php/zend and apache segmentation faults
[email protected] (tariq wali) Fri, 19 Oct 2012 15:48:07 +0530
| Newsgroups | php.install |
|---|---|
| Message-ID | <CAGQjrKYJ=1FBpygz8t2CC+WWxaJ1bdsm19=7J6T3fixVm4VvEA@mail.gmail.com> |
> Hi,
>
> I am new to the group here and would quickly like to understand if this is
> the right place to share questions on php/zend ? Just to give an idea we at
> info edge ltd run most of the web properties on LAMP stack and use various
> versions of PHP(5.2 to latest 5.4.x) with Zend Engine .
>
> Evidently we get a lot of segmentation faults as logged by apache in error
> logs and when we try to debug them they more or less point issues to zend .
> Although I am not a programmer and probably do not understand the exact
> cause of segfaults but I am willing to believe this is something to do with
> PHP . we have eliminated all doubts on hardware/apache file system and so
> forth . Here is a quick output of gdb backtrace on one of the cores that
> apache wrote on a segfault .
>
> This GDB was configured as "i386-redhat-linux-gnu"...Using host
> libthread_db library "/lib/tls/libthread_db.so.1".
>
> Core was generated by `/usr/local/apache/bin/httpd -k start'.
> Program terminated with signal 11, Segmentation fault.
> Reading symbols from /usr/lib/libz.so.1...done.
> Loaded symbols for /usr/lib/libz.so.1
> Reading symbols from /lib/libssl.so.4...done.
> Loaded symbols for /lib/libssl.so.4
> Reading symbols from /lib/libcrypto.so.4...done.
> Loaded symbols for /lib/libcrypto.so.4
> Reading symbols from /usr/lib/libgssapi_krb5.so.2...done.
> Loaded symbols for /usr/lib/libgssapi_krb5.so.2
> Reading symbols from /usr/lib/libkrb5.so.3...done.
> Loaded symbols for /usr/lib/libkrb5.so.3
> Reading symbols from /lib/libcom_err.so.2...done.
> Loaded symbols for /lib/libcom_err.so.2
> Reading symbols from /usr/lib/libk5crypto.so.3...done.
> Loaded symbols for /usr/lib/libk5crypto.so.3
> Reading symbols from /lib/libresolv.so.2...done.
> Loaded symbols for /lib/libresolv.so.2
> Reading symbols from /usr/local/apache/lib/libaprutil-0.so.0...done.
> Loaded symbols for /usr/local/apache/lib/libaprutil-0.so.0
> Reading symbols from /usr/lib/libgdbm.so.2...done.
> Loaded symbols for /usr/lib/libgdbm.so.2
> Reading symbols from /usr/lib/tls/i686/libdb-4.2.so...done.
> Loaded symbols for /usr/lib/tls/i686/libdb-4.2.so
> Reading symbols from /usr/lib/libexpat.so.0...done.
> Loaded symbols for /usr/lib/libexpat.so.0
> Reading symbols from /usr/local/apache/lib/libapr-0.so.0...done.
> Loaded symbols for /usr/local/apache/lib/libapr-0.so.0
> Reading symbols from /lib/tls/librt.so.1...done.
> Loaded symbols for /lib/tls/librt.so.1
> Reading symbols from /lib/tls/libm.so.6...done.
> Loaded symbols for /lib/tls/libm.so.6
> Reading symbols from /lib/libcrypt.so.1...done.
> Loaded symbols for /lib/libcrypt.so.1
> Reading symbols from /lib/libnsl.so.1...done.
> Loaded symbols for /lib/libnsl.so.1
> Reading symbols from /lib/tls/libpthread.so.0...done.
> Loaded symbols for /lib/tls/libpthread.so.0
> Reading symbols from /lib/libdl.so.2...done.
> Loaded symbols for /lib/libdl.so.2
> Reading symbols from /lib/tls/libc.so.6...done.
> Loaded symbols for /lib/tls/libc.so.6
> Reading symbols from /lib/ld-linux.so.2...done.
> Loaded symbols for /lib/ld-linux.so.2
> Reading symbols from /lib/libnss_files.so.2...done.
> Loaded symbols for /lib/libnss_files.so.2
> Reading symbols from /usr/local/apache/modules/libphp5.so...done.
> Loaded symbols for /usr/local/apache/modules/libphp5.so
> Reading symbols from
> /usr/local/mysql/lib/mysql/libmysqlclient.so.15...done.
> Loaded symbols for /usr/local/mysql/lib/mysql/libmysqlclient.so.15
> Reading symbols from /usr/lib/libpng12.so.0...done.
> Loaded symbols for /usr/lib/libpng12.so.0
> Reading symbols from /usr/lib/libjpeg.so.62...done.
> Loaded symbols for /usr/lib/libjpeg.so.62
> Reading symbols from /usr/lib/libcurl.so.3...done.
> Loaded symbols for /usr/lib/libcurl.so.3
> Reading symbols from /usr/lib/libidn.so.11...done.
> Loaded symbols for /usr/lib/libidn.so.11
> Reading symbols from /usr/lib/libxml2.so.2...done.
> Loaded symbols for /usr/lib/libxml2.so.2
> Reading symbols from /usr/local/apache/modules/mod_expires.so...done.
> Loaded symbols for /usr/local/apache/modules/mod_expires.so
> Reading symbols from /usr/local/apache/modules/mod_headers.so...done.
> Loaded symbols for /usr/local/apache/modules/mod_headers.so
> Reading symbols from /usr/local/apache/modules/mod_rpaf-2.0.so...done.
> Loaded symbols for /usr/local/apache/modules/mod_rpaf-2.0.so
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/xcache.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/xcache.so
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/pdo.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/pdo.so
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/pdo_mysql.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/pdo_mysql.so
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/memcache.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/memcache.so
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/wordmapping.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/wordmapping.so
> Reading symbols from /usr/lib/libstdc++.so.6...done.
> Loaded symbols for /usr/lib/libstdc++.so.6
> Reading symbols from /lib/libgcc_s.so.1...done.
> Loaded symbols for /lib/libgcc_s.so.1
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/oauth.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/oauth.so
> Reading symbols from
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/mcrypt.so...done.
> Loaded symbols for
> /usr/local/php/lib/php/extensions/no-debug-non-zts-20060613/mcrypt.so
> Reading symbols from /usr/local/lib/libmcrypt.so.4...done.
> Loaded symbols for /usr/local/lib/libmcrypt.so.4
> Reading symbols from /usr/lib/libltdl.so.3...done.
> Loaded symbols for /usr/lib/libltdl.so.3
> Reading symbols from /lib/libnss_dns.so.2...done.
> Loaded symbols for /lib/libnss_dns.so.2
> #0 0x00574e4d in _zend_mm_free_int (heap=0x8c89600, p=Variable "p" is not
> available.
> ) at /opt/php-5.2.6/Zend/zend_alloc.c:832
> 832 if (UNEXPECTED(prev->next_free_block != mm_block) ||
> UNEXPECTED(next->prev_free_block != mm_block)) {
> (gdb)
> if (UNEXPECTED(prev->next_free_block != mm_block) ||
> UNEXPECTED(next->prev_free_block != mm_block)) {
>
>
>
> ###########analyse this one from bottom to top
>
>
> #0 0x00574e4d in _zend_mm_free_int (heap=0x8c89600, p=Variable "p" is not
> available.
> ) at /opt/php-5.2.6/Zend/zend_alloc.c:832
> #1 0x00582ea1 in destroy_op_array (op_array=0xafbfbf04) at
> /opt/php-5.2.6/Zend/zend_opcode.c:234
> #2 0x005954c4 in zend_hash_destroy (ht=0xafc7408c) at
> /opt/php-5.2.6/Zend/zend_hash.c:526
> #3 0x00583162 in destroy_zend_class (pce=0x8e1fbec) at
> /opt/php-5.2.6/Zend/zend_opcode.c:186
> #4 0x00595698 in zend_hash_apply_deleter (ht=0x8c89850, p=0x8e1fbe0) at
> /opt/php-5.2.6/Zend/zend_hash.c:611
> #5 0x00595947 in zend_hash_reverse_apply (ht=0x8c89850,
> apply_func=0x57f260 <clean_non_persistent_class>)
> at /opt/php-5.2.6/Zend/zend_hash.c:760
> #6 0x0057f8fd in shutdown_executor () at
> /opt/php-5.2.6/Zend/zend_execute_API.c:291
> #7 0x0058c0f8 in zend_deactivate () at /opt/php-5.2.6/Zend/zend.c:860
> #8 0x0055454a in php_request_shutdown (dummy=0x0) at
> /opt/php-5.2.6/main/main.c:1486
> #9 0x006089de in php_handler (r=0x8df6230) at
> /opt/php-5.2.6/sapi/apache2handler/sapi_apache2.c:469
> #10 0x0809b54e in ap_run_handler (r=0x8df6230) at config.c:152
> #11 0x0809b919 in ap_invoke_handler (r=0x8df6230) at config.c:364
> #12 0x0808468d in ap_process_request (r=0x8df6230) at http_request.c:249
> #13 0x080801d9 in ap_process_http_connection (c=0x8debff8) at
> http_core.c:251
> #14 0x080a4ae6 in ap_run_process_connection (c=0x8debff8) at
> connection.c:43
> #15 0x08099d29 in child_main (child_num_arg=Variable "child_num_arg" is
> not available.
> ) at prefork.c:610
> #16 0x08099f53 in make_child (s=Variable "s" is not available.
> ) at prefork.c:704
> #17 0x0809a8b9 in ap_mpm_run (_pconf=0x8c2f0a8, plog=0x8c67188,
> s=0x8c34618) at prefork.c:839
> #18 0x0809f887 in main (argc=3, argv=0xbfe03244) at main.c:618
>
> (gdb) dump_bt executor_globals.current_execute_data
> (gdb) bt
> #0 0x00574e4d in _zend_mm_free_int (heap=0x8c89600, p=Variable "p" is not
> available.
> ) at /opt/php-5.2.6/Zend/zend_alloc.c:832
> #1 0x00582ea1 in destroy_op_array (op_array=0xafbfbf04) at
> /opt/php-5.2.6/Zend/zend_opcode.c:234
> #2 0x005954c4 in zend_hash_destroy (ht=0xafc7408c) at
> /opt/php-5.2.6/Zend/zend_hash.c:526
> #3 0x00583162 in destroy_zend_class (pce=0x8e1fbec) at
> /opt/php-5.2.6/Zend/zend_opcode.c:186
> #4 0x00595698 in zend_hash_apply_deleter (ht=0x8c89850, p=0x8e1fbe0) at
> /opt/php-5.2.6/Zend/zend_hash.c:611
> #5 0x00595947 in zend_hash_reverse_apply (ht=0x8c89850,
> apply_func=0x57f260 <clean_non_persistent_class>)
> at /opt/php-5.2.6/Zend/zend_hash.c:760
> #6 0x0057f8fd in shutdown_executor () at
> /opt/php-5.2.6/Zend/zend_execute_API.c:291
> #7 0x0058c0f8 in zend_deactivate () at /opt/php-5.2.6/Zend/zend.c:860
> #8 0x0055454a in php_request_shutdown (dummy=0x0) at
> /opt/php-5.2.6/main/main.c:1486
> #9 0x006089de in php_handler (r=0x8df6230) at
> /opt/php-5.2.6/sapi/apache2handler/sapi_apache2.c:469
> #10 0x0809b54e in ap_run_handler (r=0x8df6230) at config.c:152
> #11 0x0809b919 in ap_invoke_handler (r=0x8df6230) at config.c:364
> #12 0x0808468d in ap_process_request (r=0x8df6230) at http_request.c:249
> #13 0x080801d9 in ap_process_http_connection (c=0x8debff8) at
> http_core.c:251
> #14 0x080a4ae6 in ap_run_process_connection (c=0x8debff8) at
> connection.c:43
> #15 0x08099d29 in child_main (child_num_arg=Variable "child_num_arg" is
> not available.
> ) at prefork.c:610
> #16 0x08099f53 in make_child (s=Variable "s" is not available.
> ) at prefork.c:704
> #17 0x0809a8b9 in ap_mpm_run (_pconf=0x8c2f0a8, plog=0x8c67188,
> s=0x8c34618) at prefork.c:839
> #18 0x0809f887 in main (argc=3, argv=0xbfe03244) at main.c:618
>
>
> (gdb) bt full
> #0 0x00574e4d in _zend_mm_free_int (heap=0x8c89600, p=Variable "p" is not
> available.
> ) at /opt/php-5.2.6/Zend/zend_alloc.c:832
> prev = Variable "prev" is not available.
>
> (gdb) frame
> #0 0x00574e4d in _zend_mm_free_int (heap=0x8c89600, p=Variable "p" is not
> available.
> ) at /opt/php-5.2.6/Zend/zend_alloc.c:832
> 832 if (UNEXPECTED(prev->next_free_block != mm_block) ||
> UNEXPECTED(next->prev_free_block != mm_block)) {
> (gdb) frame 2
> #2 0x005954c4 in zend_hash_destroy (ht=0xafc7408c) at
> /opt/php-5.2.6/Zend/zend_hash.c:526
> 526 ht->pDestructor(q->pData);
> (gdb)
>
> (gdb) info locals
> p = (Bucket *) 0xafbfbf98
> q = (Bucket *) 0xafbfbecc
> (gdb) info args
> ht = (HashTable *) 0xafc7408c
> (gdb)
>
> (gdb) bt full
> #0 0x00574e4d in _zend_mm_free_int (heap=0x8c89600, p=Variable "p" is not
> available.
> ) at /opt/php-5.2.6/Zend/zend_alloc.c:832
> prev = Variable "prev" is not available
>
>
>
>
> # /opt/php-5.2.6/Zend/zend_alloc.c
>
> current_conn = ap_run_create_connection(ptrans, ap_server_conf, csd,
> my_child_num, sbh, bucket_alloc);
> if (current_conn) {
> ap_process_connection(current_conn, csd);
>
> apr_signal(AP_SIG_GRACEFUL, SIG_IGN);
> child_main(slot);
>
> make_child(ap_server_conf, free_slots[i]);
>
>
>
>
>
> #main.c
>
> if (ap_mpm_run(pconf, plog, server_conf))
> break;
>
>
> #/opt/php-5.2.6/Zend/zend_hash.c
> p = ht->pListHead;
> while (p != NULL) {
> q = p;
> p = p->pListNext;
> if (ht->pDestructor) {
> ht->pDestructor(q->pData);
> }
> if (q->pData != &q->pDataPtr) {
> pefree(q->pData, ht->persistent);
> }
> pefree(q, ht->persistent);
> }
>
>
>
>
> --
> *Tariq Wali.*
>
>
--
*Tariq Wali.*