Limit stack size (#9104)

Zend/zend_call_stack.h

@@ -0,0 +1,91 @@
+/*
+   +----------------------------------------------------------------------+
+   | Zend Engine                                                          |
+   +----------------------------------------------------------------------+
+   | Copyright (c) Zend Technologies Ltd. (http://www.zend.com)           |
+   +----------------------------------------------------------------------+
+   | This source file is subject to version 2.00 of the Zend license,     |
+   | that is bundled with this package in the file LICENSE, and is        |
+   | available through the world-wide-web at the following url:           |
+   | http://www.zend.com/license/2_00.txt.                                |
+   | If you did not receive a copy of the Zend license and are unable to  |
+   | obtain it through the world-wide-web, please send a note to          |
+   | license@zend.com so we can mail you a copy immediately.              |
+   +----------------------------------------------------------------------+
+   | Authors: Arnaud Le Blanc <arnaud.lb@gmail.com>                       |
+   +----------------------------------------------------------------------+
+*/
+
+#ifndef ZEND_CALL_STACK_H
+#define ZEND_CALL_STACK_H
+
+#include "zend.h"
+#include "zend_portability.h"
+#ifdef __APPLE__
+# include <pthread.h>
+#endif
+
+#ifdef ZEND_CHECK_STACK_LIMIT
+
+typedef struct _zend_call_stack {
+	void *base;
+	size_t max_size;
+} zend_call_stack;
+
+ZEND_API void zend_call_stack_init(void);
+
+ZEND_API bool zend_call_stack_get(zend_call_stack *stack);
+
+/** Returns an approximation of the current stack position */
+static zend_always_inline void *zend_call_stack_position(void) {
+#ifdef ZEND_WIN32
+	return _AddressOfReturnAddress();
+#elif HAVE_BUILTIN_FRAME_ADDRESS
+	return __builtin_frame_address(0);
+#else
+	void *a;
+	void *pos = (void*)&a;
+	return pos;
+#endif
+}
+
+static zend_always_inline bool zend_call_stack_overflowed(void *stack_limit) {
+	return (uintptr_t) zend_call_stack_position() <= (uintptr_t) stack_limit;
+}
+
+static inline void* zend_call_stack_limit(void *base, size_t size, size_t reserved_size)
+{
+	if (UNEXPECTED(size > (uintptr_t)base)) {
+		return (void*)0;
+	}
+
+	base = (int8_t*)base - size;
+
+	if (UNEXPECTED(UINTPTR_MAX - (uintptr_t)base < reserved_size)) {
+		return (void*)UINTPTR_MAX;
+	}
+
+	return (int8_t*)base + reserved_size;
+}
+
+static inline size_t zend_call_stack_default_size(void)
+{
+#ifdef __linux__
+	return 8 * 1024 * 1024;
+#endif
+#ifdef __FreeBSD__
+	return 8 * 1024 * 1024;
+#endif
+#ifdef __APPLE__
+	// https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Multithreading/CreatingThreads/CreatingThreads.html
+	if (pthread_main_np()) {
+		return 8 * 1024 * 1024;
+	}
+	return 512 * 1024;
+#endif
+
+	return 2 * 1024 * 1024;
+}
+
+#endif /* ZEND_CHECK_STACK_LIMIT */
+#endif /* ZEND_CALL_STACK_H */