Is this crash easily/consistently reproducible? Is it an issue you think is readily fixable? If this is the case, open a new bug.
Or is it really rare? Would it likely go unfixed/unvalidated fix for a long time? If this is the case, you should add this to bug #68439, which is a collection of hard to reproduce/rare crashes in Opcache. The #68439 crashes may go unfixed for a long time. They are hard to reproduce to fix or validate a fix. We don't want to have a bunch of Opcache bugs open in Bugzilla forever. But, we want to keep a record of such crashes. For these reasons, we're sticking all these crashes in #68439. Regards -M On Mon, Nov 24, 2014 at 1:52 PM, Eric Stenson <erics...@microsoft.com> wrote: > Internals folks-- > > Who owns Zend Opcache these days? I've got a crash dump that appears to > be a double-free of ZCG(cwd) during accel_chdir on PHP 5.5.18. > > Does this crash look familiar to anyone? > > [windbg output] > 0:000> .ecxr > eax=00000000 ebx=01b47cb0 ecx=77b12240 edx=01b00000 esi=01b12f08 > edi=01e6e6d0 > eip=6bdab9e7 esp=0194ef2c ebp=0cff53b0 iopl=0 nv up ei pl zr na pe > nc > cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b > efl=00210246 > php5!_efree+0x27: > 6bdab9e7 8b57f8 mov edx,dword ptr [edi-8] > ds:002b:01e6e6c8=???????? > 0:000> k > *** Stack trace for last set context - .thread/.cxr resets it > # ChildEBP RetAddr > 00 0194ef34 6bd52647 php5!_efree+0x27 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_alloc.c @ 2440] > 01 0194f044 6bda6ee6 php_opcache!zif_accel_chdir+0x67 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\ext\opcache\zendaccelerator.c @ 158] > 02 0194f0a4 6bda6645 php5!zend_do_fcall_common_helper_SPEC+0x176 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_vm_execute.h @ 550] > 03 0194f0dc 6bdc11c1 php5!execute_ex+0x295 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_vm_execute.h @ 363] > 04 0194f184 6bde68d0 php5!zend_call_function+0x3c1 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_execute_api.c @ 937] > 05 0194f1b8 6bde6808 php5!call_user_function_ex+0x50 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_execute_api.c @ 725] > 06 0194f1f0 6bee5ae9 php5!call_user_function+0x58 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_execute_api.c @ 699] > 07 0194f224 6bdbf51b php5!user_shutdown_function_call+0x79 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\ext\standard\basic_functions.c @ 5001] > 08 0194f238 6bee17e8 php5!zend_hash_apply+0x1b > [c:\php-sdk\php55\vc11\x86\php-5.5.18\zend\zend_hash.c @ 716] > 09 0194f290 6bdba9dc php5!php_call_shutdown_functions+0x48 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\ext\standard\basic_functions.c @ 5088] > 0a 0194f5d0 01141443 php5!php_request_shutdown+0x6c > [c:\php-sdk\php55\vc11\x86\php-5.5.18\main\main.c @ 1746] > 0b 0194f764 0114420c php_cgi!main+0x443 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\sapi\cgi\cgi_main.c @ 2505] > 0c 0194f7a4 75f086e3 php_cgi!__tmainCRTStartup+0xfd > [f:\dd\vctools\crt_bld\self_x86\crt\src\crtexe.c @ 536] > 0d 0194f7b0 77b1be99 kernel32!BaseThreadInitThunk+0xe > [d:\win8_gdr\base\win32\client\thread.c @ 65] > 0e 0194f7f4 77b1be6c ntdll!__RtlUserThreadStart+0x72 > [d:\win8_gdr\minkernel\ntdll\rtlstrt.c @ 1024] > 0f 0194f80c 00000000 ntdll!_RtlUserThreadStart+0x1b > [d:\win8_gdr\minkernel\ntdll\rtlstrt.c @ 939] > 0:000> .frame 1 > 01 0194f044 6bda6ee6 php_opcache!zif_accel_chdir+0x67 > [c:\php-sdk\php55\vc11\x86\php-5.5.18\ext\opcache\zendaccelerator.c @ 158] > 0:000> dv > ht = 0n1 > return_value = 0x0cf8e670 > return_value_ptr = 0x00000000 > this_ptr = 0x00000000 > return_value_used = 0n0 > cwd = char [260] "D:\home\site\wwwroot" > 0:000> dt php_opcache!accel_globals > +0x000 function_table : _hashtable > +0x028 internal_functions_count : 0n1774 > +0x02c counted : 0n0 > +0x030 enabled : 0 '' > +0x031 locked : 0 '' > +0x034 bind_hash : _hashtable > +0x060 accel_directives : _zend_accel_directives > +0x0b0 cwd : 0x01e6e6d0 "--- memory read error at address > 0x01e6e6d0 ---" > +0x0b4 cwd_len : 0n20 > [end windbg output] > > Looks like accel_globals.cwd is pointing at free'd memory. > > I looked through the existing bugs on Opcache, and I didn't see any that > matched this crash. I wanted to check with the internals alias before I > opened the bug. > > This is 5.5.18 NTS x86. > > Thx! > --E. > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > >
