From: Michael King <kingmt@...>
Date: 2009-03-05T22:58:37+09:00
Subject: [ruby-core:22682] Re: MBARI8 patch fixes bugs caused by incorrect 	volatile variable declarations

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I knew I was forgetting something on the original mail:

I am seeing the segfault with stack clearing set to both default level and
0x0.
I am not seeing the segfault with MRI
The segfault is in our test suite which does some app setup and config,
which is way I am working on whittling it down to something smaller and
eliminate dependencies on our custom code.
Our app does use a third party C library that we do not have source for, but
I'm not sure if its loaded at the point of the error.

uname -a
Linux mking-3.dev.xxxx.com 2.6.15-51-server #1 SMP Thu Dec 6 21:37:18 UTC
2007 i686 GNU/Linux

gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v
--enable-languages=c,c++,java,f95,objc,ada,treelang --prefix=/usr
--enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--program-suffix=-4.0 --enable-__cxa_atexit --enable-clocale=gnu
--enable-libstdcxx-debug --enable-java-awt=gtk-default --enable-gtk-cairo
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-4.0-1.4.2.0/jre --enable-mpfr
--disable-werror --with-tune=pentium4 --enable-checking=release
i486-linux-gnu
Thread model: posix
gcc version 4.0.3 (Ubuntu 4.0.3-1ubuntu5)

ruby --version
ruby 1.8.6 (2009-3-1 MBARI 8B/0x0 on patchlevel 287) [i686-linux]

configure options
--enable-readline \
--enable-zlib \
--enable-mbari-api \
--with-wipe-sites=0x0 \
CFLAGS="-O0 -g"

On Wed, Mar 4, 2009 at 5:01 PM, Brent Roman <brent@mbari.org> wrote:

>
> Michael,
>
> Could you send me the output of
> $ uname -a
> $ gcc -v
> and the configure cmd used to build with CFLAGS, etc.
> ?
>
> Ruby's conservative GC reads unintialized memory.  That can't be helped.
> When I was heavy into valgrind, I created a suppression file to
> help it recognize and suppress reporting these errors.
>
> http://www.faqs.org/docs/Linux-HOWTO/Valgrind-HOWTO.html
>
> Use --gen-suppressions=yes to automatically create suppression
> records, then tweak them by hand to make them less specific.
>
> The only valgrind reports here that concern me a bit are the invalid reads.
> I'd have to look into these a bit deeper to be sure.
>
> By the way, is it the ruby test suite or your app's that segfaults in
> drb.rb?
> (or both?)  If only in your app, is it using any non-standard 'C'
> extensions?
>
> I'm assuming you've already verified that the segfaults don't also occur
> with unpatched Ruby.
> One more thing to try is to set STACK_WIPES_SITES to 0x0000.
>
> - brent
>
>
> Michael King-2 wrote:
> >
> > I am having an issue with the MBARI patches. In our app the test suite
> has
> > a
> > segfault at line 1413 in drb.rb. I am compiling Ruby on Ubuntu 6.06,
> > 32bit,
> > GCC 4.0.3. The segfault shows up when compiling at O2 and O0(zero). At
> the
> > moment I am trying to whittle down the test to give you something
> > reproducible.
> >
> > I the meantime, I ran valgrind and the results showed an improvement over
> > MRI. I have attached the results of that valgrind run, the errors were of
> > 4
> > basic types and were in linked libraries or gc.c:
> > Conditional jump or move depends on uninitialised value(s)
> > Use of uninitialised value of size 4
> > Invalid read of size
> > Address 0x#{address} is #{X} bytes inside a block of size #{X+2} alloc'd
> >
> > - Michael
> >
> >
>
> --
> View this message in context:
> http://www.nabble.com/MBARI8-patch-fixes-bugs-caused-by-incorrect-volatile-variable-declarations-tp22259357p22341606.html
> Sent from the ruby-core mailing list archive at Nabble.com.
>
>
>

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I knew I was forgetting something on the original mail:<br><br>I am seeing =
the segfault with stack clearing set to both default level and 0x0.<br>I am=
 not seeing the segfault with MRI<br>The segfault is in our test suite whic=
h does some app setup and config, which is way I am working on whittling it=
 down to something smaller and eliminate dependencies on our custom code. <=
br>
Our app does use a third party C library that we do not have source for, bu=
t I&#39;m not sure if its loaded at the point of the error. <br><br>uname -=
a<br>Linux <a href=3D"http://mking-3.dev.xxxx.com">mking-3.dev.xxxx.com</a>=
 2.6.15-51-server #1 SMP Thu Dec 6 21:37:18 UTC 2007 i686 GNU/Linux<br>
<br>gcc -v<br>Using built-in specs.<br>Target: i486-linux-gnu<br>Configured=
 with: ../src/configure -v --enable-languages=3Dc,c++,java,f95,objc,ada,tre=
elang --prefix=3D/usr --enable-shared --with-system-zlib --libexecdir=3D/us=
r/lib --without-included-gettext --enable-threads=3Dposix --enable-nls --pr=
ogram-suffix=3D-4.0 --enable-__cxa_atexit --enable-clocale=3Dgnu --enable-l=
ibstdcxx-debug --enable-java-awt=3Dgtk-default --enable-gtk-cairo --with-ja=
va-home=3D/usr/lib/jvm/java-1.4.2-gcj-4.0-1.4.2.0/jre --enable-mpfr --disab=
le-werror --with-tune=3Dpentium4 --enable-checking=3Drelease i486-linux-gnu=
<br>
Thread model: posix<br>gcc version 4.0.3 (Ubuntu 4.0.3-1ubuntu5)<br><br>rub=
y --version<br>ruby 1.8.6 (2009-3-1 MBARI 8B/0x0 on patchlevel 287) [i686-l=
inux]<br><br>configure options<br>--enable-readline \<br>--enable-zlib \<br=
>
--enable-mbari-api \<br>--with-wipe-sites=3D0x0 \<br>CFLAGS=3D&quot;-O0 -g&=
quot;<br><br><div class=3D"gmail_quote">On Wed, Mar 4, 2009 at 5:01 PM, Bre=
nt Roman <span dir=3D"ltr">&lt;<a href=3D"mailto:brent@mbari.org">brent@mba=
ri.org</a>&gt;</span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"border-left: 1px solid rgb(204, =
204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
Michael,<br>
<br>
Could you send me the output of<br>
$ uname -a<br>
$ gcc -v<br>
and the configure cmd used to build with CFLAGS, etc.<br>
?<br>
<br>
Ruby&#39;s conservative GC reads unintialized memory. =A0That can&#39;t be =
helped.<br>
When I was heavy into valgrind, I created a suppression file to<br>
help it recognize and suppress reporting these errors.<br>
<br>
<a href=3D"http://www.faqs.org/docs/Linux-HOWTO/Valgrind-HOWTO.html" target=
=3D"_blank">http://www.faqs.org/docs/Linux-HOWTO/Valgrind-HOWTO.html</a><br=
>
<br>
Use --gen-suppressions=3Dyes to automatically create suppression<br>
records, then tweak them by hand to make them less specific.<br>
<br>
The only valgrind reports here that concern me a bit are the invalid reads.=
<br>
I&#39;d have to look into these a bit deeper to be sure.<br>
<br>
By the way, is it the ruby test suite or your app&#39;s that segfaults in<b=
r>
drb.rb?<br>
(or both?) =A0If only in your app, is it using any non-standard &#39;C&#39;=
<br>
extensions?<br>
<br>
I&#39;m assuming you&#39;ve already verified that the segfaults don&#39;t a=
lso occur<br>
with unpatched Ruby.<br>
One more thing to try is to set STACK_WIPES_SITES to 0x0000.<br>
<br>
- brent<br>
<div><div></div><div class=3D"h5"><br>
<br>
Michael King-2 wrote:<br>
&gt;<br>
&gt; I am having an issue with the MBARI patches. In our app the test suite=
 has<br>
&gt; a<br>
&gt; segfault at line 1413 in drb.rb. I am compiling Ruby on Ubuntu 6.06,<b=
r>
&gt; 32bit,<br>
&gt; GCC 4.0.3. The segfault shows up when compiling at O2 and O0(zero). At=
 the<br>
&gt; moment I am trying to whittle down the test to give you something<br>
&gt; reproducible.<br>
&gt;<br>
&gt; I the meantime, I ran valgrind and the results showed an improvement o=
ver<br>
&gt; MRI. I have attached the results of that valgrind run, the errors were=
 of<br>
&gt; 4<br>
&gt; basic types and were in linked libraries or gc.c:<br>
&gt; Conditional jump or move depends on uninitialised value(s)<br>
&gt; Use of uninitialised value of size 4<br>
&gt; Invalid read of size<br>
&gt; Address 0x#{address} is #{X} bytes inside a block of size #{X+2} alloc=
&#39;d<br>
&gt;<br>
&gt; - Michael<br>
&gt;<br>
&gt;<br>
<br>
</div></div><font color=3D"#888888">--<br>
View this message in context: <a href=3D"http://www.nabble.com/MBARI8-patch=
-fixes-bugs-caused-by-incorrect-volatile-variable-declarations-tp22259357p2=
2341606.html" target=3D"_blank">http://www.nabble.com/MBARI8-patch-fixes-bu=
gs-caused-by-incorrect-volatile-variable-declarations-tp22259357p22341606.h=
tml</a><br>

</font><div><div></div><div class=3D"h5">Sent from the ruby-core mailing li=
st archive at Nabble.com.<br>
<br>
<br>
</div></div></blockquote></div><br>

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