RE: [PHP-DEV] PHP7 Zend Heap validation

Hi thanks for answers, Initially , I first checked for leaks when USE_ZEND_ALLOC=1 , and I have found some leaks I cleared them however still was crashing due to corruption. (p->next_free_slot not readable during an emalloc ) As advised, I also checked things with USE_ZEND_ALLOC=0 , here things got weird as now it is also crashes at this point with a different call stack. ( zend_assign_to_variable ) For USE_ZEND_ALLOC=0 case, I called _CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF | _CRTDBG_CHECK_ALWAYS_DF ) in php_cli.c main function . CRT didn`t report anything in this case. From: Pierre Joye [mailto:pierre.php@gmail.com] Sent: 26 December 2015 07:07 To: Laruence Cc: Ocal, Akin; PHP internals Subject: Re: [PHP-DEV] PHP7 Zend Heap validation On Dec 26, 2015 12:30 PM, "Xinchen Hui" <laruence@php.net<mailto:laruence@php.net>> wrote: > > Hey: > > On Sat, Dec 26, 2015 at 1:01 PM, > <akin.ocal@thomsonreuters.com<mailto:akin.ocal@thomsonreuters.com>> > wrote: > > > Hi everyone, > > > > I am working on porting a pre-PHP7 database driver extension to PHP7 for > > Windows platforms. > > ( I am using PHP 7.0.1 master branch code and targeting non-ZTS 32 bit > > PHP7 on Windows Server 2012 R2 ) > > And currently as I did mechanical bits of porting ( compilation issues, > > getting functionality working > > mostly followed > > https://wiki.php.net/phpng-upgrading<https://urldefense.proofpoint.com/v2/url?u=https-3A__wiki.php.net_phpng-2Dupgrading&d=AwMFaQ&c=4ZIZThykDLcoWk-GVjSLm9hvvvzvGv0FLoWSRuCSs5Q&r=WNZrBw1Z15H_TIydi6wrAnQBZ6J3iZSKUpRWgdkYc54&m=8fmgrfX7MfZRLEX6JNcuqL0Dx-z5YQ1mOw_jjdclIAg&s=ic30D9tCrQWw3yQXhqDXBYyZGtG8pS_EyHVNRFAkwsI&e=> > > ) , my extension is > > only crash-free if I run it with > > USE_ZEND_ALLOC=0. > > > > However with USE_ZEND_ALLOC=1 , I am getting crashes inside > > zend_mm_alloc_small. As checked with Windbg : > > ... > > if (EXPECTED(heap->free_slot[bin_num] != NULL) ) > > { > > zend_mm_free_slot *p = > > heap->free_slot[bin_num]; > > if ( p->next_free_slot != NULL ) > > > > Above , p->next_free_slot is not readable. I believe , currently I am > > getting the Zend heap corrupt. > > I am running a test script and I tried disabling many things ,and > > enabling one by one to have an idea, from the looks of it , I am getting > > this issue > > around a zend_register_resource call but to me that one looks legitimate > > so I can`t easily pinpoint where the Zend heap gets corrupt. > > > > Diffrently from pre-PHP7 where we had full_mem_check , now I can see > > ZEND_MM_CHECK is placed in memory manager functions. > > > > I wanted to ask if there is any chance if we can have a heap integrity > > checker function , or what would you advise > > regarding to track down the places in our code corrupting the Zend MM ? > > > I am not familar with windows, but if it can be run in linux > > you could try with "USE_ZEND_ALLOC=0 valgrind --tool=memcheck " > > not sure if there is similar tool on windows > > > thanks > On windows you can use a couple of tools to try to find them: - http://www.softwareverify.com/<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.softwareverify.com_&d=AwMFaQ&c=4ZIZThykDLcoWk-GVjSLm9hvvvzvGv0FLoWSRuCSs5Q&r=WNZrBw1Z15H_TIydi6wrAnQBZ6J3iZSKUpRWgdkYc54&m=8fmgrfX7MfZRLEX6JNcuqL0Dx-z5YQ1mOw_jjdclIAg&s=Bo1i7yRldERDK_blhtnvasYKfauEXCgNzUyX9dN-B5o&e=> (commercial) - the debugger tools (the standalone tools) contain some limited valgrind like features - not directly related but adding --with-static-analyzer=vs is quite useful too. Latest version is Very effective Cheers,