Fix the C library runtime initialization order.

This allows libc.so to run the C runtime initializer as soon as the
dynamic linker loads the shared library, i.e. before any other initializers
(e.g. static C++ constructors in other shared libraries the executable depends
on).

This also removes the bug where the initializers from the executable itself
were run twice: once by the dynamic linker, and another time by __libc_init
as defined by libc_init_dynamic.c

1 files changed, 38 insertions, 25 deletions

diff --git a/libc/bionic/libc_init_static.c b/libc/bionic/libc_init_static.c
index ec463f7..d097b6b 100644
--- a/libc/bionic/libc_init_static.c
+++ b/libc/bionic/libc_init_static.c
@@ -28,24 +28,15 @@
 /*
  * libc_init_static.c
  *
- * This function takes the raw data block set up by the ELF loader
- * in the kernel and parses it.  It is invoked by crt0.S which makes
- * any necessary adjustments and passes calls this function using
- * the standard C calling convention.
+ * The program startup function __libc_init() defined here is
+ * used for static executables only (i.e. those that don't depend
+ * on shared libraries). It is called from arch-$ARCH/bionic/crtbegin_static.S
+ * which is directly invoked by the kernel when the program is launched.
  *
- * The arguments are:
- *  uintptr_t *elfdata	 -- The ELF loader data block; usually from the stack.
- *                          Basically a pointer to argc.
- *  void (*onexit)(void) -- Function to install into onexit
+ * The 'structors' parameter contains pointers to various initializer
+ * arrays that must be run before the program's 'main' routine is launched.
  */
 
-/*
- * Several Linux ABIs don't pass the onexit pointer, and the ones that
- * do never use it.  Therefore, unless USE_ONEXIT is defined, we just
- * ignore the onexit pointer.
- */
-/* #define USE_ONEXIT */
-
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -58,19 +49,41 @@
 #include <bionic_tls.h>
 #include <errno.h>
 
+static void call_array(void(**list)())
+{
+    // First element is -1, list is null-terminated
+    while (*++list) {
+        (*list)();
+    }
+}
+
 __noreturn void __libc_init(uintptr_t *elfdata,
                        void (*onexit)(void),
                        int (*slingshot)(int, char**, char**),
                        structors_array_t const * const structors)
 {
-/* 
- * To enable malloc checks for statically linked programs, add
- * "WITH_MALLOC_CHECK_LIBC_A := true" in device/buildspec.mk
- */
-#ifdef MALLOC_LEAK_CHECK
-    extern void malloc_debug_init();
-    __libc_init_common(elfdata, onexit, slingshot, structors, malloc_debug_init);
-#else
-    __libc_init_common(elfdata, onexit, slingshot, structors, NULL);
-#endif
+    int  argc;
+    char **argv, **envp;
+
+    /* Initialize the C runtime environment */
+    __libc_init_common(elfdata);
+
+    /* Several Linux ABIs don't pass the onexit pointer, and the ones that
+     * do never use it.  Therefore, we ignore it.
+     */
+
+    /* pre-init array. */
+    call_array(structors->preinit_array);
+
+    /* .ctors section initializers, for non-arm-eabi ABIs */
+    call_array(structors->ctors_array);
+
+    // call static constructors
+    call_array(structors->init_array);
+
+    argc = (int) *elfdata;
+    argv = (char**)(elfdata + 1);
+    envp = argv + argc + 1;
+
+    exit(slingshot(argc, argv, envp));
 }