You are viewing a plain text version of this content. The canonical link for it is here.
Posted to modperl@perl.apache.org by Cory 'G' Watson <gp...@loggerithim.org> on 2004/01/19 17:21:42 UTC
Segmentation Fault w/XML::XPath
The following perl crashes my mod_perl-ed apache at startup. I've sent
the same info to the libexpat and perl-xml lists, but noone seems to
have any good ideas. So now I'll try you guys ;)
use XML::XPath;
my $xp = XML::XPath->new(xml => "<?xml version=\"1.0\"
encoding=\"UTF-8\" ?><config><name>Foo</name></config>");
my $res = $xp->getNodeText("/config/name");
That segfaults my apache every time, but works find when run on the
command line.
This seems to be come from libexpat, and here is the gdb backtrace:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 16384 (LWP 20556)]
0x4022e245 in memmove () from /lib/libc.so.6
(gdb) bt
#0 0x4022e245 in memmove () from /lib/libc.so.6
#1 0x080e9772 in XML_GetBuffer ()
#2 0x080e95c0 in XML_Parse ()
#3 0x4036fe9d in XS_XML__Parser__Expat_ParseString ()
from /usr/local/lib/perl/5.8.2/auto/XML/Parser/Expat/Expat.so
<snip>
Valgrind's output:
==20558== Invalid write of size 4
==20558== at 0x4042A245: memmove (in /lib/libc-2.3.2.so)
==20558== by 0x80E9771: XML_GetBuffer (in
/usr/local/apache/bin/httpd)
==20558== by 0x80E95BF: XML_Parse (in /usr/local/apache/bin/httpd)
==20558== by 0x423D9E9C: XS_XML__Parser__Expat_ParseString (in
/usr/local/lib/perl/5.8.2/auto/XML/Parser/Expat/Expat.so)
==20558== Address 0x0 is not stack'd, malloc'd or free'd
==20558==
==20558== Process terminating with default action of signal 11
(SIGSEGV): dumping core
==20558== Address not mapped to object at address 0x0
==20558== at 0x4042A245: memmove (in /lib/libc-2.3.2.so)
==20558== by 0x80E9771: XML_GetBuffer (in
/usr/local/apache/bin/httpd)
==20558== by 0x80E95BF: XML_Parse (in /usr/local/apache/bin/httpd)
==20558== by 0x423D9E9C: XS_XML__Parser__Expat_ParseString (in
/usr/local/lib/perl/5.8.2/auto/XML/Parser/Expat/Expat.so)
I wrote a quick C program that did similar stuff w/libexpat (giving it
an XML string to parse), and had no problems.
I'll happily do any legwork, or give any other needed information.
Cory 'G' Watson
"The universal aptitude for ineptitude makes any human accomplishment
an incredible miracle." - Dr. John Paul Stapp
--
Reporting bugs: http://perl.apache.org/bugs/
Mail list info: http://perl.apache.org/maillist/modperl.html
Re: Segmentation Fault w/XML::XPath
Posted by Cory 'G' Watson <gp...@loggerithim.org>.
On Jan 19, 2004, at 10:51 AM, Ruslan U. Zakirov wrote:
> Cory 'G' Watson wrote:
>> The following perl crashes my mod_perl-ed apache at startup. I've
>> sent the same info to the libexpat and perl-xml lists, but noone
>> seems to have any good ideas. So now I'll try you guys ;)
>> use XML::XPath;
>> my $xp = XML::XPath->new(xml => "<?xml version=\"1.0\"
>> encoding=\"UTF-8\" ?><config><name>Foo</name></config>"); my $res =
>> $xp->getNodeText("/config/name");
>> That segfaults my apache every time, but works find when run on the
>> command line.
>
> I have something like this.
> You have to rebuild your apache with --disable-rule=EXPAT
> Best regards. Ruslan.
This fixed my problem. Thank you Ruslan!
Cory 'G' Watson
"The universal aptitude for ineptitude makes any human accomplishment
an incredible miracle." - Dr. John Paul Stapp
--
Reporting bugs: http://perl.apache.org/bugs/
Mail list info: http://perl.apache.org/maillist/modperl.html
Re: Segmentation Fault w/XML::XPath
Posted by "Ruslan U. Zakirov" <cu...@wildgate.miee.ru>.
Cory 'G' Watson wrote:
> The following perl crashes my mod_perl-ed apache at startup. I've sent
> the same info to the libexpat and perl-xml lists, but noone seems to
> have any good ideas. So now I'll try you guys ;)
>
> use XML::XPath;
>
> my $xp = XML::XPath->new(xml => "<?xml version=\"1.0\"
> encoding=\"UTF-8\" ?><config><name>Foo</name></config>");
> my $res = $xp->getNodeText("/config/name");
>
> That segfaults my apache every time, but works find when run on the
> command line.
I have something like this.
You have to rebuild your apache with --disable-rule=EXPAT
Best regards. Ruslan.
>
> This seems to be come from libexpat, and here is the gdb backtrace:
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 16384 (LWP 20556)]
> 0x4022e245 in memmove () from /lib/libc.so.6
> (gdb) bt
> #0 0x4022e245 in memmove () from /lib/libc.so.6
> #1 0x080e9772 in XML_GetBuffer ()
> #2 0x080e95c0 in XML_Parse ()
> #3 0x4036fe9d in XS_XML__Parser__Expat_ParseString ()
> from /usr/local/lib/perl/5.8.2/auto/XML/Parser/Expat/Expat.so
> <snip>
>
> Valgrind's output:
>
> ==20558== Invalid write of size 4
> ==20558== at 0x4042A245: memmove (in /lib/libc-2.3.2.so)
> ==20558== by 0x80E9771: XML_GetBuffer (in /usr/local/apache/bin/httpd)
> ==20558== by 0x80E95BF: XML_Parse (in /usr/local/apache/bin/httpd)
> ==20558== by 0x423D9E9C: XS_XML__Parser__Expat_ParseString (in
> /usr/local/lib/perl/5.8.2/auto/XML/Parser/Expat/Expat.so)
> ==20558== Address 0x0 is not stack'd, malloc'd or free'd
> ==20558==
> ==20558== Process terminating with default action of signal 11
> (SIGSEGV): dumping core
> ==20558== Address not mapped to object at address 0x0
> ==20558== at 0x4042A245: memmove (in /lib/libc-2.3.2.so)
> ==20558== by 0x80E9771: XML_GetBuffer (in /usr/local/apache/bin/httpd)
> ==20558== by 0x80E95BF: XML_Parse (in /usr/local/apache/bin/httpd)
> ==20558== by 0x423D9E9C: XS_XML__Parser__Expat_ParseString (in
> /usr/local/lib/perl/5.8.2/auto/XML/Parser/Expat/Expat.so)
>
> I wrote a quick C program that did similar stuff w/libexpat (giving it
> an XML string to parse), and had no problems.
>
> I'll happily do any legwork, or give any other needed information.
>
> Cory 'G' Watson
>
> "The universal aptitude for ineptitude makes any human accomplishment an
> incredible miracle." - Dr. John Paul Stapp
>
>
--
Reporting bugs: http://perl.apache.org/bugs/
Mail list info: http://perl.apache.org/maillist/modperl.html