diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | sysdeps/pthread/aio_error.c | 49 | ||||
| -rw-r--r-- | sysdeps/pthread/aio_misc.c | 8 |
3 files changed, 57 insertions, 8 deletions
@@ -1,3 +1,11 @@ +2015-03-06 Samuel Thibault <samuel.thibault@inria.fr> + + Fix aio_error thread-safety. + + * sysdeps/pthread/aio_error.c: New file + * sysdeps/pthread/aio_misc.c: Remove optimistic comment about + synchronization. + 2015-03-06 Florian Weimer <fweimer@redhat.com> * stdio-common/vfprintf.c (THOUSANDS_SEP_T): New typedef. diff --git a/sysdeps/pthread/aio_error.c b/sysdeps/pthread/aio_error.c new file mode 100644 index 0000000..ebe1378 --- /dev/null +++ b/sysdeps/pthread/aio_error.c @@ -0,0 +1,49 @@ +/* Return error status of asynchronous I/O request. + Copyright (C) 1997-2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + 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 + <http://www.gnu.org/licenses/>. */ + + +/* We use an UGLY hack to prevent gcc from finding us cheating. The + implementation of aio_error and aio_error64 are identical and so + we want to avoid code duplication by using aliases. But gcc sees + the different parameter lists and prints a warning. We define here + a function so that aio_error64 has no prototype. */ +#define aio_error64 XXX +#include <aio.h> +/* And undo the hack. */ +#undef aio_error64 + +#include <aio_misc.h> + + +int +aio_error (aiocbp) + const struct aiocb *aiocbp; +{ + int ret; + + /* Acquire the mutex to make sure all operations for this request are + complete. */ + pthread_mutex_lock(&__aio_requests_mutex); + ret = aiocbp->__error_code; + pthread_mutex_unlock(&__aio_requests_mutex); + + return ret; +} + +weak_alias (aio_error, aio_error64) diff --git a/sysdeps/pthread/aio_misc.c b/sysdeps/pthread/aio_misc.c index 5d2b81e..83a6cb9 100644 --- a/sysdeps/pthread/aio_misc.c +++ b/sysdeps/pthread/aio_misc.c @@ -593,14 +593,6 @@ handle_fildes_io (void *arg) /* Get the mutex. */ pthread_mutex_lock (&__aio_requests_mutex); - /* In theory we would need here a write memory barrier since the - callers test using aio_error() whether the request finished - and once this value != EINPROGRESS the field __return_value - must be committed to memory. - - But since the pthread_mutex_lock call involves write memory - barriers as well it is not necessary. */ - if (aiocbp->aiocb.__return_value == -1) aiocbp->aiocb.__error_code = errno; else |