Make exit() unwind properly (minimal version)

Zend/tests/exit_exception_handler.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Exception handler should not be invoked for exit()
+--FILE--
+<?php
+
+set_exception_handler(function($e) {
+    var_dump($e);
+});
+
+exit("Exit\n");
+
+?>
+--EXPECT--
+Exit

Zend/tests/exit_finally_1.phpt

@@ -0,0 +1,19 @@
+--TEST--
+exit() and finally (1)
+--FILE--
+<?php
+
+// TODO: In the future, we should execute the finally block.
+
+try {
+    exit("Exit\n");
+} catch (Throwable $e) {
+    echo "Not caught\n";
+} finally {
+    echo "Finally\n";
+}
+echo "Not executed\n";
+
+?>
+--EXPECT--
+Exit

Zend/tests/exit_finally_2.phpt

@@ -0,0 +1,23 @@
+--TEST--
+exit() and finally (2)
+--FILE--
+<?php
+
+// TODO: In the future, we should execute the finally block.
+
+try {
+    try {
+        exit("Exit\n");
+    } catch (Throwable $e) {
+        echo "Not caught\n";
+    } finally {
+        throw new Exception("Finally exception");
+    }
+    echo "Not executed\n";
+} catch (Exception $e) {
+    echo "Caught {$e->getMessage()}\n";
+}
+
+?>
+--EXPECT--
+Exit

Zend/tests/exit_finally_3.phpt

@@ -0,0 +1,19 @@
+--TEST--
+exit() and finally (3)
+--FILE--
+<?php
+
+// TODO: In the future, we should execute the finally block.
+
+function test() {
+    try {
+        exit("Exit\n");
+    } finally {
+        return 42;
+    }
+}
+var_dump(test());
+
+?>
+--EXPECT--
+Exit

Zend/zend.c

@@ -1621,6 +1621,11 @@ ZEND_API ZEND_COLD void zend_user_exception_handler(void) /* {{{ */
 	zval orig_user_exception_handler;
 	zval params[1], retval2;
 	zend_object *old_exception;
+
+	if (zend_is_unwind_exit(EG(exception))) {
+		return;
+	}
+
 	old_exception = EG(exception);
 	EG(exception) = NULL;
 	ZVAL_OBJ(&params[0], old_exception);
@@ -1666,8 +1671,7 @@ ZEND_API int zend_execute_scripts(int type, zval *retval, int file_count, ...) /
 					zend_user_exception_handler();
 				}
 				if (EG(exception)) {
-					zend_exception_error(EG(exception), E_ERROR);
-					ret = FAILURE;
+					ret = zend_exception_error(EG(exception), E_ERROR);
 				}
 			}
 			destroy_op_array(op_array);

Zend/zend_exceptions.c

@@ -41,6 +41,9 @@ ZEND_API zend_class_entry *zend_ce_value_error;
 ZEND_API zend_class_entry *zend_ce_arithmetic_error;
 ZEND_API zend_class_entry *zend_ce_division_by_zero_error;
 
+/* Internal pseudo-exception that is not exposed to userland. */
+static zend_class_entry zend_ce_unwind_exit;
+
 ZEND_API void (*zend_throw_exception_hook)(zval *ex);
 
 static zend_object_handlers default_exception_handlers;
@@ -81,6 +84,12 @@ void zend_exception_set_previous(zend_object *exception, zend_object *add_previo
 	if (exception == add_previous || !add_previous || !exception) {
 		return;
 	}
+
+	if (zend_is_unwind_exit(add_previous)) {
+		OBJ_RELEASE(add_previous);
+		return;
+	}
+
 	ZVAL_OBJ(&pv, add_previous);
 	if (!instanceof_function(Z_OBJCE(pv), zend_ce_throwable)) {
 		zend_error_noreturn(E_CORE_ERROR, "Previous exception must implement Throwable");
@@ -803,6 +812,8 @@ void zend_register_default_exception(void) /* {{{ */
 	INIT_CLASS_ENTRY(ce, "DivisionByZeroError", class_DivisionByZeroError_methods);
 	zend_ce_division_by_zero_error = zend_register_internal_class_ex(&ce, zend_ce_arithmetic_error);
 	zend_ce_division_by_zero_error->create_object = zend_default_exception_new;
+
+	INIT_CLASS_ENTRY(zend_ce_unwind_exit, "UnwindExit", NULL);
 }
 /* }}} */
 
@@ -898,10 +909,11 @@ static void zend_error_va(int type, const char *file, uint32_t lineno, const cha
 /* }}} */
 
 /* This function doesn't return if it uses E_ERROR */
-ZEND_API ZEND_COLD void zend_exception_error(zend_object *ex, int severity) /* {{{ */
+ZEND_API ZEND_COLD int zend_exception_error(zend_object *ex, int severity) /* {{{ */
 {
 	zval exception, rv;
 	zend_class_entry *ce_exception;
+	int result = FAILURE;
 
 	ZVAL_OBJ(&exception, ex);
 	ce_exception = ex->ce;
@@ -961,11 +973,15 @@ ZEND_API ZEND_COLD void zend_exception_error(zend_object *ex, int severity) /* {
 
 		zend_string_release_ex(str, 0);
 		zend_string_release_ex(file, 0);
+	} else if (ce_exception == &zend_ce_unwind_exit) {
+		/* We successfully unwound, nothing more to do */
+		result = SUCCESS;
 	} else {
 		zend_error(severity, "Uncaught exception '%s'", ZSTR_VAL(ce_exception->name));
 	}
 
 	OBJ_RELEASE(ex);
+	return result;
 }
 /* }}} */
 
@@ -987,3 +1003,16 @@ ZEND_API ZEND_COLD void zend_throw_exception_object(zval *exception) /* {{{ */
 	zend_throw_exception_internal(exception);
 }
 /* }}} */
+
+ZEND_API ZEND_COLD void zend_throw_unwind_exit()
+{
+	ZEND_ASSERT(!EG(exception));
+	EG(exception) = zend_objects_new(&zend_ce_unwind_exit);
+	EG(opline_before_exception) = EG(current_execute_data)->opline;
+	EG(current_execute_data)->opline = EG(exception_op);
+}
+
+ZEND_API zend_bool zend_is_unwind_exit(zend_object *ex)
+{
+	return ex->ce == &zend_ce_unwind_exit;
+}

Zend/zend_exceptions.h

@@ -66,7 +66,10 @@ ZEND_API zend_object *zend_throw_error_exception(zend_class_entry *exception_ce,
 extern ZEND_API void (*zend_throw_exception_hook)(zval *ex);
 
 /* show an exception using zend_error(severity,...), severity should be E_ERROR */
-ZEND_API ZEND_COLD void zend_exception_error(zend_object *exception, int severity);
+ZEND_API ZEND_COLD int zend_exception_error(zend_object *exception, int severity);
+
+ZEND_API ZEND_COLD void zend_throw_unwind_exit(void);
+ZEND_API zend_bool zend_is_unwind_exit(zend_object *ex);
 
 #include "zend_globals.h"
 

Zend/zend_execute_API.c

@@ -1141,8 +1141,7 @@ ZEND_API int zend_eval_stringl_ex(const char *str, size_t str_len, zval *retval_
 
 	result = zend_eval_stringl(str, str_len, retval_ptr, string_name);
 	if (handle_exceptions && EG(exception)) {
-		zend_exception_error(EG(exception), E_ERROR);
-		result = FAILURE;
+		result = zend_exception_error(EG(exception), E_ERROR);
 	}
 	return result;
 }

Zend/zend_vm_def.h

@@ -6893,8 +6893,8 @@ ZEND_VM_COLD_HANDLER(79, ZEND_EXIT, ANY, ANY)
 		} while (0);
 		FREE_OP1();
 	}
-	zend_bailout();
-	ZEND_VM_NEXT_OPCODE(); /* Never reached */
+	zend_throw_unwind_exit();
+	HANDLE_EXCEPTION();
 }
 
 ZEND_VM_HANDLER(57, ZEND_BEGIN_SILENCE, ANY, ANY)
@@ -7271,7 +7271,7 @@ ZEND_VM_HELPER(zend_dispatch_try_catch_finally_helper, ANY, ANY, uint32_t try_ca
 	zend_object *ex = EG(exception);
 
 	/* Walk try/catch/finally structures upwards, performing the necessary actions */
-	while (try_catch_offset != (uint32_t) -1) {
+	for (; try_catch_offset != (uint32_t) -1; try_catch_offset--) {
 		zend_try_catch_element *try_catch =
 			&EX(func)->op_array.try_catch_array[try_catch_offset];
 
@@ -7281,6 +7281,11 @@ ZEND_VM_HELPER(zend_dispatch_try_catch_finally_helper, ANY, ANY, uint32_t try_ca
 			ZEND_VM_JMP_EX(&EX(func)->op_array.opcodes[try_catch->catch_op], 0);
 
 		} else if (op_num < try_catch->finally_op) {
+			if (ex && zend_is_unwind_exit(ex)) {
+				/* Don't execute finally blocks on exit (for now) */
+				continue;
+			}
+
 			/* Go to finally block */
 			zval *fast_call = EX_VAR(EX(func)->op_array.opcodes[try_catch->finally_end].op1.var);
 			cleanup_live_vars(execute_data, op_num, try_catch->finally_op);
@@ -7310,8 +7315,6 @@ ZEND_VM_HELPER(zend_dispatch_try_catch_finally_helper, ANY, ANY, uint32_t try_ca
 				ex = Z_OBJ_P(fast_call);
 			}
 		}
-
-		try_catch_offset--;
 	}
 
 	/* Uncaught exception */

Zend/zend_vm_execute.h

@@ -2322,8 +2322,8 @@ static ZEND_VM_COLD ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_EXIT_SPEC_HANDLER
 		} while (0);
 		FREE_OP(opline->op1_type, opline->op1.var);
 	}
-	zend_bailout();
-	ZEND_VM_NEXT_OPCODE(); /* Never reached */
+	zend_throw_unwind_exit();
+	HANDLE_EXCEPTION();
 }
 
 static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_BEGIN_SILENCE_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
@@ -2476,9 +2476,10 @@ static zend_never_inline ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_dispatch_try
 {
 	/* May be NULL during generator closing (only finally blocks are executed) */
 	zend_object *ex = EG(exception);
+	zend_bool is_unwind_exit = ex && zend_is_unwind_exit(ex);
 
 	/* Walk try/catch/finally structures upwards, performing the necessary actions */
-	while (try_catch_offset != (uint32_t) -1) {
+	for (; try_catch_offset != (uint32_t) -1; try_catch_offset--) {
 		zend_try_catch_element *try_catch =
 			&EX(func)->op_array.try_catch_array[try_catch_offset];
 
@@ -2488,6 +2489,11 @@ static zend_never_inline ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_dispatch_try
 			ZEND_VM_JMP_EX(&EX(func)->op_array.opcodes[try_catch->catch_op], 0);
 
 		} else if (op_num < try_catch->finally_op) {
+			if (is_unwind_exit) {
+				/* Don't execute finally blocks on exit (for now) */
+				continue;
+			}
+
 			/* Go to finally block */
 			zval *fast_call = EX_VAR(EX(func)->op_array.opcodes[try_catch->finally_end].op1.var);
 			cleanup_live_vars(execute_data, op_num, try_catch->finally_op);
@@ -2517,8 +2523,6 @@ static zend_never_inline ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_dispatch_try
 				ex = Z_OBJ_P(fast_call);
 			}
 		}
-
-		try_catch_offset--;
 	}
 
 	/* Uncaught exception */

ext/curl/tests/bug68937.phpt

@@ -3,7 +3,6 @@ Bug # #68937 (Segfault in curl_multi_exec)
 --SKIPIF--
 <?php
 include 'skipif.inc';
-if (getenv('SKIP_ASAN')) die('skip some curl versions leak on longjmp');
 ?>
 --FILE--
 <?php

ext/curl/tests/bug68937_2.phpt

@@ -3,7 +3,6 @@ Bug # #68937 (Segfault in curl_multi_exec)
 --SKIPIF--
 <?php
 include 'skipif.inc';
-if (getenv('SKIP_ASAN')) die('skip some curl versions leak on longjmp');
 ?>
 --FILE--
 <?php

ext/opcache/ZendAccelerator.c

@@ -4484,9 +4484,10 @@ static int accel_preload(const char *config)
 					zend_user_exception_handler();
 				}
 				if (EG(exception)) {
-					zend_exception_error(EG(exception), E_ERROR);
-					CG(unclean_shutdown) = 1;
-					ret = FAILURE;
+					ret = zend_exception_error(EG(exception), E_ERROR);
+					if (ret == FAILURE) {
+						CG(unclean_shutdown) = 1;
+					}
 				}
 			}
 			destroy_op_array(op_array);

ext/session/tests/bug60634.phpt

@@ -40,20 +40,6 @@ session_start();
 session_write_close();
 echo "um, hi\n";
 
-/*
- * write() calls die(). This results in calling session_flush() which calls
- * write() in request shutdown. The code is inside save handler still and
- * calls save close handler.
- *
- * Because session_write_close() fails by die(), write() is called twice.
- * close() is still called at request shutdown since session is active.
- */
-
 ?>
 --EXPECT--
 write: goodbye cruel world
-
-Warning: Unknown: Cannot call session save handler in a recursive manner in Unknown on line 0
-
-Warning: Unknown: Failed to write session data using user defined save handler. (session.save_path: ) in Unknown on line 0
-close: goodbye cruel world

ext/soap/soap.c

@@ -1382,8 +1382,10 @@ PHP_METHOD(SoapServer, handle)
 	xmlFreeDoc(doc_request);
 
 	if (EG(exception)) {
-		php_output_discard();
-		_soap_server_exception(service, function, ZEND_THIS);
+		if (!zend_is_unwind_exit(EG(exception))) {
+			php_output_discard();
+			_soap_server_exception(service, function, ZEND_THIS);
+		}
 		goto fail;
 	}
 
@@ -1576,15 +1578,17 @@ PHP_METHOD(SoapServer, handle)
 	efree(fn_name);
 
 	if (EG(exception)) {
-		php_output_discard();
-		_soap_server_exception(service, function, ZEND_THIS);
-		if (service->type == SOAP_CLASS) {
+		if (!zend_is_unwind_exit(EG(exception))) {
+			php_output_discard();
+			_soap_server_exception(service, function, ZEND_THIS);
+			if (service->type == SOAP_CLASS) {
 #if defined(HAVE_PHP_SESSION) && !defined(COMPILE_DL_SESSION)
-			if (soap_obj && service->soap_class.persistence != SOAP_PERSISTENCE_SESSION) {
+				if (soap_obj && service->soap_class.persistence != SOAP_PERSISTENCE_SESSION) {
 #else
-			if (soap_obj) {
+				if (soap_obj) {
 #endif
-				zval_ptr_dtor(soap_obj);
+					zval_ptr_dtor(soap_obj);
+				}
 			}
 		}
 		goto fail;

ext/xsl/tests/bug33853.phpt

@@ -3,7 +3,6 @@ Bug #33853 (php:function call __autoload with lowercase param)
 --SKIPIF--
 <?php
 if (!extension_loaded('xsl')) die('skip xsl not loaded');
-if (getenv('SKIP_ASAN')) die('xfail bailing out across foreign C code');
 ?>
 --FILE--
 <?php

sapi/phpdbg/phpdbg_prompt.c

@@ -1711,6 +1711,11 @@ void phpdbg_execute_ex(zend_execute_data *execute_data) /* {{{ */
 		}
 #endif
 
+		if (exception && zend_is_unwind_exit(exception)) {
+			/* Restore bailout based exit. */
+			zend_bailout();
+		}
+
 		if (PHPDBG_G(flags) & PHPDBG_PREVENT_INTERACTIVE) {
 			phpdbg_print_opline_ex(execute_data, 0);
 			goto next;