diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2b08204a4b89..7e5f12b8edf6 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -18,6 +18,7 @@ config X86_32 select HAVE_GENERIC_DMA_COHERENT select MODULES_USE_ELF_REL select OLD_SIGACTION + select GENERIC_VDSO_32 config X86_64 def_bool y @@ -112,6 +113,7 @@ config X86 select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL + select GENERIC_GETTIMEOFDAY select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 select HAVE_ACPI_APEI if ACPI select HAVE_ACPI_APEI_NMI if ACPI @@ -190,6 +192,7 @@ config X86 select HAVE_SYSCALL_TRACEPOINTS select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER + select HAVE_GENERIC_VDSO select HOTPLUG_SMT if SMP select IRQ_FORCED_THREADING select NEED_SG_DMA_LENGTH diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile index c66b333a08ac..6cae61116c68 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -3,6 +3,13 @@ # Building vDSO images for x86. # +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE| +ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE +include $(srctree)/lib/vdso/Makefile + +KBUILD_CFLAGS += $(DISABLE_LTO) KASAN_SANITIZE := n UBSAN_SANITIZE := n OBJECT_FILES_NON_STANDARD := y @@ -50,6 +57,7 @@ VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \ $(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE $(call if_changed,vdso) + $(call if_changed,vdso_check) HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi hostprogs-y += vdso2c @@ -120,6 +128,7 @@ $(obj)/%.so: $(obj)/%.so.dbg $(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE $(call if_changed,vdso) + $(call if_changed,vdso_check) CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds) VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1 @@ -161,6 +170,7 @@ $(obj)/vdso32.so.dbg: FORCE \ $(obj)/vdso32/system_call.o \ $(obj)/vdso32/sigreturn.o $(call if_changed,vdso) + $(call if_changed,vdso_check) # # The DSO images are built using a special linker script. diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index 8a88e738f87d..f211a5ce5b91 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -1,341 +1,59 @@ /* - * Copyright 2006 Andi Kleen, SUSE Labs. - * Subject to the GNU Public License, v.2 - * * Fast user context implementation of clock_gettime, gettimeofday, and time. * + * Copyright 2006 Andi Kleen, SUSE Labs. + * Copyright 2019 ARM Limited + * * 32 Bit compat layer by Stefani Seibold * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany - * - * The code should have no internal unresolved relocations. - * Check with readelf after changing. */ - -#include -#include -#include -#include -#include -#include -#include -#include #include #include +#include -#define gtod (&VVAR(vsyscall_gtod_data)) +#include "../../../../lib/vdso/gettimeofday.c" -extern int __vdso_clock_gettime(clockid_t clock, struct timespec *ts); -extern int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz); +extern int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz); extern time_t __vdso_time(time_t *t); -#ifdef CONFIG_PARAVIRT_CLOCK -extern u8 pvclock_page[PAGE_SIZE] - __attribute__((visibility("hidden"))); -#endif - -#ifdef CONFIG_HYPERV_TSCPAGE -extern u8 hvclock_page[PAGE_SIZE] - __attribute__((visibility("hidden"))); -#endif - -#ifndef BUILD_VDSO32 - -notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) +int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) { - long ret; - asm ("syscall" : "=a" (ret), "=m" (*ts) : - "0" (__NR_clock_gettime), "D" (clock), "S" (ts) : - "memory", "rcx", "r11"); - return ret; + return __cvdso_gettimeofday(tv, tz); } -notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) -{ - long ret; - - asm ("syscall" : "=a" (ret), "=m" (*tv), "=m" (*tz) : - "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : - "memory", "rcx", "r11"); - return ret; -} - - -#else - -notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) -{ - long ret; - - asm ( - "mov %%ebx, %%edx \n" - "mov %[clock], %%ebx \n" - "call __kernel_vsyscall \n" - "mov %%edx, %%ebx \n" - : "=a" (ret), "=m" (*ts) - : "0" (__NR_clock_gettime), [clock] "g" (clock), "c" (ts) - : "memory", "edx"); - return ret; -} - -notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) -{ - long ret; - - asm ( - "mov %%ebx, %%edx \n" - "mov %[tv], %%ebx \n" - "call __kernel_vsyscall \n" - "mov %%edx, %%ebx \n" - : "=a" (ret), "=m" (*tv), "=m" (*tz) - : "0" (__NR_gettimeofday), [tv] "g" (tv), "c" (tz) - : "memory", "edx"); - return ret; -} - -#endif - -#ifdef CONFIG_PARAVIRT_CLOCK -static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void) -{ - return (const struct pvclock_vsyscall_time_info *)&pvclock_page; -} - -static notrace u64 vread_pvclock(int *mode) -{ - const struct pvclock_vcpu_time_info *pvti = &get_pvti0()->pvti; - u64 ret; - u64 last; - u32 version; - - /* - * Note: The kernel and hypervisor must guarantee that cpu ID - * number maps 1:1 to per-CPU pvclock time info. - * - * Because the hypervisor is entirely unaware of guest userspace - * preemption, it cannot guarantee that per-CPU pvclock time - * info is updated if the underlying CPU changes or that that - * version is increased whenever underlying CPU changes. - * - * On KVM, we are guaranteed that pvti updates for any vCPU are - * atomic as seen by *all* vCPUs. This is an even stronger - * guarantee than we get with a normal seqlock. - * - * On Xen, we don't appear to have that guarantee, but Xen still - * supplies a valid seqlock using the version field. - * - * We only do pvclock vdso timing at all if - * PVCLOCK_TSC_STABLE_BIT is set, and we interpret that bit to - * mean that all vCPUs have matching pvti and that the TSC is - * synced, so we can just look at vCPU 0's pvti. - */ - - do { - version = pvclock_read_begin(pvti); - - if (unlikely(!(pvti->flags & PVCLOCK_TSC_STABLE_BIT))) { - *mode = VCLOCK_NONE; - return 0; - } - - ret = __pvclock_read_cycles(pvti, rdtsc_ordered()); - } while (pvclock_read_retry(pvti, version)); - - /* refer to vread_tsc() comment for rationale */ - last = gtod->cycle_last; - - if (likely(ret >= last)) - return ret; - - return last; -} -#endif -#ifdef CONFIG_HYPERV_TSCPAGE -static notrace u64 vread_hvclock(int *mode) -{ - const struct ms_hyperv_tsc_page *tsc_pg = - (const struct ms_hyperv_tsc_page *)&hvclock_page; - u64 current_tick = hv_read_tsc_page(tsc_pg); - - if (current_tick != U64_MAX) - return current_tick; - - *mode = VCLOCK_NONE; - return 0; -} -#endif - -notrace static u64 vread_tsc(void) -{ - u64 ret = (u64)rdtsc_ordered(); - u64 last = gtod->cycle_last; - - if (likely(ret >= last)) - return ret; - - /* - * GCC likes to generate cmov here, but this branch is extremely - * predictable (it's just a function of time and the likely is - * very likely) and there's a data dependence, so force GCC - * to generate a branch instead. I don't barrier() because - * we don't actually need a barrier, and if this function - * ever gets inlined it will generate worse code. - */ - asm volatile (""); - return last; -} - -notrace static inline u64 vgetsns(int *mode) -{ - u64 v; - cycles_t cycles; - - if (gtod->vclock_mode == VCLOCK_TSC) - cycles = vread_tsc(); - - /* - * For any memory-mapped vclock type, we need to make sure that gcc - * doesn't cleverly hoist a load before the mode check. Otherwise we - * might end up touching the memory-mapped page even if the vclock in - * question isn't enabled, which will segfault. Hence the barriers. - */ -#ifdef CONFIG_PARAVIRT_CLOCK - else if (gtod->vclock_mode == VCLOCK_PVCLOCK) { - barrier(); - cycles = vread_pvclock(mode); - } -#endif -#ifdef CONFIG_HYPERV_TSCPAGE - else if (gtod->vclock_mode == VCLOCK_HVCLOCK) { - barrier(); - cycles = vread_hvclock(mode); - } -#endif - else - return 0; - v = (cycles - gtod->cycle_last) & gtod->mask; - return v * gtod->mult; -} - -/* Code size doesn't matter (vdso is 4k anyway) and this is faster. */ -notrace static int __always_inline do_realtime(struct timespec *ts) -{ - unsigned long seq; - u64 ns; - int mode; - - do { - seq = gtod_read_begin(gtod); - mode = gtod->vclock_mode; - ts->tv_sec = gtod->wall_time_sec; - ns = gtod->wall_time_snsec; - ns += vgetsns(&mode); - ns >>= gtod->shift; - } while (unlikely(gtod_read_retry(gtod, seq))); - - ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); - ts->tv_nsec = ns; - - return mode; -} - -notrace static int __always_inline do_monotonic(struct timespec *ts) -{ - unsigned long seq; - u64 ns; - int mode; - - do { - seq = gtod_read_begin(gtod); - mode = gtod->vclock_mode; - ts->tv_sec = gtod->monotonic_time_sec; - ns = gtod->monotonic_time_snsec; - ns += vgetsns(&mode); - ns >>= gtod->shift; - } while (unlikely(gtod_read_retry(gtod, seq))); - - ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); - ts->tv_nsec = ns; - - return mode; -} - -notrace static void do_realtime_coarse(struct timespec *ts) -{ - unsigned long seq; - do { - seq = gtod_read_begin(gtod); - ts->tv_sec = gtod->wall_time_coarse_sec; - ts->tv_nsec = gtod->wall_time_coarse_nsec; - } while (unlikely(gtod_read_retry(gtod, seq))); -} - -notrace static void do_monotonic_coarse(struct timespec *ts) -{ - unsigned long seq; - do { - seq = gtod_read_begin(gtod); - ts->tv_sec = gtod->monotonic_time_coarse_sec; - ts->tv_nsec = gtod->monotonic_time_coarse_nsec; - } while (unlikely(gtod_read_retry(gtod, seq))); -} - -notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) -{ - switch (clock) { - case CLOCK_REALTIME: - if (do_realtime(ts) == VCLOCK_NONE) - goto fallback; - break; - case CLOCK_MONOTONIC: - if (do_monotonic(ts) == VCLOCK_NONE) - goto fallback; - break; - case CLOCK_REALTIME_COARSE: - do_realtime_coarse(ts); - break; - case CLOCK_MONOTONIC_COARSE: - do_monotonic_coarse(ts); - break; - default: - goto fallback; - } - - return 0; -fallback: - return vdso_fallback_gettime(clock, ts); -} -int clock_gettime(clockid_t, struct timespec *) - __attribute__((weak, alias("__vdso_clock_gettime"))); - -notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) -{ - if (likely(tv != NULL)) { - if (unlikely(do_realtime((struct timespec *)tv) == VCLOCK_NONE)) - return vdso_fallback_gtod(tv, tz); - tv->tv_usec /= 1000; - } - if (unlikely(tz != NULL)) { - tz->tz_minuteswest = gtod->tz_minuteswest; - tz->tz_dsttime = gtod->tz_dsttime; - } - - return 0; -} -int gettimeofday(struct timeval *, struct timezone *) +int gettimeofday(struct __kernel_old_timeval *, struct timezone *) __attribute__((weak, alias("__vdso_gettimeofday"))); -/* - * This will break when the xtime seconds get inaccurate, but that is - * unlikely - */ -notrace time_t __vdso_time(time_t *t) +time_t __vdso_time(time_t *t) { - /* This is atomic on x86 so we don't need any locks. */ - time_t result = READ_ONCE(gtod->wall_time_sec); - - if (t) - *t = result; - return result; + return __cvdso_time(t); } -time_t time(time_t *t) - __attribute__((weak, alias("__vdso_time"))); + +time_t time(time_t *t) __attribute__((weak, alias("__vdso_time"))); + + +#if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64) +/* both 64-bit and x32 use these */ +extern int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts); + +int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +int clock_gettime(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_gettime"))); + +#else +/* i386 only */ +extern int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts); + +int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) +{ + return __cvdso_clock_gettime32(clock, ts); +} + +int clock_gettime(clockid_t, struct old_timespec32 *) + __attribute__((weak, alias("__vdso_clock_gettime"))); + +#endif diff --git a/arch/x86/entry/vdso/vdsox32.lds.S b/arch/x86/entry/vdso/vdsox32.lds.S index 05cd1c5c4a15..16a8050a4fb6 100644 --- a/arch/x86/entry/vdso/vdsox32.lds.S +++ b/arch/x86/entry/vdso/vdsox32.lds.S @@ -21,6 +21,7 @@ VERSION { __vdso_gettimeofday; __vdso_getcpu; __vdso_time; + __vdso_clock_getres; local: *; }; } diff --git a/arch/x86/entry/vsyscall/Makefile b/arch/x86/entry/vsyscall/Makefile index a9f4856f622a..83126271de24 100644 --- a/arch/x86/entry/vsyscall/Makefile +++ b/arch/x86/entry/vsyscall/Makefile @@ -1,7 +1,5 @@ # # Makefile for the x86 low level vsyscall code # -obj-y := vsyscall_gtod.o - obj-$(CONFIG_X86_VSYSCALL_EMULATION) += vsyscall_64.o vsyscall_emu_64.o diff --git a/arch/x86/entry/vsyscall/vsyscall_gtod.c b/arch/x86/entry/vsyscall/vsyscall_gtod.c deleted file mode 100644 index e1216dd95c04..000000000000 --- a/arch/x86/entry/vsyscall/vsyscall_gtod.c +++ /dev/null @@ -1,78 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (C) 2001 Andrea Arcangeli SuSE - * Copyright 2003 Andi Kleen, SuSE Labs. - * - * Modified for x86 32 bit architecture by - * Stefani Seibold - * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany - * - * Thanks to hpa@transmeta.com for some useful hint. - * Special thanks to Ingo Molnar for his early experience with - * a different vsyscall implementation for Linux/IA32 and for the name. - * - */ - -#include -#include -#include - -int vclocks_used __read_mostly; - -DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data); - -void update_vsyscall_tz(void) -{ - vsyscall_gtod_data.tz_minuteswest = sys_tz.tz_minuteswest; - vsyscall_gtod_data.tz_dsttime = sys_tz.tz_dsttime; -} - -void update_vsyscall(struct timekeeper *tk) -{ - int vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode; - struct vsyscall_gtod_data *vdata = &vsyscall_gtod_data; - - /* Mark the new vclock used. */ - BUILD_BUG_ON(VCLOCK_MAX >= 32); - WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << vclock_mode)); - - gtod_write_begin(vdata); - - /* copy vsyscall data */ - vdata->vclock_mode = vclock_mode; - vdata->cycle_last = tk->tkr_mono.cycle_last; - vdata->mask = tk->tkr_mono.mask; - vdata->mult = tk->tkr_mono.mult; - vdata->shift = tk->tkr_mono.shift; - - vdata->wall_time_sec = tk->xtime_sec; - vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec; - - vdata->monotonic_time_sec = tk->xtime_sec - + tk->wall_to_monotonic.tv_sec; - vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec - + ((u64)tk->wall_to_monotonic.tv_nsec - << tk->tkr_mono.shift); - while (vdata->monotonic_time_snsec >= - (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { - vdata->monotonic_time_snsec -= - ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift; - vdata->monotonic_time_sec++; - } - - vdata->wall_time_coarse_sec = tk->xtime_sec; - vdata->wall_time_coarse_nsec = (long)(tk->tkr_mono.xtime_nsec >> - tk->tkr_mono.shift); - - vdata->monotonic_time_coarse_sec = - vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec; - vdata->monotonic_time_coarse_nsec = - vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec; - - while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) { - vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC; - vdata->monotonic_time_coarse_sec++; - } - - gtod_write_end(vdata); -} diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index b6033680d458..19b695ff2c68 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -2,7 +2,7 @@ #ifndef _ASM_X86_PVCLOCK_H #define _ASM_X86_PVCLOCK_H -#include +#include #include /* some helper functions for xen and kvm pv clock sources */ diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h new file mode 100644 index 000000000000..520d4ead2d1b --- /dev/null +++ b/arch/x86/include/asm/vdso/gettimeofday.h @@ -0,0 +1,191 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Fast user context implementation of clock_gettime, gettimeofday, and time. + * + * Copyright (C) 2019 ARM Limited. + * Copyright 2006 Andi Kleen, SUSE Labs. + * 32 Bit compat layer by Stefani Seibold + * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany + */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include +#include +#include +#include +#include +#include +#include + +#define __vdso_data (VVAR(_vdso_data)) + +#define VDSO_HAS_TIME 1 + +#ifdef CONFIG_PARAVIRT_CLOCK +extern u8 pvclock_page[PAGE_SIZE] + __attribute__((visibility("hidden"))); +#endif + +#ifdef CONFIG_HYPERV_TSCPAGE +extern u8 hvclock_page[PAGE_SIZE] + __attribute__((visibility("hidden"))); +#endif + +#ifndef BUILD_VDSO32 + +static __always_inline +long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) +{ + long ret; + + asm ("syscall" : "=a" (ret), "=m" (*_ts) : + "0" (__NR_clock_gettime), "D" (_clkid), "S" (_ts) : + "rcx", "r11"); + + return ret; +} + +static __always_inline +long gettimeofday_fallback(struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + long ret; + + asm("syscall" : "=a" (ret) : + "0" (__NR_gettimeofday), "D" (_tv), "S" (_tz) : "memory"); + + return ret; +} + +#else + +static __always_inline +long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) +{ + long ret; + + asm ( + "mov %%ebx, %%edx \n" + "mov %[clock], %%ebx \n" + "call __kernel_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret), "=m" (*_ts) + : "0" (__NR_clock_gettime), [clock] "g" (_clkid), "c" (_ts) + : "edx"); + + return ret; +} + +static __always_inline +long gettimeofday_fallback(struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + long ret; + + asm( + "mov %%ebx, %%edx \n" + "mov %2, %%ebx \n" + "call __kernel_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret) + : "0" (__NR_gettimeofday), "g" (_tv), "c" (_tz) + : "memory", "edx"); + + return ret; +} + +#endif + +#ifdef CONFIG_PARAVIRT_CLOCK +static const struct pvclock_vsyscall_time_info *get_pvti0(void) +{ + return (const struct pvclock_vsyscall_time_info *)&pvclock_page; +} + +static u64 vread_pvclock(void) +{ + const struct pvclock_vcpu_time_info *pvti = &get_pvti0()->pvti; + u32 version; + u64 ret; + + /* + * Note: The kernel and hypervisor must guarantee that cpu ID + * number maps 1:1 to per-CPU pvclock time info. + * + * Because the hypervisor is entirely unaware of guest userspace + * preemption, it cannot guarantee that per-CPU pvclock time + * info is updated if the underlying CPU changes or that that + * version is increased whenever underlying CPU changes. + * + * On KVM, we are guaranteed that pvti updates for any vCPU are + * atomic as seen by *all* vCPUs. This is an even stronger + * guarantee than we get with a normal seqlock. + * + * On Xen, we don't appear to have that guarantee, but Xen still + * supplies a valid seqlock using the version field. + * + * We only do pvclock vdso timing at all if + * PVCLOCK_TSC_STABLE_BIT is set, and we interpret that bit to + * mean that all vCPUs have matching pvti and that the TSC is + * synced, so we can just look at vCPU 0's pvti. + */ + + do { + version = pvclock_read_begin(pvti); + + if (unlikely(!(pvti->flags & PVCLOCK_TSC_STABLE_BIT))) + return U64_MAX; + + ret = __pvclock_read_cycles(pvti, rdtsc_ordered()); + } while (pvclock_read_retry(pvti, version)); + + return ret; +} +#endif + +#ifdef CONFIG_HYPERV_TSCPAGE +static u64 vread_hvclock(void) +{ + const struct ms_hyperv_tsc_page *tsc_pg = + (const struct ms_hyperv_tsc_page *)&hvclock_page; + + return hv_read_tsc_page(tsc_pg); +} +#endif + +static inline u64 __arch_get_hw_counter(s32 clock_mode) +{ + if (clock_mode == VCLOCK_TSC) + return (u64)rdtsc_ordered(); + /* + * For any memory-mapped vclock type, we need to make sure that gcc + * doesn't cleverly hoist a load before the mode check. Otherwise we + * might end up touching the memory-mapped page even if the vclock in + * question isn't enabled, which will segfault. Hence the barriers. + */ +#ifdef CONFIG_PARAVIRT_CLOCK + if (clock_mode == VCLOCK_PVCLOCK) { + barrier(); + return vread_pvclock(); + } +#endif +#ifdef CONFIG_HYPERV_TSCPAGE + if (clock_mode == VCLOCK_HVCLOCK) { + barrier(); + return vread_hvclock(); + } +#endif + return U64_MAX; +} + +static __always_inline const struct vdso_data *__arch_get_vdso_data(void) +{ + return __vdso_data; +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/x86/include/asm/vdso/vsyscall.h b/arch/x86/include/asm/vdso/vsyscall.h new file mode 100644 index 000000000000..0026ab2123ce --- /dev/null +++ b/arch/x86/include/asm/vdso/vsyscall.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSO_VSYSCALL_H +#define __ASM_VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include +#include +#include +#include +#include + +int vclocks_used __read_mostly; + +DEFINE_VVAR(struct vdso_data, _vdso_data); +/* + * Update the vDSO data page to keep in sync with kernel timekeeping. + */ +static __always_inline +struct vdso_data *__x86_get_k_vdso_data(void) +{ + return _vdso_data; +} +#define __arch_get_k_vdso_data __x86_get_k_vdso_data + +static __always_inline +int __x86_get_clock_mode(struct timekeeper *tk) +{ + int vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode; + + /* Mark the new vclock used. */ + BUILD_BUG_ON(VCLOCK_MAX >= 32); + WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << vclock_mode)); + + return vclock_mode; +} +#define __arch_get_clock_mode __x86_get_clock_mode + +/* The asm-generic header needs to be included after the definitions above */ +#include + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_VSYSCALL_H */ diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 056a61c8c5c7..44ec25be6bb5 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -3,40 +3,15 @@ #define _ASM_X86_VGTOD_H #include -#include +#include +#include +#include #ifdef BUILD_VDSO32_64 typedef u64 gtod_long_t; #else typedef unsigned long gtod_long_t; #endif -/* - * vsyscall_gtod_data will be accessed by 32 and 64 bit code at the same time - * so be carefull by modifying this structure. - */ -struct vsyscall_gtod_data { - unsigned seq; - - int vclock_mode; - u64 cycle_last; - u64 mask; - u32 mult; - u32 shift; - - /* open coded 'struct timespec' */ - u64 wall_time_snsec; - gtod_long_t wall_time_sec; - gtod_long_t monotonic_time_sec; - u64 monotonic_time_snsec; - gtod_long_t wall_time_coarse_sec; - gtod_long_t wall_time_coarse_nsec; - gtod_long_t monotonic_time_coarse_sec; - gtod_long_t monotonic_time_coarse_nsec; - - int tz_minuteswest; - int tz_dsttime; -}; -extern struct vsyscall_gtod_data vsyscall_gtod_data; extern int vclocks_used; static inline bool vclock_was_used(int vclock) @@ -44,37 +19,4 @@ static inline bool vclock_was_used(int vclock) return READ_ONCE(vclocks_used) & (1 << vclock); } -static inline unsigned gtod_read_begin(const struct vsyscall_gtod_data *s) -{ - unsigned ret; - -repeat: - ret = READ_ONCE(s->seq); - if (unlikely(ret & 1)) { - cpu_relax(); - goto repeat; - } - smp_rmb(); - return ret; -} - -static inline int gtod_read_retry(const struct vsyscall_gtod_data *s, - unsigned start) -{ - smp_rmb(); - return unlikely(s->seq != start); -} - -static inline void gtod_write_begin(struct vsyscall_gtod_data *s) -{ - ++s->seq; - smp_wmb(); -} - -static inline void gtod_write_end(struct vsyscall_gtod_data *s) -{ - smp_wmb(); - ++s->seq; -} - #endif /* _ASM_X86_VGTOD_H */ diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h index 3f32dfc2ab73..2dbde48f27a9 100644 --- a/arch/x86/include/asm/vvar.h +++ b/arch/x86/include/asm/vvar.h @@ -32,19 +32,20 @@ extern char __vvar_page; #define DECLARE_VVAR(offset, type, name) \ - extern type vvar_ ## name __attribute__((visibility("hidden"))); + extern type vvar_ ## name[CS_BASES] \ + __attribute__((visibility("hidden"))); #define VVAR(name) (vvar_ ## name) #define DEFINE_VVAR(type, name) \ - type name \ + type name[CS_BASES] \ __attribute__((section(".vvar_" #name), aligned(16))) __visible #endif /* DECLARE_VVAR(offset, type, name) */ -DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data) +DECLARE_VVAR(128, struct vdso_data, _vdso_data) #undef DECLARE_VVAR diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index 637982efecd8..899d0fbbd339 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -15,6 +15,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ +#include #include #include #include