Re: SegFault 11 on 5.5.6 on function return

On Mon, 2013-12-09 at 11:25 -0600, Ralph Schindler wrote: > Hi all, > > We started noticing Segfaults in Travis when PHP was upgraded to 5.5.6. > I've tested this particular issue on both linux and mac and can > produce the segfault in both place. > > Looking at the backtrace (provided), can anyone offer assistance as to > what changed between 5.5.5 and 5.5.6 that might be causing this? > > I've been able to isolate the last line of PHP code that executes before > the segfault: > > > > https://github.com/sebastianbergmann/phpunit/blob/3.7/PHPUnit/Util/Type.php#L203 > > I know the value of $value there to be null when this SegFault occurs. > > Also, the backtrace seems to hint at a problem in the garbage collector > since the source of the issue emanates from gc_remove_from_buffer(). > > My guesses... > > Is it possible that either the garbage collector is running and > destroying the stack, and that when unwinding the stack frames it is in > an inconsistent state and/or the return value for that particular > function is not placed on the stack so that the stack is in the proper > context when the return is processed? > > I can do additional research if anyone would like to point me in the > right direction, or I can provide access to a VM where this particular > backtrace was produced from. > > Thanks in advance. > -ralph RETVAL_ZVAL_FAST comes to mind.... Nikita, Dmitry? -- Regards, Mike