diff options
Diffstat (limited to 'nptl-pthread_kill-must-send-signals-to-a-specific-th.patch')
| -rw-r--r-- | nptl-pthread_kill-must-send-signals-to-a-specific-th.patch | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/nptl-pthread_kill-must-send-signals-to-a-specific-th.patch b/nptl-pthread_kill-must-send-signals-to-a-specific-th.patch new file mode 100644 index 0000000..87683c3 --- /dev/null +++ b/nptl-pthread_kill-must-send-signals-to-a-specific-th.patch @@ -0,0 +1,162 @@ +From eae81d70574e923ce3c59078b8df857ae192efa6 Mon Sep 17 00:00:00 2001 +From: Florian Weimer <fweimer@redhat.com> +Date: Fri, 1 Oct 2021 18:16:41 +0200 +Subject: [PATCH] nptl: pthread_kill must send signals to a specific thread [BZ + #28407] + +The choice between the kill vs tgkill system calls is not just about +the TID reuse race, but also about whether the signal is sent to the +whole process (and any thread in it) or to a specific thread. + +This was caught by the openposix test suite: + + LTP: openposix test suite - FAIL: SIGUSR1 is member of new thread pendingset. + <https://gitlab.com/cki-project/kernel-tests/-/issues/764> + +Fixes commit 526c3cf11ee9367344b6b15d669e4c3cb461a2be ("nptl: Fix race +between pthread_kill and thread exit (bug 12889)"). + +Reviewed-by: Carlos O'Donell <carlos@redhat.com> +Tested-by: Carlos O'Donell <carlos@redhat.com> +--- + nptl/pthread_kill.c | 4 +- + sysdeps/pthread/Makefile | 1 + + sysdeps/pthread/tst-pthread-raise-blocked-self.c | 92 ++++++++++++++++++++++++ + 3 files changed, 94 insertions(+), 3 deletions(-) + create mode 100644 sysdeps/pthread/tst-pthread-raise-blocked-self.c + +diff --git a/nptl/pthread_kill.c b/nptl/pthread_kill.c +index a44dc8f..35bf1f9 100644 +--- a/nptl/pthread_kill.c ++++ b/nptl/pthread_kill.c +@@ -40,7 +40,7 @@ __pthread_kill_implementation (pthread_t threadid, int signo, int no_tid) + below. POSIX only guarantees delivery of a single signal, + which may not be the right one.) */ + pid_t tid = INTERNAL_SYSCALL_CALL (gettid); +- int ret = INTERNAL_SYSCALL_CALL (kill, tid, signo); ++ int ret = INTERNAL_SYSCALL_CALL (tgkill, __getpid (), tid, signo); + return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0; + } + +@@ -59,8 +59,6 @@ __pthread_kill_implementation (pthread_t threadid, int signo, int no_tid) + ret = no_tid; + else + { +- /* Using tgkill is a safety measure. pd->exit_lock ensures that +- the target thread cannot exit. */ + ret = INTERNAL_SYSCALL_CALL (tgkill, __getpid (), pd->tid, signo); + ret = INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0; + } +diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile +index d4bd2d4..0af9c59 100644 +--- a/sysdeps/pthread/Makefile ++++ b/sysdeps/pthread/Makefile +@@ -121,6 +121,7 @@ tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \ + tst-pthread-setuid-loop \ + tst-pthread_cancel-exited \ + tst-pthread_cancel-select-loop \ ++ tst-pthread-raise-blocked-self \ + tst-pthread_kill-exited \ + tst-pthread_kill-exiting \ + # tests +diff --git a/sysdeps/pthread/tst-pthread-raise-blocked-self.c b/sysdeps/pthread/tst-pthread-raise-blocked-self.c +new file mode 100644 +index 0000000..128e1a6 +--- /dev/null ++++ b/sysdeps/pthread/tst-pthread-raise-blocked-self.c +@@ -0,0 +1,92 @@ ++/* Test that raise sends signal to current thread even if blocked. ++ Copyright (C) 2021 Free Software Foundation, Inc. ++ This file is part of the GNU C Library. ++ ++ The GNU C 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; either ++ version 2.1 of the License, or (at your option) any later version. ++ ++ The GNU C 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 the GNU C Library; if not, see ++ <https://www.gnu.org/licenses/>. */ ++ ++#include <signal.h> ++#include <support/check.h> ++#include <support/xsignal.h> ++#include <support/xthread.h> ++#include <pthread.h> ++#include <unistd.h> ++ ++/* Used to create a dummy thread ID distinct from all other thread ++ IDs. */ ++static void * ++noop (void *ignored) ++{ ++ return NULL; ++} ++ ++static volatile pthread_t signal_thread; ++ ++static void ++signal_handler (int signo) ++{ ++ signal_thread = pthread_self (); ++} ++ ++/* Used to ensure that waiting_thread has launched and can accept ++ signals. */ ++static pthread_barrier_t barrier; ++ ++static void * ++waiting_thread (void *ignored) ++{ ++ xpthread_barrier_wait (&barrier); ++ pause (); ++ return NULL; ++} ++ ++static int ++do_test (void) ++{ ++ xsignal (SIGUSR1, signal_handler); ++ xpthread_barrier_init (&barrier, NULL, 2); ++ ++ /* Distinct thread ID value to */ ++ pthread_t dummy = xpthread_create (NULL, noop, NULL); ++ signal_thread = dummy; ++ ++ pthread_t helper = xpthread_create (NULL, waiting_thread, NULL); ++ ++ /* Make sure that the thread is running. */ ++ xpthread_barrier_wait (&barrier); ++ ++ /* Block signals on this thread. */ ++ sigset_t set; ++ sigfillset (&set); ++ xpthread_sigmask (SIG_BLOCK, &set, NULL); ++ ++ /* Send the signal to this thread. It must not be delivered. */ ++ raise (SIGUSR1); ++ TEST_VERIFY (signal_thread == dummy); ++ ++ /* Wait a bit to give a chance for signal delivery (increases ++ chances of failure with bug 28407). */ ++ usleep (50 * 1000); ++ ++ /* Unblocking should cause synchronous delivery of the signal. */ ++ xpthread_sigmask (SIG_UNBLOCK, &set, NULL); ++ TEST_VERIFY (signal_thread == pthread_self ()); ++ ++ xpthread_cancel (helper); ++ xpthread_join (helper); ++ xpthread_join (dummy); ++ return 0; ++} ++ ++#include <support/test-driver.c> +-- +1.8.3.1 + |