[Midnightbsd-cvs] src [10557] trunk/lib/libc/stdlib: add cxa thread atexit
laffer1 at midnightbsd.org
laffer1 at midnightbsd.org
Thu Jun 7 20:55:39 EDT 2018
Revision: 10557
http://svnweb.midnightbsd.org/src/?rev=10557
Author: laffer1
Date: 2018-06-07 20:55:38 -0400 (Thu, 07 Jun 2018)
Log Message:
-----------
add cxa thread atexit
Added Paths:
-----------
trunk/lib/libc/stdlib/cxa_thread_atexit.c
trunk/lib/libc/stdlib/cxa_thread_atexit_impl.c
Added: trunk/lib/libc/stdlib/cxa_thread_atexit.c
===================================================================
--- trunk/lib/libc/stdlib/cxa_thread_atexit.c (rev 0)
+++ trunk/lib/libc/stdlib/cxa_thread_atexit.c 2018-06-08 00:55:38 UTC (rev 10557)
@@ -0,0 +1,41 @@
+/* $MidnightBSD$ */
+/*-
+ * Copyright (c) 2017 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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 AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: stable/10/lib/libc/stdlib/cxa_thread_atexit.c 312590 2017-01-21 12:30:07Z kib $");
+
+#include "libc_private.h"
+
+int
+__cxa_thread_atexit(void (*dtor_func)(void *), void *obj, void *dso_symbol)
+{
+
+ return (__cxa_thread_atexit_hidden(dtor_func, obj, dso_symbol));
+}
Property changes on: trunk/lib/libc/stdlib/cxa_thread_atexit.c
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+MidnightBSD=%H
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Added: svn:mime-type
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+text/plain
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Added: trunk/lib/libc/stdlib/cxa_thread_atexit_impl.c
===================================================================
--- trunk/lib/libc/stdlib/cxa_thread_atexit_impl.c (rev 0)
+++ trunk/lib/libc/stdlib/cxa_thread_atexit_impl.c 2018-06-08 00:55:38 UTC (rev 10557)
@@ -0,0 +1,154 @@
+/* $MidnightBSD$ */
+/*-
+ * Copyright (c) 2016 Mahdi Mokhtari <mokhi64 at gmail.com>
+ * Copyright (c) 2016, 2017 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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 AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: stable/10/lib/libc/stdlib/cxa_thread_atexit_impl.c 312590 2017-01-21 12:30:07Z kib $");
+
+#include <sys/queue.h>
+#include "namespace.h"
+#include <errno.h>
+#include <link.h>
+#include <pthread.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "un-namespace.h"
+#include "libc_private.h"
+
+/*
+ * C++11 introduces the thread_local scope (like __thread with some
+ * additions). As a key-feature it should support non-trivial
+ * destructors, registered with __cxa_thread_atexit() to be executed
+ * at the thread termination.
+ *
+ * The implemention keeps a _Thread_local list of destructors per each
+ * thread, and calls __cxa_thread_call_dtors() on each thread's exit
+ * to do cleanup. For a thread calling exit(3), in particular, for
+ * the initial thread returning from main(), we call
+ * __cxa_thread_call_dtors() inside exit().
+ *
+ * It could be possible that a dynamically loaded library, use
+ * thread_local variable but is dlclose()'d before thread exit. The
+ * destructor of this variable will then try to access the address,
+ * for calling it but it's unloaded, so it'll crash. We're using
+ * __elf_phdr_match_addr() to detect and prevent such cases and so
+ * prevent the crash.
+ */
+
+#define CXA_DTORS_ITERATIONS 4
+
+struct cxa_thread_dtor {
+ void *obj;
+ void (*func)(void *);
+ void *dso;
+ LIST_ENTRY(cxa_thread_dtor) entry;
+};
+static _Thread_local LIST_HEAD(dtor_list, cxa_thread_dtor) dtors =
+ LIST_HEAD_INITIALIZER(dtors);
+
+int
+__cxa_thread_atexit_impl(void (*dtor_func)(void *), void *obj,
+ void *dso_symbol)
+{
+
+ return (__cxa_thread_atexit_hidden(dtor_func, obj, dso_symbol));
+}
+
+int
+__cxa_thread_atexit_hidden(void (*dtor_func)(void *), void *obj,
+ void *dso_symbol)
+{
+ struct cxa_thread_dtor *new_dtor;
+
+ new_dtor = malloc(sizeof(*new_dtor));
+ if (new_dtor == NULL) {
+ errno = ENOMEM; /* forcibly override malloc(3) error */
+ return (-1);
+ }
+
+ new_dtor->obj = obj;
+ new_dtor->func = dtor_func;
+ new_dtor->dso = dso_symbol;
+ LIST_INSERT_HEAD(&dtors, new_dtor, entry);
+ return (0);
+}
+
+static void
+walk_cb_call(struct cxa_thread_dtor *dtor)
+{
+ struct dl_phdr_info phdr_info;
+
+ if (_rtld_addr_phdr(dtor->dso, &phdr_info) &&
+ __elf_phdr_match_addr(&phdr_info, dtor->func))
+ dtor->func(dtor->obj);
+ else
+ fprintf(stderr, "__cxa_thread_call_dtors: dtr %p from "
+ "unloaded dso, skipping\n", (void *)(dtor->func));
+}
+
+static void
+walk_cb_nocall(struct cxa_thread_dtor *dtor __unused)
+{
+}
+
+static void
+cxa_thread_walk(void (*cb)(struct cxa_thread_dtor *))
+{
+ struct cxa_thread_dtor *dtor, *tdtor;
+
+ LIST_FOREACH_SAFE(dtor, &dtors, entry, tdtor) {
+ LIST_REMOVE(dtor, entry);
+ cb(dtor);
+ free(dtor);
+ }
+}
+
+/*
+ * This is the callback function we use to call destructors, once for
+ * each thread. It is called in exit(3) in libc/stdlib/exit.c and
+ * before exit_thread() in libthr/thread/thr_exit.c.
+ */
+void
+__cxa_thread_call_dtors(void)
+{
+ int i;
+
+ for (i = 0; i < CXA_DTORS_ITERATIONS && !LIST_EMPTY(&dtors); i++)
+ cxa_thread_walk(walk_cb_call);
+
+ if (!LIST_EMPTY(&dtors)) {
+ fprintf(stderr, "Thread %p is exiting with more "
+ "thread-specific dtors created after %d iterations "
+ "of destructor calls\n",
+ _pthread_self(), i);
+ cxa_thread_walk(walk_cb_nocall);
+ }
+}
Property changes on: trunk/lib/libc/stdlib/cxa_thread_atexit_impl.c
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+MidnightBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
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