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author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-05-31 10:47:52 -0300 |
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committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-09-10 08:22:11 -0300 |
commit | f7876a01a1b4b0f77eadc9063e992b7b51f90a3f (patch) | |
tree | d8a3481aa61c371d6fe6ba642f1e6da85f4824bd | |
parent | 1a2aad377a9c041c4a7feb7fa645bd411fd18b63 (diff) | |
download | glibc-f7876a01a1b4b0f77eadc9063e992b7b51f90a3f.tar.gz |
nptl: Set cancellation type and state on pthread_exit (BZ #28267)
It is required by POSIX XSH 2.9.5 Thread Cancellation under the heading
Thread Cancellation Cleanup Handlers.
Checked x86_64-linux-gnu.
-rw-r--r-- | nptl/Makefile | 3 | ||||
-rw-r--r-- | nptl/cancellation.c | 7 | ||||
-rw-r--r-- | nptl/pthread_cancel.c | 1 | ||||
-rw-r--r-- | nptl/pthread_exit.c | 4 | ||||
-rw-r--r-- | nptl/pthread_testcancel.c | 1 | ||||
-rw-r--r-- | nptl/tst-cleanup5.c | 129 | ||||
-rw-r--r-- | sysdeps/nptl/pthreadP.h | 18 |
7 files changed, 152 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 44f8417845..7cef9487bf 100644 --- a/nptl/cancellation.c +++ b/nptl/cancellation.c @@ -41,7 +41,6 @@ __pthread_enable_asynccancel (void) && !(ch & EXITING_BITMASK) && !(ch & TERMINATED_BITMASK)) { - THREAD_SETMEM (self, result, PTHREAD_CANCELED); __do_cancel (); } @@ -63,3 +62,9 @@ __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 a8aa3b3d15..868cf676a3 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 f54388a8e2..14a73043bf 100644 --- a/nptl/pthread_exit.c +++ b/nptl/pthread_exit.c @@ -31,9 +31,7 @@ __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 7a7a199b6d..6c613462ab 100644 --- a/nptl/pthread_testcancel.c +++ b/nptl/pthread_testcancel.c @@ -29,7 +29,6 @@ ___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..f1f81a40fe --- /dev/null +++ b/nptl/tst-cleanup5.c @@ -0,0 +1,129 @@ +/* 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_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_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 0e39afecc6..aebddb361b 100644 --- a/sysdeps/nptl/pthreadP.h +++ b/sysdeps/nptl/pthreadP.h @@ -267,20 +267,30 @@ 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. */ |