Fix the C library initialization to avoid calling static C++ constructors twice.
The problem was due to the fact that, in the case of dynamic executables,
the dynamic linker calls the DT_PREINIT_ARRAY, DT_INIT and DT_INIT_ARRAY
constructors when loading shared libraries and dynamic executables,
*before* calling the executable's entry point (i.e. arch-$ARCH/bionic/crtbegin_dynamic.c)
which in turns call __libc_init() in libc.so, as defined by bionic/libc_init_dynamic.c
The latter did call these constructors array again, mistakenly.
The patch also updates the documentation of many related functions.
Also adds a new section to linker/README.TXT explaining restrictions on
C library usage.
The patch has been tested on a Dream for stability issues with
proprietary blobs:
- H264 decoding works
- Camera + Video recording works
- GPS works
- Sensors work
The tests in system/extra/tests/bionic/libc/common/test_static_cpp_mutex.cpp has been
run and shows the static C++ constructor being called only once.
diff --git a/libc/private/bionic_preinit.h b/libc/private/bionic_preinit.h
new file mode 100644
index 0000000..b74a8b4
--- /dev/null
+++ b/libc/private/bionic_preinit.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * 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 OWNER 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.
+ */
+
+#ifndef _BIONIC_PREINIT_H
+#define _BIONIC_PREINIT_H
+
+#include "pthread_internal.h"
+#include "bionic_tls.h"
+#include <asm/page.h>
+
+/* this function is used to perform a minimal initialization of the
+ * the C library. This must be performed before any other call to
+ * other functions, in either the dynamic linker's startup code
+ * or libc_init_static.c
+ *
+ * 'main_thread' and 'tls_area' must be persistent variables,
+ * which means they must be either global, or allocated in the
+ * main thread's stack frame and never, ever, freed before
+ * program exit.
+ *
+ * VERY IMPORTANT NOTE:
+ *
+ * THIS IMPLEMENTATION SHOULD NOT USE GLOBAL VARIABLES.
+ *
+ * The reason is the dynamic linker's tricky usage of C library
+ * functions and later renaming of their symbols. See the
+ * "C Library Usage Restriction" section in bionic/linker/README.TXT
+ * for details.
+ */
+
+extern unsigned __get_sp(void);
+extern pid_t gettid(void);
+
+static __inline__ void
+__libc_preinit( pthread_internal_t* main_thread,
+ void* tls_area[BIONIC_TLS_SLOTS] )
+{
+ pthread_attr_t thread_attr;
+
+ /* Setup the main thread's information */
+ unsigned stacktop = (__get_sp() & ~(PAGE_SIZE - 1)) + PAGE_SIZE;
+ unsigned stacksize = 128 * 1024;
+ unsigned stackbottom = stacktop - stacksize;
+
+ pthread_attr_init(&thread_attr);
+ pthread_attr_setstack(&thread_attr, (void*)stackbottom, stacksize);
+ _init_thread(main_thread, gettid(), &thread_attr, (void*)stackbottom);
+ __init_tls(tls_area, main_thread);
+}
+
+#endif /* _BIONIC_INIT_H */