From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by yquem.inria.fr (Postfix) with ESMTP id 66FD4BC57 for ; Wed, 1 Dec 2010 16:10:13 +0100 (CET) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqsAAJ/z9UzRVda2imdsb2JhbACiNVcIFQEBAQoJDAcPBh6qGot8AQWOCgEEhUeKag X-IronPort-AV: E=Sophos;i="4.59,283,1288566000"; d="scan'208";a="81064612" Received: from mail-iw0-f182.google.com ([209.85.214.182]) by mail4-smtp-sop.national.inria.fr with ESMTP; 01 Dec 2010 16:10:12 +0100 Received: by iwn39 with SMTP id 39so8953768iwn.27 for ; Wed, 01 Dec 2010 07:10:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:cc:content-type; bh=Qq6hZWyofbsMi0lllYXbNDj8PKqYHVdgg+mk/9h5v9E=; b=fkzi9jDQi7KC97a5bdkFsVkjgSU0VUSqW8E/XT3Od0FJ2kB3fpxDgYIGUp2CLiHNoO Za/gqabXq8YHmLy1yHHqceXrT7cZnBEIqop158LYfCV1olPa92T95E4lnVYB6q3ooE/1 6YQzt7xZVm55gbCyI18D0/3h/lTkJCsWRgpxg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; b=OTPyPGY/BEzKTGnerQsgB9+exiFDI74asrtt4yDk3aEtdIGLjxca8gZQyiCcHdXuwR Tlw0yyjOQK4/7HOlmagr8TwBZC0pbqsgr2kymXk23TJSr2Hg9rCGKQgtmZD5xhbswI6K FQOZJdtb1gCESewv8H0+2Dv2c85hUUWGw8tqc= Received: by 10.231.35.134 with SMTP id p6mr9034800ibd.177.1291216211033; Wed, 01 Dec 2010 07:10:11 -0800 (PST) MIME-Version: 1.0 Received: by 10.231.176.134 with HTTP; Wed, 1 Dec 2010 07:08:46 -0800 (PST) In-Reply-To: <20101201105157.GC2196@siouxsie> References: <20101130231804.GB21723@siouxsie> <20101201091541.GA3917@siouxsie> <20101201105157.GC2196@siouxsie> From: Philippe Veber Date: Wed, 1 Dec 2010 16:08:46 +0100 Message-ID: Subject: Re: [Caml-list] Tips to find the cause of a seg fault To: oliver@first.in-berlin.de Cc: caml users Content-Type: multipart/alternative; boundary=00032557532696599504965ab37b X-Spam: no; 0.00; in-berlin:01 0100,:01 in-berlin:01 0100,:01 segfault:01 bug:01 usr:01 lib:01 unhandled:01 non-free:01 bindings:01 non-free:01 bug:01 segfault:01 usr:01 --00032557532696599504965ab37b Content-Type: text/plain; charset=ISO-8859-1 2010/12/1 > On Wed, Dec 01, 2010 at 11:26:19AM +0100, Philippe Veber wrote: > > 2010/12/1 > > > > > Hi, > > > > > > > > > On Wed, Dec 01, 2010 at 09:32:16AM +0100, Philippe Veber wrote: > > > > Actually I was not confident I could extract a small program > reproducing > > > the > > > > issue until ... you had me try ! I could get a very tiny example that > > > > behaves exactly the same, which does not involve opengl at all, only > sdl. > > > > Here it is : > > > [...] > > > > > > > > > After installing some sdl-related packages, I could comopile the code. > > > So far it does not crash. > > > > > > What actions do create the segfault for you? > > > > > > > roll the mouse wheel up or down fast with the cursor on the window. > However, > > I know that this problem does not occur everywhere, so you might well > > observe nothing ... > [...] > > No crash happened. > > > Normally I'm very gifted to crash software.... by just looking at it. > > If there is a bug, it will find me ;) > > Did you tried another X-driver? > > In your valgrind printout there was mentioned "libnvidia". > And a crash seems to have been occured at that part: > > > > ==11306== by 0x4215D5: camlHum__entry (in > > /home/pveber/hum/_build/src/hum.native) > > ==11306== by 0xC5767A7: ??? > > ==11306== > > ==11306== Conditional jump or move depends on uninitialised value(s) > > ==11306== at 0x7695580: ??? (in > > /usr/lib/nvidia-current/libnvidia-glcore.so.260.19.06) > > ==11306== by 0x1000000000000: ??? > > ==11306== > > vex amd64->IR: unhandled instruction bytes: 0xFF 0xD8 0xC 0xF9 0xFF 0xD8 > > ==11306== valgrind: Unrecognised instruction at address 0x4992cb. > > ==11306== Your program just tried to execute an instruction that Valgrind > > > So, please chack this. Maybe one of the free drivers does work better, > or maybe an update could help. > > If you update your kernel, then you might also need to update the > X-drivers, because the nvidia stuff is non-free binary stuff, > and maybe some bindings don't work correctly with a new kernel. > > > I once experienced problems the other way around: crashing blender > with the free drivers, just by scaling into a view more and more, > and no crash with the non-free drivers. > > This X11-driver part is really a desert... > > ...and even if you don't use OpenGL commands... the driver that you > installed > and configured will be used nevretheless, and if there is something wrong, > you > will get your crashes. > > Look if the X11-driver-bindings are all up to date for the driver you use > now, > they are. > and also try another X11-driver... > I sure will. The thing is in my last example, there is no warning from the nvidia driver anymore, so I'd think the bug must be in the sdl part. I should also check if this doesn't come from the touchpad driver, using a real mouse on the same system. Anyway thanks for your comments ! ph. --00032557532696599504965ab37b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

2010/12/1 <oliver@first.in-berlin.de>
On Wed, Dec 01, 2010 at 11:26:19AM +0100, Philippe Veber = wrote:
> 2010/12/1 <oliver@firs= t.in-berlin.de>
>
> > Hi,
> >
> >
> > On Wed, Dec 01, 2010 at 09:32:16AM +0100, Philippe Veber wrote: > > > Actually I was not confident I could extract a small program= reproducing
> > the
> > > issue until ... you had me try ! I could get a very tiny exa= mple that
> > > behaves exactly the same, which does not involve opengl at a= ll, only sdl.
> > > Here it is :
> > [...]
> >
> >
> > After installing some sdl-related packages, I could comopile the = code.
> > So far it does not crash.
> >
> > What actions do create the segfault for you?
> >
>
> roll the mouse wheel up or down fast with the cursor on the window. Ho= wever,
> I know that this problem does not occur everywhere, so you might well<= br> > observe nothing ...
[...]

No crash happened.


Normally I'm very gifted to crash software.... by just looking at it.
If there is a bug, it will find me =A0;)

Did you tried another X-driver?

In your valgrind printout there was mentioned "libnvidia".
And a crash seems to have been occured at that part:


> =3D=3D11306=3D=3D =A0 =A0by 0x4215D5: camlHum__entry (in
> /home/pveber/hum/_build/src/hum.native)
> =3D=3D11306=3D=3D =A0 =A0by 0xC5767A7: ???
> =3D=3D11306=3D=3D
> =3D=3D11306=3D=3D Conditional jump or move depends on uninitialised va= lue(s)
> =3D=3D11306=3D=3D =A0 =A0at 0x7695580: ??? (in
> /usr/lib/nvidia-current/libnvidia-glcore.so.260.19.06)
> =3D=3D11306=3D=3D =A0 =A0by 0x1000000000000: ???
> =3D=3D11306=3D=3D
> vex amd64->IR: unhandled instruction bytes: 0xFF 0xD8 0xC 0xF9 0xFF= 0xD8
> =3D=3D11306=3D=3D valgrind: Unrecognised instruction at address 0x4992= cb.
> =3D=3D11306=3D=3D Your program just tried to execute an instruction th= at Valgrind


So, please chack this. Maybe one of the free drivers does work better= ,
or maybe an update could help.

If you update your kernel, then you might also need to update the
X-drivers, because the nvidia stuff is non-free binary stuff,
and maybe some bindings don't work correctly with a new kernel.


I once experienced problems the other way around: crashing blender
with the free drivers, just by scaling into a view more and more,
and no crash with the non-free drivers.

This X11-driver part is really a desert...

...and even if you don't use OpenGL commands... the driver that you ins= talled
and configured will be used nevretheless, and if there is something wrong, = you
will get your crashes.

Look if the X11-driver-bindings are all up to date for the driver you use n= ow,
they are.
=A0
and also try another X11-driver...
I sure will.
The thing is in my last example, there is no warning from the nvidia driv= er anymore, so I'd think the bug must be in the sdl part. I should also= check if this doesn't come from the touchpad driver, using a real mous= e on the same system.
Anyway thanks for your comments !

ph.

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