Messages in this thread Patch in this message | | | From | Mark Salyzyn <> | Subject | [PATCH 1/3] arm: vdso: Rewrite gettimeofday to more closely match arm64 variant | Date | Mon, 11 Sep 2017 09:18:12 -0700 |
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Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski <apinski@cavium.com>, rework it for use in both arm and arm64, overlapping any optimizations for each architecture.
Side effects include renaming some vdso_datapage.h variables, adding a few more to enhance features and functionality to match.
Signed-off-by: Mark Salyzyn <salyzyn@android.com> --- arch/arm/include/asm/vdso_datapage.h | 10 +- arch/arm/kernel/vdso.c | 21 +- arch/arm/vdso/compiler.h | 69 ++++++ arch/arm/vdso/datapage.h | 25 +++ arch/arm/vdso/vdso.lds.S | 1 + arch/arm/vdso/vgettimeofday.c | 423 ++++++++++++++++++++--------------- 6 files changed, 364 insertions(+), 185 deletions(-) create mode 100644 arch/arm/vdso/compiler.h create mode 100644 arch/arm/vdso/datapage.h
diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h index 9be259442fca..d57c296f7f52 100644 --- a/arch/arm/include/asm/vdso_datapage.h +++ b/arch/arm/include/asm/vdso_datapage.h @@ -29,8 +29,8 @@ * 32 bytes. */ struct vdso_data { - u32 seq_count; /* sequence count - odd during updates */ - u16 tk_is_cntvct; /* fall back to syscall if false */ + u32 tb_seq_count; /* sequence count - odd during updates */ + u16 use_syscall; /* fall back to syscall if true */ u16 cs_shift; /* clocksource shift */ u32 xtime_coarse_sec; /* coarse time */ u32 xtime_coarse_nsec; @@ -38,7 +38,7 @@ struct vdso_data { u32 wtm_clock_sec; /* wall to monotonic offset */ u32 wtm_clock_nsec; u32 xtime_clock_sec; /* CLOCK_REALTIME - seconds */ - u32 cs_mult; /* clocksource multiplier */ + u32 cs_mono_mult; /* clocksource multiplier */ u64 cs_cycle_last; /* last cycle value */ u64 cs_mask; /* clocksource mask */ @@ -46,6 +46,10 @@ struct vdso_data { u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */ u32 tz_minuteswest; /* timezone info for gettimeofday(2) */ u32 tz_dsttime; + + u32 cs_raw_mult; /* Raw clocksource multipler */ + u32 raw_time_sec; /* Raw time */ + u32 raw_time_nsec; }; union vdso_data_store { diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c index a4d6dc0f2427..74bede343ffc 100644 --- a/arch/arm/kernel/vdso.c +++ b/arch/arm/kernel/vdso.c @@ -189,6 +189,7 @@ static void __init patch_vdso(void *ehdr) if (!cntvct_ok) { vdso_nullpatch_one(&einfo, "__vdso_gettimeofday"); vdso_nullpatch_one(&einfo, "__vdso_clock_gettime"); + vdso_nullpatch_one(&einfo, "__vdso_clock_getres"); } } @@ -274,14 +275,14 @@ void arm_install_vdso(struct mm_struct *mm, unsigned long addr) static void vdso_write_begin(struct vdso_data *vdata) { - ++vdso_data->seq_count; + ++vdso_data->tb_seq_count; smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */ } static void vdso_write_end(struct vdso_data *vdata) { smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */ - ++vdso_data->seq_count; + ++vdso_data->tb_seq_count; } static bool tk_is_cntvct(const struct timekeeper *tk) @@ -305,10 +306,10 @@ static bool tk_is_cntvct(const struct timekeeper *tk) * counter again, making it even, indicating to userspace that the * update is finished. * - * Userspace is expected to sample seq_count before reading any other - * fields from the data page. If seq_count is odd, userspace is + * Userspace is expected to sample tb_seq_count before reading any other + * fields from the data page. If tb_seq_count is odd, userspace is * expected to wait until it becomes even. After copying data from - * the page, userspace must sample seq_count again; if it has changed + * the page, userspace must sample tb_seq_count again; if it has changed * from its previous value, userspace must retry the whole sequence. * * Calls to update_vsyscall are serialized by the timekeeping core. @@ -326,7 +327,7 @@ void update_vsyscall(struct timekeeper *tk) vdso_write_begin(vdso_data); - vdso_data->tk_is_cntvct = tk_is_cntvct(tk); + vdso_data->use_syscall = !tk_is_cntvct(tk); vdso_data->xtime_coarse_sec = tk->xtime_sec; vdso_data->xtime_coarse_nsec = (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); @@ -335,9 +336,15 @@ void update_vsyscall(struct timekeeper *tk) if (vdso_data->tk_is_cntvct) { vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; + vdso_data->raw_clock_sec = tk->raw_time.tv_sec; + vdso_data->raw_clock_nsec = (tk->raw_time.tv_nsec << + tk->raw_time.shift) + + tk->tkr_raw.xtime_nsec; vdso_data->xtime_clock_sec = tk->xtime_sec; vdso_data->xtime_clock_snsec = tk->tkr_mono.xtime_nsec; - vdso_data->cs_mult = tk->tkr_mono.mult; + vdso_data->cs_mono_mult = tk->tkr_mono.mult; + vdso_data->cs_raw_mult = tk->tkr_raw.mult; + /* tkr_mono.shift == tkr_raw.shift */ vdso_data->cs_shift = tk->tkr_mono.shift; vdso_data->cs_mask = tk->tkr_mono.mask; } diff --git a/arch/arm/vdso/compiler.h b/arch/arm/vdso/compiler.h new file mode 100644 index 000000000000..ef1d664fb4fa --- /dev/null +++ b/arch/arm/vdso/compiler.h @@ -0,0 +1,69 @@ +/* + * Userspace implementations of fallback calls + * + * Copyright (C) 2017 Cavium, Inc. + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author: Will Deacon <will.deacon@arm.com> + * Rewriten into C by: Andrew Pinski <apinski@cavium.com> + */ + +#ifndef __VDSO_COMPILER_H +#define __VDSO_COMPILER_H + +#include <asm/arch_timer.h> +#include <asm/processor.h> +#include <asm/unistd.h> +#include <linux/compiler.h> + +#ifndef CONFIG_AEABI +#error This code depends on AEABI system call conventions +#endif + +#define DEFINE_FALLBACK(name, type_arg1, name_arg1, type_arg2, name_arg2) \ +static notrace long name##_fallback(type_arg1 _##name_arg1, \ + type_arg2 _##name_arg2) \ +{ \ + register type_arg1 name_arg1 asm("r0") = _##name_arg1; \ + register type_arg2 name_arg2 asm("r1") = _##name_arg2; \ + register long ret asm ("r0"); \ + register long nr asm("r7") = __NR_##name; \ + \ + asm volatile( \ + " swi #0\n" \ + : "=r" (ret) \ + : "r" (name_arg1), "r" (name_arg2), "r" (nr) \ + : "memory"); \ + \ + return ret; \ +} + +#define __arch_counter_get_cntvct() arch_counter_get_cntvct() + +/* Avoid unresolved references emitted by GCC */ + +void __aeabi_unwind_cpp_pr0(void) +{ +} + +void __aeabi_unwind_cpp_pr1(void) +{ +} + +void __aeabi_unwind_cpp_pr2(void) +{ +} + +#endif /* __VDSO_COMPILER_H */ diff --git a/arch/arm/vdso/datapage.h b/arch/arm/vdso/datapage.h new file mode 100644 index 000000000000..e3088bdfb946 --- /dev/null +++ b/arch/arm/vdso/datapage.h @@ -0,0 +1,25 @@ +/* + * Userspace implementations of __get_datapage + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __VDSO_DATAPAGE_H +#define __VDSO_DATAPAGE_H + +#include <linux/types.h> +#include <asm/vdso_datapage.h> + +extern const struct vdso_data *__get_datapage(void); + +#endif /* __VDSO_DATAPAGE_H */ diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S index 89ca89f12d23..1d81e8c3acf6 100644 --- a/arch/arm/vdso/vdso.lds.S +++ b/arch/arm/vdso/vdso.lds.S @@ -82,6 +82,7 @@ VERSION global: __vdso_clock_gettime; __vdso_gettimeofday; + __vdso_clock_getres; local: *; }; } diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c index 79214d5ff097..786ff319aead 100644 --- a/arch/arm/vdso/vgettimeofday.c +++ b/arch/arm/vdso/vgettimeofday.c @@ -1,282 +1,355 @@ /* - * Copyright 2015 Mentor Graphics Corporation. + * Userspace implementations of gettimeofday() and friends. * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; version 2 of the - * License. + * Copyright (C) 2017 Cavium, Inc. + * Copyright (C) 2015 Mentor Graphics Corporation + * Copyright (C) 2012 ARM Limited * - * This program 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 - * General Public License for more details. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * Author: Will Deacon <will.deacon@arm.com> + * Rewriten from arch64 version into C by: Andrew Pinski <apinski@cavium.com> + * Reworked and rebased over arm version by: Mark Salyzyn <salyzyn@android.com> */ -#include <linux/compiler.h> -#include <linux/hrtimer.h> -#include <linux/time.h> -#include <asm/arch_timer.h> #include <asm/barrier.h> -#include <asm/bug.h> -#include <asm/page.h> -#include <asm/unistd.h> -#include <asm/vdso_datapage.h> +#include <linux/time.h> +#include <linux/hrtimer.h> -#ifndef CONFIG_AEABI -#error This code depends on AEABI system call conventions -#endif +#include "compiler.h" +#include "datapage.h" -extern struct vdso_data *__get_datapage(void); +DEFINE_FALLBACK(gettimeofday, struct timeval *, tv, struct timezone *, tz) +DEFINE_FALLBACK(clock_gettime, clockid_t, clock, struct timespec *, ts) +DEFINE_FALLBACK(clock_getres, clockid_t, clock, struct timespec *, ts) -static notrace u32 __vdso_read_begin(const struct vdso_data *vdata) +static notrace u32 vdso_read_begin(const struct vdso_data *vd) { u32 seq; -repeat: - seq = ACCESS_ONCE(vdata->seq_count); - if (seq & 1) { - cpu_relax(); - goto repeat; - } - return seq; -} -static notrace u32 vdso_read_begin(const struct vdso_data *vdata) -{ - u32 seq; + do { + seq = READ_ONCE(vd->tb_seq_count); + + if ((seq & 1) == 0) + break; - seq = __vdso_read_begin(vdata); + cpu_relax(); + } while (true); - smp_rmb(); /* Pairs with smp_wmb in vdso_write_end */ + smp_rmb(); /* Pairs with second smp_wmb in update_vsyscall */ return seq; } -static notrace int vdso_read_retry(const struct vdso_data *vdata, u32 start) +static notrace int vdso_read_retry(const struct vdso_data *vd, u32 start) { - smp_rmb(); /* Pairs with smp_wmb in vdso_write_begin */ - return vdata->seq_count != start; -} + u32 seq; -static notrace long clock_gettime_fallback(clockid_t _clkid, - struct timespec *_ts) -{ - register struct timespec *ts asm("r1") = _ts; - register clockid_t clkid asm("r0") = _clkid; - register long ret asm ("r0"); - register long nr asm("r7") = __NR_clock_gettime; - - asm volatile( - " swi #0\n" - : "=r" (ret) - : "r" (clkid), "r" (ts), "r" (nr) - : "memory"); - - return ret; + smp_rmb(); /* Pairs with first smp_wmb in update_vsyscall */ + seq = READ_ONCE(vd->tb_seq_count); + return seq != start; } -static notrace int do_realtime_coarse(struct timespec *ts, - struct vdso_data *vdata) -{ - u32 seq; +#ifdef CONFIG_ARM_ARCH_TIMER - do { - seq = vdso_read_begin(vdata); +/* + * Returns the clock delta, in nanoseconds left-shifted by the clock + * shift. + */ +static __always_inline notrace u64 get_clock_shifted_nsec(const u64 cycle_last, + const u32 mult, + const u64 mask) +{ + u64 res; - ts->tv_sec = vdata->xtime_coarse_sec; - ts->tv_nsec = vdata->xtime_coarse_nsec; + /* Read the virtual counter. */ + res = __arch_counter_get_cntvct(); - } while (vdso_read_retry(vdata, seq)); + res = res - cycle_last; - return 0; + res &= mask; + return res * mult; } -static notrace int do_monotonic_coarse(struct timespec *ts, - struct vdso_data *vdata) +/* Code size doesn't matter (vdso is 4k/16k/64k anyway) and this is faster. */ +static __always_inline notrace int do_realtime(const struct vdso_data *vd, + struct timespec *ts) { - struct timespec tomono; - u32 seq; + u32 seq, mult, shift; + u64 nsec, cycle_last; +#ifdef ARCH_CLOCK_FIXED_MASK + static const u64 mask = ARCH_CLOCK_FIXED_MASK; +#else + u64 mask; +#endif + + typeof(((struct vdso_data *)vd)->xtime_clock_sec) sec; do { - seq = vdso_read_begin(vdata); + seq = vdso_read_begin(vd); - ts->tv_sec = vdata->xtime_coarse_sec; - ts->tv_nsec = vdata->xtime_coarse_nsec; + if (vd->use_syscall) + return -1; + + cycle_last = vd->cs_cycle_last; - tomono.tv_sec = vdata->wtm_clock_sec; - tomono.tv_nsec = vdata->wtm_clock_nsec; + mult = vd->cs_mono_mult; + shift = vd->cs_shift; +#ifndef ARCH_CLOCK_FIXED_MASK + mask = vd->cs_mask; +#endif - } while (vdso_read_retry(vdata, seq)); + sec = vd->xtime_clock_sec; + nsec = vd->xtime_clock_snsec; - ts->tv_sec += tomono.tv_sec; - timespec_add_ns(ts, tomono.tv_nsec); + } while (unlikely(vdso_read_retry(vd, seq))); + + nsec += get_clock_shifted_nsec(cycle_last, mult, mask); + nsec >>= shift; + /* open coding timespec_add_ns to save a ts->tv_nsec = 0 */ + ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); + ts->tv_nsec = nsec; return 0; } -#ifdef CONFIG_ARM_ARCH_TIMER - -static notrace u64 get_ns(struct vdso_data *vdata) +static __always_inline notrace int do_monotonic(const struct vdso_data *vd, + struct timespec *ts) { - u64 cycle_delta; - u64 cycle_now; - u64 nsec; - - cycle_now = arch_counter_get_cntvct(); + u32 seq, mult, shift; + u64 nsec, cycle_last; +#ifdef ARCH_CLOCK_FIXED_MASK + static const u64 mask = ARCH_CLOCK_FIXED_MASK; +#else + u64 mask; +#endif - cycle_delta = (cycle_now - vdata->cs_cycle_last) & vdata->cs_mask; + typeof(((struct vdso_data *)vd)->wtm_clock_nsec) wtm_nsec; + typeof(ts->tv_sec) sec; - nsec = (cycle_delta * vdata->cs_mult) + vdata->xtime_clock_snsec; - nsec >>= vdata->cs_shift; + do { + seq = vdso_read_begin(vd); - return nsec; -} + if (vd->use_syscall) + return -1; -static notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata) -{ - u64 nsecs; - u32 seq; + cycle_last = vd->cs_cycle_last; - do { - seq = vdso_read_begin(vdata); + mult = vd->cs_mono_mult; + shift = vd->cs_shift; +#ifndef ARCH_CLOCK_FIXED_MASK + mask = vd->cs_mask; +#endif - if (!vdata->tk_is_cntvct) - return -1; + sec = vd->xtime_clock_sec; + nsec = vd->xtime_clock_snsec; - ts->tv_sec = vdata->xtime_clock_sec; - nsecs = get_ns(vdata); + sec += vd->wtm_clock_sec; + wtm_nsec = vd->wtm_clock_nsec; - } while (vdso_read_retry(vdata, seq)); + } while (unlikely(vdso_read_retry(vd, seq))); - ts->tv_nsec = 0; - timespec_add_ns(ts, nsecs); + nsec += get_clock_shifted_nsec(cycle_last, mult, mask); + nsec >>= shift; + nsec += wtm_nsec; + /* open coding timespec_add_ns to save a ts->tv_nsec = 0 */ + ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); + ts->tv_nsec = nsec; return 0; } -static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata) +static __always_inline notrace int do_monotonic_raw(const struct vdso_data *vd, + struct timespec *ts) { - struct timespec tomono; - u64 nsecs; - u32 seq; + u32 seq, mult, shift; + u64 nsec, cycle_last; +#ifdef ARCH_CLOCK_FIXED_MASK + static const u64 mask = ARCH_CLOCK_FIXED_MASK; +#else + u64 mask; +#endif + + typeof(((struct vdso_data *)vd)->raw_time_sec) sec; do { - seq = vdso_read_begin(vdata); + seq = vdso_read_begin(vd); - if (!vdata->tk_is_cntvct) + if (vd->use_syscall) return -1; - ts->tv_sec = vdata->xtime_clock_sec; - nsecs = get_ns(vdata); + cycle_last = vd->cs_cycle_last; + + mult = vd->cs_raw_mult; + shift = vd->cs_shift; +#ifndef ARCH_CLOCK_FIXED_MASK + mask = vd->cs_mask; +#endif - tomono.tv_sec = vdata->wtm_clock_sec; - tomono.tv_nsec = vdata->wtm_clock_nsec; + sec = vd->raw_time_sec; + nsec = vd->raw_time_nsec; - } while (vdso_read_retry(vdata, seq)); + } while (unlikely(vdso_read_retry(vd, seq))); - ts->tv_sec += tomono.tv_sec; - ts->tv_nsec = 0; - timespec_add_ns(ts, nsecs + tomono.tv_nsec); + nsec += get_clock_shifted_nsec(cycle_last, mult, mask); + nsec >>= shift; + /* open coding timespec_add_ns to save a ts->tv_nsec = 0 */ + ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); + ts->tv_nsec = nsec; return 0; } #else /* CONFIG_ARM_ARCH_TIMER */ -static notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata) +static notrace int do_realtime(const struct vdso_data *vd, + struct timespec *ts) { return -1; } -static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata) +static notrace int do_monotonic(const struct vdso_data *vd, + struct timespec *ts) +{ + return -1; +} + +static notrace int do_monotonic_raw(const struct vdso_data *vd, + struct timespec *ts) { return -1; } #endif /* CONFIG_ARM_ARCH_TIMER */ -notrace int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts) +static notrace void do_realtime_coarse(const struct vdso_data *vd, + struct timespec *ts) { - struct vdso_data *vdata; - int ret = -1; + u32 seq; - vdata = __get_datapage(); + typeof(((struct vdso_data *)vd)->xtime_coarse_sec) sec; + typeof(((struct vdso_data *)vd)->xtime_coarse_nsec) nsec; - switch (clkid) { - case CLOCK_REALTIME_COARSE: - ret = do_realtime_coarse(ts, vdata); - break; - case CLOCK_MONOTONIC_COARSE: - ret = do_monotonic_coarse(ts, vdata); - break; + do { + seq = vdso_read_begin(vd); + + sec = vd->xtime_coarse_sec; + nsec = vd->xtime_coarse_nsec; + + } while (unlikely(vdso_read_retry(vd, seq))); + + ts->tv_sec = sec; + ts->tv_nsec = nsec; +} + +static notrace void do_monotonic_coarse(const struct vdso_data *vd, + struct timespec *ts) +{ + u32 seq; + u64 nsec; + + typeof(((struct vdso_data *)vd)->wtm_clock_nsec) wtm_nsec; + typeof(ts->tv_sec) sec; + + do { + + seq = vdso_read_begin(vd); + + sec = vd->xtime_coarse_sec; + nsec = vd->xtime_coarse_nsec; + + sec += vd->wtm_clock_sec; + wtm_nsec = vd->wtm_clock_nsec; + + } while (unlikely(vdso_read_retry(vd, seq))); + + nsec += wtm_nsec; + /* open coding timespec_add_ns to save a ts->tv_nsec = 0 */ + ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec); + ts->tv_nsec = nsec; +} + +notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) +{ + const struct vdso_data *vd = __get_datapage(); + + switch (clock) { case CLOCK_REALTIME: - ret = do_realtime(ts, vdata); + if (do_realtime(vd, ts)) + goto fallback; break; case CLOCK_MONOTONIC: - ret = do_monotonic(ts, vdata); + if (do_monotonic(vd, ts)) + goto fallback; break; - default: + case CLOCK_MONOTONIC_RAW: + if (do_monotonic_raw(vd, ts)) + goto fallback; + break; + case CLOCK_REALTIME_COARSE: + do_realtime_coarse(vd, ts); break; + case CLOCK_MONOTONIC_COARSE: + do_monotonic_coarse(vd, ts); + break; + default: + goto fallback; } - if (ret) - ret = clock_gettime_fallback(clkid, ts); - - return ret; -} - -static notrace long gettimeofday_fallback(struct timeval *_tv, - struct timezone *_tz) -{ - register struct timezone *tz asm("r1") = _tz; - register struct timeval *tv asm("r0") = _tv; - register long ret asm ("r0"); - register long nr asm("r7") = __NR_gettimeofday; - - asm volatile( - " swi #0\n" - : "=r" (ret) - : "r" (tv), "r" (tz), "r" (nr) - : "memory"); - - return ret; + return 0; +fallback: + return clock_gettime_fallback(clock, ts); } notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) { - struct timespec ts; - struct vdso_data *vdata; - int ret; + const struct vdso_data *vd = __get_datapage(); - vdata = __get_datapage(); + if (likely(tv != NULL)) { + struct timespec ts; - ret = do_realtime(&ts, vdata); - if (ret) - return gettimeofday_fallback(tv, tz); + if (do_realtime(vd, &ts)) + return gettimeofday_fallback(tv, tz); - if (tv) { tv->tv_sec = ts.tv_sec; tv->tv_usec = ts.tv_nsec / 1000; } - if (tz) { - tz->tz_minuteswest = vdata->tz_minuteswest; - tz->tz_dsttime = vdata->tz_dsttime; - } - return ret; -} - -/* Avoid unresolved references emitted by GCC */ + if (unlikely(tz != NULL)) { + tz->tz_minuteswest = vd->tz_minuteswest; + tz->tz_dsttime = vd->tz_dsttime; + } -void __aeabi_unwind_cpp_pr0(void) -{ + return 0; } -void __aeabi_unwind_cpp_pr1(void) +int __vdso_clock_getres(clockid_t clock_id, struct timespec *res) { -} + typeof(res->tv_nsec) nsec; + + if (clock_id == CLOCK_REALTIME || + clock_id == CLOCK_MONOTONIC || + clock_id == CLOCK_MONOTONIC_RAW) + nsec = MONOTONIC_RES_NSEC; + else if (clock_id == CLOCK_REALTIME_COARSE || + clock_id == CLOCK_MONOTONIC_COARSE) + nsec = LOW_RES_NSEC; + else + return clock_getres_fallback(clock_id, res); + + if (likely(res != NULL)) { + res->tv_sec = 0; + res->tv_nsec = nsec; + } -void __aeabi_unwind_cpp_pr2(void) -{ + return 0; } -- 2.14.1.581.gf28d330327-goog
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