Index: lib/libc/Versions.def =================================================================== --- lib/libc/Versions.def +++ lib/libc/Versions.def @@ -27,6 +27,10 @@ FBSD_1.4 { } FBSD_1.3; +# This version was first added to 12.0-current. +FBSD_1.5 { +} FBSD_1.4; + # This is our private namespace. Any global interfaces that are # strictly for use only by other FreeBSD applications and libraries @@ -35,4 +39,4 @@ # # Please do NOT increment the version of this namespace. FBSDprivate_1.0 { -} FBSD_1.4; +} FBSD_1.5; Index: lib/libc/include/libc_private.h =================================================================== --- lib/libc/include/libc_private.h +++ lib/libc/include/libc_private.h @@ -267,6 +267,12 @@ void _malloc_thread_cleanup(void); /* + * This function is used by the threading libraries to notify libc that a + * thread is exiting, so its thread-local dtors should be called. + */ +void __cxa_thread_call_dtors(void); + +/* * These functions are used by the threading libraries in order to protect * malloc across fork(). */ Index: lib/libc/stdlib/Makefile.inc =================================================================== --- lib/libc/stdlib/Makefile.inc +++ lib/libc/stdlib/Makefile.inc @@ -5,7 +5,7 @@ .PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/stdlib ${LIBC_SRCTOP}/stdlib MISRCS+=_Exit.c a64l.c abort.c abs.c atexit.c atof.c atoi.c atol.c atoll.c \ - bsearch.c div.c exit.c getenv.c getopt.c getopt_long.c \ + bsearch.c cxa_thread_atexit.c div.c exit.c getenv.c getopt.c getopt_long.c \ getsubopt.c hcreate.c hcreate_r.c hdestroy_r.c heapsort.c heapsort_b.c \ hsearch_r.c imaxabs.c imaxdiv.c \ insque.c l64a.c labs.c ldiv.c llabs.c lldiv.c lsearch.c \ Index: lib/libc/stdlib/Symbol.map =================================================================== --- lib/libc/stdlib/Symbol.map +++ lib/libc/stdlib/Symbol.map @@ -116,8 +116,13 @@ reallocarray; }; +FBSD_1.5 { + __cxa_thread_atexit; +}; + FBSDprivate_1.0 { __system; _system; __libc_system; + __cxa_thread_call_dtors; }; Index: lib/libc/stdlib/cxa_thread_atexit.c =================================================================== --- /dev/null +++ lib/libc/stdlib/cxa_thread_atexit.c @@ -0,0 +1,140 @@ +/*- + * Copyright (c) 2016 Mahdi Mokhtari + * All rights reserved. + * + * 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 +__FBSDID("$FreeBSD$"); + +#include +#include "namespace.h" +#include +#include +#include +#include +#include +#include +#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 idea of implementing this is to keep a _Thread_local list of + * destructors per each thread, and calling __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'll + * 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); + } +} Index: lib/libc/stdlib/exit.c =================================================================== --- lib/libc/stdlib/exit.c +++ lib/libc/stdlib/exit.c @@ -63,6 +63,12 @@ _thread_autoinit_dummy_decl = 1; + /* + * We're dealing with cleaning up thread_local destructors in the case of + * the process termination through main() exit. + * Other cases are handled elsewhere. + */ + __cxa_thread_call_dtors(); __cxa_finalize(NULL); if (__cleanup) (*__cleanup)(); Index: lib/libc/tests/stdlib/Makefile =================================================================== --- lib/libc/tests/stdlib/Makefile +++ lib/libc/tests/stdlib/Makefile @@ -1,9 +1,15 @@ # $FreeBSD$ +.include + ATF_TESTS_C+= heapsort_test ATF_TESTS_C+= mergesort_test ATF_TESTS_C+= qsort_test ATF_TESTS_C+= tsearch_test +.if ${COMPILER_FEATURES:Mc++11} +ATF_TESTS_CXX+= cxa_thread_atexit_test +ATF_TESTS_CXX+= cxa_thread_atexit_nothr_test +.endif # TODO: t_getenv_thread, t_mi_vector_hash NETBSD_ATF_TESTS_C+= abs_test @@ -33,6 +39,10 @@ CFLAGS+= -I${.CURDIR} +CXXFLAGS.cxa_thread_atexit_test+= -std=c++11 +CXXFLAGS.cxa_thread_atexit_nothr_test+= -std=c++11 +LIBADD.cxa_thread_atexit_test+= pthread + .for t in h_getopt h_getopt_long CFLAGS.$t+= -I${LIBNETBSD_SRCDIR} -I${SRCTOP}/contrib/netbsd-tests LDFLAGS.$t+= -L${LIBNETBSD_OBJDIR} Index: lib/libc/tests/stdlib/Makefile.depend =================================================================== --- lib/libc/tests/stdlib/Makefile.depend +++ lib/libc/tests/stdlib/Makefile.depend @@ -8,7 +8,10 @@ include/xlocale \ lib/${CSU_DIR} \ lib/atf/libatf-c \ + lib/atf/libatf-c++ \ lib/libc \ + lib/libc++ \ + lib/libthr \ lib/libcompiler_rt \ lib/libnetbsd \ lib/libutil \ Index: lib/libc/tests/stdlib/cxa_thread_atexit_nothr_test.cc =================================================================== --- /dev/null +++ lib/libc/tests/stdlib/cxa_thread_atexit_nothr_test.cc @@ -0,0 +1,102 @@ +/*- + * Copyright (c) 2016 Mahdi Mokhtari + * Copyright (c) 2016 The FreeBSD Foundation + * All rights reserved. + * + * 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 +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include + +static FILE *output = NULL; + +struct Foo { + Foo() { ATF_REQUIRE(fprintf(output, "Created\n") > 0); } + ~Foo() { ATF_REQUIRE(fprintf(output, "Destroyed\n") > 0); } + void use() { ATF_REQUIRE(fprintf(output, "Used\n") > 0); } +}; + +static thread_local Foo f; + +/* + * This test must not be linked to libpthread. + */ +ATF_TEST_CASE_WITHOUT_HEAD(cxx__nothr); +ATF_TEST_CASE_BODY(cxx__nothr) +{ + void *libthr_handle; + + /* Avoid coredump during f construction. */ + output = stderr; + + libthr_handle = dlopen("libthr.so.3", RTLD_LAZY | RTLD_GLOBAL | + RTLD_NOLOAD); + ATF_REQUIRE(libthr_handle == NULL); +} + +static void +check_local_main(void) +{ + static const char out_log[] = "Created\nUsed\nDestroyed\n"; + + fflush(output); + ATF_REQUIRE(atf::utils::compare_file("test_main.txt", out_log)); +} + +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thread_local_main); +ATF_TEST_CASE_BODY(cxx__thread_local_main) +{ + + ATF_REQUIRE((output = fopen("test_main.txt", "w")) != NULL); + f.use(); + atexit(check_local_main); +} + +extern "C" int __cxa_thread_atexit(void (*)(void *), void *, void *); + +static void +again(void *arg) +{ + + __cxa_thread_atexit(again, arg, &output); +} + +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thread_inf_dtors); +ATF_TEST_CASE_BODY(cxx__thread_inf_dtors) +{ + + again(NULL); +} + +ATF_INIT_TEST_CASES(tcs) +{ + + ATF_ADD_TEST_CASE(tcs, cxx__nothr); + ATF_ADD_TEST_CASE(tcs, cxx__thread_local_main); + ATF_ADD_TEST_CASE(tcs, cxx__thread_inf_dtors); +} Index: lib/libc/tests/stdlib/cxa_thread_atexit_test.cc =================================================================== --- /dev/null +++ lib/libc/tests/stdlib/cxa_thread_atexit_test.cc @@ -0,0 +1,180 @@ +/*- + * Copyright (c) 2016 Mahdi Mokhtari + * All rights reserved. + * + * 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 +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include +#include + +static FILE *output = NULL; + +struct Foo { + Foo() { ATF_REQUIRE(fprintf(output, "Created\n") > 0); } + ~Foo() { ATF_REQUIRE(fprintf(output, "Destroyed\n") > 0); } + void use() { ATF_REQUIRE(fprintf(output, "Used\n") > 0); } +}; + +struct Bar { + Bar() {} + ~Bar() { + thread_local static Foo foo; + ATF_REQUIRE(fprintf(output, "DIED\n") > 0); + } + void use() {} +}; + +extern "C" int __cxa_thread_atexit(void (*)(void *), void *, void *); + +static void +again(void *arg) +{ + + __cxa_thread_atexit(again, arg, &output); +} + +struct Baz { + Baz() {} + ~Baz() { + again(NULL); + } + void use() {} +}; + +static thread_local Foo f; +static thread_local Foo g; +static thread_local Bar h; +static thread_local Baz e; + +/* + * This test must be linked to libpthread. + */ +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thr); +ATF_TEST_CASE_BODY(cxx__thr) +{ + void *libthr_handle; + + /* Avoid coredump during f construction. */ + output = stderr; + + libthr_handle = dlopen("libthr.so.3", RTLD_LAZY | RTLD_GLOBAL | + RTLD_NOLOAD); + ATF_REQUIRE(libthr_handle != NULL); + dlclose(libthr_handle); +} + +/* + * In this test f.use() will test cxa_thread_atexit() in non-threaded mode. + * After f.use() main will be threaded and we'll have one additional thread + * with its own TLS data. + */ +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thread_local_before); +ATF_TEST_CASE_BODY(cxx__thread_local_before) +{ + static const char out_log[] = "Created\nCreated\nUsed\nCreated\n" + "Created\nUsed\nCreated\nDIED\nDestroyed\nDestroyed\nDestroyed\n"; + + ATF_REQUIRE((output = fopen("test_before.txt", "w")) != NULL); + + f.use(); + std::thread t([]() { f.use(); }); + t.join(); + + fflush(output); + + ATF_REQUIRE(atf::utils::compare_file("test_before.txt", out_log)); +} + +/* + * In this test, f.use() will test __cxa_thread_atexit() + * in threaded mode (but still in main-threaed). + */ +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thread_local_after); +ATF_TEST_CASE_BODY(cxx__thread_local_after) +{ + static const char out_log[] = "Created\nCreated\nUsed\nCreated\n" + "DIED\nDestroyed\nDestroyed\nDestroyed\nCreated\nCreated\nUsed\n"; + + ATF_REQUIRE((output = fopen("test_after.txt", "w")) != NULL); + + std::thread t([]() { g.use(); }); + t.join(); + sleep(1); + g.use(); + + fflush(output); + + ATF_REQUIRE(atf::utils::compare_file("test_after.txt", out_log)); +} + +/* + * In this test, we register a new dtor while dtors are being run + * in __cxa_thread_atexit(). + */ +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thread_local_add_while_calling_dtors); +ATF_TEST_CASE_BODY(cxx__thread_local_add_while_calling_dtors) +{ + static const char out_log[] = "Created\nCreated\nCreated\nDIED\n" + "Destroyed\nDestroyed\nDestroyed\n"; + + ATF_REQUIRE((output = fopen("test_add_meanwhile.txt", "w")) != NULL); + + std::thread t([]() { h.use(); }); + t.join(); + sleep(1); + + fflush(output); + + ATF_REQUIRE(atf::utils::compare_file("test_add_meanwhile.txt", out_log)); +} + +ATF_TEST_CASE_WITHOUT_HEAD(cxx__thread_inf_dtors); +ATF_TEST_CASE_BODY(cxx__thread_inf_dtors) +{ + + /* + * Only added to make isolated run of this test not + * coredumping. Construction of Foo objects require filled + * output. + */ + output = stderr; + + std::thread t([]() { e.use(); }); + t.join(); +} + +ATF_INIT_TEST_CASES(tcs) +{ + + ATF_ADD_TEST_CASE(tcs, cxx__thr); + ATF_ADD_TEST_CASE(tcs, cxx__thread_local_before); + ATF_ADD_TEST_CASE(tcs, cxx__thread_local_after); + ATF_ADD_TEST_CASE(tcs, cxx__thread_local_add_while_calling_dtors); + ATF_ADD_TEST_CASE(tcs, cxx__thread_inf_dtors); +} Index: lib/libthr/thread/thr_exit.c =================================================================== --- lib/libthr/thread/thr_exit.c +++ lib/libthr/thread/thr_exit.c @@ -153,8 +153,12 @@ __pthread_cleanup_pop_imp(1); } - if (done) + if (done) { + /* Tell libc that it should call non-trivial TLS dtors. */ + __cxa_thread_call_dtors(); + exit_thread(); /* Never return! */ + } return (_URC_NO_REASON); } @@ -258,6 +262,8 @@ while (curthread->cleanup != NULL) { __pthread_cleanup_pop_imp(1); } + __cxa_thread_call_dtors(); + exit_thread(); } @@ -265,6 +271,7 @@ while (curthread->cleanup != NULL) { __pthread_cleanup_pop_imp(1); } + __cxa_thread_call_dtors(); exit_thread(); #endif /* _PTHREAD_FORCED_UNWIND */