From 6d97330d7acc47898b3a2bf4c8588d4bd7114269 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Wed, 16 Jun 2021 11:12:25 -0300 Subject: [PATCH] linux: Only use 64-bit syscall if required for clock_nanosleep For !__ASSUME_TIME64_SYSCALLS there is no need to issue a 64-bit syscall if the provided timeout fits in a 32-bit one. The 64-bit usage should be rare since the timeout is a relative one. Checked on i686-linux-gnu on a 4.15 kernel and on a 5.11 kernel (with and without --enable-kernel=5.1) and on x86_64-linux-gnu. Reviewed-by: Lukasz Majewski --- sysdeps/unix/sysv/linux/clock_nanosleep.c | 46 +++++++++++++++++-------------- time/Makefile | 9 ++++++ time/tst-clock_nanosleep.c | 40 +++++++++++++++++---------- 3 files changed, 59 insertions(+), 36 deletions(-) diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c index 007f173..74e2407 100644 --- a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -27,8 +27,9 @@ /* We can simply use the syscall. The CPU clocks are not supported with this function. */ int -__clock_nanosleep_time64 (clockid_t clock_id, int flags, const struct __timespec64 *req, - struct __timespec64 *rem) +__clock_nanosleep_time64 (clockid_t clock_id, int flags, + const struct __timespec64 *req, + struct __timespec64 *rem) { if (clock_id == CLOCK_THREAD_CPUTIME_ID) return EINVAL; @@ -37,33 +38,36 @@ __clock_nanosleep_time64 (clockid_t clock_id, int flags, const struct __timespec /* If the call is interrupted by a signal handler or encounters an error, it returns a positive value similar to errno. */ + #ifndef __NR_clock_nanosleep_time64 # define __NR_clock_nanosleep_time64 __NR_clock_nanosleep #endif - int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, clock_id, - flags, req, rem); - -#ifndef __ASSUME_TIME64_SYSCALLS - if (r == 0 || r != -ENOSYS) - return -r; - if (! in_time_t_range (req->tv_sec)) + int r; +#ifdef __ASSUME_TIME64_SYSCALLS + r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, clock_id, flags, req, + rem); +#else + if (!in_time_t_range (req->tv_sec)) { - __set_errno (EOVERFLOW); - return -1; + r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, clock_id, flags, + req, rem); + if (r == -ENOSYS) + r = -EOVERFLOW; } - - struct timespec tr32; - struct timespec ts32 = valid_timespec64_to_timespec (*req); - r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, clock_id, flags, - &ts32, &tr32); - if (INTERNAL_SYSCALL_ERROR_P (r)) + else { - if (r == -EINTR && rem != NULL && (flags & TIMER_ABSTIME) == 0) - *rem = valid_timespec_to_timespec64 (tr32); + struct timespec tr32; + struct timespec ts32 = valid_timespec64_to_timespec (*req); + r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, clock_id, flags, &ts32, + &tr32); + if (INTERNAL_SYSCALL_ERROR_P (r)) + { + if (r == -EINTR && rem != NULL && (flags & TIMER_ABSTIME) == 0) + *rem = valid_timespec_to_timespec64 (tr32); + } } -#endif /* __ASSUME_TIME64_SYSCALLS */ - +#endif return -r; } diff --git a/time/Makefile b/time/Makefile index c84bd5d..0bea849 100644 --- a/time/Makefile +++ b/time/Makefile @@ -86,6 +86,15 @@ $(objpfx)tst-strftime2.out: $(gen-locales) $(objpfx)tst-strftime3.out: $(gen-locales) endif +ifeq (yes,$(build-shared)) +librt = $(common-objpfx)rt/librt.so +else +librt = $(common-objpfx)rt/librt.a +endif + +$(objpfx)tst-clock_nanosleep: $(librt) +$(objpfx)tst-clock_nanosleep-time64: $(librt) + tz-cflags = -DTZDIR='"$(zonedir)"' \ -DTZDEFAULT='"$(localtime-file)"' \ -DTZDEFRULES='"$(posixrules-file)"' diff --git a/time/tst-clock_nanosleep.c b/time/tst-clock_nanosleep.c index 4753743..a5a7f94 100644 --- a/time/tst-clock_nanosleep.c +++ b/time/tst-clock_nanosleep.c @@ -20,38 +20,48 @@ #include #include #include - +#include +#include +#include /* Test that clock_nanosleep() does sleep. */ -static int -do_test (void) +static void +clock_nanosleep_test (void) { /* Current time. */ struct timeval tv1; - (void) gettimeofday (&tv1, NULL); + gettimeofday (&tv1, NULL); - struct timespec ts; - ts.tv_sec = 1; - ts.tv_nsec = 0; + struct timespec ts = { 1, 0 }; TEMP_FAILURE_RETRY (clock_nanosleep (CLOCK_REALTIME, 0, &ts, &ts)); /* At least one second must have passed. */ struct timeval tv2; - (void) gettimeofday (&tv2, NULL); + gettimeofday (&tv2, NULL); tv2.tv_sec -= tv1.tv_sec; tv2.tv_usec -= tv1.tv_usec; if (tv2.tv_usec < 0) --tv2.tv_sec; - if (tv2.tv_sec < 1) - { - puts ("clock_nanosleep didn't sleep long enough"); - return 1; - } + TEST_VERIFY (tv2.tv_sec >= 1); +} + +static void +clock_nanosleep_large_timeout (void) +{ + support_create_timer (0, 100000000, false, NULL); + struct timespec ts = { TYPE_MAXIMUM (time_t), 0 }; + int r = clock_nanosleep (CLOCK_REALTIME, 0, &ts, NULL); + TEST_VERIFY (r == EINTR || r == EOVERFLOW); +} +static int +do_test (void) +{ + clock_nanosleep_test (); + clock_nanosleep_large_timeout (); return 0; } -#define TEST_FUNCTION do_test () -#include "../test-skeleton.c" +#include -- 2.7.4