Home Original page

Exception not properly caught when opcache enabled

Bug #65665 Exception not properly caught when opcache enabled
Submitted: 2013-09-13 00:15 UTC Modified: 2013-09-15 06:06 UTC
From: ryan dot brothers at gmail dot com Assigned: dmitry (profile)
Status: Closed Package: opcache
PHP Version: 5.5.3 OS: Linux
Private report: No CVE-ID: None

 [2013-09-13 00:15 UTC] ryan dot brothers at gmail dot com

Description:
------------
When running the following script with opcache enabled, the exception is not caught by the correct catch block.  The exception should be caught by the 'caught by 1' block, but it is instead caught by the 'caught by 2' block.  Disabling opcache causes the exception to be caught in the correct block.

Run the script with:

php -n -d zend_extension=opcache.so -d opcache.enable_cli=1 script.php


Test script:
---------------
<?php
try
{
    switch (1)
    {
        case 0:
            try
            {

            }
            catch (Exception $e)
            {

            }

            break;

        case 1:
            try
            {
                throw new Exception('aaa');
            }
            catch (Exception $e)
            {
                echo 'caught by 1';
                exit;
            }

            break;
    }
}
catch (Exception $e)
{
    echo 'caught by 2';
    exit;
}


Expected result:
----------------
caught by 1

Actual result:
--------------
caught by 2

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports

 [2013-09-13 15:31 UTC] jpauli@php.net

This is an optimizer bug.
If you run with opcache.optimization_level=0 , the bug disappears.

I guess the bug is in the optimizer pass that handles ZEND_CATCH.
PS : I reproduced with a 5.4 base.

 [2013-09-13 17:16 UTC] Danack at basereality dot com

Running with -d opcache.optimization_level=0xfffffffd shows the correct behaviour. 
That flag is the equivalent to turning on all optimizations except:

'ZEND_OPTIMIZER_PASS_2' /* Constant conversion and jumps */

 [2013-09-14 06:58 UTC] krakjoe@php.net

Assuming we are just going to disable unsafe optimizations, PR #450 should do it 
???

 [2013-09-15 06:06 UTC] laruence@php.net

Hey:
   I got a different fix:

$ git diff
diff --git a/Optimizer/block_pass.c b/Optimizer/block_pass.c
index b8c3814..fd76322 100644
--- a/Optimizer/block_pass.c
+++ b/Optimizer/block_pass.c
@@ -1278,8 +1278,17 @@ static void assemble_code_blocks(zend_cfg *cfg, 
zend_op_array *op_array)
 	if (op_array->last_try_catch) {
 		int i;
 		for (i = 0; i< op_array->last_try_catch; i++) {
-			op_array->try_catch_array[i].try_op = cfg->try[i]-
>start_opline - new_opcodes;
-			op_array->try_catch_array[i].catch_op = cfg->catch[i]-
>start_opline - new_opcodes;
+			if (cfg->try[i]->access) {
+				op_array->try_catch_array[i].try_op = cfg->try[i]-
>start_opline - new_opcodes;
+			} else {
+				op_array->try_catch_array[i].try_op = 0;
+			}
+
+			if (cfg->catch[i]->access) {
+				op_array->try_catch_array[i].catch_op = cfg-
>catch[i]->start_opline - new_opcodes;
+			} else {
+				op_array->try_catch_array[i].catch_op = 0;
+			}
 		}
 		efree(cfg->try);
 		efree(cfg->catch);


dmitry, could you please verify this?

thanks