Bug #71804 [Opn]: proc_close does not return exit code

Edit report at https://bugs.php.net/bug.php?id=71804&edit=1 ID: 71804 User updated by: mark at mpen dot ca Reported by: mark at mpen dot ca Summary: proc_close does not return exit code Status: Open Type: Bug Package: Program Execution Operating System: Ubuntu 14.10 PHP Version: 7.0.4 Block user comment: N Private report: N New Comment: Thank you for investigating, disabling sigchild fixed it for me. I don't *think* I need sigchild anymore (I'm not entirely sure what it does), so this should be fine for me, but something should probably be done about this to warn others because it looks like a breaking change. Previous Comments: ------------------------------------------------------------------------ [2016-03-20 05:43:01] as@php.net In the PHP 7 trace, I noticed that the parent process is setting a signal handler for SIGCHLD. (Search for "rt_sigaction(SIGCHLD".) Searching backwards from there, I was able to reproduce the bug by recompiling with --enable-sigchild (already present in your binary). This switch is from 15+ years ago (commit 674f4bac) and causes PHP to reap all child processes asynchronously: https://github.com/php/php-src/blob/PHP-7.0.4/main/main.c#L1515-L1523 proc_close also attempts to reap the child process here: https://github.com/php/php-src/blob/PHP-7.0.4/ext/standard/proc_open.c#L228 but at that point it has already been reaped by sigchld_handler so waitpid returns -1. The only way I can think of fixing this is to keep track of exit statuses in sigchld_handler and check that in proc_close if PHP_SIGCHILD is defined. Very ugly. Alternatively we might be able to deprecate --enable-sigchild. For your specific case, you likely do not need --enable-sigchild, and recompiling without it should fix your issue. ------------------------------------------------------------------------ [2016-03-17 16:12:46] mark at mpen dot ca Not sure how to attach files; it wouldn't let me submit them as patches. I've uploaded them to pastebin: - PHP 5.6 strace: http://pastebin.com/SNuJGAZW - PHp 7.0.4 strace: http://pastebin.com/akrFjzpT ------------------------------------------------------------------------ [2016-03-15 04:22:56] as@php.net Having trouble reproducing. Can you attach strace output for 5.6 and 7? Invoke like: $ strace -ttt -T -f -s1024 -o strace.log php test.php Thanks. ------------------------------------------------------------------------ [2016-03-11 19:00:30] mark at mpen dot ca Description: ------------ proc_close always return exit code -1 on PHP 7 when it should be 0 (as it does on PHP 5.6). $ php7 --version PHP 7.0.4 (cli) (built: Mar 11 2016 10:54:16) ( NTS ) Copyright (c) 1997-2016 The PHP Group Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies Compiled with: ./configure --with-openssl --with-layout=GNU --with-pear --enable-ftp --with-mysqli=mysqlnd --with-pdo-mysql=mysqlnd --enable-session --enable-libxml --enable-xml --with-zlib=yes --enable-mbstring=all --with-gettext --with-pspell --with-gd --enable-gd-native-ttf --with-freetype-dir=/usr/local/lib/ --with-jpeg-dir=/usr/local/lib/ --enable-sockets --enable-pcntl --enable-sigchild --with-mcrypt=/usr/local/lib --enable-posix --enable-dom --enable-simplexml --with-readline --enable-bcmath Test script: --------------- <?php $proc = proc_open("pwd",[1=>['pipe','w']], $pipes); var_dump(stream_get_contents($pipes[1])); fclose($pipes[1]); var_dump(proc_close($proc)); Expected result: ---------------- Exit code 0 Actual result: -------------- Exit code -1 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=71804&edit=1