Date: Sat, 21 Jan 2017 12:30:07 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r312590 - in stable/10/lib/libc: include stdlib Message-ID: <201701211230.v0LCU7ad015750@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kib Date: Sat Jan 21 12:30:07 2017 New Revision: 312590 URL: https://svnweb.freebsd.org/changeset/base/312590 Log: MFC r311651: Export __cxa_thread_atexit_impl as an alias for __cxa_thread_atexit. Added: stable/10/lib/libc/stdlib/cxa_thread_atexit_impl.c - copied unchanged from r311651, head/lib/libc/stdlib/cxa_thread_atexit_impl.c Modified: stable/10/lib/libc/include/libc_private.h stable/10/lib/libc/stdlib/Makefile.inc stable/10/lib/libc/stdlib/Symbol.map stable/10/lib/libc/stdlib/cxa_thread_atexit.c Directory Properties: stable/10/ (props changed) Modified: stable/10/lib/libc/include/libc_private.h ============================================================================== --- stable/10/lib/libc/include/libc_private.h Sat Jan 21 11:47:30 2017 (r312589) +++ stable/10/lib/libc/include/libc_private.h Sat Jan 21 12:30:07 2017 (r312590) @@ -268,6 +268,8 @@ void _malloc_thread_cleanup(void); * thread is exiting, so its thread-local dtors should be called. */ void __cxa_thread_call_dtors(void); +int __cxa_thread_atexit_hidden(void (*dtor_func)(void *), void *obj, + void *dso_symbol) __hidden; /* * These functions are used by the threading libraries in order to protect Modified: stable/10/lib/libc/stdlib/Makefile.inc ============================================================================== --- stable/10/lib/libc/stdlib/Makefile.inc Sat Jan 21 11:47:30 2017 (r312589) +++ stable/10/lib/libc/stdlib/Makefile.inc Sat Jan 21 12:30:07 2017 (r312590) @@ -5,7 +5,9 @@ .PATH: ${.CURDIR}/${LIBC_ARCH}/stdlib ${.CURDIR}/stdlib MISRCS+=_Exit.c a64l.c abort.c abs.c atexit.c atof.c atoi.c atol.c atoll.c \ - bsearch.c cxa_thread_atexit.c div.c exit.c getenv.c getopt.c getopt_long.c \ + bsearch.c \ + cxa_thread_atexit.c cxa_thread_atexit_impl.c \ + div.c exit.c getenv.c getopt.c getopt_long.c \ getsubopt.c hcreate.c heapsort.c imaxabs.c imaxdiv.c \ insque.c l64a.c labs.c ldiv.c llabs.c lldiv.c lsearch.c \ merge.c ptsname.c qsort.c qsort_r.c quick_exit.c radixsort.c rand.c \ Modified: stable/10/lib/libc/stdlib/Symbol.map ============================================================================== --- stable/10/lib/libc/stdlib/Symbol.map Sat Jan 21 11:47:30 2017 (r312589) +++ stable/10/lib/libc/stdlib/Symbol.map Sat Jan 21 12:30:07 2017 (r312590) @@ -106,6 +106,7 @@ FBSD_1.3 { FBSD_1.5 { __cxa_thread_atexit; + __cxa_thread_atexit_impl; }; FBSDprivate_1.0 { Modified: stable/10/lib/libc/stdlib/cxa_thread_atexit.c ============================================================================== --- stable/10/lib/libc/stdlib/cxa_thread_atexit.c Sat Jan 21 11:47:30 2017 (r312589) +++ stable/10/lib/libc/stdlib/cxa_thread_atexit.c Sat Jan 21 12:30:07 2017 (r312590) @@ -1,7 +1,10 @@ /*- - * Copyright (c) 2016 Mahdi Mokhtari <mokhi64@gmail.com> + * Copyright (c) 2017 The FreeBSD Foundation * All rights reserved. * + * Portions of this software were developed by Konstantin Belousov + * under sponsorship from the FreeBSD Foundation. + * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: @@ -27,114 +30,11 @@ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); -#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(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); - } + return (__cxa_thread_atexit_hidden(dtor_func, obj, dso_symbol)); } Copied: stable/10/lib/libc/stdlib/cxa_thread_atexit_impl.c (from r311651, head/lib/libc/stdlib/cxa_thread_atexit_impl.c) ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ stable/10/lib/libc/stdlib/cxa_thread_atexit_impl.c Sat Jan 21 12:30:07 2017 (r312590, copy of r311651, head/lib/libc/stdlib/cxa_thread_atexit_impl.c) @@ -0,0 +1,153 @@ +/*- + * Copyright (c) 2016 Mahdi Mokhtari <mokhi64@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$"); + +#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); + } +}
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201701211230.v0LCU7ad015750>