Upstream atexit

Change-Id: Ia454a2181b5058ed9783dc02b6b1805d0e4d2715
(cherry picked from commit 53c3c271dc)

libc/Android.mk

@@ -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 \

libc/bionic/abort.cpp

@@ -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()

libc/bionic/libc_init_common.cpp

@@ -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"

libc/bionic/libc_init_dynamic.cpp

@@ -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

libc/bionic/libc_init_static.cpp

@@ -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) {

libc/private/thread_private.h

@@ -33,6 +33,10 @@ struct __thread_private_tag_t {
 #define _THREAD_PRIVATE_MUTEX_UNLOCK(name) \
 	pthread_mutex_unlock( &__THREAD_NAME(name)._private_lock )
 
+/* 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);
 

libc/upstream-openbsd/android/include/openbsd-compat.h

@@ -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

libc/upstream-openbsd/android/include/thread_private.h

@@ -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_ */

libc/upstream-openbsd/lib/libc/stdlib/atexit.c

@@ -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;
-
+static int restartloop;
-/*
- * 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.
- */
 
 /*
  * 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;
+restart:
-	n = original_ind = p != NULL ? p->ind : 0;
+	restartloop = 0;
-	while (p != NULL) {
+	for (p = __atexit; p != NULL; p = p->next) {
-		if (p->fns[n].cxa_func != NULL /* not called */
+		for (n = p->ind; --n >= 0;) {
-				&& (dso == NULL || dso == p->fns[n].fn_dso)) { /* correct DSO */
+			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 (restartloop)
-			if ((__atexit->ind != original_ind) || (__atexit != original_atexit)) {
+				goto restart;
-				// 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;
 		}
 	}
 
-	--call_depth;
+	call_depth--;
 
 	/*
 	 * If called via exit(), unmap the pages since we have now run
@@ -219,7 +170,7 @@ void
 __atexit_register_cleanup(void (*func)(void))
 {
 	struct atexit *p;
-        size_t pgsize = getpagesize();
+	int pgsize = getpagesize();
 
 	if (pgsize < sizeof(*p))
 		return;
@@ -241,10 +192,11 @@ __atexit_register_cleanup(void (*func)(void))
 		if (mprotect(p, pgsize, PROT_READ | PROT_WRITE))
 			goto unlock;
 	}
-        p->fns[0].cxa_func = (void (*)(void*))func;
+	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();
 }

libc/upstream-openbsd/lib/libc/stdlib/atexit.h

@@ -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
+extern struct atexit *__atexit;		/* points to head of LIFO stack */
-
-__LIBC_HIDDEN__ extern struct atexit *__atexit;		/* points to head of LIFO stack */
 
 int	__cxa_atexit(void (*)(void *), void *, void *);
 void	__cxa_finalize(void *);
-
-__END_DECLS