From: Nikita Popov <nikic@php.net>
Date: Sat, 18 Jan 2014 11:30:44 +0000 (+0100)
Subject: Fix argument unpacking across stack pages
X-Git-Tag: php-5.6.0alpha1~13
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=31a2ac470cba47a396a9b6c815700fbec51c6032;p=php

Fix argument unpacking across stack pages

If multiple unpacks were used (or mixed with normal arguments)
parts of the arguments could land on different stack pages. If
this occurs the arguments will now be copied to a new stack page.

The code used to do this is copied verbatim from the PHP 5.4 branch
and only modified to reduce the amount of inlined code.
---

diff --git a/Zend/tests/arg_unpack/many_args.phpt b/Zend/tests/arg_unpack/many_args.phpt
new file mode 100644
index 0000000000..0ef5a30d6d
--- /dev/null
+++ b/Zend/tests/arg_unpack/many_args.phpt
@@ -0,0 +1,15 @@
+--TEST--
+Argument unpacking with many arguments
+--FILE--
+<?php
+
+function fn(...$args) {
+    var_dump(count($args));
+}
+
+$array = array_fill(0, 10000, 42);
+fn(...$array, ...$array);
+
+?>
+--EXPECT--
+int(20000)
diff --git a/Zend/zend_execute.c b/Zend/zend_execute.c
index 174b165c7e..31caceecbe 100644
--- a/Zend/zend_execute.c
+++ b/Zend/zend_execute.c
@@ -1691,6 +1691,42 @@ static zend_always_inline zend_bool zend_is_by_ref_func_arg_fetch(zend_op *oplin
 }
 /* }}} */
 
+static void **zend_vm_stack_push_args_with_copy(int count TSRMLS_DC) /* {{{ */
+{
+	zend_vm_stack p = EG(argument_stack);
+
+	zend_vm_stack_extend(count + 1 TSRMLS_CC);
+
+	EG(argument_stack)->top += count;
+	*(EG(argument_stack)->top) = (void*)(zend_uintptr_t)count;
+	while (count-- > 0) {
+		void *data = *(--p->top);
+
+		if (UNEXPECTED(p->top == ZEND_VM_STACK_ELEMETS(p))) {
+			zend_vm_stack r = p;
+
+			EG(argument_stack)->prev = p->prev;
+			p = p->prev;
+			efree(r);
+		}
+		*(ZEND_VM_STACK_ELEMETS(EG(argument_stack)) + count) = data;
+	}
+	return EG(argument_stack)->top++;
+}
+/* }}} */
+
+static zend_always_inline void** zend_vm_stack_push_args(int count TSRMLS_DC) /* {{{ */
+{
+	if (UNEXPECTED(EG(argument_stack)->top - ZEND_VM_STACK_ELEMETS(EG(argument_stack)) < count)
+		|| UNEXPECTED(EG(argument_stack)->top == EG(argument_stack)->end)) {
+		return zend_vm_stack_push_args_with_copy(count TSRMLS_CC);
+	}
+	*(EG(argument_stack)->top) = (void*)(zend_uintptr_t)count;
+	return EG(argument_stack)->top++;
+}
+/* }}} */
+
+
 #define ZEND_VM_NEXT_OPCODE() \
 	CHECK_SYMBOL_TABLES() \
 	ZEND_VM_INC_OPCODE(); \
diff --git a/Zend/zend_vm_def.h b/Zend/zend_vm_def.h
index 37af82cef2..1e8a831551 100644
--- a/Zend/zend_vm_def.h
+++ b/Zend/zend_vm_def.h
@@ -1947,8 +1947,12 @@ ZEND_VM_HELPER(zend_do_fcall_common_helper, ANY, ANY)
 	}
 
 	num_args = opline->extended_value + EX(call)->num_additional_args;
-	EX(function_state).arguments = zend_vm_stack_top(TSRMLS_C);
-	zend_vm_stack_push((void*)(zend_uintptr_t) num_args TSRMLS_CC);
+	if (EX(call)->num_additional_args) {
+		EX(function_state).arguments = zend_vm_stack_push_args(num_args TSRMLS_CC);
+	} else {
+		EX(function_state).arguments = zend_vm_stack_top(TSRMLS_C);
+		zend_vm_stack_push((void*)(zend_uintptr_t) num_args TSRMLS_CC);
+	}
 	LOAD_OPLINE();
 
 	if (fbc->type == ZEND_INTERNAL_FUNCTION) {
diff --git a/Zend/zend_vm_execute.h b/Zend/zend_vm_execute.h
index 0651389f74..7e613cd6e8 100644
--- a/Zend/zend_vm_execute.h
+++ b/Zend/zend_vm_execute.h
@@ -527,8 +527,12 @@ static int ZEND_FASTCALL zend_do_fcall_common_helper_SPEC(ZEND_OPCODE_HANDLER_AR
 	}
 
 	num_args = opline->extended_value + EX(call)->num_additional_args;
-	EX(function_state).arguments = zend_vm_stack_top(TSRMLS_C);
-	zend_vm_stack_push((void*)(zend_uintptr_t) num_args TSRMLS_CC);
+	if (EX(call)->num_additional_args) {
+		EX(function_state).arguments = zend_vm_stack_push_args(num_args TSRMLS_CC);
+	} else {
+		EX(function_state).arguments = zend_vm_stack_top(TSRMLS_C);
+		zend_vm_stack_push((void*)(zend_uintptr_t) num_args TSRMLS_CC);
+	}
 	LOAD_OPLINE();
 
 	if (fbc->type == ZEND_INTERNAL_FUNCTION) {