Libraries: Move to Userland/Libraries/

Author: https://github.com/awesomekling
Commit: 13d7c09125

Userland/Libraries/LibC/crt0.cpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Types.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/internals.h>
+#include <unistd.h>
+
+extern "C" {
+
+extern u32 __stack_chk_guard;
+
+int main(int, char**, char**);
+
+// Tell the compiler that this may be called from somewhere else.
+int _start(int argc, char** argv, char** env);
+
+int _start(int argc, char** argv, char** env)
+{
+    u32 original_stack_chk = __stack_chk_guard;
+    arc4random_buf(&__stack_chk_guard, sizeof(__stack_chk_guard));
+
+    if (__stack_chk_guard == 0)
+        __stack_chk_guard = original_stack_chk;
+
+    environ = env;
+    __environ_is_malloced = false;
+
+    __libc_init();
+
+    _init();
+
+    extern void (*__init_array_start[])(int, char**, char**) __attribute__((visibility("hidden")));
+    extern void (*__init_array_end[])(int, char**, char**) __attribute__((visibility("hidden")));
+
+    const size_t size = __init_array_end - __init_array_start;
+    for (size_t i = 0; i < size; i++)
+        (*__init_array_start[i])(argc, argv, env);
+
+    int status = main(argc, argv, environ);
+
+    exit(status);
+
+    // We should never get here, but if we ever do, make sure to
+    // restore the stack guard to the value we entered _start with.
+    // Then we won't trigger the stack canary check on the way out.
+    __stack_chk_guard = original_stack_chk;
+
+    return 20150614;
+}
+}