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From: Adhemerval Zanella <azanella@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/azanella/pthread-multiple-fixes] nptl: Set cancellation type and state on pthread_exit Date: Fri, 20 Aug 2021 17:55:28 +0000 (GMT) [thread overview] Message-ID: <20210820175528.44C0638A8801@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=7ce598e7e1f725dd324840643b9c71c43457598f commit 7ce598e7e1f725dd324840643b9c71c43457598f Author: Adhemerval Zanella <adhemerval.zanella@linaro.org> Date: Mon May 31 10:47:52 2021 -0300 nptl: Set cancellation type and state on pthread_exit It is required by POSIX XSH 2.9.5 Thread Cancellation under the heading Thread Cancellation Cleanup Handlers. Checked x86_64-linux-gnu. Diff: --- nptl/Makefile | 3 +- nptl/cancellation.c | 7 ++- nptl/pthread_cancel.c | 1 - nptl/pthread_exit.c | 4 +- nptl/pthread_testcancel.c | 1 - nptl/tst-cleanup5.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++ sysdeps/nptl/pthreadP.h | 18 ++++-- 7 files changed, 180 insertions(+), 11 deletions(-) diff --git a/nptl/Makefile b/nptl/Makefile index ff4d590f11..e1e195cc15 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -306,7 +306,8 @@ tests = tst-attr2 tst-attr3 tst-default-attr \ tst-pthread-gdb-attach tst-pthread-gdb-attach-static \ tst-pthread_exit-nothreads \ tst-pthread_exit-nothreads-static \ - tst-thread-setspecific + tst-thread-setspecific \ + tst-cleanup5 tests-nolibpthread = \ tst-pthread_exit-nothreads \ diff --git a/nptl/cancellation.c b/nptl/cancellation.c index 05962784d5..6478c029de 100644 --- a/nptl/cancellation.c +++ b/nptl/cancellation.c @@ -42,7 +42,6 @@ __pthread_enable_asynccancel (void) && !(ch & EXITING_BITMASK) && !(ch & TERMINATED_BITMASK)) { - THREAD_SETMEM (self, result, PTHREAD_CANCELED); __do_cancel (); } @@ -64,3 +63,9 @@ __pthread_disable_asynccancel (int oldtype) self->canceltype = PTHREAD_CANCEL_DEFERRED; } libc_hidden_def (__pthread_disable_asynccancel) + +void +__do_cancel (void) +{ + __exit_thread (PTHREAD_CANCELED); +} diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c index cc25ff21f3..38f637c5cf 100644 --- a/nptl/pthread_cancel.c +++ b/nptl/pthread_cancel.c @@ -107,7 +107,6 @@ __pthread_cancel (pthread_t th) __libc_multiple_threads = 1; #endif - THREAD_SETMEM (pd, result, PTHREAD_CANCELED); if (pd->cancelstate == PTHREAD_CANCEL_ENABLE && pd->canceltype == PTHREAD_CANCEL_ASYNCHRONOUS) __do_cancel (); diff --git a/nptl/pthread_exit.c b/nptl/pthread_exit.c index 6abf66463e..978f4042ef 100644 --- a/nptl/pthread_exit.c +++ b/nptl/pthread_exit.c @@ -32,9 +32,7 @@ __pthread_exit (void *value) " must be installed for pthread_exit to work\n"); } - THREAD_SETMEM (THREAD_SELF, result, value); - - __do_cancel (); + __exit_thread (value); } libc_hidden_def (__pthread_exit) weak_alias (__pthread_exit, pthread_exit) diff --git a/nptl/pthread_testcancel.c b/nptl/pthread_testcancel.c index 31185d89f2..f728a35524 100644 --- a/nptl/pthread_testcancel.c +++ b/nptl/pthread_testcancel.c @@ -30,7 +30,6 @@ ___pthread_testcancel (void) && !(cancelhandling & EXITING_BITMASK) && !(cancelhandling & TERMINATED_BITMASK)) { - THREAD_SETMEM (self, result, PTHREAD_CANCELED); __do_cancel (); } } diff --git a/nptl/tst-cleanup5.c b/nptl/tst-cleanup5.c new file mode 100644 index 0000000000..6cc1c141e9 --- /dev/null +++ b/nptl/tst-cleanup5.c @@ -0,0 +1,157 @@ +/* Check if cancellation state and type is correctly set on thread exit. + 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 <support/check.h> +#include <support/xthread.h> +#include <support/xunistd.h> + +static int pipefds[2]; +static pthread_barrier_t b; + +static void +clh (void *arg) +{ + /* Although POSIX state setting either the cancellation state or type is + undefined during cleanup handler execution, both calls should be safe + since none has any side-effect (they should not change current state + neither trigger a pending cancellation). */ + + int state; + TEST_VERIFY (pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state) == 0); + TEST_COMPARE (state, PTHREAD_CANCEL_DISABLE); + + int type; + TEST_VERIFY (pthread_setcanceltype (PTHREAD_CANCEL_DEFERRED, &type) == 0); + TEST_COMPARE (type, PTHREAD_CANCEL_DEFERRED); +} + +/* Check if a thread with PTHREAD_CANCEL_DEFERRED cancellation on + pthread_cleanup_pop sets the correct state and type as pthread_exit. */ +static void * +tf_cancel_deferred (void *arg) +{ + xpthread_barrier_wait (&b); + + pthread_cleanup_push (clh, NULL); + + char c; + read (pipefds[0], &c, 1); + + pthread_cleanup_pop (1); + + return NULL; +} + +/* Check if a thread with PTHREAD_CANCEL_ASYNCHRONOUS cancellation on + blocked read() sets the correct state and type as pthread_exit. */ +static void * +tf_cancel_async (void *arg) +{ + TEST_VERIFY (pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, NULL) + == 0); + + xpthread_barrier_wait (&b); + + pthread_cleanup_push (clh, NULL); + + char c; + read (pipefds[0], &c, 1); + + pthread_cleanup_pop (1); + + return NULL; +} + +/* Check if a thread with PTHREAD_CANCEL_DEFERRED cancellation on + blocked read() sets the correct state and type as pthread_exit. */ +static void * +tf_testcancel (void *arg) +{ + xpthread_barrier_wait (&b); + + pthread_cleanup_push (clh, NULL); + + char c; + read (pipefds[0], &c, 1); + + pthread_testcancel (); + + pthread_cleanup_pop (1); + + return NULL; +} + +#define EXIT_EXPECTED_VALUE ((void *) 42) + +/* Check if a thread with PTHREAD_CANCEL_DEFERRED cancellation on + pthread_exit() sets the correct state and type. */ +static void * +tf_exit (void *arg) +{ + xpthread_barrier_wait (&b); + + pthread_cleanup_push (clh, NULL); + + pthread_exit (EXIT_EXPECTED_VALUE); + + pthread_cleanup_pop (1); + + return NULL; +} + +static int +do_test (void) +{ + xpipe (pipefds); + + xpthread_barrier_init (&b, NULL, 2); + { + pthread_t th = xpthread_create (NULL, tf_cancel_deferred, NULL); + xpthread_barrier_wait (&b); + xpthread_cancel (th); + void *r = xpthread_join (th); + TEST_VERIFY (r == PTHREAD_CANCELED); + } + + { + pthread_t th = xpthread_create (NULL, tf_cancel_async, NULL); + xpthread_barrier_wait (&b); + xpthread_cancel (th); + void *r = xpthread_join (th); + TEST_VERIFY (r == PTHREAD_CANCELED); + } + + { + pthread_t th = xpthread_create (NULL, tf_testcancel, NULL); + xpthread_barrier_wait (&b); + xpthread_cancel (th); + void *r = xpthread_join (th); + TEST_VERIFY (r == PTHREAD_CANCELED); + } + + { + pthread_t th = xpthread_create (NULL, tf_exit, NULL); + xpthread_barrier_wait (&b); + void *r = xpthread_join (th); + TEST_VERIFY (r == EXIT_EXPECTED_VALUE); + } + + return 0; +} + +#include <support/test-driver.c> diff --git a/sysdeps/nptl/pthreadP.h b/sysdeps/nptl/pthreadP.h index 374657a2fd..d968a91cfd 100644 --- a/sysdeps/nptl/pthreadP.h +++ b/sysdeps/nptl/pthreadP.h @@ -268,20 +268,30 @@ extern void __pthread_unregister_cancel (__pthread_unwind_buf_t *__buf) __cleanup_fct_attribute; libc_hidden_proto (__pthread_unregister_cancel) -/* Called when a thread reacts on a cancellation request. */ -static inline void -__attribute ((noreturn, always_inline)) -__do_cancel (void) +static _Noreturn inline void +__exit_thread (void *value) { struct pthread *self = THREAD_SELF; /* Make sure we get no more cancellations. */ THREAD_ATOMIC_BIT_SET (self, cancelhandling, EXITING_BIT); + THREAD_SETMEM (self, result, value); + + /* It is required by POSIX XSH 2.9.5 Thread Cancellation under the heading + Thread Cancellation Cleanup Handlers and also avoid further cancellation + wrapper to act on cancellation. */ + THREAD_SETMEM (self, cancelstate, PTHREAD_CANCEL_DISABLE); + THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_DEFERRED); + __pthread_unwind ((__pthread_unwind_buf_t *) THREAD_GETMEM (self, cleanup_jmp_buf)); } +/* It is a wrapper over __exit_thread (PTHREAD_CANCELED). It is has its own + implementation because it might be called by arch-specific asm code. */ +_Noreturn void __do_cancel (void) attribute_hidden; + /* Internal prototypes. */
next reply other threads:[~2021-08-20 17:55 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-20 17:55 Adhemerval Zanella [this message] -- strict thread matches above, loose matches on Subject: below -- 2021-06-08 20:48 Adhemerval Zanella
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