diff options
Diffstat (limited to 'nptl')
| -rw-r--r-- | nptl/Makefile | 3 | ||||
| -rw-r--r-- | nptl/futex-internal.c | 126 |
2 files changed, 129 insertions, 0 deletions
diff --git a/nptl/Makefile b/nptl/Makefile index 94c3873623..5a7558d943 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -97,6 +97,7 @@ libpthread-routines = \ flockfile \ ftrylockfile \ funlockfile \ + futex-internal \ herrno \ libpthread-compat \ lowlevellock \ @@ -314,6 +315,8 @@ CFLAGS-fsync.c += -fexceptions -fasynchronous-unwind-tables CFLAGS-pt-system.c += -fexceptions +CFLAGS-futex-internal.c += -fexceptions -fasynchronous-unwind-tables + LDLIBS-tst-once5 = -lstdc++ CFLAGS-tst-thread_local1.o = -std=gnu++11 LDLIBS-tst-thread_local1 = -lstdc++ diff --git a/nptl/futex-internal.c b/nptl/futex-internal.c new file mode 100644 index 0000000000..89b4ba76e9 --- /dev/null +++ b/nptl/futex-internal.c @@ -0,0 +1,126 @@ +/* futex helper functions for glibc-internal use. + Copyright (C) 2020-2021 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 <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_common32 (unsigned int* futex_word, + unsigned int expected, int op, + const struct __timespec64* abstime, + int private, bool cancel) +{ + struct timespec ts32, *pts32 = NULL; + if (abstime != NULL) + { + if (! in_time_t_range (abstime->tv_sec)) + return -EOVERFLOW; + + ts32 = valid_timespec64_to_timespec (*abstime); + pts32 = &ts32; + } + + if (cancel) + return INTERNAL_SYSCALL_CANCEL (futex, futex_word, op, expected, + pts32, NULL /* Unused. */, + FUTEX_BITSET_MATCH_ANY); + else + return INTERNAL_SYSCALL_CALL (futex, futex_word, op, expected, + pts32, NULL /* Unused. */, + FUTEX_BITSET_MATCH_ANY); +} +#endif /* ! __ASSUME_TIME64_SYSCALLS */ + +static int +__futex_abstimed_wait_common64 (unsigned int* futex_word, + unsigned int expected, clockid_t clockid, + const struct __timespec64* abstime, + int private, bool cancel) +{ + 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); + + if (cancel) + err = INTERNAL_SYSCALL_CANCEL (futex_time64, futex_word, op, expected, + abstime, NULL /* Unused. */, + FUTEX_BITSET_MATCH_ANY); + else + err = INTERNAL_SYSCALL_CALL (futex_time64, futex_word, op, expected, + abstime, NULL /* Ununsed. */, + FUTEX_BITSET_MATCH_ANY); +#ifndef __ASSUME_TIME64_SYSCALLS + if (err == -ENOSYS) + err = __futex_abstimed_wait_common32 (futex_word, expected, op, abstime, + private, cancel); +#endif + + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + case -ETIMEDOUT: + case -EINVAL: + 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 -ENOSYS: /* Must have been caused by a glibc bug. */ + /* No other errors are documented at this time. */ + default: + futex_fatal_error (); + } +} + +int +__futex_abstimed_wait64 (unsigned int* futex_word, unsigned int expected, + clockid_t clockid, + const struct __timespec64* abstime, int private) +{ + return __futex_abstimed_wait_common64 (futex_word, expected, clockid, + abstime, private, false); +} +libpthread_hidden_def (__futex_abstimed_wait64) + +int +__futex_abstimed_wait_cancelable64 (unsigned int* futex_word, + unsigned int expected, clockid_t clockid, + const struct __timespec64* abstime, + int private) +{ + return __futex_abstimed_wait_common64 (futex_word, expected, clockid, + abstime, private, true); +} +libpthread_hidden_def (__futex_abstimed_wait_cancelable64) |