Bug #73668 [Csd]: "SIGFPE Arithmetic exception" in opcache when divide by minus 1

Edit report at https://bugs.php.net/bug.php?id=73668&edit=1 ID: 73668 Updated by: nikic@php.net Reported by: richardh at channelgrabber dot com Summary: "SIGFPE Arithmetic exception" in opcache when divide by minus 1 Status: Closed Type: Bug Package: opcache Operating System: Ubuntu 14.04.1 LTS PHP Version: 7.1.0 -Assigned To: +Assigned To: nikic Block user comment: N Private report: N New Comment: That must be a record length reproduce script... Previous Comments: ------------------------------------------------------------------------ [2016-12-06 21:26:49] nikic@php.net Automatic comment on behalf of nikic Revision: http://git.php.net/?p=php-src.git;a=commit;h=76c4a3db080e347663a3999ae38b78cf26dd4c84 Log: Fix bug #73668 ------------------------------------------------------------------------ [2016-12-06 12:44:54] richardh at channelgrabber dot com Description: ------------ We recently switched to PHP 7.1.0 and noticed that when https://github.com/Setasign/FPDF/blob/master/fpdf.php was included it caused PHP to exit with SIGFPE. We installed the debug symbols and ran it through GDB a few times, reducing the issue down to lines 901 and 902 (https://github.com/Setasign/FPDF/blob/master/fpdf.php#L901). From this we created the reduced test case attached below. The backtrace from the error is: #0 0x00007ffff5b069a7 in zend_inference_calc_range (op_array=op_array@entry=0x7ffff6075008, ssa=ssa@entry=0x7ffff6097028, var=var@entry=1, widening=widening@entry=0, narrowing=narrowing@entry=1, tmp=tmp@entry=0x7fffffffa7f0) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/Optimizer/zend_inference.c:727 #1 0x00007ffff5b0c21f in zend_infer_ranges (op_array=op_array@entry=0x7ffff6075008, ssa=ssa@entry=0x7ffff6097028) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/Optimizer/zend_inference.c:1954 #2 0x00007ffff5b133f3 in zend_ssa_inference (arena=arena@entry=0x7fffffffa960, op_array=op_array@entry=0x7ffff6075008, script=0x7ffff6075000, ssa=ssa@entry=0x7ffff6097028) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/Optimizer/zend_inference.c:4181 #3 0x00007ffff5afb7f7 in zend_dfa_analyze_op_array (op_array=0x7ffff6075008, ctx=ctx@entry=0x7fffffffa960, ssa=0x7ffff6097028, flags=0x7ffff6097024) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/Optimizer/dfa_pass.c:106 #4 0x00007ffff5aef7e7 in zend_optimize_script (script=script@entry=0x7ffff6075000, optimization_level=2147467263, debug_level=0) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/Optimizer/zend_optimizer.c:967 #5 0x00007ffff5adf1c4 in cache_script_in_shared_memory (from_shared_memory=<synthetic pointer>, key_length=22, key=0x7ffff5d2e6cc <accel_globals+556> "test.php:223344:223384", new_persistent_script=0x7ffff6075000) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/ZendAccelerator.c:1271 #6 persistent_compile_file (file_handle=<optimized out>, type=8) at /build/php7.1-kMIlXM/php7.1-7.1.0/ext/opcache/ZendAccelerator.c:1863 #7 0x00007ffff589ff9d in xdebug_compile_file (file_handle=<optimized out>, type=<optimized out>) at /build/xdebug-_hXbf9/xdebug-2.5.0/build-7.1/xdebug.c:2153 #8 0x00005555557b469d in zend_execute_scripts () #9 0x0000555555754b18 in php_execute_script () #10 0x000055555584e1c9 in ?? () #11 0x000055555563d92f in main () Test script: --------------- <?php $a/-1; ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=73668&edit=1