X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust-comm%2Flttng-ust-fd-tracker.c;h=c9b5fdc0250c72d3538fe6fc9d35b77c45ce3d31;hb=cd61d9bfa5fd334b086831dcbdec63da6c0d1a16;hp=1118163a201af456ac6ed28d490e09f458af08ef;hpb=283f4bec47781f7a39dde82d02e53add02155f9c;p=lttng-ust.git diff --git a/liblttng-ust-comm/lttng-ust-fd-tracker.c b/liblttng-ust-comm/lttng-ust-fd-tracker.c index 1118163a..c9b5fdc0 100644 --- a/liblttng-ust-comm/lttng-ust-fd-tracker.c +++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c @@ -1,23 +1,10 @@ /* - * Copyright (C) 2016 - Aravind HT - * 2016 - Mathieu Desnoyers + * SPDX-License-Identifier: LGPL-2.1-only * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; only - * version 2.1 of the License. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * Copyright (C) 2016 Aravind HT + * Copyright (C) 2016 Mathieu Desnoyers */ -#define _GNU_SOURCE #include #include #include @@ -32,12 +19,14 @@ #include #include #include +#include +#include #include #include #include #include -#include +#include #include #include @@ -75,9 +64,11 @@ static int ust_safe_guard_saved_cancelstate; /* * Track whether we are within lttng-ust or application, for close - * system call override by LD_PRELOAD library. + * system call override by LD_PRELOAD library. This also tracks whether + * we are invoking close() from a signal handler nested on an + * application thread. */ -static DEFINE_URCU_TLS(int, thread_fd_tracking); +static DEFINE_URCU_TLS(int, ust_fd_mutex_nest); /* fd_set used to book keep fd being used by lttng-ust. */ static fd_set *lttng_fd_set; @@ -90,7 +81,7 @@ static int init_done; */ void lttng_ust_fixup_fd_tracker_tls(void) { - asm volatile ("" : : "m" (URCU_TLS(thread_fd_tracking))); + asm volatile ("" : : "m" (URCU_TLS(ust_fd_mutex_nest))); } /* @@ -134,37 +125,63 @@ void lttng_ust_init_fd_tracker(void) void lttng_ust_lock_fd_tracker(void) { + sigset_t sig_all_blocked, orig_mask; int ret, oldstate; ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); if (ret) { ERR("pthread_setcancelstate: %s", strerror(ret)); } - URCU_TLS(thread_fd_tracking) = 1; - /* - * Ensure the compiler don't move the store after the close() - * call in case close() would be marked as leaf. - */ - cmm_barrier(); - pthread_mutex_lock(&ust_safe_guard_fd_mutex); - ust_safe_guard_saved_cancelstate = oldstate; + sigfillset(&sig_all_blocked); + ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); + if (ret) { + ERR("pthread_sigmask: %s", strerror(ret)); + } + if (!URCU_TLS(ust_fd_mutex_nest)++) { + /* + * Ensure the compiler don't move the store after the close() + * call in case close() would be marked as leaf. + */ + cmm_barrier(); + pthread_mutex_lock(&ust_safe_guard_fd_mutex); + ust_safe_guard_saved_cancelstate = oldstate; + } + ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); + if (ret) { + ERR("pthread_sigmask: %s", strerror(ret)); + } } void lttng_ust_unlock_fd_tracker(void) { + sigset_t sig_all_blocked, orig_mask; int ret, newstate, oldstate; + bool restore_cancel = false; - newstate = ust_safe_guard_saved_cancelstate; - pthread_mutex_unlock(&ust_safe_guard_fd_mutex); + sigfillset(&sig_all_blocked); + ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); + if (ret) { + ERR("pthread_sigmask: %s", strerror(ret)); + } /* * Ensure the compiler don't move the store before the close() * call, in case close() would be marked as leaf. */ cmm_barrier(); - URCU_TLS(thread_fd_tracking) = 0; - ret = pthread_setcancelstate(newstate, &oldstate); + if (!--URCU_TLS(ust_fd_mutex_nest)) { + newstate = ust_safe_guard_saved_cancelstate; + restore_cancel = true; + pthread_mutex_unlock(&ust_safe_guard_fd_mutex); + } + ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); if (ret) { - ERR("pthread_setcancelstate: %s", strerror(ret)); + ERR("pthread_sigmask: %s", strerror(ret)); + } + if (restore_cancel) { + ret = pthread_setcancelstate(newstate, &oldstate); + if (ret) { + ERR("pthread_setcancelstate: %s", strerror(ret)); + } } } @@ -255,7 +272,7 @@ int lttng_ust_add_fd_to_tracker(int fd) * constructors. */ lttng_ust_init_fd_tracker(); - assert(URCU_TLS(thread_fd_tracking)); + assert(URCU_TLS(ust_fd_mutex_nest)); if (IS_FD_STD(fd)) { ret = dup_std_fd(fd); @@ -288,7 +305,7 @@ void lttng_ust_delete_fd_from_tracker(int fd) */ lttng_ust_init_fd_tracker(); - assert(URCU_TLS(thread_fd_tracking)); + assert(URCU_TLS(ust_fd_mutex_nest)); /* Not a valid fd. */ assert(IS_FD_VALID(fd)); /* Deleting an fd which was not set. */ @@ -318,7 +335,7 @@ int lttng_ust_safe_close_fd(int fd, int (*close_cb)(int fd)) * If called from lttng-ust, we directly call close without * validating whether the FD is part of the tracked set. */ - if (URCU_TLS(thread_fd_tracking)) + if (URCU_TLS(ust_fd_mutex_nest)) return close_cb(fd); lttng_ust_lock_fd_tracker(); @@ -354,7 +371,7 @@ int lttng_ust_safe_fclose_stream(FILE *stream, int (*fclose_cb)(FILE *stream)) * If called from lttng-ust, we directly call fclose without * validating whether the FD is part of the tracked set. */ - if (URCU_TLS(thread_fd_tracking)) + if (URCU_TLS(ust_fd_mutex_nest)) return fclose_cb(stream); fd = fileno(stream); @@ -417,7 +434,7 @@ int lttng_ust_safe_closefrom_fd(int lowfd, int (*close_cb)(int fd)) * If called from lttng-ust, we directly call close without * validating whether the FD is part of the tracked set. */ - if (URCU_TLS(thread_fd_tracking)) { + if (URCU_TLS(ust_fd_mutex_nest)) { for (i = lowfd; i < lttng_ust_max_fd; i++) { if (close_cb(i) < 0) { switch (errno) {