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/bionic/libc_init_common.c b/libc/bionic/libc_init_common.c
index de4919d..523afcf 100644
--- a/libc/bionic/libc_init_common.c
+++ b/libc/bionic/libc_init_common.c
@@ -39,8 +39,11 @@
#include <bionic_tls.h>
#include <errno.h>
-extern void _init(void);
-extern void _fini(void);
+/* This contains the common C library initialization code.
+ * To understand what happens here, you should read the
+ * "Initialization and Finalization" section of the file
+ * named bionic/linker/README.TXT
+ */
static void call_array(void(**list)())
{
@@ -50,15 +53,6 @@
}
}
-static void __bionic_do_global_dtors(structors_array_t const * const p)
-{
- call_array(p->fini_array);
- //_fini();
-}
-
-extern unsigned __get_sp(void);
-extern pid_t gettid(void);
-
char* __progname;
char **environ;
@@ -69,30 +63,28 @@
int __system_properties_init(void);
+/* This function can be run under two different contexts:
+ *
+ * - for statically linked executables (i.e. those who do
+ * not depend on shared libraries at all), it will be
+ * called from the __libc_init() function defined in
+ * bionic/libc_init_static.c
+ *
+ * - for dynamic executables, it will be called from the
+ * __libc_init() function defined in bionic/libc_init_dynamic.c
+ *
+ */
void __libc_init_common(uintptr_t *elfdata,
void (*onexit)(void),
int (*slingshot)(int, char**, char**),
structors_array_t const * const structors,
void (*pre_ctor_hook)())
{
- pthread_internal_t thread;
- pthread_attr_t thread_attr;
- void *tls_area[BIONIC_TLS_SLOTS];
int argc;
char **argv, **envp, **envend;
struct auxentry *auxentry;
unsigned int page_size = 0, page_shift = 0;
- /* The main thread's stack has empirically shown to be 84k */
- unsigned stacktop = (__get_sp() & ~(PAGE_SIZE - 1)) + PAGE_SIZE;
- unsigned stacksize = 128 * 1024; //84 * 1024;
- unsigned stackbottom = stacktop - stacksize;
-
- pthread_attr_init(&thread_attr);
- pthread_attr_setstack(&thread_attr, (void*)stackbottom, stacksize);
- _init_thread(&thread, gettid(), &thread_attr, (void*)stackbottom);
- __init_tls(tls_area, &thread);
-
argc = (int) *elfdata++;
argv = (char**) elfdata;
envp = argv+(argc+1);
@@ -106,17 +98,17 @@
if (pre_ctor_hook) pre_ctor_hook();
- // XXX: we should execute the .fini_array upon exit
+ if (structors != NULL) {
+ // pre-init array.
+ call_array(structors->preinit_array);
- // pre-init array.
- // XXX: I'm not sure what's the different with the init array.
- call_array(structors->preinit_array);
+ // for compatibility with non-eabi binary, call the .ctors section
+ // this is only useful for static non-ARM (e.g. x86) executables.
+ call_array(structors->ctors_array);
- // for compatibility with non-eabi binary, call the .ctors section
- call_array(structors->ctors_array);
-
- // call static constructors
- call_array(structors->init_array);
+ // call static constructors
+ call_array(structors->init_array);
+ }
exit(slingshot(argc, argv, envp));
}
diff --git a/libc/bionic/libc_init_dynamic.c b/libc/bionic/libc_init_dynamic.c
index 8cf24b4..e1ff13d 100644
--- a/libc/bionic/libc_init_dynamic.c
+++ b/libc/bionic/libc_init_dynamic.c
@@ -25,18 +25,29 @@
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+
/*
* 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.
+ * This function is called for dynamic executables after the dynamic
+ * linker has loaded and initialized all dependent shared libraries.
+ *
+ * It takes the raw data block set up by the ELF loader
+ * in the kernel and parses it.
*
* 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
+ * elfdata -- The ELF loader data block; usually from the stack.
+ * Basically a pointer to argc.
+ *
+ * onexit -- Function to call on exit, can be NULL.
+ *
+ * slingshot -- Address of the program's main function
+ *
+ * structors -- Table of constructor functions arrays that must
+ * be called before the slingshot.
+ *
+ * It is called from the assembly fragment found in
+ * arch-$ARCH/bionic/crtbegin_dynamic.S
*/
/*
@@ -62,5 +73,18 @@
int (*slingshot)(int, char**, char**),
structors_array_t const * const structors)
{
- __libc_init_common(elfdata, onexit, slingshot, structors, malloc_debug_init);
+ /* NOTE: At this point, the dynamic linker has *already* called
+ * all initializers properly, so we ignore 'structors' to
+ * avoid calling them twice.
+ */
+
+ /* NOTE2: Is it worthwhile to use malloc_debug_init() in the case of
+ * of the non-debug shared C library ?
+ *
+ * The implementation in bionic/malloc_leak.c contains a lot
+ * of code which will turn to be unused, and we add a dispatch
+ * overhead to malloc() et al. that proved to be significant
+ * in the past (e.g. making boot sequence 5% slower)
+ */
+ __libc_init_common(elfdata, onexit, slingshot, NULL, malloc_debug_init);
}
diff --git a/libc/bionic/libc_init_static.c b/libc/bionic/libc_init_static.c
index ec463f7..d7af640 100644
--- a/libc/bionic/libc_init_static.c
+++ b/libc/bionic/libc_init_static.c
@@ -25,18 +25,30 @@
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+
/*
* 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.
+ * This function is called for static executables, i.e. those that
+ * dont depend on shared libraries and are directly started by the
+ * Linux kernel.
+ *
+ * It takes the raw data block set up by the ELF loader
+ * in the kernel and parses it.
*
* 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
+ * elfdata -- The ELF loader data block; usually from the stack.
+ * Basically a pointer to argc.
+ *
+ * onexit -- Function to call on exit, can be NULL.
+ *
+ * slingshot -- Address of the program's main function
+ *
+ * structors -- Table of constructor functions arrays that must
+ * be called before the slingshot.
+ *
+ * It is called from the assembly fragment found in
+ * arch-$ARCH/bionic/crtbegin_static.S
*/
/*
@@ -51,18 +63,19 @@
#include <stdlib.h>
#include <stdint.h>
#include <elf.h>
-#include "pthread_internal.h"
-#include "atexit.h"
+#include "bionic_preinit.h"
#include "libc_init_common.h"
-#include <bionic_tls.h>
-#include <errno.h>
-
__noreturn void __libc_init(uintptr_t *elfdata,
void (*onexit)(void),
int (*slingshot)(int, char**, char**),
structors_array_t const * const structors)
{
+ pthread_internal_t thread;
+ void *tls_area[BIONIC_TLS_SLOTS];
+
+ __libc_preinit( &thread, tls_area );
+
/*
* To enable malloc checks for statically linked programs, add
* "WITH_MALLOC_CHECK_LIBC_A := true" in device/buildspec.mk
diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
deleted file mode 100644
index eb4e80c..0000000
--- a/libc/bionic/pthread_internal.h
+++ /dev/null
@@ -1,115 +0,0 @@
-/*
- * Copyright (C) 2008 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 _PTHREAD_INTERNAL_H_
-#define _PTHREAD_INTERNAL_H_
-
-#include <pthread.h>
-
-__BEGIN_DECLS
-
-typedef struct pthread_internal_t
-{
- struct pthread_internal_t* next;
- struct pthread_internal_t** pref;
- pthread_attr_t attr;
- pid_t kernel_id;
- pthread_cond_t join_cond;
- int join_count;
- void* return_value;
- int intern;
- __pthread_cleanup_t* cleanup_stack;
- void** tls; /* thread-local storage area */
-} pthread_internal_t;
-
-extern void _init_thread(pthread_internal_t * thread, pid_t kernel_id, pthread_attr_t * attr, void * stack_base);
-
-/* needed by posix-timers.c */
-
-static __inline__ void timespec_add( struct timespec* a, const struct timespec* b )
-{
- a->tv_sec += b->tv_sec;
- a->tv_nsec += b->tv_nsec;
- if (a->tv_nsec >= 1000000000) {
- a->tv_nsec -= 1000000000;
- a->tv_sec += 1;
- }
-}
-
-static __inline__ void timespec_sub( struct timespec* a, const struct timespec* b )
-{
- a->tv_sec -= b->tv_sec;
- a->tv_nsec -= b->tv_nsec;
- if (a->tv_nsec < 0) {
- a->tv_nsec += 1000000000;
- a->tv_sec -= 1;
- }
-}
-
-static __inline__ void timespec_zero( struct timespec* a )
-{
- a->tv_sec = a->tv_nsec = 0;
-}
-
-static __inline__ int timespec_is_zero( const struct timespec* a )
-{
- return (a->tv_sec == 0 && a->tv_nsec == 0);
-}
-
-static __inline__ int timespec_cmp( const struct timespec* a, const struct timespec* b )
-{
- if (a->tv_sec < b->tv_sec) return -1;
- if (a->tv_sec > b->tv_sec) return +1;
- if (a->tv_nsec < b->tv_nsec) return -1;
- if (a->tv_nsec > b->tv_nsec) return +1;
- return 0;
-}
-
-static __inline__ int timespec_cmp0( const struct timespec* a )
-{
- if (a->tv_sec < 0) return -1;
- if (a->tv_sec > 0) return +1;
- if (a->tv_nsec < 0) return -1;
- if (a->tv_nsec > 0) return +1;
- return 0;
-}
-
-extern int __pthread_cond_timedwait(pthread_cond_t*,
- pthread_mutex_t*,
- const struct timespec*,
- clockid_t);
-
-extern int __pthread_cond_timedwait_relative(pthread_cond_t*,
- pthread_mutex_t*,
- const struct timespec*);
-
-/* needed by fork.c */
-extern void __timer_table_start_stop(int stop);
-
-__END_DECLS
-
-#endif /* _PTHREAD_INTERNAL_H_ */