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author | Lukasz Majewski <lukma@denx.de> | 2020-09-08 10:54:35 +0200 |
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committer | Lukasz Majewski <lukma@denx.de> | 2020-10-04 17:12:41 +0200 |
commit | b2cdadde4d5c2b49b0f486a141ae0443ab8be375 (patch) | |
tree | 2a2ad3f6c1dfbdd45a6dd79c806da05a79c7e156 /sysdeps | |
parent | be9b0b9a012780a403a266c90878efffb9a5f3ca (diff) | |
download | glibc-b2cdadde4d5c2b49b0f486a141ae0443ab8be375.tar.gz glibc-b2cdadde4d5c2b49b0f486a141ae0443ab8be375.tar.xz glibc-b2cdadde4d5c2b49b0f486a141ae0443ab8be375.zip |
Y2038: nptl: Provide futex_abstimed_wait64 supporting 64 bit time
This is the helper function, which uses struct __timespec64 to provide 64 bit absolute time to futex syscalls. The aim of this function is to move convoluted pre-processor macro code from sysdeps/nptl/lowlevellock-futex.h to C function in futex-internal.c The futex_abstimed_wait64 function has been put into a separate file on the purpose - to avoid issues apparent on the m68k architecture related to small number of available registers (there is not enough registers to put all necessary arguments in them if the above function would be added to futex-internal.h with __always_inline attribute). Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'sysdeps')
-rw-r--r-- | sysdeps/nptl/futex-internal.c | 70 | ||||
-rw-r--r-- | sysdeps/nptl/futex-internal.h | 6 |
2 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/nptl/futex-internal.c b/sysdeps/nptl/futex-internal.c index a2e355bf86..f418ed2dbb 100644 --- a/sysdeps/nptl/futex-internal.c +++ b/sysdeps/nptl/futex-internal.c @@ -47,6 +47,29 @@ __futex_abstimed_wait_cancelable32 (unsigned int* futex_word, pts32, NULL /* Unused. */, FUTEX_BITSET_MATCH_ANY); } + +static int +__futex_abstimed_wait32 (unsigned int* futex_word, + unsigned int expected, clockid_t clockid, + const struct __timespec64* abstime, + int private) +{ + struct timespec ts32; + + if (abstime != NULL && ! 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); + + if (abstime != NULL) + ts32 = valid_timespec64_to_timespec (*abstime); + + return INTERNAL_SYSCALL_CALL (futex, futex_word, op, expected, + abstime != NULL ? &ts32 : NULL, + NULL /* Unused. */, FUTEX_BITSET_MATCH_ANY); +} #endif int @@ -99,3 +122,50 @@ __futex_abstimed_wait_cancelable64 (unsigned int* futex_word, futex_fatal_error (); } } + +int +__futex_abstimed_wait64 (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_CALL (futex_time64, futex_word, op, expected, + abstime, NULL /* Unused. */, + FUTEX_BITSET_MATCH_ANY); +#ifndef __ASSUME_TIME64_SYSCALLS + if (err == -ENOSYS) + err = __futex_abstimed_wait32 (futex_word, expected, + clockid, abstime, private); +#endif + 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 (); + } +} diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 7f3910ad98..1ba0d61938 100644 --- a/sysdeps/nptl/futex-internal.h +++ b/sysdeps/nptl/futex-internal.h @@ -529,4 +529,10 @@ __futex_abstimed_wait_cancelable64 (unsigned int* futex_word, const struct __timespec64* abstime, int private) attribute_hidden; +int +__futex_abstimed_wait64 (unsigned int* futex_word, unsigned int expected, + clockid_t clockid, + const struct __timespec64* abstime, + int private) attribute_hidden; + #endif /* futex-internal.h */ |