Limit stack usage

php · Sep 16, 2022 · b669a8a · b669a8a
1 parent 17b0e49
commit b669a8a
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Showing 32 changed files with 1,501 additions and 13 deletions.
diff --git a/Zend/Zend.m4 b/Zend/Zend.m4
@@ -146,7 +146,56 @@ _LT_AC_TRY_DLOPEN_SELF([
 ])
 
 dnl Checks for library functions.
-AC_CHECK_FUNCS(getpid kill sigsetjmp)
+AC_CHECK_FUNCS(getpid kill sigsetjmp pthread_getattr_np pthread_attr_get_np pthread_get_stackaddr_np pthread_attr_getstack pthread_attr_getstacksize pthread_attr_getstackaddr)
+
+dnl Test whether the target system has __libc_stack_end
+AC_MSG_CHECKING(whether libc has __libc_stack_end)
+
+AC_RUN_IFELSE([AC_LANG_SOURCE([[
+extern void* __libc_stack_end;
+int main()
+{
+  void *test = __libc_stack_end;
+  return 0;
+}
+]])], [
+  AC_DEFINE([HAVE_LIBC_STACK_END], 1, [Define if the target system has __libc_stack_end])
+  AC_MSG_RESULT(yes)
+], [
+  AC_MSG_RESULT(no)
+], [
+  AC_MSG_RESULT(no)
+])
+
+dnl Test whether the stack grows downwards
+dnl Assumes contiguous stack
+AC_MSG_CHECKING(whether the stack grows downwards)
+
+AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#include <stdint.h>
+
+int (*volatile f)(uintptr_t);
+
+int stack_grows_downwards(uintptr_t arg) {
+    int local;
+    return (uintptr_t)&local < arg;
+}
+
+int main() {
+    int local;
+
+    f = stack_grows_downwards;
+    return f((uintptr_t)&local) ? 0 : 1;
+}
+]])], [
+  AC_DEFINE([ZEND_STACK_GROWS_DOWNWARDS], 1, [Define if the stack grows downwards])
+  AC_DEFINE([ZEND_CHECK_STACK_LIMIT], 1, [Define if checking the stack limit is supported])
+  AC_MSG_RESULT(yes)
+], [
+  AC_MSG_RESULT(no)
+], [
+  AC_MSG_RESULT(no)
+])
 
 ZEND_CHECK_FLOAT_PRECISION
 ])

diff --git a/Zend/tests/stack_limit_001.phpt b/Zend/tests/stack_limit_001.phpt
@@ -0,0 +1,63 @@
+--TEST--
+Stack limit 001 - Stack limit checks with max_allowed_stack_size detection
+--EXTENSIONS--
+zend_test
+--INI--
+; TODO
+memory_limit=2G
+--FILE--
+<?php
+
+var_dump(zend_test_zend_call_stack_get());
+
+class Test1 {
+    public function __destruct() {
+        new Test1;
+    }
+}
+
+class Test2 {
+    public function __clone() {
+        clone $this;
+    }
+}
+
+function replace() {
+    return preg_replace_callback('#.#', function () {
+        return replace();
+    }, 'x');
+}
+
+try {
+    new Test1;
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    clone new Test2;
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    replace();
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECTF--
+array(4) {
+  ["base"]=>
+  string(%d) "0x%x"
+  ["max_size"]=>
+  string(%d) "0x%x"
+  ["position"]=>
+  string(%d) "0x%x"
+  ["EG(stack_limit)"]=>
+  string(%d) "0x%x"
+}
+Maximum call stack size reached. Infinite recursion?
+Maximum call stack size reached. Infinite recursion?
+Maximum call stack size reached. Infinite recursion?
diff --git a/Zend/tests/stack_limit_002.phpt b/Zend/tests/stack_limit_002.phpt
@@ -0,0 +1,64 @@
+--TEST--
+Stack limit 002 - Stack limit checks with max_allowed_stack_size detection (fibers)
+--EXTENSIONS--
+zend_test
+--FILE--
+<?php
+
+var_dump(zend_test_zend_call_stack_get());
+
+class Test1 {
+    public function __destruct() {
+        new Test1;
+    }
+}
+
+class Test2 {
+    public function __clone() {
+        clone $this;
+    }
+}
+
+function replace() {
+    return preg_replace_callback('#.#', function () {
+        return replace();
+    }, 'x');
+}
+
+$fiber = new Fiber(function (): void {
+    try {
+        new Test1;
+    } catch (Error $e) {
+        echo $e->getMessage(), "\n";
+    }
+
+    try {
+        clone new Test2;
+    } catch (Error $e) {
+        echo $e->getMessage(), "\n";
+    }
+
+    try {
+        replace();
+    } catch (Error $e) {
+        echo $e->getMessage(), "\n";
+    }
+});
+
+$fiber->start();
+
+?>
+--EXPECTF--
+array(4) {
+  ["base"]=>
+  string(%d) "0x%x"
+  ["max_size"]=>
+  string(%d) "0x%x"
+  ["position"]=>
+  string(%d) "0x%x"
+  ["EG(stack_limit)"]=>
+  string(%d) "0x%x"
+}
+Maximum call stack size reached. Infinite recursion?
+Maximum call stack size reached. Infinite recursion?
+Maximum call stack size reached. Infinite recursion?
diff --git a/Zend/tests/stack_limit_003.phpt b/Zend/tests/stack_limit_003.phpt
@@ -0,0 +1,62 @@
+--TEST--
+Stack limit 002 - Stack limit checks with fixed max_allowed_stack_size
+--EXTENSIONS--
+zend_test
+--INI--
+zend.max_allowed_stack_size=128K
+--FILE--
+<?php
+
+var_dump(zend_test_zend_call_stack_get());
+
+class Test1 {
+    public function __destruct() {
+        new Test1;
+    }
+}
+
+class Test2 {
+    public function __clone() {
+        clone $this;
+    }
+}
+
+function replace() {
+    return preg_replace_callback('#.#', function () {
+        return replace();
+    }, 'x');
+}
+
+try {
+    new Test1;
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    clone new Test2;
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    replace();
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECTF--
+array(4) {
+  ["base"]=>
+  string(%d) "0x%x"
+  ["max_size"]=>
+  string(%d) "0x%x"
+  ["position"]=>
+  string(%d) "0x%x"
+  ["EG(stack_limit)"]=>
+  string(%d) "0x%x"
+}
+Maximum call stack size reached. Infinite recursion?
+Maximum call stack size reached. Infinite recursion?
+Maximum call stack size reached. Infinite recursion?
diff --git a/Zend/tests/stack_limit_004.phpt b/Zend/tests/stack_limit_004.phpt
@@ -0,0 +1,50 @@
+--TEST--
+Stack limit 004 - Stack limit checks with fixed max_allowed_stack_size (fibers)
+--EXTENSIONS--
+zend_test
+--FILE--
+<?php
+
+var_dump(zend_test_zend_call_stack_get());
+
+class Test1 {
+    public function __destruct() {
+        new Test1;
+    }
+}
+
+$callback = function (): int {
+    try {
+        new Test1;
+    } catch (Error $e) {
+        return count($e->getTrace());
+    }
+
+    throw new \Exception();
+};
+
+ini_set('fiber.stack_size', '100K');
+$fiber = new Fiber($callback);
+$fiber->start();
+$depth1 = $fiber->getReturn();
+
+ini_set('fiber.stack_size', '50K');
+$fiber = new Fiber($callback);
+$fiber->start();
+$depth2 = $fiber->getReturn();
+
+var_dump($depth1 > $depth2);
+
+?>
+--EXPECTF--
+array(4) {
+  ["base"]=>
+  string(%d) "0x%x"
+  ["max_size"]=>
+  string(%d) "0x%x"
+  ["position"]=>
+  string(%d) "0x%x"
+  ["EG(stack_limit)"]=>
+  string(%d) "0x%x"
+}
+bool(true)
diff --git a/Zend/tests/stack_limit_005.phpt b/Zend/tests/stack_limit_005.phpt
@@ -0,0 +1,64 @@
+--TEST--
+Stack limit 005 - Internal stack limit check in zend_compile_expr()
+--EXTENSIONS--
+zend_test
+--INI--
+zend.max_allowed_stack_size=128K
+--FILE--
+<?php
+
+$test
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+    ->f()->f()->f()->f()->f()->f()->f()->f()->f()->f()
+;
+
+--EXPECTF--
+Fatal error: Maximum call stack size reached. Try splitting expression in %s on line 3