| Message ID | 20191030200052.497-1-adhemerval.zanella@linaro.org |
|---|---|
| State | Accepted |
| Commit | b865eed0ac73e385b32de7f97003f44e4798b8d4 |
| Headers | show |
| Series | [1/5] Consolidate futex-internal.h | expand |
On 10/30/19 4:00 PM, Adhemerval Zanella wrote: > NPTL is already Linux specific, there is no need to parametrize futex > operations and add a sysdep Linux specific implementation. This patch > moves the relevant Linux code to nptl one. > > Checked on x86_64-linux-gnu and i686-linux-gnu. OK for master. Reviewed-by: Carlos O'Donell <carlos@redhat.com> > --- > sysdeps/nptl/futex-internal.h | 211 +++++++++++++++++-- > sysdeps/unix/sysv/linux/futex-internal.h | 255 ----------------------- > 2 files changed, 196 insertions(+), 270 deletions(-) > delete mode 100644 sysdeps/unix/sysv/linux/futex-internal.h > > diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h > index 4e6e8fa324..76921466f0 100644 > --- a/sysdeps/nptl/futex-internal.h > +++ b/sysdeps/nptl/futex-internal.h > @@ -74,11 +74,35 @@ > # error FUTEX_PRIVATE must be equal to 0 > #endif > > +/* Calls __libc_fatal with an error message. Convenience function for > + concrete implementations of the futex interface. */ > +static __always_inline __attribute__ ((__noreturn__)) void > +futex_fatal_error (void) > +{ > + __libc_fatal ("The futex facility returned an unexpected error code.\n"); > +} > + > + > +/* The Linux kernel treats provides absolute timeouts based on the > + CLOCK_REALTIME clock and relative timeouts measured against the > + CLOCK_MONOTONIC clock. > + > + We expect a Linux kernel version of 2.6.22 or more recent (since this > + version, EINTR is not returned on spurious wake-ups anymore). */ > + > /* Returns EINVAL if PSHARED is neither PTHREAD_PROCESS_PRIVATE nor > PTHREAD_PROCESS_SHARED; otherwise, returns 0 if PSHARED is supported, and > ENOTSUP if not. */ > static __always_inline int > -futex_supports_pshared (int pshared); > +futex_supports_pshared (int pshared) > +{ > + if (__glibc_likely (pshared == PTHREAD_PROCESS_PRIVATE)) > + return 0; > + else if (pshared == PTHREAD_PROCESS_SHARED) > + return 0; > + else > + return EINVAL; > +} > > /* Atomically wrt other futex operations on the same futex, this blocks iff > the value *FUTEX_WORD matches the expected value. This is > @@ -112,7 +136,27 @@ futex_supports_pshared (int pshared); > a futex_wait call when synchronizing similar to Dekker synchronization. > However, we make no such guarantee here. */ > static __always_inline int > -futex_wait (unsigned int *futex_word, unsigned int expected, int private); > +futex_wait (unsigned int *futex_word, unsigned int expected, int private) > +{ > + int err = lll_futex_timed_wait (futex_word, expected, NULL, private); > + switch (err) > + { > + case 0: > + case -EAGAIN: > + case -EINTR: > + return -err; > + > + case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ > + 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 (); > + } > +} > > /* Like futex_wait but does not provide any indication why we stopped waiting. > Thus, when this function returns, you have to always check FUTEX_WORD to > @@ -132,7 +176,30 @@ futex_wait_simple (unsigned int *futex_word, unsigned int expected, > /* Like futex_wait but is a POSIX cancellation point. */ > static __always_inline int > futex_wait_cancelable (unsigned int *futex_word, unsigned int expected, > - int private); > + int private) > +{ > + int oldtype; > + oldtype = __pthread_enable_asynccancel (); > + int err = lll_futex_timed_wait (futex_word, expected, NULL, private); > + __pthread_disable_asynccancel (oldtype); > + switch (err) > + { > + case 0: > + case -EAGAIN: > + case -EINTR: > + return -err; > + > + case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ > + 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 (); > + } > +} > > /* Like futex_wait, but will eventually time out (i.e., stop being > blocked) after the duration of time provided (i.e., RELTIME) has > @@ -144,32 +211,134 @@ futex_wait_cancelable (unsigned int *futex_word, unsigned int expected, > */ > static __always_inline int > futex_reltimed_wait (unsigned int* futex_word, unsigned int expected, > - const struct timespec* reltime, int private); > + const struct timespec* reltime, int private) > +{ > + int err = lll_futex_timed_wait (futex_word, expected, reltime, private); > + switch (err) > + { > + case 0: > + case -EAGAIN: > + case -EINTR: > + case -ETIMEDOUT: > + 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 (); > + } > +} > > /* Like futex_reltimed_wait but is a POSIX cancellation point. */ > static __always_inline int > futex_reltimed_wait_cancelable (unsigned int* futex_word, > unsigned int expected, > - const struct timespec* reltime, int private); > + const struct timespec* reltime, int private) > +{ > + int oldtype; > + oldtype = LIBC_CANCEL_ASYNC (); > + int err = lll_futex_timed_wait (futex_word, expected, reltime, private); > + LIBC_CANCEL_RESET (oldtype); > + switch (err) > + { > + case 0: > + case -EAGAIN: > + case -EINTR: > + case -ETIMEDOUT: > + 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 (); > + } > +} > > /* Check whether the specified clockid is supported by > futex_abstimed_wait and futex_abstimed_wait_cancelable. */ > static __always_inline int > -futex_abstimed_supported_clockid (clockid_t clockid); > +futex_abstimed_supported_clockid (clockid_t clockid) > +{ > + return lll_futex_supported_clockid (clockid); > +} > > /* Like futex_reltimed_wait, but the provided timeout (ABSTIME) is an > absolute point in time; a call will time out after this point in time. */ > static __always_inline int > futex_abstimed_wait (unsigned int* futex_word, unsigned int expected, > clockid_t clockid, > - const struct timespec* abstime, int private); > + const struct timespec* abstime, int private) > +{ > + /* 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; > + int err = lll_futex_clock_wait_bitset (futex_word, expected, > + clockid, abstime, > + private); > + switch (err) > + { > + case 0: > + case -EAGAIN: > + case -EINTR: > + case -ETIMEDOUT: > + return -err; > + > + case -EFAULT: /* Must have been caused by a glibc or application bug. */ > + case -EINVAL: /* Either due to wrong alignment, unsupported > + clockid 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 (); > + } > +} > > /* Like futex_reltimed_wait but is a POSIX cancellation point. */ > static __always_inline int > futex_abstimed_wait_cancelable (unsigned int* futex_word, > unsigned int expected, > clockid_t clockid, > - const struct timespec* abstime, int private); > + const struct timespec* abstime, int private) > +{ > + /* 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; > + int oldtype; > + oldtype = __pthread_enable_asynccancel (); > + int err = lll_futex_clock_wait_bitset (futex_word, expected, > + clockid, abstime, > + private); > + __pthread_disable_asynccancel (oldtype); > + switch (err) > + { > + case 0: > + case -EAGAIN: > + case -EINTR: > + case -ETIMEDOUT: > + 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 (); > + } > +} > > /* Atomically wrt other futex operations on the same futex, this unblocks the > specified number of processes, or all processes blocked on this futex if > @@ -190,14 +359,26 @@ futex_abstimed_wait_cancelable (unsigned int* futex_word, > object destruction (see above); therefore, we must not report or abort > on most errors. */ > static __always_inline void > -futex_wake (unsigned int* futex_word, int processes_to_wake, int private); > - > -/* Calls __libc_fatal with an error message. Convenience function for > - concrete implementations of the futex interface. */ > -static __always_inline __attribute__ ((__noreturn__)) void > -futex_fatal_error (void) > +futex_wake (unsigned int* futex_word, int processes_to_wake, int private) > { > - __libc_fatal ("The futex facility returned an unexpected error code.\n"); > + int res = lll_futex_wake (futex_word, processes_to_wake, private); > + /* No error. Ignore the number of woken processes. */ > + if (res >= 0) > + return; > + switch (res) > + { > + case -EFAULT: /* Could have happened due to memory reuse. */ > + case -EINVAL: /* Could be either due to incorrect alignment (a bug in > + glibc or in the application) or due to memory being > + reused for a PI futex. We cannot distinguish between the > + two causes, and one of them is correct use, so we do not > + act in this case. */ > + return; > + case -ENOSYS: /* Must have been caused by a glibc bug. */ > + /* No other errors are documented at this time. */ > + default: > + futex_fatal_error (); > + } > } > > #endif /* futex-internal.h */ > diff --git a/sysdeps/unix/sysv/linux/futex-internal.h b/sysdeps/unix/sysv/linux/futex-internal.h > deleted file mode 100644 > index 5a4f4ff818..0000000000 > --- a/sysdeps/unix/sysv/linux/futex-internal.h > +++ /dev/null > @@ -1,255 +0,0 @@ > -/* futex operations for glibc-internal use. Linux version. > - Copyright (C) 2014-2019 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/>. */ > - > -#ifndef FUTEX_INTERNAL_H > -#define FUTEX_INTERNAL_H > - > -#include <sysdeps/nptl/futex-internal.h> > -#include <errno.h> > -#include <lowlevellock-futex.h> > -#include <sysdep-cancel.h> > - > -/* See sysdeps/nptl/futex-internal.h for documentation; this file only > - contains Linux-specific comments. > - > - The Linux kernel treats provides absolute timeouts based on the > - CLOCK_REALTIME clock and relative timeouts measured against the > - CLOCK_MONOTONIC clock. > - > - We expect a Linux kernel version of 2.6.22 or more recent (since this > - version, EINTR is not returned on spurious wake-ups anymore). */ > - > -/* FUTEX_SHARED is always supported by the Linux kernel. */ > -static __always_inline int > -futex_supports_pshared (int pshared) > -{ > - if (__glibc_likely (pshared == PTHREAD_PROCESS_PRIVATE)) > - return 0; > - else if (pshared == PTHREAD_PROCESS_SHARED) > - return 0; > - else > - return EINVAL; > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_wait (unsigned int *futex_word, unsigned int expected, int private) > -{ > - int err = lll_futex_timed_wait (futex_word, expected, NULL, private); > - switch (err) > - { > - case 0: > - case -EAGAIN: > - case -EINTR: > - return -err; > - > - case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ > - 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 (); > - } > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_wait_cancelable (unsigned int *futex_word, unsigned int expected, > - int private) > -{ > - int oldtype; > - oldtype = __pthread_enable_asynccancel (); > - int err = lll_futex_timed_wait (futex_word, expected, NULL, private); > - __pthread_disable_asynccancel (oldtype); > - switch (err) > - { > - case 0: > - case -EAGAIN: > - case -EINTR: > - return -err; > - > - case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ > - 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 (); > - } > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_reltimed_wait (unsigned int *futex_word, unsigned int expected, > - const struct timespec *reltime, int private) > -{ > - int err = lll_futex_timed_wait (futex_word, expected, reltime, private); > - switch (err) > - { > - case 0: > - case -EAGAIN: > - case -EINTR: > - case -ETIMEDOUT: > - 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 (); > - } > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_reltimed_wait_cancelable (unsigned int *futex_word, > - unsigned int expected, > - const struct timespec *reltime, int private) > -{ > - int oldtype; > - oldtype = LIBC_CANCEL_ASYNC (); > - int err = lll_futex_timed_wait (futex_word, expected, reltime, private); > - LIBC_CANCEL_RESET (oldtype); > - switch (err) > - { > - case 0: > - case -EAGAIN: > - case -EINTR: > - case -ETIMEDOUT: > - 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 (); > - } > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_abstimed_supported_clockid (clockid_t clockid) > -{ > - return lll_futex_supported_clockid (clockid); > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_abstimed_wait (unsigned int *futex_word, unsigned int expected, > - clockid_t clockid, > - const struct timespec *abstime, int private) > -{ > - /* 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; > - int err = lll_futex_clock_wait_bitset (futex_word, expected, > - clockid, abstime, > - private); > - switch (err) > - { > - case 0: > - case -EAGAIN: > - case -EINTR: > - case -ETIMEDOUT: > - return -err; > - > - case -EFAULT: /* Must have been caused by a glibc or application bug. */ > - case -EINVAL: /* Either due to wrong alignment, unsupported > - clockid 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 (); > - } > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline int > -futex_abstimed_wait_cancelable (unsigned int *futex_word, > - unsigned int expected, > - clockid_t clockid, > - const struct timespec *abstime, int private) > -{ > - /* 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; > - int oldtype; > - oldtype = __pthread_enable_asynccancel (); > - int err = lll_futex_clock_wait_bitset (futex_word, expected, > - clockid, abstime, > - private); > - __pthread_disable_asynccancel (oldtype); > - switch (err) > - { > - case 0: > - case -EAGAIN: > - case -EINTR: > - case -ETIMEDOUT: > - 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 (); > - } > -} > - > -/* See sysdeps/nptl/futex-internal.h for details. */ > -static __always_inline void > -futex_wake (unsigned int *futex_word, int processes_to_wake, int private) > -{ > - int res = lll_futex_wake (futex_word, processes_to_wake, private); > - /* No error. Ignore the number of woken processes. */ > - if (res >= 0) > - return; > - switch (res) > - { > - case -EFAULT: /* Could have happened due to memory reuse. */ > - case -EINVAL: /* Could be either due to incorrect alignment (a bug in > - glibc or in the application) or due to memory being > - reused for a PI futex. We cannot distinguish between the > - two causes, and one of them is correct use, so we do not > - act in this case. */ > - return; > - case -ENOSYS: /* Must have been caused by a glibc bug. */ > - /* No other errors are documented at this time. */ > - default: > - futex_fatal_error (); > - } > -} > - > -#endif /* futex-internal.h */ > -- Cheers, Carlos.
diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 4e6e8fa324..76921466f0 100644 --- a/sysdeps/nptl/futex-internal.h +++ b/sysdeps/nptl/futex-internal.h @@ -74,11 +74,35 @@ # error FUTEX_PRIVATE must be equal to 0 #endif +/* Calls __libc_fatal with an error message. Convenience function for + concrete implementations of the futex interface. */ +static __always_inline __attribute__ ((__noreturn__)) void +futex_fatal_error (void) +{ + __libc_fatal ("The futex facility returned an unexpected error code.\n"); +} + + +/* The Linux kernel treats provides absolute timeouts based on the + CLOCK_REALTIME clock and relative timeouts measured against the + CLOCK_MONOTONIC clock. + + We expect a Linux kernel version of 2.6.22 or more recent (since this + version, EINTR is not returned on spurious wake-ups anymore). */ + /* Returns EINVAL if PSHARED is neither PTHREAD_PROCESS_PRIVATE nor PTHREAD_PROCESS_SHARED; otherwise, returns 0 if PSHARED is supported, and ENOTSUP if not. */ static __always_inline int -futex_supports_pshared (int pshared); +futex_supports_pshared (int pshared) +{ + if (__glibc_likely (pshared == PTHREAD_PROCESS_PRIVATE)) + return 0; + else if (pshared == PTHREAD_PROCESS_SHARED) + return 0; + else + return EINVAL; +} /* Atomically wrt other futex operations on the same futex, this blocks iff the value *FUTEX_WORD matches the expected value. This is @@ -112,7 +136,27 @@ futex_supports_pshared (int pshared); a futex_wait call when synchronizing similar to Dekker synchronization. However, we make no such guarantee here. */ static __always_inline int -futex_wait (unsigned int *futex_word, unsigned int expected, int private); +futex_wait (unsigned int *futex_word, unsigned int expected, int private) +{ + int err = lll_futex_timed_wait (futex_word, expected, NULL, private); + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + return -err; + + case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ + 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 (); + } +} /* Like futex_wait but does not provide any indication why we stopped waiting. Thus, when this function returns, you have to always check FUTEX_WORD to @@ -132,7 +176,30 @@ futex_wait_simple (unsigned int *futex_word, unsigned int expected, /* Like futex_wait but is a POSIX cancellation point. */ static __always_inline int futex_wait_cancelable (unsigned int *futex_word, unsigned int expected, - int private); + int private) +{ + int oldtype; + oldtype = __pthread_enable_asynccancel (); + int err = lll_futex_timed_wait (futex_word, expected, NULL, private); + __pthread_disable_asynccancel (oldtype); + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + return -err; + + case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ + 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 (); + } +} /* Like futex_wait, but will eventually time out (i.e., stop being blocked) after the duration of time provided (i.e., RELTIME) has @@ -144,32 +211,134 @@ futex_wait_cancelable (unsigned int *futex_word, unsigned int expected, */ static __always_inline int futex_reltimed_wait (unsigned int* futex_word, unsigned int expected, - const struct timespec* reltime, int private); + const struct timespec* reltime, int private) +{ + int err = lll_futex_timed_wait (futex_word, expected, reltime, private); + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + case -ETIMEDOUT: + 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 (); + } +} /* Like futex_reltimed_wait but is a POSIX cancellation point. */ static __always_inline int futex_reltimed_wait_cancelable (unsigned int* futex_word, unsigned int expected, - const struct timespec* reltime, int private); + const struct timespec* reltime, int private) +{ + int oldtype; + oldtype = LIBC_CANCEL_ASYNC (); + int err = lll_futex_timed_wait (futex_word, expected, reltime, private); + LIBC_CANCEL_RESET (oldtype); + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + case -ETIMEDOUT: + 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 (); + } +} /* Check whether the specified clockid is supported by futex_abstimed_wait and futex_abstimed_wait_cancelable. */ static __always_inline int -futex_abstimed_supported_clockid (clockid_t clockid); +futex_abstimed_supported_clockid (clockid_t clockid) +{ + return lll_futex_supported_clockid (clockid); +} /* Like futex_reltimed_wait, but the provided timeout (ABSTIME) is an absolute point in time; a call will time out after this point in time. */ static __always_inline int futex_abstimed_wait (unsigned int* futex_word, unsigned int expected, clockid_t clockid, - const struct timespec* abstime, int private); + const struct timespec* abstime, int private) +{ + /* 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; + int err = lll_futex_clock_wait_bitset (futex_word, expected, + clockid, abstime, + private); + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + case -ETIMEDOUT: + return -err; + + case -EFAULT: /* Must have been caused by a glibc or application bug. */ + case -EINVAL: /* Either due to wrong alignment, unsupported + clockid 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 (); + } +} /* Like futex_reltimed_wait but is a POSIX cancellation point. */ static __always_inline int futex_abstimed_wait_cancelable (unsigned int* futex_word, unsigned int expected, clockid_t clockid, - const struct timespec* abstime, int private); + const struct timespec* abstime, int private) +{ + /* 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; + int oldtype; + oldtype = __pthread_enable_asynccancel (); + int err = lll_futex_clock_wait_bitset (futex_word, expected, + clockid, abstime, + private); + __pthread_disable_asynccancel (oldtype); + switch (err) + { + case 0: + case -EAGAIN: + case -EINTR: + case -ETIMEDOUT: + 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 (); + } +} /* Atomically wrt other futex operations on the same futex, this unblocks the specified number of processes, or all processes blocked on this futex if @@ -190,14 +359,26 @@ futex_abstimed_wait_cancelable (unsigned int* futex_word, object destruction (see above); therefore, we must not report or abort on most errors. */ static __always_inline void -futex_wake (unsigned int* futex_word, int processes_to_wake, int private); - -/* Calls __libc_fatal with an error message. Convenience function for - concrete implementations of the futex interface. */ -static __always_inline __attribute__ ((__noreturn__)) void -futex_fatal_error (void) +futex_wake (unsigned int* futex_word, int processes_to_wake, int private) { - __libc_fatal ("The futex facility returned an unexpected error code.\n"); + int res = lll_futex_wake (futex_word, processes_to_wake, private); + /* No error. Ignore the number of woken processes. */ + if (res >= 0) + return; + switch (res) + { + case -EFAULT: /* Could have happened due to memory reuse. */ + case -EINVAL: /* Could be either due to incorrect alignment (a bug in + glibc or in the application) or due to memory being + reused for a PI futex. We cannot distinguish between the + two causes, and one of them is correct use, so we do not + act in this case. */ + return; + case -ENOSYS: /* Must have been caused by a glibc bug. */ + /* No other errors are documented at this time. */ + default: + futex_fatal_error (); + } } #endif /* futex-internal.h */ diff --git a/sysdeps/unix/sysv/linux/futex-internal.h b/sysdeps/unix/sysv/linux/futex-internal.h deleted file mode 100644 index 5a4f4ff818..0000000000 --- a/sysdeps/unix/sysv/linux/futex-internal.h +++ /dev/null @@ -1,255 +0,0 @@ -/* futex operations for glibc-internal use. Linux version. - Copyright (C) 2014-2019 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/>. */ - -#ifndef FUTEX_INTERNAL_H -#define FUTEX_INTERNAL_H - -#include <sysdeps/nptl/futex-internal.h> -#include <errno.h> -#include <lowlevellock-futex.h> -#include <sysdep-cancel.h> - -/* See sysdeps/nptl/futex-internal.h for documentation; this file only - contains Linux-specific comments. - - The Linux kernel treats provides absolute timeouts based on the - CLOCK_REALTIME clock and relative timeouts measured against the - CLOCK_MONOTONIC clock. - - We expect a Linux kernel version of 2.6.22 or more recent (since this - version, EINTR is not returned on spurious wake-ups anymore). */ - -/* FUTEX_SHARED is always supported by the Linux kernel. */ -static __always_inline int -futex_supports_pshared (int pshared) -{ - if (__glibc_likely (pshared == PTHREAD_PROCESS_PRIVATE)) - return 0; - else if (pshared == PTHREAD_PROCESS_SHARED) - return 0; - else - return EINVAL; -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_wait (unsigned int *futex_word, unsigned int expected, int private) -{ - int err = lll_futex_timed_wait (futex_word, expected, NULL, private); - switch (err) - { - case 0: - case -EAGAIN: - case -EINTR: - return -err; - - case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ - 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 (); - } -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_wait_cancelable (unsigned int *futex_word, unsigned int expected, - int private) -{ - int oldtype; - oldtype = __pthread_enable_asynccancel (); - int err = lll_futex_timed_wait (futex_word, expected, NULL, private); - __pthread_disable_asynccancel (oldtype); - switch (err) - { - case 0: - case -EAGAIN: - case -EINTR: - return -err; - - case -ETIMEDOUT: /* Cannot have happened as we provided no timeout. */ - 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 (); - } -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_reltimed_wait (unsigned int *futex_word, unsigned int expected, - const struct timespec *reltime, int private) -{ - int err = lll_futex_timed_wait (futex_word, expected, reltime, private); - switch (err) - { - case 0: - case -EAGAIN: - case -EINTR: - case -ETIMEDOUT: - 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 (); - } -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_reltimed_wait_cancelable (unsigned int *futex_word, - unsigned int expected, - const struct timespec *reltime, int private) -{ - int oldtype; - oldtype = LIBC_CANCEL_ASYNC (); - int err = lll_futex_timed_wait (futex_word, expected, reltime, private); - LIBC_CANCEL_RESET (oldtype); - switch (err) - { - case 0: - case -EAGAIN: - case -EINTR: - case -ETIMEDOUT: - 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 (); - } -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_abstimed_supported_clockid (clockid_t clockid) -{ - return lll_futex_supported_clockid (clockid); -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_abstimed_wait (unsigned int *futex_word, unsigned int expected, - clockid_t clockid, - const struct timespec *abstime, int private) -{ - /* 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; - int err = lll_futex_clock_wait_bitset (futex_word, expected, - clockid, abstime, - private); - switch (err) - { - case 0: - case -EAGAIN: - case -EINTR: - case -ETIMEDOUT: - return -err; - - case -EFAULT: /* Must have been caused by a glibc or application bug. */ - case -EINVAL: /* Either due to wrong alignment, unsupported - clockid 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 (); - } -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline int -futex_abstimed_wait_cancelable (unsigned int *futex_word, - unsigned int expected, - clockid_t clockid, - const struct timespec *abstime, int private) -{ - /* 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; - int oldtype; - oldtype = __pthread_enable_asynccancel (); - int err = lll_futex_clock_wait_bitset (futex_word, expected, - clockid, abstime, - private); - __pthread_disable_asynccancel (oldtype); - switch (err) - { - case 0: - case -EAGAIN: - case -EINTR: - case -ETIMEDOUT: - 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 (); - } -} - -/* See sysdeps/nptl/futex-internal.h for details. */ -static __always_inline void -futex_wake (unsigned int *futex_word, int processes_to_wake, int private) -{ - int res = lll_futex_wake (futex_word, processes_to_wake, private); - /* No error. Ignore the number of woken processes. */ - if (res >= 0) - return; - switch (res) - { - case -EFAULT: /* Could have happened due to memory reuse. */ - case -EINVAL: /* Could be either due to incorrect alignment (a bug in - glibc or in the application) or due to memory being - reused for a PI futex. We cannot distinguish between the - two causes, and one of them is correct use, so we do not - act in this case. */ - return; - case -ENOSYS: /* Must have been caused by a glibc bug. */ - /* No other errors are documented at this time. */ - default: - futex_fatal_error (); - } -} - -#endif /* futex-internal.h */