Brieuc SCHAFF, 12.07.2012 15:47:
We are using lxml in several of our applications with Python 2.6 and from time to time, the application stops responding after a segmentation fault error, and this kind of backtrace:
*Jul 1 15:35:01 server4 httpd: *** glibc detected *** /usr/sbin/apache2: malloc(): smallbin double linked list corrupted: 0x00007f583a03f500 **** *Jul 1 15:35:01 server4 httpd: ======= Backtrace: =========* *Jul 1 15:35:01 server4 httpd: /lib/libc.so.6(+0x77806)[0x7f58376c2806]* *Jul 1 15:35:01 server4 httpd: /lib/libc.so.6(+0x7bb39)[0x7f58376c6b39]* *Jul 1 15:35:01 server4 httpd: /lib/libc.so.6(__libc_malloc+0x6e)[0x7f58376c77de]* *Jul 1 15:35:01 server4 httpd: /usr/lib/libxml2.so.2(xmlInitParserCtxt+0x317)[0x7f58343f2887]* *Jul 1 15:35:01 server4 httpd: /usr/lib/libxml2.so.2(xmlNewParserCtxt+0x2c)[0x7f58343f2acc]* *Jul 1 15:35:01 server4 httpd: /usr/lib/python2.6/dist-packages/lxml/etree.so(+0x54eda)[0x7f5818db6eda]* *Jul 1 15:35:01 server4 httpd: [...] *Jul 1 15:35:01 server4 httpd: /usr/lib/apache2/modules/mod_wsgi.so(+0x12fdb)[0x7f582fe9bfdb]* *Jul 1 15:35:01 server4 httpd: /usr/lib/apache2/modules/mod_wsgi.so(+0x17eed)[0x7f582fea0eed]* *Jul 1 15:35:01 server4 httpd: /usr/lib/libapr-1.so.0(+0x29eb3)[0x7f5837c14eb3]* *Jul 1 15:35:01 server4 httpd: /lib/libpthread.so.0(+0x69ca)[0x7f58379d49ca]* *Jul 1 15:35:01 server4 httpd: /lib/libc.so.6(clone+0x6d)[0x7f5837731cdd]*
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*Jul 11 10:44:48 server4 httpd: *** glibc detected *** /usr/sbin/apache2: munmap_chunk(): invalid pointer: 0x00007f3968b8cb68 **** *Jul 11 10:44:48 server4 httpd: ======= Backtrace: =========* *Jul 11 10:44:48 server4 httpd: /lib/libc.so.6(+0x77806)[0x7f39789dd806]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(xmlResetError+0x22)[0x7f39755038e2]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(__xmlRaiseError+0x237)[0x7f3975504e07]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(__xmlSimpleError+0x6b)[0x7f397550543b]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(xmlParserInputBufferGrow+0x16b)[0x7f397553271b]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(xmlParserInputGrow+0x4c)[0x7f397550739c]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(+0x3bd52)[0x7f397550bd52]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(xmlParseDocument+0x4b8)[0x7f39755204c8]* *Jul 11 10:44:48 server4 httpd: /usr/lib/libxml2.so.2(+0x505c5)[0x7f39755205c5]* *Jul 11 10:44:48 server4 httpd: /usr/lib/python2.6/dist-packages/lxml/etree.so(+0x8fab0)[0x7f3958ad8ab0]* [...]
Stopping apache and restarting it fix the issue, but we have no idea why this is happening. We use Unbuntu 10.10's package of lxml, which is version 2.2.4.
*>>> print("%-20s: %s" % ('Python', sys.version_info))* *Python : (2, 6, 5, 'final', 0)* *>>> print("%-20s: %s" % ('lxml.etree', etree.LXML_VERSION))* *lxml.etree : (2, 2, 4, 0)* *>>> print("%-20s: %s" % ('libxml used', etree.LIBXML_VERSION))* *libxml used : (2, 7, 6)* *>>> print("%-20s: %s" % ('libxml compiled', etree.LIBXML_COMPILED_VERSION))* *libxml compiled : (2, 7, 6)* *>>> print("%-20s: %s" % ('libxslt used', etree.LIBXSLT_VERSION))* *libxslt used : (1, 1, 26)* *>>> print("%-20s: %s" % ('libxslt compiled', etree.LIBXSLT_COMPILED_VERSION))* *libxslt compiled : (1, 1, 26)* * * Do you have any idea of what could cause these issues?
First of all, you should make sure that this isn't due to the system running out of memory for some reason. The stack trace above might (!) hint at that possibility.
I wonder if upgrading to a newer version of the library could change anything.
Given how straight forward it is to builds lxml on Ubuntu, I'd just give the latest release a try. Stefan