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Upstream atexit

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Change-Id: Ia454a2181b5058ed9783dc02b6b1805d0e4d2715
This commit is contained in:
Dmitriy Ivanov 2014-07-11 12:59:16 -07:00
parent 83ce99d8b7
commit 53c3c271dc
10 changed files with 68 additions and 142 deletions
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5
libc/Android.mk
View file

@ -67,7 +67,6 @@ libc_common_src_files := \
bionic/unlockpt.c \
stdio/snprintf.c\
stdio/sprintf.c \
stdlib/atexit.c \
unistd/syslog.c \
# Fortify implementations of libc functions.
@ -463,6 +462,7 @@ libc_upstream_openbsd_src_files := \
upstream-openbsd/lib/libc/stdio/wprintf.c \
upstream-openbsd/lib/libc/stdio/wscanf.c \
upstream-openbsd/lib/libc/stdio/wsetup.c \
upstream-openbsd/lib/libc/stdlib/atexit.c \
upstream-openbsd/lib/libc/stdlib/atoi.c \
upstream-openbsd/lib/libc/stdlib/atol.c \
upstream-openbsd/lib/libc/stdlib/atoll.c \
@ -549,7 +549,6 @@ libc_common_cppflags := \
# Define some common includes
# ========================================================
libc_common_c_includes += \
$(LOCAL_PATH)/stdlib \
$(LOCAL_PATH)/stdio \
# ========================================================
@ -735,6 +734,7 @@ LOCAL_SRC_FILES := $(libc_upstream_openbsd_src_files)
LOCAL_CFLAGS := \
$(libc_common_cflags) \
-Wno-sign-compare -Wno-uninitialized -Wno-unused-parameter \
-I$(LOCAL_PATH)/private \
-I$(LOCAL_PATH)/upstream-openbsd/android/include \
-I$(LOCAL_PATH)/upstream-openbsd/lib/libc/include \
-I$(LOCAL_PATH)/upstream-openbsd/lib/libc/gdtoa/ \
@ -767,6 +767,7 @@ LOCAL_CFLAGS := \
$(libc_common_cflags) \
-Wno-sign-compare -Wno-uninitialized \
-fvisibility=hidden \
-I$(LOCAL_PATH)/private \
-I$(LOCAL_PATH)/upstream-openbsd/android/include \
-I$(LOCAL_PATH)/upstream-openbsd/lib/libc/include \
-include openbsd-compat.h \

1
libc/bionic/abort.cpp
View file

@ -30,7 +30,6 @@
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "atexit.h"
#ifdef __arm__
extern "C" __LIBC_HIDDEN__ void __libc_android_abort()

1
libc/bionic/libc_init_common.cpp
View file

@ -39,7 +39,6 @@
#include <sys/resource.h>
#include <unistd.h>
#include "atexit.h"
#include "private/bionic_auxv.h"
#include "private/bionic_ssp.h"
#include "private/bionic_tls.h"

2
libc/bionic/libc_init_dynamic.cpp
View file

@ -48,7 +48,6 @@
#include <stdlib.h>
#include <stdint.h>
#include <elf.h>
#include "atexit.h"
#include "libc_init_common.h"
#include "private/bionic_tls.h"
@ -58,6 +57,7 @@ extern "C" {
extern void malloc_debug_init(void);
extern void malloc_debug_fini(void);
extern void netdClientInit(void);
extern int __cxa_atexit(void (*)(void *), void *, void *);
};
// We flag the __libc_preinit function as a constructor to ensure

3
libc/bionic/libc_init_static.cpp
View file

@ -46,7 +46,6 @@
#include <sys/auxv.h>
#include <sys/mman.h>
#include "atexit.h"
#include "libc_init_common.h"
#include "pthread_internal.h"
@ -60,6 +59,8 @@
// itself at the start of a page.
#define PAGE_END(x) PAGE_START((x) + (PAGE_SIZE-1))
extern "C" int __cxa_atexit(void (*)(void *), void *, void *);
static void call_array(void(**list)()) {
// First element is -1, list is null-terminated
while (*++list) {

8
libc/private/thread_private.h
View file

@ -33,8 +33,12 @@ struct __thread_private_tag_t {
#define _THREAD_PRIVATE_MUTEX_UNLOCK(name) \
pthread_mutex_unlock( &__THREAD_NAME(name)._private_lock )
__LIBC_HIDDEN__ void _thread_atexit_lock(void);
__LIBC_HIDDEN__ void _thread_atexit_unlock(void);
/* Note that these aren't compatible with the usual OpenBSD ones which lazy-initialize! */
#define _MUTEX_LOCK(l) pthread_mutex_lock((pthread_mutex_t*) l)
#define _MUTEX_UNLOCK(l) pthread_mutex_unlock((pthread_mutex_t*) l)
__LIBC_HIDDEN__ void _thread_atexit_lock(void);
__LIBC_HIDDEN__ void _thread_atexit_unlock(void);
#define _ATEXIT_LOCK() _thread_atexit_lock()
#define _ATEXIT_UNLOCK() _thread_atexit_unlock()

2
libc/upstream-openbsd/android/include/openbsd-compat.h
View file

@ -40,4 +40,6 @@
__LIBC64_HIDDEN__ extern const short *_tolower_tab_;
__LIBC64_HIDDEN__ extern const short *_toupper_tab_;
__LIBC_HIDDEN__ extern struct atexit *__atexit;
#endif

26
libc/upstream-openbsd/android/include/thread_private.h
View file

@ -1,26 +0,0 @@
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _THREAD_PRIVATE_H_
#define _THREAD_PRIVATE_H_
#include <pthread.h>
/* Note that these aren't compatible with the usual OpenBSD ones which lazy-initialize! */
#define _MUTEX_LOCK(l) pthread_mutex_lock((pthread_mutex_t*) l)
#define _MUTEX_UNLOCK(l) pthread_mutex_unlock((pthread_mutex_t*) l)
#endif /* _THREAD_PRIVATE_H_ */

150
libc/stdlib/atexit.c → libc/upstream-openbsd/lib/libc/stdlib/atexit.c
View file

@ -1,4 +1,4 @@
/* $OpenBSD: atexit.c,v 1.14 2007/09/05 20:47:47 chl Exp $ */
/* $OpenBSD: atexit.c,v 1.20 2014/07/11 09:51:37 kettenis Exp $ */
/*
* Copyright (c) 2002 Daniel Hartmeier
* All rights reserved.
@ -35,57 +35,16 @@
#include <string.h>
#include <unistd.h>
#include "atexit.h"
#include "private/thread_private.h"
#include "thread_private.h"
struct atexit *__atexit;
/*
* TODO: Read this before upstreaming:
*
* As of Apr 2014 there is a bug regaring function type detection logic in
* Free/Open/NetBSD implementations of __cxa_finalize().
*
* What it is about:
* First of all there are two kind of atexit handlers:
* 1) void handler(void) - this is the regular type
* available for to user via atexit(.) function call.
*
* 2) void internal_handler(void*) - this is the type
* __cxa_atexit() function expects. This handler is used
* by C++ compiler to register static destructor calls.
* Note that calling this function as the handler of type (1)
* results in incorrect this pointer in static d-tors.
*
* What is wrong with BSD implementations:
*
* They use dso argument to identify the handler type. The problem
* with it is dso is also used to identify the handlers associated
* with particular dynamic library and allow __cxa_finalize to call correct
* set of functions on dlclose(). And it cannot identify both.
*
* What is correct way to identify function type?
*
* Consider this:
* 1. __cxa_finalize and __cxa_atexit are part of libc and do not have access to hidden
* &__dso_handle.
* 2. __cxa_atexit has only 3 arguments: function pointer, function argument, dso.
* none of them can be reliably used to pass information about handler type.
* 3. following http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor (3.3.5.3 - B)
* translation of user atexit -> __cxa_atexit(f, NULL, NULL) results in crashes
* on exit() after dlclose() of a library with an atexit() call.
*
* One way to resolve this is to always call second form of handler, which will
* result in storing unused argument in register/stack depending on architecture
* and should not present any problems.
*
* Another way is to make them dso-local in one way or the other.
*/
static int restartloop;
/*
* Function pointers are stored in a linked list of pages. The list
* is initially empty, and pages are allocated on demand. The first
* function pointer in the first allocated page (the last one in
* the linked list) was reserved for the cleanup function.
* the linked list) is reserved for the cleanup function.
*
* Outside the following functions, all pages are mprotect()'ed
* to prevent unintentional/malicious corruption.
@ -103,7 +62,7 @@ __cxa_atexit(void (*func)(void *), void *arg, void *dso)
{
struct atexit *p = __atexit;
struct atexit_fn *fnp;
size_t pgsize = getpagesize();
int pgsize = getpagesize();
int ret = -1;
if (pgsize < sizeof(*p))
@ -132,11 +91,12 @@ __cxa_atexit(void (*func)(void *), void *arg, void *dso)
__atexit = p;
}
fnp = &p->fns[p->ind++];
fnp->cxa_func = func;
fnp->fn_ptr = func;
fnp->fn_arg = arg;
fnp->fn_dso = dso;
if (mprotect(p, pgsize, PROT_READ))
goto unlock;
restartloop = 1;
ret = 0;
unlock:
_ATEXIT_UNLOCK();
@ -151,50 +111,41 @@ unlock:
void
__cxa_finalize(void *dso)
{
struct atexit *p, *q, *original_atexit;
struct atexit *p, *q;
struct atexit_fn fn;
int n, pgsize = getpagesize(), original_ind;
int n, pgsize = getpagesize();
static int call_depth;
_ATEXIT_LOCK();
call_depth++;
p = original_atexit = __atexit;
n = original_ind = p != NULL ? p->ind : 0;
while (p != NULL) {
if (p->fns[n].cxa_func != NULL /* not called */
&& (dso == NULL || dso == p->fns[n].fn_dso)) { /* correct DSO */
restart:
restartloop = 0;
for (p = __atexit; p != NULL; p = p->next) {
for (n = p->ind; --n >= 0;) {
if (p->fns[n].fn_ptr == NULL)
continue; /* already called */
if (dso != NULL && dso != p->fns[n].fn_dso)
continue; /* wrong DSO */
/*
* Mark handler as having been already called to avoid
* dupes and loops, then call the appropriate function.
*/
fn = p->fns[n];
if (mprotect(p, pgsize, PROT_READ | PROT_WRITE) == 0) {
p->fns[n].cxa_func = NULL;
p->fns[n].fn_ptr = NULL;
mprotect(p, pgsize, PROT_READ);
}
_ATEXIT_UNLOCK();
(*fn.cxa_func)(fn.fn_arg);
(*fn.fn_ptr)(fn.fn_arg);
_ATEXIT_LOCK();
// check for new atexit handlers
if ((__atexit->ind != original_ind) || (__atexit != original_atexit)) {
// need to restart now to preserve correct
// call order - LIFO
p = original_atexit = __atexit;
n = original_ind = p->ind;
continue;
}
}
if (n == 0) {
p = p->next;
n = p != NULL ? p->ind : 0;
} else {
--n;
if (restartloop)
goto restart;
}
}
--call_depth;
call_depth--;
/*
* If called via exit(), unmap the pages since we have now run
@ -218,33 +169,34 @@ __cxa_finalize(void *dso)
void
__atexit_register_cleanup(void (*func)(void))
{
struct atexit *p;
size_t pgsize = getpagesize();
struct atexit *p;
int pgsize = getpagesize();
if (pgsize < sizeof(*p))
return;
_ATEXIT_LOCK();
p = __atexit;
while (p != NULL && p->next != NULL)
p = p->next;
if (p == NULL) {
p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, 0);
if (p == MAP_FAILED)
goto unlock;
p->ind = 1;
p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) /
sizeof(p->fns[0]);
p->next = NULL;
__atexit = p;
} else {
if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
goto unlock;
}
p->fns[0].cxa_func = (void (*)(void*))func;
p->fns[0].fn_arg = NULL;
p->fns[0].fn_dso = NULL;
mprotect(p, pgsize, PROT_READ);
if (pgsize < sizeof(*p))
return;
_ATEXIT_LOCK();
p = __atexit;
while (p != NULL && p->next != NULL)
p = p->next;
if (p == NULL) {
p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, 0);
if (p == MAP_FAILED)
goto unlock;
p->ind = 1;
p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) /
sizeof(p->fns[0]);
p->next = NULL;
__atexit = p;
} else {
if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
goto unlock;
}
p->fns[0].fn_ptr = (void (*)(void *))func;
p->fns[0].fn_arg = NULL;
p->fns[0].fn_dso = NULL;
mprotect(p, pgsize, PROT_READ);
restartloop = 1;
unlock:
_ATEXIT_UNLOCK();
_ATEXIT_UNLOCK();
}

12
libc/stdlib/atexit.h → libc/upstream-openbsd/lib/libc/stdlib/atexit.h
View file

@ -1,4 +1,4 @@
/* $OpenBSD: atexit.h,v 1.7 2007/09/03 14:40:16 millert Exp $ */
/* $OpenBSD: atexit.h,v 1.9 2014/06/18 19:01:10 kettenis Exp $ */
/*
* Copyright (c) 2002 Daniel Hartmeier
@ -30,24 +30,18 @@
*
*/
#include <sys/cdefs.h>
struct atexit {
struct atexit *next; /* next in list */
int ind; /* next index in this table */
int max; /* max entries >= ATEXIT_SIZE */
struct atexit_fn {
void (*cxa_func)(void *);
void (*fn_ptr)(void *);
void *fn_arg; /* argument for CXA callback */
void *fn_dso; /* shared module handle */
} fns[1]; /* the table itself */
};
__BEGIN_DECLS
__LIBC_HIDDEN__ extern struct atexit *__atexit; /* points to head of LIFO stack */
extern struct atexit *__atexit; /* points to head of LIFO stack */
int __cxa_atexit(void (*)(void *), void *, void *);
void __cxa_finalize(void *);
__END_DECLS