t change cannot be done
>just in asm-*/siginfo.h headers - at least places where siginfo_t
>is present within some structures ever visible to userland a dummy
>8 byte pad needs to be inserted.

As userspace expects a size of 128 bytes, and with the change
the size now *is* 128 bytes, why would a pad be required?

Mit freundlichen Gruessen / Best Regards

Ulrich Weigand

  Dr. Ulrich Weigand
  Linux for S/390 Design & Development
  IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen
  Phone: +49-7031/16-3727   ---   Email:

             reply	other threads:[~2003-07-14 18:17 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-07-14 18:31 Ulrich Weigand [this message]
2003-07-14 18:35 ` sizeof (siginfo_t) problem Jakub Jelinek
  -- strict thread matches above, loose matches on Subject: below --
2003-07-15 11:58 Martin Schwidefsky
2003-07-14 18:52 Ulrich Weigand
2003-07-14 12:40 Jakub Jelinek
2003-07-14 13:55 ` Jamie Lokier
2003-07-14 15:02   ` Andreas Schwab
2003-07-14 15:48 ` David Mosberger
2003-07-14 15:57   ` Jakub Jelinek
2003-07-14 16:52 ` Stephen Rothwell
2003-07-14 17:00   ` Jakub Jelinek
2003-07-14 17:11     ` Stephen Rothwell
2003-07-14 17:14       ` Jakub Jelinek
2003-07-14 17:25         ` Stephen Rothwell
2003-07-14 17:45           ` Jakub Jelinek
2003-07-19 18:32   ` Anton Blanchard
2003-07-21  0:08     ` Stephen Rothwell
2003-07-22 13:42       ` Russell King
2003-07-22 13:57         ` Stephen Rothwell

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