diff options
Diffstat (limited to 'sysdeps/nptl')
| -rw-r--r-- | sysdeps/nptl/Makefile | 2 | ||||
| -rw-r--r-- | sysdeps/nptl/futex-internal.c | 95 | ||||
| -rw-r--r-- | sysdeps/nptl/futex-internal.h | 10 |
3 files changed, 106 insertions, 1 deletions
diff --git a/sysdeps/nptl/Makefile b/sysdeps/nptl/Makefile index 0631a870c8..a65be3b7ea 100644 --- a/sysdeps/nptl/Makefile +++ b/sysdeps/nptl/Makefile @@ -17,7 +17,7 @@ # <https://www.gnu.org/licenses/>. ifeq ($(subdir),nptl) -libpthread-sysdep_routines += errno-loc +libpthread-sysdep_routines += errno-loc futex-internal endif ifeq ($(subdir),rt) diff --git a/sysdeps/nptl/futex-internal.c b/sysdeps/nptl/futex-internal.c new file mode 100644 index 0000000000..5e52f17dee --- /dev/null +++ b/sysdeps/nptl/futex-internal.c @@ -0,0 +1,95 @@ +/* futex helper functions for glibc-internal use. + Copyright (C) 2020 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 <errno.h> +#include <sysdep.h> +#include <time.h> +#include <futex-internal.h> +#include <kernel-features.h> + +#ifndef __ASSUME_TIME64_SYSCALLS +static int +__futex_abstimed_wait_cancellable32 (unsigned int* futex_word, + unsigned int expected, clockid_t clockid, + const struct __timespec64* abstime, + int private) +{ + if (! in_time_t_range (abstime->tv_sec)) + return -EOVERFLOW; + + unsigned int clockbit = (clockid == CLOCK_REALTIME) + ? FUTEX_CLOCK_REALTIME : 0; + int op = __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private); + + struct timespec ts32 = valid_timespec64_to_timespec (*abstime); + return INTERNAL_SYSCALL_CANCEL (futex, futex_word, op, expected, + &ts32, NULL /* Unused. */, + FUTEX_BITSET_MATCH_ANY); +} +#endif + +int +__futex_abstimed_wait_cancelable64 (unsigned int* futex_word, + unsigned int expected, clockid_t clockid, + const struct __timespec64* abstime, + int private) +{ + unsigned int clockbit; + int err; + + /* Work around the fact that the kernel rejects negative timeout values + despite them being valid. */ + if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0))) + return ETIMEDOUT; + + if (! lll_futex_supported_clockid (clockid)) + return EINVAL; + + clockbit = (clockid == CLOCK_REALTIME) ? FUTEX_CLOCK_REALTIME : 0; + int op = __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private); + + err = INTERNAL_SYSCALL_CANCEL (futex_time64, futex_word, op, expected, + abstime, NULL /* Unused. */, + FUTEX_BITSET_MATCH_ANY); +#ifndef __ASSUME_TIME64_SYSCALLS +if (err == -ENOSYS) + err = __futex_abstimed_wait_cancellable32 (futex_word, expected, + clockid, abstime, private); +#endif + + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + case -ETIMEDOUT: + case -EOVERFLOW: /* Passed absolute timeout uses 64 bit time_t type, but + underlying kernel does not support 64 bit time_t futex + syscalls. */ + return -err; + + case -EFAULT: /* Must have been caused by a glibc or application bug. */ + case -EINVAL: /* Either due to wrong alignment or due to the timeout not + being normalized. Must have been caused by a glibc or + application bug. */ + case -ENOSYS: /* Must have been caused by a glibc bug. */ + /* No other errors are documented at this time. */ + default: + futex_fatal_error (); + } +} diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 159aae82dc..84ab3f3853 100644 --- a/sysdeps/nptl/futex-internal.h +++ b/sysdeps/nptl/futex-internal.h @@ -519,4 +519,14 @@ futex_timed_wait_cancel64 (pid_t *tidp, pid_t tid, futex_fatal_error (); } } + +/* The futex_abstimed_wait_cancelable64 has been moved to a separate file + to avoid problems with exhausting available registers on some architectures + - e.g. on m68k architecture. */ +int +__futex_abstimed_wait_cancelable64 (unsigned int* futex_word, + unsigned int expected, clockid_t clockid, + const struct __timespec64* abstime, + int private) attribute_hidden; + #endif /* futex-internal.h */ |