In an effort to unify the common code for managing the vdso library in between all the architectures that support it, this patch tries to provide a common format for the vdso datapage.

As a result of this, this patch generalized the data structures in vgtod.h from x86 private includes to general includes (include/vdso).

Cc: Arnd Bergmann arnd@arndb.de Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- include/vdso/datapage.h | 91 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 include/vdso/datapage.h

diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h new file mode 100644 index 000000000000..bb7087eec9bd --- /dev/null +++ b/include/vdso/datapage.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_DATAPAGE_H +#define __VDSO_DATAPAGE_H + +#ifdef __KERNEL__ + +#ifndef __ASSEMBLY__ + +#include <linux/bits.h> +#include <linux/time.h> +#include <linux/types.h> + +#define VDSO_BASES (CLOCK_TAI + 1) +#define VDSO_HRES (BIT(CLOCK_REALTIME) | \ + BIT(CLOCK_MONOTONIC) | \ + BIT(CLOCK_BOOTTIME) | \ + BIT(CLOCK_TAI)) +#define VDSO_COARSE (BIT(CLOCK_REALTIME_COARSE) | \ + BIT(CLOCK_MONOTONIC_COARSE)) +#define VDSO_RAW (BIT(CLOCK_MONOTONIC_RAW)) + +#define CS_HRES_COARSE 0 +#define CS_RAW 1 +#define CS_BASES (CS_RAW + 1) + +/** + * struct vdso_timestamp - basetime per clock_id + * @sec: seconds + * @nsec: nanoseconds + * + * There is one vdso_timestamp object in vvar for each vDSO-accelerated + * clock_id. For high-resolution clocks, this encodes the time + * corresponding to vdso_data.cycle_last. For coarse clocks this encodes + * the actual time. + * + * To be noticed that for highres clocks nsec is left-shifted by + * vdso_data.cs[x].shift. + */ +struct vdso_timestamp { + u64 sec; + u64 nsec; +}; + +/** + * struct vdso_data - vdso datapage representation + * @seq: timebase sequence counter + * @clock_mode: clock mode + * @cycle_last: timebase at clocksource init + * @mask: clocksource mask + * @mult: clocksource multiplier + * @shift: clocksource shift + * @basetime[clock_id]: basetime per clock_id + * @tz_minuteswest: minutes west of Greenwich + * @tz_dsttime: type of DST correction + * @hrtimer_res: hrtimer resolution + * + * vdso_data will be accessed by 64 bit and compat code at the same time + * so we should be careful before modifying this structure. + */ +struct vdso_data { + u32 seq; + + s32 clock_mode; + u64 cycle_last; + u64 mask; + u32 mult; + u32 shift; + + struct vdso_timestamp basetime[VDSO_BASES]; + + s32 tz_minuteswest; + s32 tz_dsttime; + u32 hrtimer_res; +}; + +/* + * We use the hidden visibility to prevent the compiler from generating a GOT + * relocation. Not only is going through a GOT useless (the entry couldn't and + * must not be overridden by another library), it does not even work: the linker + * cannot generate an absolute address to the data page. + * + * With the hidden visibility, the compiler simply generates a PC-relative + * relocation, and this is what we need. + */ +extern struct vdso_data _vdso_data[CS_BASES] __attribute__((visibility("hidden"))); + +#endif /* !__ASSEMBLY__ */ + +#endif /* __KERNEL__ */ + +#endif /* __VDSO_DATAPAGE_H */

With the definition of the unified vDSO library the implementations of update_vsyscall and update_vsyscall_tz became quite similar across architectures.

Define a unified implementation of this two functions in kernel/vdso and provide the bindings that can be implemented by every architecture that takes advantage of the unified vDSO library.

Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- include/asm-generic/vdso/vsyscall.h | 56 +++++++++++ include/linux/timekeeper_internal.h | 9 ++ include/vdso/vsyscall.h | 11 +++ kernel/Makefile | 1 + kernel/vdso/Makefile | 2 + kernel/vdso/vsyscall.c | 139 ++++++++++++++++++++++++++++ 6 files changed, 218 insertions(+) create mode 100644 include/asm-generic/vdso/vsyscall.h create mode 100644 include/vdso/vsyscall.h create mode 100644 kernel/vdso/Makefile create mode 100644 kernel/vdso/vsyscall.c

diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h new file mode 100644 index 000000000000..9a4b9fbcc9b6 --- /dev/null +++ b/include/asm-generic/vdso/vsyscall.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_VSYSCALL_H +#define __ASM_GENERIC_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#ifndef __arch_get_k_vdso_data +static __always_inline +struct vdso_data *__arch_get_k_vdso_data(void) +{ + return NULL; +} +#endif /* __arch_get_k_vdso_data */ + +#ifndef __arch_update_vdso_data +static __always_inline +int __arch_update_vdso_data(void) +{ + return 0; +} +#endif /* __arch_update_vdso_data */ + +#ifndef __arch_get_clock_mode +static __always_inline +int __arch_get_clock_mode(struct timekeeper *tk) +{ + return 0; +} +#endif /* __arch_get_clock_mode */ + +#ifndef __arch_use_vsyscall +static __always_inline +int __arch_use_vsyscall(struct vdso_data *vdata) +{ + return 1; +} +#endif /* __arch_use_vsyscall */ + +#ifndef __arch_update_vsyscall +static __always_inline +void __arch_update_vsyscall(struct vdso_data *vdata, + struct timekeeper *tk) +{ +} +#endif /* __arch_update_vsyscall */ + +#ifndef __arch_sync_vdso_data +static __always_inline +void __arch_sync_vdso_data(struct vdso_data *vdata) +{ +} +#endif /* __arch_sync_vdso_data */ + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_GENERIC_VSYSCALL_H */ diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index 7acb953298a7..8177e75a71eb 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -135,9 +135,18 @@ struct timekeeper {

#ifdef CONFIG_GENERIC_TIME_VSYSCALL

+#ifdef CONFIG_HAVE_GENERIC_VDSO + +void update_vsyscall(struct timekeeper *tk); +void update_vsyscall_tz(void); + +#else + extern void update_vsyscall(struct timekeeper *tk); extern void update_vsyscall_tz(void);

+#endif /* CONFIG_HAVE_GENERIC_VDSO */ + #else

static inline void update_vsyscall(struct timekeeper *tk) diff --git a/include/vdso/vsyscall.h b/include/vdso/vsyscall.h new file mode 100644 index 000000000000..2c6134e0c23d --- /dev/null +++ b/include/vdso/vsyscall.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_VSYSCALL_H +#define __VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include <asm/vdso/vsyscall.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* __VDSO_VSYSCALL_H */ diff --git a/kernel/Makefile b/kernel/Makefile index 33824f0385b3..56a98ebb7772 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -48,6 +48,7 @@ obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_STACKTRACE) += stacktrace.o +obj-$(CONFIG_HAVE_GENERIC_VDSO) += vdso/ obj-y += time/ obj-$(CONFIG_FUTEX) += futex.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o diff --git a/kernel/vdso/Makefile b/kernel/vdso/Makefile new file mode 100644 index 000000000000..ad0d3b1a475c --- /dev/null +++ b/kernel/vdso/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_HAVE_GENERIC_VDSO) += vsyscall.o diff --git a/kernel/vdso/vsyscall.c b/kernel/vdso/vsyscall.c new file mode 100644 index 000000000000..49409eece728 --- /dev/null +++ b/kernel/vdso/vsyscall.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 ARM Ltd. + * + * Generic implementation of update_vsyscall and update_vsyscall_tz. + */ + +#include <linux/hrtimer.h> +#include <linux/timekeeper_internal.h> +#include <vdso/datapage.h> +#include <vdso/helpers.h> +#include <vdso/vsyscall.h> + +void update_vsyscall(struct timekeeper *tk) +{ + struct vdso_data *vdata = __arch_get_k_vdso_data(); + struct vdso_timestamp *vdso_ts; + u64 nsec; + + if (__arch_update_vdso_data()) { + /* + * Some architectures might want to skip the update of the + * data page. + */ + return; + } + + /* copy vsyscall data */ + vdso_write_begin(vdata); + + vdata[CS_HRES_COARSE].clock_mode = __arch_get_clock_mode(tk); + vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk); + + /* CLOCK_REALTIME_COARSE */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE]; + vdso_ts->sec = tk->xtime_sec; + vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; + /* CLOCK_MONOTONIC_COARSE */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE]; + vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; + nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; + nsec = nsec + tk->wall_to_monotonic.tv_nsec; + while (nsec >= NSEC_PER_SEC) { + nsec = nsec - NSEC_PER_SEC; + vdso_ts->sec++; + } + vdso_ts->nsec = nsec; + + if (__arch_use_vsyscall(vdata)) { + vdata[CS_HRES_COARSE].cycle_last = + tk->tkr_mono.cycle_last; + vdata[CS_HRES_COARSE].mask = + tk->tkr_mono.mask; + vdata[CS_HRES_COARSE].mult = + tk->tkr_mono.mult; + vdata[CS_HRES_COARSE].shift = + tk->tkr_mono.shift; + vdata[CS_RAW].cycle_last = + tk->tkr_raw.cycle_last; + vdata[CS_RAW].mask = + tk->tkr_raw.mask; + vdata[CS_RAW].mult = + tk->tkr_raw.mult; + vdata[CS_RAW].shift = + tk->tkr_raw.shift; + /* CLOCK_REALTIME */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME]; + vdso_ts->sec = tk->xtime_sec; + vdso_ts->nsec = tk->tkr_mono.xtime_nsec; + /* CLOCK_MONOTONIC */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC]; + vdso_ts->sec = tk->xtime_sec + + tk->wall_to_monotonic.tv_sec; + nsec = tk->tkr_mono.xtime_nsec; + nsec = nsec + + ((u64)tk->wall_to_monotonic.tv_nsec << + tk->tkr_mono.shift); + while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { + nsec = nsec - + (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift); + vdso_ts->sec++; + } + vdso_ts->nsec = nsec; + /* CLOCK_MONOTONIC_RAW */ + vdso_ts = + &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW]; + vdso_ts->sec = tk->raw_sec; + vdso_ts->nsec = tk->tkr_raw.xtime_nsec; + /* CLOCK_BOOTTIME */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME]; + vdso_ts->sec = tk->xtime_sec + + tk->wall_to_monotonic.tv_sec; + nsec = tk->tkr_mono.xtime_nsec; + nsec = nsec + + ((u64)(tk->wall_to_monotonic.tv_nsec + + ktime_to_ns(tk->offs_boot)) << + tk->tkr_mono.shift); + while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { + nsec = nsec - + (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift); + vdso_ts->sec++; + } + vdso_ts->nsec = nsec; + /* CLOCK_TAI */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI]; + vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset; + vdso_ts->nsec = tk->tkr_mono.xtime_nsec; + + /* + * Read without the seqlock held by clock_getres(). + * Note: No need to have a second copy. + */ + WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution); + } + + __arch_update_vsyscall(vdata, tk); + + vdso_write_end(vdata); + + __arch_sync_vdso_data(vdata); +} + +void update_vsyscall_tz(void) +{ + struct vdso_data *vdata = __arch_get_k_vdso_data(); + + if (__arch_use_vsyscall(vdata)) { + vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest; + vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime; + } + + __arch_sync_vdso_data(vdata); +}

To take advantage of the commonly defined vdso interface for gettimeofday the architectural code requires an adaptation.

Re-implement the gettimeofday vdso in C in order to use lib/vdso.

With the new implementation arm64 gains support for CLOCK_BOOTTIME and CLOCK_TAI.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/Kconfig | 2 + arch/arm64/include/asm/vdso/gettimeofday.h | 84 ++++++ arch/arm64/include/asm/vdso/vsyscall.h | 53 ++++ arch/arm64/include/asm/vdso_datapage.h | 48 --- arch/arm64/kernel/asm-offsets.c | 33 +- arch/arm64/kernel/vdso.c | 51 +--- arch/arm64/kernel/vdso/Makefile | 34 ++- arch/arm64/kernel/vdso/gettimeofday.S | 334 --------------------- arch/arm64/kernel/vdso/vgettimeofday.c | 28 ++ 9 files changed, 221 insertions(+), 446 deletions(-) create mode 100644 arch/arm64/include/asm/vdso/gettimeofday.h create mode 100644 arch/arm64/include/asm/vdso/vsyscall.h delete mode 100644 arch/arm64/include/asm/vdso_datapage.h delete mode 100644 arch/arm64/kernel/vdso/gettimeofday.S create mode 100644 arch/arm64/kernel/vdso/vgettimeofday.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 697ea0510729..952c9f8cf3b8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -107,6 +107,7 @@ config ARM64 select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL + select GENERIC_GETTIMEOFDAY select HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND select HAVE_PCI @@ -160,6 +161,7 @@ config ARM64 select HAVE_SYSCALL_TRACEPOINTS select HAVE_KPROBES select HAVE_KRETPROBES + select HAVE_GENERIC_VDSO select IOMMU_DMA if IOMMU_SUPPORT select IRQ_DOMAIN select IRQ_FORCED_THREADING diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h new file mode 100644 index 000000000000..dcfe408b9b11 --- /dev/null +++ b/arch/arm64/include/asm/vdso/gettimeofday.h @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 ARM Limited + */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include <asm/unistd.h> +#include <uapi/linux/time.h> + +static __always_inline notrace int gettimeofday_fallback( + struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + register struct timezone *tz asm("x1") = _tz; + register struct __kernel_old_timeval *tv asm("x0") = _tv; + register long ret asm ("x0"); + register long nr asm("x8") = __NR_gettimeofday; + + asm volatile( + " svc #0\n" + : "=r" (ret) + : "r" (tv), "r" (tz), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace long clock_gettime_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("x1") = _ts; + register clockid_t clkid asm("x0") = _clkid; + register long ret asm ("x0"); + register long nr asm("x8") = __NR_clock_gettime; + + asm volatile( + " svc #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace int clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("x1") = _ts; + register clockid_t clkid asm("x0") = _clkid; + register long ret asm ("x0"); + register long nr asm("x8") = __NR_clock_getres; + + asm volatile( + " svc #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace u64 __arch_get_hw_counter(s32 clock_mode) +{ + u64 res; + + asm volatile("mrs %0, cntvct_el0" : "=r" (res) :: "memory"); + + return res; +} + +static __always_inline +notrace const struct vdso_data *__arch_get_vdso_data(void) +{ + return _vdso_data; +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/arm64/include/asm/vdso/vsyscall.h b/arch/arm64/include/asm/vdso/vsyscall.h new file mode 100644 index 000000000000..0c731bfc7c8c --- /dev/null +++ b/arch/arm64/include/asm/vdso/vsyscall.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSO_VSYSCALL_H +#define __ASM_VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include <linux/timekeeper_internal.h> +#include <vdso/datapage.h> + +#define VDSO_PRECISION_MASK ~(0xFF00ULL<<48) + +extern struct vdso_data *vdso_data; + +/* + * Update the vDSO data page to keep in sync with kernel timekeeping. + */ +static __always_inline +struct vdso_data *__arm64_get_k_vdso_data(void) +{ + return vdso_data; +} +#define __arch_get_k_vdso_data __arm64_get_k_vdso_data + +static __always_inline +int __arm64_get_clock_mode(struct timekeeper *tk) +{ + u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct; + + return use_syscall; +} +#define __arch_get_clock_mode __arm64_get_clock_mode + +static __always_inline +int __arm64_use_vsyscall(struct vdso_data *vdata) +{ + return !vdata[CS_HRES_COARSE].clock_mode; +} +#define __arch_use_vsyscall __arm64_use_vsyscall + +static __always_inline +void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk) +{ + vdata[CS_HRES_COARSE].mask = VDSO_PRECISION_MASK; + vdata[CS_RAW].mask = VDSO_PRECISION_MASK; +} +#define __arch_update_vsyscall __arm64_update_vsyscall + +/* The asm-generic header needs to be included after the definitions above */ +#include <asm-generic/vdso/vsyscall.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_VSYSCALL_H */ diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h deleted file mode 100644 index f89263c8e11a..000000000000 --- a/arch/arm64/include/asm/vdso_datapage.h +++ /dev/null @@ -1,48 +0,0 @@ -/* - * 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/. - */ -#ifndef __ASM_VDSO_DATAPAGE_H -#define __ASM_VDSO_DATAPAGE_H - -#ifdef __KERNEL__ - -#ifndef __ASSEMBLY__ - -struct vdso_data { - __u64 cs_cycle_last; /* Timebase at clocksource init */ - __u64 raw_time_sec; /* Raw time */ - __u64 raw_time_nsec; - __u64 xtime_clock_sec; /* Kernel time */ - __u64 xtime_clock_nsec; - __u64 xtime_coarse_sec; /* Coarse time */ - __u64 xtime_coarse_nsec; - __u64 wtm_clock_sec; /* Wall to monotonic time */ - __u64 wtm_clock_nsec; - __u32 tb_seq_count; /* Timebase sequence counter */ - /* cs_* members must be adjacent and in this order (ldp accesses) */ - __u32 cs_mono_mult; /* NTP-adjusted clocksource multiplier */ - __u32 cs_shift; /* Clocksource shift (mono = raw) */ - __u32 cs_raw_mult; /* Raw clocksource multiplier */ - __u32 tz_minuteswest; /* Whacky timezone stuff */ - __u32 tz_dsttime; - __u32 use_syscall; - __u32 hrtimer_res; -}; - -#endif /* !__ASSEMBLY__ */ - -#endif /* __KERNEL__ */ - -#endif /* __ASM_VDSO_DATAPAGE_H */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 947e39896e28..9e4b7ccbab2f 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -25,13 +25,13 @@ #include <linux/kvm_host.h> #include <linux/preempt.h> #include <linux/suspend.h> +#include <vdso/datapage.h> #include <asm/cpufeature.h> #include <asm/fixmap.h> #include <asm/thread_info.h> #include <asm/memory.h> #include <asm/smp_plat.h> #include <asm/suspend.h> -#include <asm/vdso_datapage.h> #include <linux/kbuild.h> #include <linux/arm-smccc.h>

@@ -100,17 +100,28 @@ int main(void) DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); DEFINE(NSEC_PER_SEC, NSEC_PER_SEC); BLANK(); - DEFINE(VDSO_CS_CYCLE_LAST, offsetof(struct vdso_data, cs_cycle_last)); - DEFINE(VDSO_RAW_TIME_SEC, offsetof(struct vdso_data, raw_time_sec)); - DEFINE(VDSO_XTIME_CLK_SEC, offsetof(struct vdso_data, xtime_clock_sec)); - DEFINE(VDSO_XTIME_CRS_SEC, offsetof(struct vdso_data, xtime_coarse_sec)); - DEFINE(VDSO_XTIME_CRS_NSEC, offsetof(struct vdso_data, xtime_coarse_nsec)); - DEFINE(VDSO_WTM_CLK_SEC, offsetof(struct vdso_data, wtm_clock_sec)); - DEFINE(VDSO_TB_SEQ_COUNT, offsetof(struct vdso_data, tb_seq_count)); - DEFINE(VDSO_CS_MONO_MULT, offsetof(struct vdso_data, cs_mono_mult)); - DEFINE(VDSO_CS_SHIFT, offsetof(struct vdso_data, cs_shift)); + DEFINE(VDSO_SEQ, offsetof(struct vdso_data, seq)); + DEFINE(VDSO_CLK_MODE, offsetof(struct vdso_data, clock_mode)); + DEFINE(VDSO_CYCLE_LAST, offsetof(struct vdso_data, cycle_last)); + DEFINE(VDSO_MASK, offsetof(struct vdso_data, mask)); + DEFINE(VDSO_MULT, offsetof(struct vdso_data, mult)); + DEFINE(VDSO_SHIFT, offsetof(struct vdso_data, shift)); + DEFINE(VDSO_REALTIME_SEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME].sec)); + DEFINE(VDSO_REALTIME_NSEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME].nsec)); + DEFINE(VDSO_MONO_SEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC].sec)); + DEFINE(VDSO_MONO_NSEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC].nsec)); + DEFINE(VDSO_MONO_RAW_SEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_RAW].sec)); + DEFINE(VDSO_MONO_RAW_NSEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_RAW].nsec)); + DEFINE(VDSO_BOOTTIME_SEC, offsetof(struct vdso_data, basetime[CLOCK_BOOTTIME].sec)); + DEFINE(VDSO_BOOTTIME_NSEC, offsetof(struct vdso_data, basetime[CLOCK_BOOTTIME].nsec)); + DEFINE(VDSO_TAI_SEC, offsetof(struct vdso_data, basetime[CLOCK_TAI].sec)); + DEFINE(VDSO_TAI_NSEC, offsetof(struct vdso_data, basetime[CLOCK_TAI].nsec)); + DEFINE(VDSO_RT_COARSE_SEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME_COARSE].sec)); + DEFINE(VDSO_RT_COARSE_NSEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME_COARSE].nsec)); + DEFINE(VDSO_MONO_COARSE_SEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_COARSE].sec)); + DEFINE(VDSO_MONO_COARSE_NSEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_COARSE].nsec)); DEFINE(VDSO_TZ_MINWEST, offsetof(struct vdso_data, tz_minuteswest)); - DEFINE(VDSO_USE_SYSCALL, offsetof(struct vdso_data, use_syscall)); + DEFINE(VDSO_TZ_DSTTIME, offsetof(struct vdso_data, tz_dsttime)); BLANK(); DEFINE(TVAL_TV_SEC, offsetof(struct timeval, tv_sec)); DEFINE(TSPEC_TV_SEC, offsetof(struct timespec, tv_sec)); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 8074cbd3a3a8..23c38303a52a 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -31,11 +31,13 @@ #include <linux/slab.h> #include <linux/timekeeper_internal.h> #include <linux/vmalloc.h> +#include <vdso/datapage.h> +#include <vdso/helpers.h> +#include <vdso/vsyscall.h>

#include <asm/cacheflush.h> #include <asm/signal32.h> #include <asm/vdso.h> -#include <asm/vdso_datapage.h>

extern char vdso_start[], vdso_end[]; static unsigned long vdso_pages __ro_after_init; @@ -44,10 +46,10 @@ static unsigned long vdso_pages __ro_after_init; * The vDSO data page. */ static union { - struct vdso_data data; + struct vdso_data data[CS_BASES]; u8 page[PAGE_SIZE]; } vdso_data_store __page_aligned_data; -struct vdso_data *vdso_data = &vdso_data_store.data; +struct vdso_data *vdso_data = vdso_data_store.data;

#ifdef CONFIG_COMPAT /* @@ -280,46 +282,3 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, up_write(&mm->mmap_sem); return PTR_ERR(ret); } - -/* - * Update the vDSO data page to keep in sync with kernel timekeeping. - */ -void update_vsyscall(struct timekeeper *tk) -{ - u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct; - - ++vdso_data->tb_seq_count; - smp_wmb(); - - vdso_data->use_syscall = use_syscall; - vdso_data->xtime_coarse_sec = tk->xtime_sec; - vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >> - tk->tkr_mono.shift; - vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec; - vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec; - - /* Read without the seqlock held by clock_getres() */ - WRITE_ONCE(vdso_data->hrtimer_res, hrtimer_resolution); - - if (!use_syscall) { - /* tkr_mono.cycle_last == tkr_raw.cycle_last */ - vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; - vdso_data->raw_time_sec = tk->raw_sec; - vdso_data->raw_time_nsec = tk->tkr_raw.xtime_nsec; - vdso_data->xtime_clock_sec = tk->xtime_sec; - vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; - 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; - } - - smp_wmb(); - ++vdso_data->tb_seq_count; -} - -void update_vsyscall_tz(void) -{ - vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; - vdso_data->tz_dsttime = sys_tz.tz_dsttime; -} diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index fa230ff09aa1..00bcfd2672cf 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -6,7 +6,12 @@ # Heavily based on the vDSO Makefiles for other archs. #

-obj-vdso := gettimeofday.o note.o sigreturn.o +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64 +include $(srctree)/lib/vdso/Makefile + +obj-vdso := vgettimeofday.o note.o sigreturn.o

# Build rules targets := $(obj-vdso) vdso.so vdso.so.dbg @@ -15,6 +20,24 @@ obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \ --build-id -n -T

+ccflags-y := -fno-common -fno-builtin -fno-stack-protector +ccflags-y += -DDISABLE_BRANCH_PROFILING + +VDSO_LDFLAGS := -Bsymbolic + +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os +KBUILD_CFLAGS += $(DISABLE_LTO) +KASAN_SANITIZE := n +UBSAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y +KCOV_INSTRUMENT := n + +ifeq ($(c-gettimeofday-y),) +CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny +else +CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -include $(c-gettimeofday-y) +endif + # Disable gcov profiling for VDSO code GCOV_PROFILE := n

@@ -28,6 +51,7 @@ $(obj)/vdso.o : $(obj)/vdso.so # Link rule for the .so file, .lds has to be first $(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE $(call if_changed,ld) + $(call if_changed,vdso_check)

# Strip rule for the .so file $(obj)/%.so: OBJCOPYFLAGS := -S @@ -42,13 +66,9 @@ quiet_cmd_vdsosym = VDSOSYM $@ include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE $(call if_changed,vdsosym)

-# Assembly rules for the .S files -$(obj-vdso): %.o: %.S FORCE - $(call if_changed_dep,vdsoas) - # Actual build commands -quiet_cmd_vdsoas = VDSOA $@ - cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $< +quiet_cmd_vdsocc = VDSOCC $@ + cmd_vdsocc = $(CC) $(a_flags) $(c_flags) -c -o $@ $<

# Install commands for the unstripped file quiet_cmd_vdso_install = INSTALL $@ diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S deleted file mode 100644 index 856fee6d3512..000000000000 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ /dev/null @@ -1,334 +0,0 @@ -/* - * Userspace implementations of gettimeofday() and friends. - * - * 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 - */ - -#include <linux/linkage.h> -#include <asm/asm-offsets.h> -#include <asm/unistd.h> - -#define NSEC_PER_SEC_LO16 0xca00 -#define NSEC_PER_SEC_HI16 0x3b9a - -vdso_data .req x6 -seqcnt .req w7 -w_tmp .req w8 -x_tmp .req x8 - -/* - * Conventions for macro arguments: - * - An argument is write-only if its name starts with "res". - * - All other arguments are read-only, unless otherwise specified. - */ - - .macro seqcnt_acquire -9999: ldr seqcnt, [vdso_data, #VDSO_TB_SEQ_COUNT] - tbnz seqcnt, #0, 9999b - dmb ishld - .endm - - .macro seqcnt_check fail - dmb ishld - ldr w_tmp, [vdso_data, #VDSO_TB_SEQ_COUNT] - cmp w_tmp, seqcnt - b.ne \fail - .endm - - .macro syscall_check fail - ldr w_tmp, [vdso_data, #VDSO_USE_SYSCALL] - cbnz w_tmp, \fail - .endm - - .macro get_nsec_per_sec res - mov \res, #NSEC_PER_SEC_LO16 - movk \res, #NSEC_PER_SEC_HI16, lsl #16 - .endm - - /* - * Returns the clock delta, in nanoseconds left-shifted by the clock - * shift. - */ - .macro get_clock_shifted_nsec res, cycle_last, mult - /* Read the virtual counter. */ - isb - mrs x_tmp, cntvct_el0 - /* Calculate cycle delta and convert to ns. */ - sub \res, x_tmp, \cycle_last - /* We can only guarantee 56 bits of precision. */ - movn x_tmp, #0xff00, lsl #48 - and \res, x_tmp, \res - mul \res, \res, \mult - /* - * Fake address dependency from the value computed from the counter - * register to subsequent data page accesses so that the sequence - * locking also orders the read of the counter. - */ - and x_tmp, \res, xzr - add vdso_data, vdso_data, x_tmp - .endm - - /* - * Returns in res_{sec,nsec} the REALTIME timespec, based on the - * "wall time" (xtime) and the clock_mono delta. - */ - .macro get_ts_realtime res_sec, res_nsec, \ - clock_nsec, xtime_sec, xtime_nsec, nsec_to_sec - add \res_nsec, \clock_nsec, \xtime_nsec - udiv x_tmp, \res_nsec, \nsec_to_sec - add \res_sec, \xtime_sec, x_tmp - msub \res_nsec, x_tmp, \nsec_to_sec, \res_nsec - .endm - - /* - * Returns in res_{sec,nsec} the timespec based on the clock_raw delta, - * used for CLOCK_MONOTONIC_RAW. - */ - .macro get_ts_clock_raw res_sec, res_nsec, clock_nsec, nsec_to_sec - udiv \res_sec, \clock_nsec, \nsec_to_sec - msub \res_nsec, \res_sec, \nsec_to_sec, \clock_nsec - .endm - - /* sec and nsec are modified in place. */ - .macro add_ts sec, nsec, ts_sec, ts_nsec, nsec_to_sec - /* Add timespec. */ - add \sec, \sec, \ts_sec - add \nsec, \nsec, \ts_nsec - - /* Normalise the new timespec. */ - cmp \nsec, \nsec_to_sec - b.lt 9999f - sub \nsec, \nsec, \nsec_to_sec - add \sec, \sec, #1 -9999: - cmp \nsec, #0 - b.ge 9998f - add \nsec, \nsec, \nsec_to_sec - sub \sec, \sec, #1 -9998: - .endm - - .macro clock_gettime_return, shift=0 - .if \shift == 1 - lsr x11, x11, x12 - .endif - stp x10, x11, [x1, #TSPEC_TV_SEC] - mov x0, xzr - ret - .endm - - .macro jump_slot jumptable, index, label - .if (. - \jumptable) != 4 * (\index) - .error "Jump slot index mismatch" - .endif - b \label - .endm - - .text - -/* int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); */ -ENTRY(__kernel_gettimeofday) - .cfi_startproc - adr vdso_data, _vdso_data - /* If tv is NULL, skip to the timezone code. */ - cbz x0, 2f - - /* Compute the time of day. */ -1: seqcnt_acquire - syscall_check fail=4f - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_mono_mult, w12 = cs_shift */ - ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT] - ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] - - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - seqcnt_check fail=1b - get_ts_realtime res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9 - - /* Convert ns to us. */ - mov x13, #1000 - lsl x13, x13, x12 - udiv x11, x11, x13 - stp x10, x11, [x0, #TVAL_TV_SEC] -2: - /* If tz is NULL, return 0. */ - cbz x1, 3f - ldp w4, w5, [vdso_data, #VDSO_TZ_MINWEST] - stp w4, w5, [x1, #TZ_MINWEST] -3: - mov x0, xzr - ret -4: - /* Syscall fallback. */ - mov x8, #__NR_gettimeofday - svc #0 - ret - .cfi_endproc -ENDPROC(__kernel_gettimeofday) - -#define JUMPSLOT_MAX CLOCK_MONOTONIC_COARSE - -/* int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); */ -ENTRY(__kernel_clock_gettime) - .cfi_startproc - cmp w0, #JUMPSLOT_MAX - b.hi syscall - adr vdso_data, _vdso_data - adr x_tmp, jumptable - add x_tmp, x_tmp, w0, uxtw #2 - br x_tmp - - ALIGN -jumptable: - jump_slot jumptable, CLOCK_REALTIME, realtime - jump_slot jumptable, CLOCK_MONOTONIC, monotonic - b syscall - b syscall - jump_slot jumptable, CLOCK_MONOTONIC_RAW, monotonic_raw - jump_slot jumptable, CLOCK_REALTIME_COARSE, realtime_coarse - jump_slot jumptable, CLOCK_MONOTONIC_COARSE, monotonic_coarse - - .if (. - jumptable) != 4 * (JUMPSLOT_MAX + 1) - .error "Wrong jumptable size" - .endif - - ALIGN -realtime: - seqcnt_acquire - syscall_check fail=syscall - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_mono_mult, w12 = cs_shift */ - ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT] - ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] - - /* All computations are done with left-shifted nsecs. */ - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - seqcnt_check fail=realtime - get_ts_realtime res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9 - clock_gettime_return, shift=1 - - ALIGN -monotonic: - seqcnt_acquire - syscall_check fail=syscall - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_mono_mult, w12 = cs_shift */ - ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT] - ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] - ldp x3, x4, [vdso_data, #VDSO_WTM_CLK_SEC] - - /* All computations are done with left-shifted nsecs. */ - lsl x4, x4, x12 - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - seqcnt_check fail=monotonic - get_ts_realtime res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9 - - add_ts sec=x10, nsec=x11, ts_sec=x3, ts_nsec=x4, nsec_to_sec=x9 - clock_gettime_return, shift=1 - - ALIGN -monotonic_raw: - seqcnt_acquire - syscall_check fail=syscall - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_raw_mult, w12 = cs_shift */ - ldp w12, w11, [vdso_data, #VDSO_CS_SHIFT] - ldp x13, x14, [vdso_data, #VDSO_RAW_TIME_SEC] - - /* All computations are done with left-shifted nsecs. */ - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - seqcnt_check fail=monotonic_raw - get_ts_clock_raw res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, nsec_to_sec=x9 - - add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9 - clock_gettime_return, shift=1 - - ALIGN -realtime_coarse: - seqcnt_acquire - ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC] - seqcnt_check fail=realtime_coarse - clock_gettime_return - - ALIGN -monotonic_coarse: - seqcnt_acquire - ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC] - ldp x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC] - seqcnt_check fail=monotonic_coarse - - /* Computations are done in (non-shifted) nsecs. */ - get_nsec_per_sec res=x9 - add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9 - clock_gettime_return - - ALIGN -syscall: /* Syscall fallback. */ - mov x8, #__NR_clock_gettime - svc #0 - ret - .cfi_endproc -ENDPROC(__kernel_clock_gettime) - -/* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ -ENTRY(__kernel_clock_getres) - .cfi_startproc - cmp w0, #CLOCK_REALTIME - ccmp w0, #CLOCK_MONOTONIC, #0x4, ne - ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f - - adr vdso_data, _vdso_data - ldr w2, [vdso_data, #CLOCK_REALTIME_RES] - b 2f -1: - cmp w0, #CLOCK_REALTIME_COARSE - ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f - ldr x2, 5f -2: - cbz x1, 3f - stp xzr, x2, [x1] - -3: /* res == NULL. */ - mov w0, wzr - ret - -4: /* Syscall fallback. */ - mov x8, #__NR_clock_getres - svc #0 - ret -5: - .quad CLOCK_COARSE_RES - .cfi_endproc -ENDPROC(__kernel_clock_getres) diff --git a/arch/arm64/kernel/vdso/vgettimeofday.c b/arch/arm64/kernel/vdso/vgettimeofday.c new file mode 100644 index 000000000000..bbc83b6e2b1a --- /dev/null +++ b/arch/arm64/kernel/vdso/vgettimeofday.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM64 userspace implementations of gettimeofday() and similar. + * + * Copyright (C) 2018 ARM Limited + * + */ +#include <linux/time.h> +#include <linux/types.h> + +notrace int __kernel_clock_gettime(clockid_t clock, + struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +notrace int __kernel_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +notrace int __kernel_clock_getres(clockid_t clock_id, + struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock_id, res); +} +

vDSO requires gettimeofday and clock_gettime syscalls to implement the fallback mechanism.

Add the missing syscall numbers to unistd.h for arm64.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Cc: Arnd Bergmann arnd@arndb.de Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/include/asm/unistd.h | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 70e6882853c0..81cc05acccc9 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -33,8 +33,13 @@ #define __NR_compat_exit 1 #define __NR_compat_read 3 #define __NR_compat_write 4 +#define __NR_compat_gettimeofday 78 #define __NR_compat_sigreturn 119 #define __NR_compat_rt_sigreturn 173 +#define __NR_compat_clock_getres 247 +#define __NR_compat_clock_gettime 263 +#define __NR_compat_clock_gettime64 403 +#define __NR_compat_clock_getres_time64 406

/* * The following SVCs are ARM private.

Update asm-offsets for arm64 to generate the correct offsets for compat signals.

They will be useful for the implementation of the compat sigreturn trampolines in vDSO context.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/kernel/asm-offsets.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 9e4b7ccbab2f..c0d8b9f40022 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -30,6 +30,7 @@ #include <asm/fixmap.h> #include <asm/thread_info.h> #include <asm/memory.h> +#include <asm/signal32.h> #include <asm/smp_plat.h> #include <asm/suspend.h> #include <linux/kbuild.h> @@ -77,6 +78,11 @@ int main(void) DEFINE(S_STACKFRAME, offsetof(struct pt_regs, stackframe)); DEFINE(S_FRAME_SIZE, sizeof(struct pt_regs)); BLANK(); +#ifdef CONFIG_COMPAT + DEFINE(COMPAT_SIGFRAME_REGS_OFFSET, offsetof(struct compat_sigframe, uc.uc_mcontext.arm_r0)); + DEFINE(COMPAT_RT_SIGFRAME_REGS_OFFSET, offsetof(struct compat_rt_sigframe, sig.uc.uc_mcontext.arm_r0)); + BLANK(); +#endif DEFINE(MM_CONTEXT_ID, offsetof(struct mm_struct, context.id.counter)); BLANK(); DEFINE(VMA_VM_MM, offsetof(struct vm_area_struct, vm_mm));

Provide the arm64 compat (AArch32) vDSO in kernel/vdso32 in a similar way to what happens in kernel/vdso.

The compat vDSO leverages on an adaptation of the arm architecture code with few changes: - Use of lib/vdso for gettimeofday - Implementation of syscall based fallback - Introduction of clock_getres for the compat library - Implementation of trampolines - Implementation of elf note

To build the compat vDSO a 32 bit compiler is required and needs to be specified via CONFIG_CROSS_COMPILE_COMPAT_VDSO.

The implementation of the configuration option will be contained in a future patch.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/include/asm/vdso/compat_barrier.h | 51 +++++ .../include/asm/vdso/compat_gettimeofday.h | 108 ++++++++++ arch/arm64/kernel/vdso32/.gitignore | 2 + arch/arm64/kernel/vdso32/Makefile | 184 ++++++++++++++++++ arch/arm64/kernel/vdso32/note.c | 15 ++ arch/arm64/kernel/vdso32/sigreturn.S | 62 ++++++ arch/arm64/kernel/vdso32/vdso.S | 19 ++ arch/arm64/kernel/vdso32/vdso.lds.S | 82 ++++++++ arch/arm64/kernel/vdso32/vgettimeofday.c | 59 ++++++ 9 files changed, 582 insertions(+) create mode 100644 arch/arm64/include/asm/vdso/compat_barrier.h create mode 100644 arch/arm64/include/asm/vdso/compat_gettimeofday.h create mode 100644 arch/arm64/kernel/vdso32/.gitignore create mode 100644 arch/arm64/kernel/vdso32/Makefile create mode 100644 arch/arm64/kernel/vdso32/note.c create mode 100644 arch/arm64/kernel/vdso32/sigreturn.S create mode 100644 arch/arm64/kernel/vdso32/vdso.S create mode 100644 arch/arm64/kernel/vdso32/vdso.lds.S create mode 100644 arch/arm64/kernel/vdso32/vgettimeofday.c

diff --git a/arch/arm64/include/asm/vdso/compat_barrier.h b/arch/arm64/include/asm/vdso/compat_barrier.h new file mode 100644 index 000000000000..ea24ea856b07 --- /dev/null +++ b/arch/arm64/include/asm/vdso/compat_barrier.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 ARM Limited + */ +#ifndef __COMPAT_BARRIER_H +#define __COMPAT_BARRIER_H + +#ifndef __ASSEMBLY__ +/* + * Warning: This code is meant to be used with + * ENABLE_COMPAT_VDSO only. + */ +#ifndef ENABLE_COMPAT_VDSO +#error This header is meant to be used with ENABLE_COMPAT_VDSO only +#endif + +#ifdef dmb +#undef dmb +#endif + +#if __LINUX_ARM_ARCH__ >= 7 +#define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory") +#elif __LINUX_ARM_ARCH__ == 6 +#define dmb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \ + : : "r" (0) : "memory") +#else +#define dmb(x) __asm__ __volatile__ ("" : : : "memory") +#endif + +#if __LINUX_ARM_ARCH__ >= 8 +#define aarch32_smp_mb() dmb(ish) +#define aarch32_smp_rmb() dmb(ishld) +#define aarch32_smp_wmb() dmb(ishst) +#else +#define aarch32_smp_mb() dmb(ish) +#define aarch32_smp_rmb() aarch32_smp_mb() +#define aarch32_smp_wmb() dmb(ishst) +#endif + + +#undef smp_mb +#undef smp_rmb +#undef smp_wmb + +#define smp_mb() aarch32_smp_mb() +#define smp_rmb() aarch32_smp_rmb() +#define smp_wmb() aarch32_smp_wmb() + +#endif /* !__ASSEMBLY__ */ + +#endif /* __COMPAT_BARRIER_H */ diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h new file mode 100644 index 000000000000..e9d44b363bf2 --- /dev/null +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h @@ -0,0 +1,108 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 ARM Limited + */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include <asm/unistd.h> +#include <uapi/linux/time.h> + +#include <asm/vdso/compat_barrier.h> + +static __always_inline notrace int gettimeofday_fallback( + struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + register struct timezone *tz asm("r1") = _tz; + register struct __kernel_old_timeval *tv asm("r0") = _tv; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat_gettimeofday; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (tv), "r" (tz), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace long clock_gettime_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat_clock_gettime64; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace int clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat_clock_getres_time64; + + /* The checks below are required for ABI consistency with arm */ + if ((_clkid >= MAX_CLOCKS) && (_ts == NULL)) + return -EINVAL; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace u64 __arch_get_hw_counter(s32 clock_mode) +{ + u64 res; + + isb(); + asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (res)); + + return res; +} + +static __always_inline notrace const struct vdso_data *__arch_get_vdso_data(void) +{ + const struct vdso_data *ret; + + /* + * This simply puts &_vdso_data into ret. The reason why we don't use + * `ret = _vdso_data` is that the compiler tends to optimise this in a + * very suboptimal way: instead of keeping &_vdso_data in a register, + * it goes through a relocation almost every time _vdso_data must be + * accessed (even in subfunctions). This is both time and space + * consuming: each relocation uses a word in the code section, and it + * has to be loaded at runtime. + * + * This trick hides the assignment from the compiler. Since it cannot + * track where the pointer comes from, it will only use one relocation + * where __arch_get_vdso_data() is called, and then keep the result in + * a register. + */ + asm volatile("mov %0, %1" : "=r"(ret) : "r"(_vdso_data)); + + return ret; +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/arm64/kernel/vdso32/.gitignore b/arch/arm64/kernel/vdso32/.gitignore new file mode 100644 index 000000000000..4fea950fa5ed --- /dev/null +++ b/arch/arm64/kernel/vdso32/.gitignore @@ -0,0 +1,2 @@ +vdso.lds +vdso.so.raw diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile new file mode 100644 index 000000000000..0f1a02ccacbc --- /dev/null +++ b/arch/arm64/kernel/vdso32/Makefile @@ -0,0 +1,184 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for vdso32 +# + +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32 +include $(srctree)/lib/vdso/Makefile + +COMPATCC := $(CROSS_COMPILE_COMPAT)gcc + +# Same as cc-*option, but using COMPATCC instead of CC +cc32-option = $(call try-run,\ + $(COMPATCC) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2)) +cc32-disable-warning = $(call try-run,\ + $(COMPATCC) -W$(strip $(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1))) +cc32-ldoption = $(call try-run,\ + $(COMPATCC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2)) + +# We cannot use the global flags to compile the vDSO files, the main reason +# being that the 32-bit compiler may be older than the main (64-bit) compiler +# and therefore may not understand flags set using $(cc-option ...). Besides, +# arch-specific options should be taken from the arm Makefile instead of the +# arm64 one. +# As a result we set our own flags here. + +# From top-level Makefile +# NOSTDINC_FLAGS +VDSO_CPPFLAGS := -nostdinc -isystem $(shell $(COMPATCC) -print-file-name=include) +VDSO_CPPFLAGS += $(LINUXINCLUDE) +VDSO_CPPFLAGS += $(KBUILD_CPPFLAGS) + +# Common C and assembly flags +# From top-level Makefile +VDSO_CAFLAGS := $(VDSO_CPPFLAGS) +VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) +ifdef CONFIG_DEBUG_INFO +VDSO_CAFLAGS += -g +endif +ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(COMPATCC)), y) +VDSO_CAFLAGS += -DCC_HAVE_ASM_GOTO +endif + +# From arm Makefile +VDSO_CAFLAGS += $(call cc32-option,-fno-dwarf2-cfi-asm) +VDSO_CAFLAGS += -mabi=aapcs-linux -mfloat-abi=soft +ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) +VDSO_CAFLAGS += -mbig-endian +else +VDSO_CAFLAGS += -mlittle-endian +endif + +# From arm vDSO Makefile +VDSO_CAFLAGS += -fPIC -fno-builtin -fno-stack-protector +VDSO_CAFLAGS += -DDISABLE_BRANCH_PROFILING + +# Try to compile for ARMv8. If the compiler is too old and doesn't support it, +# fall back to v7. There is no easy way to check for what architecture the code +# is being compiled, so define a macro specifying that (see arch/arm/Makefile). +VDSO_CAFLAGS += $(call cc32-option,-march=armv8-a -D__LINUX_ARM_ARCH__=8,\ + -march=armv7-a -D__LINUX_ARM_ARCH__=7) + +VDSO_CFLAGS := $(VDSO_CAFLAGS) +VDSO_CFLAGS += -DENABLE_COMPAT_VDSO=1 +# KBUILD_CFLAGS from top-level Makefile +VDSO_CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \ + -fno-strict-aliasing -fno-common \ + -Werror-implicit-function-declaration \ + -Wno-format-security \ + -std=gnu89 +VDSO_CFLAGS += -O2 +# Some useful compiler-dependent flags from top-level Makefile +VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,) +VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign) +VDSO_CFLAGS += $(call cc32-option,-fno-strict-overflow) +VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes) +VDSO_CFLAGS += $(call cc32-option,-Werror=date-time) +VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types) + +# The 32-bit compiler does not provide 128-bit integers, which are used in +# some headers that are indirectly included from the vDSO code. +# This hack makes the compiler happy and should trigger a warning/error if +# variables of such type are referenced. +VDSO_CFLAGS += -D__uint128_t='void*' +# Silence some warnings coming from headers that operate on long's +# (on GCC 4.8 or older, there is unfortunately no way to silence this warning) +VDSO_CFLAGS += $(call cc32-disable-warning,shift-count-overflow) +VDSO_CFLAGS += -Wno-int-to-pointer-cast + +VDSO_AFLAGS := $(VDSO_CAFLAGS) +VDSO_AFLAGS += -D__ASSEMBLY__ + +VDSO_LDFLAGS := $(VDSO_CPPFLAGS) +# From arm vDSO Makefile +VDSO_LDFLAGS += -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1 +VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096 +VDSO_LDFLAGS += -nostdlib -shared -mfloat-abi=soft +VDSO_LDFLAGS += $(call cc32-ldoption,-Wl$(comma)--hash-style=sysv) +VDSO_LDFLAGS += $(call cc32-ldoption,-Wl$(comma)--build-id) +VDSO_LDFLAGS += $(call cc32-ldoption,-fuse-ld=bfd) + + +# Borrow vdsomunge.c from the arm vDSO +# We have to use a relative path because scripts/Makefile.host prefixes +# $(hostprogs-y) with $(obj) +munge := ../../../arm/vdso/vdsomunge +hostprogs-y := $(munge) + +c-obj-vdso := note.o +c-obj-vdso-gettimeofday := vgettimeofday.o +asm-obj-vdso := sigreturn.o + +ifneq ($(c-gettimeofday-y),) +VDSO_CFLAGS_gettimeofday_o += -include $(c-gettimeofday-y) +endif + +# Build rules +targets := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) vdso.so vdso.so.dbg vdso.so.raw +c-obj-vdso := $(addprefix $(obj)/, $(c-obj-vdso)) +c-obj-vdso-gettimeofday := $(addprefix $(obj)/, $(c-obj-vdso-gettimeofday)) +asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso)) +obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso) + +obj-y += vdso.o +extra-y += vdso.lds +CPPFLAGS_vdso.lds += -P -C -U$(ARCH) + +# Force dependency (vdso.s includes vdso.so through incbin) +$(obj)/vdso.o: $(obj)/vdso.so + +include/generated/vdso32-offsets.h: $(obj)/vdso.so.dbg FORCE + $(call if_changed,vdsosym) + +# Strip rule for vdso.so +$(obj)/vdso.so: OBJCOPYFLAGS := -S +$(obj)/vdso.so: $(obj)/vdso.so.dbg FORCE + $(call if_changed,objcopy) + +$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/$(munge) FORCE + $(call if_changed,vdsomunge) + +# Link rule for the .so file, .lds has to be first +$(obj)/vdso.so.raw: $(src)/vdso.lds $(obj-vdso) FORCE + $(call if_changed,vdsold) + $(call if_changed,vdso_check) + +# Compilation rules for the vDSO sources +$(c-obj-vdso): %.o: %.c FORCE + $(call if_changed_dep,vdsocc) +$(c-obj-vdso-gettimeofday): %.o: %.c FORCE + $(call if_changed_dep,vdsocc_gettimeofday) +$(asm-obj-vdso): %.o: %.S FORCE + $(call if_changed_dep,vdsoas) + +# Actual build commands +quiet_cmd_vdsold = VDSOL $@ + cmd_vdsold = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_LDFLAGS) \ + -Wl,-T $(filter %.lds,$^) $(filter %.o,$^) -o $@ +quiet_cmd_vdsocc = VDSOC $@ + cmd_vdsocc = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) -c -o $@ $< +quiet_cmd_vdsocc_gettimeofday = VDSOC_GTD $@ + cmd_vdsocc_gettimeofday = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_CFLAGS) $(VDSO_CFLAGS_gettimeofday_o) -c -o $@ $< +quiet_cmd_vdsoas = VDSOA $@ + cmd_vdsoas = $(COMPATCC) -Wp,-MD,$(depfile) $(VDSO_AFLAGS) -c -o $@ $< + +quiet_cmd_vdsomunge = MUNGE $@ + cmd_vdsomunge = $(obj)/$(munge) $< $@ + +# Generate vDSO offsets using helper script (borrowed from the 64-bit vDSO) +gen-vdsosym := $(srctree)/$(src)/../vdso/gen_vdso_offsets.sh +quiet_cmd_vdsosym = VDSOSYM $@ +# The AArch64 nm should be able to read an AArch32 binary + cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ + +# Install commands for the unstripped file +quiet_cmd_vdso_install = INSTALL $@ + cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/vdso32.so + +vdso.so: $(obj)/vdso.so.dbg + @mkdir -p $(MODLIB)/vdso + $(call cmd,vdso_install) + +vdso_install: vdso.so diff --git a/arch/arm64/kernel/vdso32/note.c b/arch/arm64/kernel/vdso32/note.c new file mode 100644 index 000000000000..eff5bf9efb8b --- /dev/null +++ b/arch/arm64/kernel/vdso32/note.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2012-2018 ARM Limited + * + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + */ + +#include <linux/uts.h> +#include <linux/version.h> +#include <linux/elfnote.h> +#include <linux/build-salt.h> + +ELFNOTE32("Linux", 0, LINUX_VERSION_CODE); +BUILD_SALT; diff --git a/arch/arm64/kernel/vdso32/sigreturn.S b/arch/arm64/kernel/vdso32/sigreturn.S new file mode 100644 index 000000000000..1a81277c2d09 --- /dev/null +++ b/arch/arm64/kernel/vdso32/sigreturn.S @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * This file provides both A32 and T32 versions, in accordance with the + * arm sigreturn code. + * + * Copyright (C) 2018 ARM Limited + */ + +#include <linux/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/unistd.h> + +#define ARM_ENTRY(name) \ + ENTRY(name) + +#define ARM_ENDPROC(name) \ + .type name, %function; \ + END(name) + + .text + + .arm + .fnstart + .save {r0-r15} + .pad #COMPAT_SIGFRAME_REGS_OFFSET + nop +ARM_ENTRY(__kernel_sigreturn_arm) + mov r7, #__NR_compat_sigreturn + svc #0 + .fnend +ARM_ENDPROC(__kernel_sigreturn_arm) + + .fnstart + .save {r0-r15} + .pad #COMPAT_RT_SIGFRAME_REGS_OFFSET + nop +ARM_ENTRY(__kernel_rt_sigreturn_arm) + mov r7, #__NR_compat_rt_sigreturn + svc #0 + .fnend +ARM_ENDPROC(__kernel_rt_sigreturn_arm) + + .thumb + .fnstart + .save {r0-r15} + .pad #COMPAT_SIGFRAME_REGS_OFFSET + nop +ARM_ENTRY(__kernel_sigreturn_thumb) + mov r7, #__NR_compat_sigreturn + svc #0 + .fnend +ARM_ENDPROC(__kernel_sigreturn_thumb) + + .fnstart + .save {r0-r15} + .pad #COMPAT_RT_SIGFRAME_REGS_OFFSET + nop +ARM_ENTRY(__kernel_rt_sigreturn_thumb) + mov r7, #__NR_compat_rt_sigreturn + svc #0 + .fnend +ARM_ENDPROC(__kernel_rt_sigreturn_thumb) diff --git a/arch/arm64/kernel/vdso32/vdso.S b/arch/arm64/kernel/vdso32/vdso.S new file mode 100644 index 000000000000..e72ac7bc4c04 --- /dev/null +++ b/arch/arm64/kernel/vdso32/vdso.S @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2012 ARM Limited + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/const.h> +#include <asm/page.h> + + .globl vdso32_start, vdso32_end + .section .rodata + .balign PAGE_SIZE +vdso32_start: + .incbin "arch/arm64/kernel/vdso32/vdso.so" + .balign PAGE_SIZE +vdso32_end: + + .previous diff --git a/arch/arm64/kernel/vdso32/vdso.lds.S b/arch/arm64/kernel/vdso32/vdso.lds.S new file mode 100644 index 000000000000..a3944927eaeb --- /dev/null +++ b/arch/arm64/kernel/vdso32/vdso.lds.S @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Adapted from arm64 version. + * + * GNU linker script for the VDSO library. + * Heavily based on the vDSO linker scripts for other archs. + * + * Copyright (C) 2012-2018 ARM Limited + */ + +#include <linux/const.h> +#include <asm/page.h> +#include <asm/vdso.h> + +OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm") +OUTPUT_ARCH(arm) + +SECTIONS +{ + PROVIDE_HIDDEN(_vdso_data = . - PAGE_SIZE); + . = VDSO_LBASE + SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + .note : { *(.note.*) } :text :note + + .dynamic : { *(.dynamic) } :text :dynamic + + .rodata : { *(.rodata*) } :text + + .text : { *(.text*) } :text =0xe7f001f2 + + .got : { *(.got) } + .rel.plt : { *(.rel.plt) } + + /DISCARD/ : { + *(.note.GNU-stack) + *(.data .data.* .gnu.linkonce.d.* .sdata*) + *(.bss .sbss .dynbss .dynsbss) + } +} + +/* + * We must supply the ELF program headers explicitly to get just one + * PT_LOAD segment, and set the flags explicitly to make segments read-only. + */ +PHDRS +{ + text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ + note PT_NOTE FLAGS(4); /* PF_R */ +} + +VERSION +{ + LINUX_2.6 { + global: + __vdso_clock_gettime; + __vdso_gettimeofday; + __vdso_clock_getres; + __kernel_sigreturn_arm; + __kernel_sigreturn_thumb; + __kernel_rt_sigreturn_arm; + __kernel_rt_sigreturn_thumb; + __vdso_clock_gettime64; + local: *; + }; +} + +/* + * Make the sigreturn code visible to the kernel. + */ +VDSO_compat_sigreturn_arm = __kernel_sigreturn_arm; +VDSO_compat_sigreturn_thumb = __kernel_sigreturn_thumb; +VDSO_compat_rt_sigreturn_arm = __kernel_rt_sigreturn_arm; +VDSO_compat_rt_sigreturn_thumb = __kernel_rt_sigreturn_thumb; diff --git a/arch/arm64/kernel/vdso32/vgettimeofday.c b/arch/arm64/kernel/vdso32/vgettimeofday.c new file mode 100644 index 000000000000..a6c8afe14ebc --- /dev/null +++ b/arch/arm64/kernel/vdso32/vgettimeofday.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM64 compat userspace implementations of gettimeofday() and similar. + * + * Copyright (C) 2018 ARM Limited + * + */ +#include <linux/time.h> +#include <linux/types.h> + +notrace int __vdso_clock_gettime(clockid_t clock, + struct old_timespec32 *ts) +{ + /* The checks below are required for ABI consistency with arm */ + if ((u32)ts >= TASK_SIZE_32) + return -EFAULT; + + return __cvdso_clock_gettime32(clock, ts); +} + +notrace int __vdso_clock_gettime64(clockid_t clock, + struct __kernel_timespec *ts) +{ + /* The checks below are required for ABI consistency with arm */ + if ((u32)ts >= TASK_SIZE_32) + return -EFAULT; + + return __cvdso_clock_gettime(clock, ts); +} + +notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +notrace int __vdso_clock_getres(clockid_t clock_id, + struct old_timespec32 *res) +{ + /* The checks below are required for ABI consistency with arm */ + if ((u32)res >= TASK_SIZE_32) + return -EFAULT; + + return __cvdso_clock_getres_time32(clock_id, res); +} + +/* Avoid unresolved references emitted by GCC */ + +void __aeabi_unwind_cpp_pr0(void) +{ +} + +void __aeabi_unwind_cpp_pr1(void) +{ +} + +void __aeabi_unwind_cpp_pr2(void) +{ +}

If CONFIG_GENERIC_COMPAT_VDSO is enabled, compat vDSO are installed in a compat (32 bit) process instead of sigpage.

Add the necessary code to setup the vDSO required pages.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/kernel/vdso.c | 90 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 88 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index aa1fb25a9fe4..ad3a81b2c7ce 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -40,12 +40,22 @@ #include <asm/vdso.h>

extern char vdso_start[], vdso_end[]; +#ifdef CONFIG_COMPAT_VDSO +extern char vdso32_start[], vdso32_end[]; +#endif /* CONFIG_COMPAT_VDSO */

/* vdso_lookup arch_index */ enum arch_vdso_type { ARM64_VDSO = 0, +#ifdef CONFIG_COMPAT_VDSO + ARM64_VDSO32 = 1, +#endif /* CONFIG_COMPAT_VDSO */ }; +#ifdef CONFIG_COMPAT_VDSO +#define VDSO_TYPES (ARM64_VDSO32 + 1) +#else #define VDSO_TYPES (ARM64_VDSO + 1) +#endif /* CONFIG_COMPAT_VDSO */

struct __vdso_abi { const char *name; @@ -64,6 +74,13 @@ static struct __vdso_abi vdso_lookup[VDSO_TYPES] __ro_after_init = { .vdso_code_start = vdso_start, .vdso_code_end = vdso_end, }, +#ifdef CONFIG_COMPAT_VDSO + { + .name = "vdso32", + .vdso_code_start = vdso32_start, + .vdso_code_end = vdso32_end, + }, +#endif /* CONFIG_COMPAT_VDSO */ };

/* @@ -174,24 +191,52 @@ static int __setup_additional_pages(enum arch_vdso_type arch_index, /* * Create and map the vectors page for AArch32 tasks. */ +#ifdef CONFIG_COMPAT_VDSO +static int aarch32_vdso_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + return __vdso_remap(ARM64_VDSO32, sm, new_vma); +} +#endif /* CONFIG_COMPAT_VDSO */ + /* * aarch32_vdso_pages: * 0 - kuser helpers * 1 - sigreturn code + * or (CONFIG_COMPAT_VDSO): + * 0 - kuser helpers + * 1 - vdso data + * 2 - vdso code */ #define C_VECTORS 0 +#ifdef CONFIG_COMPAT_VDSO +#define C_VVAR 1 +#define C_VDSO 2 +#define C_PAGES (C_VDSO + 1) +#else #define C_SIGPAGE 1 #define C_PAGES (C_SIGPAGE + 1) +#endif /* CONFIG_COMPAT_VDSO */ static struct page *aarch32_vdso_pages[C_PAGES] __ro_after_init; -static const struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { +static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { { .name = "[vectors]", /* ABI */ .pages = &aarch32_vdso_pages[C_VECTORS], }, +#ifdef CONFIG_COMPAT_VDSO + { + .name = "[vvar]", + }, + { + .name = "[vdso]", + .mremap = aarch32_vdso_mremap, + }, +#else { .name = "[sigpage]", /* ABI */ .pages = &aarch32_vdso_pages[C_SIGPAGE], }, +#endif /* CONFIG_COMPAT_VDSO */ };

static int aarch32_alloc_kuser_vdso_page(void) @@ -214,7 +259,33 @@ static int aarch32_alloc_kuser_vdso_page(void) return 0; }

-static int __init aarch32_alloc_vdso_pages(void) +#ifdef CONFIG_COMPAT_VDSO +static int __aarch32_alloc_vdso_pages(void) +{ + int ret; + + vdso_lookup[ARM64_VDSO32].dm = &aarch32_vdso_spec[C_VVAR]; + vdso_lookup[ARM64_VDSO32].cm = &aarch32_vdso_spec[C_VDSO]; + + ret = __vdso_init(ARM64_VDSO32); + if (ret) + return ret; + + ret = aarch32_alloc_kuser_vdso_page(); + if (ret) { + unsigned long c_vvar = + (unsigned long)page_to_virt(aarch32_vdso_pages[C_VVAR]); + unsigned long c_vdso = + (unsigned long)page_to_virt(aarch32_vdso_pages[C_VDSO]); + + free_page(c_vvar); + free_page(c_vdso); + } + + return ret; +} +#else +static int __aarch32_alloc_vdso_pages(void) { extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; @@ -235,6 +306,12 @@ static int __init aarch32_alloc_vdso_pages(void)

return ret; } +#endif /* CONFIG_COMPAT_VDSO */ + +static int __init aarch32_alloc_vdso_pages(void) +{ + return __aarch32_alloc_vdso_pages(); +} arch_initcall(aarch32_alloc_vdso_pages);

static int aarch32_kuser_helpers_setup(struct mm_struct *mm) @@ -256,6 +333,7 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm) return PTR_ERR_OR_ZERO(ret); }

+#ifndef CONFIG_COMPAT_VDSO static int aarch32_sigreturn_setup(struct mm_struct *mm) { unsigned long addr; @@ -283,6 +361,7 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm) out: return PTR_ERR_OR_ZERO(ret); } +#endif /* !CONFIG_COMPAT_VDSO */

int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) { @@ -296,7 +375,14 @@ int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (ret) goto out;

+#ifdef CONFIG_COMPAT_VDSO + ret = __setup_additional_pages(ARM64_VDSO32, + mm, + bprm, + uses_interp); +#else ret = aarch32_sigreturn_setup(mm); +#endif /* CONFIG_COMPAT_VDSO */

out: up_write(&mm->mmap_sem);

When the compat vDSO is enabled, the sigreturn trampolines are not anymore available through [sigpage] but through [vdso].

Add the relevant code the enable the feature.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm64/include/asm/vdso.h | 3 +++ arch/arm64/kernel/signal32.c | 26 ++++++++++++++++++++++++++ 2 files changed, 29 insertions(+)

diff --git a/arch/arm64/include/asm/vdso.h b/arch/arm64/include/asm/vdso.h index 839ce0031bd5..9b197e5ea759 100644 --- a/arch/arm64/include/asm/vdso.h +++ b/arch/arm64/include/asm/vdso.h @@ -28,6 +28,9 @@ #ifndef __ASSEMBLY__

#include <generated/vdso-offsets.h> +#ifdef CONFIG_COMPAT_VDSO +#include <generated/vdso32-offsets.h> +#endif

#define VDSO_SYMBOL(base, name) \ ({ \ diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c index 74e06d8c7c2b..4fca2e1937b2 100644 --- a/arch/arm64/kernel/signal32.c +++ b/arch/arm64/kernel/signal32.c @@ -29,6 +29,7 @@ #include <asm/traps.h> #include <linux/uaccess.h> #include <asm/unistd.h> +#include <asm/vdso.h>

struct compat_vfp_sigframe { compat_ulong_t magic; @@ -352,6 +353,30 @@ static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka, retcode = ptr_to_compat(ka->sa.sa_restorer); } else { /* Set up sigreturn pointer */ +#ifdef CONFIG_COMPAT_VDSO + void *vdso_base = current->mm->context.vdso; + void *vdso_trampoline; + + if (ka->sa.sa_flags & SA_SIGINFO) { + if (thumb) { + vdso_trampoline = VDSO_SYMBOL(vdso_base, + compat_rt_sigreturn_thumb); + } else { + vdso_trampoline = VDSO_SYMBOL(vdso_base, + compat_rt_sigreturn_arm); + } + } else { + if (thumb) { + vdso_trampoline = VDSO_SYMBOL(vdso_base, + compat_sigreturn_thumb); + } else { + vdso_trampoline = VDSO_SYMBOL(vdso_base, + compat_sigreturn_arm); + } + } + + retcode = ptr_to_compat(vdso_trampoline) + thumb; +#else unsigned int idx = thumb << 1;

if (ka->sa.sa_flags & SA_SIGINFO) @@ -359,6 +384,7 @@ static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,

retcode = (unsigned long)current->mm->context.vdso + (idx << 2) + thumb; +#endif }

regs->regs[0] = usig;

The arm vDSO library requires some adaptations to use to take advantage of the newly introduced generic vDSO library.

Introduce the following changes: - Modification vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday - Implementation of elf note

Cc: Russell King linux@armlinux.org.uk Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/arm/Kconfig | 3 + arch/arm/include/asm/vdso/gettimeofday.h | 96 ++++++++ arch/arm/include/asm/vdso/vsyscall.h | 71 ++++++ arch/arm/include/asm/vdso_datapage.h | 29 +-- arch/arm/kernel/vdso.c | 87 +------- arch/arm/vdso/Makefile | 13 +- arch/arm/vdso/note.c | 15 ++ arch/arm/vdso/vdso.lds.S | 2 + arch/arm/vdso/vgettimeofday.c | 268 ++--------------------- 9 files changed, 222 insertions(+), 362 deletions(-) create mode 100644 arch/arm/include/asm/vdso/gettimeofday.h create mode 100644 arch/arm/include/asm/vdso/vsyscall.h create mode 100644 arch/arm/vdso/note.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 8869742a85df..795cd2f7f437 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -53,6 +53,8 @@ config ARM select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER + select GENERIC_GETTIMEOFDAY + select GENERIC_VDSO_32 select HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT @@ -101,6 +103,7 @@ config ARM select HAVE_SYSCALL_TRACEPOINTS select HAVE_UID16 select HAVE_VIRT_CPU_ACCOUNTING_GEN + select HAVE_GENERIC_VDSO select IRQ_FORCED_THREADING select MODULES_USE_ELF_REL select NEED_DMA_MAP_STATE diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h new file mode 100644 index 000000000000..eeeb319840ba --- /dev/null +++ b/arch/arm/include/asm/vdso/gettimeofday.h @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 ARM Limited + */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include <asm/barrier.h> +#include <asm/cp15.h> +#include <asm/unistd.h> +#include <uapi/linux/time.h> + +#ifndef CONFIG_AEABI +#error This code depends on AEABI system call conventions +#endif + +extern struct vdso_data *__get_datapage(void); + +static __always_inline notrace int gettimeofday_fallback( + struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + register struct timezone *tz asm("r1") = _tz; + register struct __kernel_old_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; +} + +static __always_inline notrace long clock_gettime_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_clock_gettime64; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace int clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_clock_getres_time64; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline notrace u64 __arch_get_hw_counter(int clock_mode) +{ +#ifdef CONFIG_ARM_ARCH_TIMER + u64 cycle_now; + + isb(); + cycle_now = read_sysreg(CNTVCT); + + return cycle_now; +#else + return -EINVAL; /* use fallback */ +#endif +} + +static __always_inline notrace const struct vdso_data *__arch_get_vdso_data(void) +{ + return __get_datapage(); +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h new file mode 100644 index 000000000000..c4166f317071 --- /dev/null +++ b/arch/arm/include/asm/vdso/vsyscall.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSO_VSYSCALL_H +#define __ASM_VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include <linux/timekeeper_internal.h> +#include <vdso/datapage.h> +#include <asm/cacheflush.h> + +extern struct vdso_data *vdso_data; +extern bool cntvct_ok; + +static __always_inline +bool tk_is_cntvct(const struct timekeeper *tk) +{ + if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) + return false; + + if (!tk->tkr_mono.clock->archdata.vdso_direct) + return false; + + return true; +} + +/* + * Update the vDSO data page to keep in sync with kernel timekeeping. + */ +static __always_inline +struct vdso_data *__arm_get_k_vdso_data(void) +{ + return vdso_data; +} +#define __arch_get_k_vdso_data __arm_get_k_vdso_data + +static __always_inline +int __arm_update_vdso_data(void) +{ + return !cntvct_ok; +} +#define __arch_update_vdso_data __arm_update_vdso_data + +static __always_inline +int __arm_get_clock_mode(struct timekeeper *tk) +{ + u32 __tk_is_cntvct = tk_is_cntvct(tk); + + return __tk_is_cntvct; +} +#define __arch_get_clock_mode __arm_get_clock_mode + +static __always_inline +int __arm_use_vsyscall(struct vdso_data *vdata) +{ + return vdata[CS_HRES_COARSE].clock_mode; +} +#define __arch_use_vsyscall __arm_use_vsyscall + +static __always_inline +void __arm_sync_vdso_data(struct vdso_data *vdata) +{ + flush_dcache_page(virt_to_page(vdata)); +} +#define __arch_sync_vdso_data __arm_sync_vdso_data + +/* The asm-generic header needs to be included after the definitions above */ +#include <asm-generic/vdso/vsyscall.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_VSYSCALL_H */ diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h index 9be259442fca..bfdbbd2b5fe7 100644 --- a/arch/arm/include/asm/vdso_datapage.h +++ b/arch/arm/include/asm/vdso_datapage.h @@ -22,35 +22,12 @@

#ifndef __ASSEMBLY__

+#include <vdso/datapage.h> #include <asm/page.h>

-/* Try to be cache-friendly on systems that don't implement the - * generic timer: fit the unconditionally updated fields in the first - * 32 bytes. - */ -struct vdso_data { - u32 seq_count; /* sequence count - odd during updates */ - u16 tk_is_cntvct; /* fall back to syscall if false */ - u16 cs_shift; /* clocksource shift */ - u32 xtime_coarse_sec; /* coarse time */ - u32 xtime_coarse_nsec; - - u32 wtm_clock_sec; /* wall to monotonic offset */ - u32 wtm_clock_nsec; - u32 xtime_clock_sec; /* CLOCK_REALTIME - seconds */ - u32 cs_mult; /* clocksource multiplier */ - - u64 cs_cycle_last; /* last cycle value */ - u64 cs_mask; /* clocksource mask */ - - u64 xtime_clock_snsec; /* CLOCK_REALTIME sub-ns base */ - u32 tz_minuteswest; /* timezone info for gettimeofday(2) */ - u32 tz_dsttime; -}; - union vdso_data_store { - struct vdso_data data; - u8 page[PAGE_SIZE]; + struct vdso_data data[CS_BASES]; + u8 page[PAGE_SIZE]; };

#endif /* !__ASSEMBLY__ */ diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c index f4dd7f9663c1..9a9cea8b333d 100644 --- a/arch/arm/kernel/vdso.c +++ b/arch/arm/kernel/vdso.c @@ -34,6 +34,8 @@ #include <asm/vdso.h> #include <asm/vdso_datapage.h> #include <clocksource/arm_arch_timer.h> +#include <vdso/helpers.h> +#include <vdso/vsyscall.h>

#define MAX_SYMNAME 64

@@ -48,7 +50,7 @@ unsigned int vdso_total_pages __ro_after_init; * The VDSO data page. */ static union vdso_data_store vdso_data_store __page_aligned_data; -static struct vdso_data *vdso_data = &vdso_data_store.data; +struct vdso_data *vdso_data = vdso_data_store.data;

static struct page *vdso_data_page __ro_after_init; static const struct vm_special_mapping vdso_data_mapping = { @@ -88,7 +90,7 @@ struct elfinfo { /* Cached result of boot-time check for whether the arch timer exists, * and if so, whether the virtual counter is useable. */ -static bool cntvct_ok __ro_after_init; +bool cntvct_ok __ro_after_init;

static bool __init cntvct_functional(void) { @@ -274,84 +276,3 @@ void arm_install_vdso(struct mm_struct *mm, unsigned long addr) mm->context.vdso = addr; }

-static void vdso_write_begin(struct vdso_data *vdata) -{ - ++vdso_data->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; -} - -static bool tk_is_cntvct(const struct timekeeper *tk) -{ - if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) - return false; - - if (!tk->tkr_mono.clock->archdata.vdso_direct) - return false; - - return true; -} - -/** - * update_vsyscall - update the vdso data page - * - * Increment the sequence counter, making it odd, indicating to - * userspace that an update is in progress. Update the fields used - * for coarse clocks and, if the architected system timer is in use, - * the fields used for high precision clocks. Increment the sequence - * 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 - * expected to wait until it becomes even. After copying data from - * the page, userspace must sample 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. - */ -void update_vsyscall(struct timekeeper *tk) -{ - struct timespec64 *wtm = &tk->wall_to_monotonic; - - if (!cntvct_ok) { - /* The entry points have been zeroed, so there is no - * point in updating the data page. - */ - return; - } - - vdso_write_begin(vdso_data); - - vdso_data->tk_is_cntvct = 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); - vdso_data->wtm_clock_sec = wtm->tv_sec; - vdso_data->wtm_clock_nsec = wtm->tv_nsec; - - if (vdso_data->tk_is_cntvct) { - vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; - 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_shift = tk->tkr_mono.shift; - vdso_data->cs_mask = tk->tkr_mono.mask; - } - - vdso_write_end(vdso_data); - - flush_dcache_page(virt_to_page(vdso_data)); -} - -void update_vsyscall_tz(void) -{ - vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; - vdso_data->tz_dsttime = sys_tz.tz_dsttime; - flush_dcache_page(virt_to_page(vdso_data)); -} diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile index fadf554d9391..0c8a819ef4f1 100644 --- a/arch/arm/vdso/Makefile +++ b/arch/arm/vdso/Makefile @@ -1,7 +1,13 @@ # SPDX-License-Identifier: GPL-2.0 + +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32 +include $(srctree)/lib/vdso/Makefile + hostprogs-y := vdsomunge

-obj-vdso := vgettimeofday.o datapage.o +obj-vdso := vgettimeofday.o datapage.o note.o

# Build rules targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds @@ -25,7 +31,11 @@ CFLAGS_REMOVE_vdso.o = -pg

# Force -O2 to avoid libgcc dependencies CFLAGS_REMOVE_vgettimeofday.o = -pg -Os +ifeq ($(c-gettimeofday-y),) CFLAGS_vgettimeofday.o = -O2 +else +CFLAGS_vgettimeofday.o = -O2 -include $(c-gettimeofday-y) +endif

# Disable gcov profiling for VDSO code GCOV_PROFILE := n @@ -39,6 +49,7 @@ $(obj)/vdso.o : $(obj)/vdso.so # Link rule for the .so file $(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE $(call if_changed,ld) + $(call if_changed,vdso_check)

$(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE $(call if_changed,vdsomunge) diff --git a/arch/arm/vdso/note.c b/arch/arm/vdso/note.c new file mode 100644 index 000000000000..eff5bf9efb8b --- /dev/null +++ b/arch/arm/vdso/note.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2012-2018 ARM Limited + * + * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. + * Here we can supply some information useful to userland. + */ + +#include <linux/uts.h> +#include <linux/version.h> +#include <linux/elfnote.h> +#include <linux/build-salt.h> + +ELFNOTE32("Linux", 0, LINUX_VERSION_CODE); +BUILD_SALT; diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S index 89ca89f12d23..05581140fd12 100644 --- a/arch/arm/vdso/vdso.lds.S +++ b/arch/arm/vdso/vdso.lds.S @@ -82,6 +82,8 @@ VERSION global: __vdso_clock_gettime; __vdso_gettimeofday; + __vdso_clock_getres; + __vdso_clock_gettime64; local: *; }; } diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c index 7bdbf5d5c47d..0964b07890eb 100644 --- a/arch/arm/vdso/vgettimeofday.c +++ b/arch/arm/vdso/vgettimeofday.c @@ -1,271 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * Copyright 2015 Mentor Graphics Corporation. + * ARM userspace implementations of gettimeofday() and similar. * - * 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) 2018 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. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see http://www.gnu.org/licenses/. */ - -#include <linux/compiler.h> -#include <linux/hrtimer.h> #include <linux/time.h> -#include <asm/barrier.h> -#include <asm/bug.h> -#include <asm/cp15.h> -#include <asm/page.h> -#include <asm/unistd.h> -#include <asm/vdso_datapage.h> - -#ifndef CONFIG_AEABI -#error This code depends on AEABI system call conventions -#endif - -extern struct vdso_data *__get_datapage(void); - -static notrace u32 __vdso_read_begin(const struct vdso_data *vdata) -{ - u32 seq; -repeat: - seq = READ_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; - - seq = __vdso_read_begin(vdata); - - smp_rmb(); /* Pairs with smp_wmb in vdso_write_end */ - return seq; -} - -static notrace int vdso_read_retry(const struct vdso_data *vdata, u32 start) -{ - smp_rmb(); /* Pairs with smp_wmb in vdso_write_begin */ - return vdata->seq_count != start; -} - -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; -} - -static notrace int do_realtime_coarse(struct timespec *ts, - struct vdso_data *vdata) -{ - u32 seq; - - do { - seq = vdso_read_begin(vdata); - - ts->tv_sec = vdata->xtime_coarse_sec; - ts->tv_nsec = vdata->xtime_coarse_nsec; - - } while (vdso_read_retry(vdata, seq)); - - return 0; -} - -static notrace int do_monotonic_coarse(struct timespec *ts, - struct vdso_data *vdata) -{ - struct timespec tomono; - u32 seq; - - do { - seq = vdso_read_begin(vdata); - - ts->tv_sec = vdata->xtime_coarse_sec; - ts->tv_nsec = vdata->xtime_coarse_nsec; - - tomono.tv_sec = vdata->wtm_clock_sec; - tomono.tv_nsec = vdata->wtm_clock_nsec; - - } while (vdso_read_retry(vdata, seq)); - - ts->tv_sec += tomono.tv_sec; - timespec_add_ns(ts, tomono.tv_nsec); - - return 0; -} - -#ifdef CONFIG_ARM_ARCH_TIMER - -static notrace u64 get_ns(struct vdso_data *vdata) -{ - u64 cycle_delta; - u64 cycle_now; - u64 nsec; +#include <linux/types.h>

- isb(); - cycle_now = read_sysreg(CNTVCT); - - cycle_delta = (cycle_now - vdata->cs_cycle_last) & vdata->cs_mask; - - nsec = (cycle_delta * vdata->cs_mult) + vdata->xtime_clock_snsec; - nsec >>= vdata->cs_shift; - - return nsec; -} - -static notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata) +notrace int __vdso_clock_gettime(clockid_t clock, + struct old_timespec32 *ts) { - u64 nsecs; - u32 seq; - - do { - seq = vdso_read_begin(vdata); - - if (!vdata->tk_is_cntvct) - return -1; - - ts->tv_sec = vdata->xtime_clock_sec; - nsecs = get_ns(vdata); - - } while (vdso_read_retry(vdata, seq)); - - ts->tv_nsec = 0; - timespec_add_ns(ts, nsecs); - - return 0; + return __cvdso_clock_gettime32(clock, ts); }

-static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata) +notrace int __vdso_clock_gettime64(clockid_t clock, + struct __kernel_timespec *ts) { - struct timespec tomono; - u64 nsecs; - u32 seq; - - do { - seq = vdso_read_begin(vdata); - - if (!vdata->tk_is_cntvct) - return -1; - - ts->tv_sec = vdata->xtime_clock_sec; - nsecs = get_ns(vdata); - - tomono.tv_sec = vdata->wtm_clock_sec; - tomono.tv_nsec = vdata->wtm_clock_nsec; - - } while (vdso_read_retry(vdata, seq)); - - ts->tv_sec += tomono.tv_sec; - ts->tv_nsec = 0; - timespec_add_ns(ts, nsecs + tomono.tv_nsec); - - return 0; + return __cvdso_clock_gettime(clock, ts); }

-#else /* CONFIG_ARM_ARCH_TIMER */ - -static notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata) +notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) { - return -1; + return __cvdso_gettimeofday(tv, tz); }

-static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata) +notrace int __vdso_clock_getres(clockid_t clock_id, + struct old_timespec32 *res) { - return -1; -} - -#endif /* CONFIG_ARM_ARCH_TIMER */ - -notrace int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts) -{ - struct vdso_data *vdata; - int ret = -1; - - vdata = __get_datapage(); - - switch (clkid) { - case CLOCK_REALTIME_COARSE: - ret = do_realtime_coarse(ts, vdata); - break; - case CLOCK_MONOTONIC_COARSE: - ret = do_monotonic_coarse(ts, vdata); - break; - case CLOCK_REALTIME: - ret = do_realtime(ts, vdata); - break; - case CLOCK_MONOTONIC: - ret = do_monotonic(ts, vdata); - break; - default: - break; - } - - 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; -} - -notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) -{ - struct timespec ts; - struct vdso_data *vdata; - int ret; - - vdata = __get_datapage(); - - ret = do_realtime(&ts, vdata); - if (ret) - 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; + return __cvdso_clock_getres_time32(clock_id, res); }

/* Avoid unresolved references emitted by GCC */

The mips vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library.

Introduce the following changes: - Modification of vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday

Cc: Ralf Baechle ralf@linux-mips.org Cc: Paul Burton paul.burton@mips.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/mips/Kconfig | 2 + arch/mips/include/asm/vdso.h | 78 +------ arch/mips/include/asm/vdso/gettimeofday.h | 175 ++++++++++++++ arch/mips/{ => include/asm}/vdso/vdso.h | 6 +- arch/mips/include/asm/vdso/vsyscall.h | 43 ++++ arch/mips/kernel/vdso.c | 37 +-- arch/mips/vdso/Makefile | 25 +- arch/mips/vdso/elf.S | 2 +- arch/mips/vdso/gettimeofday.c | 273 ---------------------- arch/mips/vdso/sigreturn.S | 2 +- arch/mips/vdso/vdso.lds.S | 4 + arch/mips/vdso/vgettimeofday.c | 57 +++++ 12 files changed, 316 insertions(+), 388 deletions(-) create mode 100644 arch/mips/include/asm/vdso/gettimeofday.h rename arch/mips/{ => include/asm}/vdso/vdso.h (90%) create mode 100644 arch/mips/include/asm/vdso/vsyscall.h delete mode 100644 arch/mips/vdso/gettimeofday.c create mode 100644 arch/mips/vdso/vgettimeofday.c

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 70d3200476bf..390c052cac9a 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -34,6 +34,7 @@ config MIPS select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL + select GENERIC_GETTIMEOFDAY select HANDLE_DOMAIN_IRQ select HAVE_ARCH_COMPILER_H select HAVE_ARCH_JUMP_LABEL @@ -72,6 +73,7 @@ config MIPS select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP + select HAVE_GENERIC_VDSO select IRQ_FORCED_THREADING select ISA if EISA select MODULES_USE_ELF_RELA if MODULES && 64BIT diff --git a/arch/mips/include/asm/vdso.h b/arch/mips/include/asm/vdso.h index 91bf0c2c265c..285241da2284 100644 --- a/arch/mips/include/asm/vdso.h +++ b/arch/mips/include/asm/vdso.h @@ -12,6 +12,7 @@ #define __ASM_VDSO_H

#include <linux/mm_types.h> +#include <vdso/datapage.h>

#include <asm/barrier.h>

@@ -53,84 +54,9 @@ extern struct mips_vdso_image vdso_image_o32; extern struct mips_vdso_image vdso_image_n32; #endif

-/** - * union mips_vdso_data - Data provided by the kernel for the VDSO. - * @xtime_sec: Current real time (seconds part). - * @xtime_nsec: Current real time (nanoseconds part, shifted). - * @wall_to_mono_sec: Wall-to-monotonic offset (seconds part). - * @wall_to_mono_nsec: Wall-to-monotonic offset (nanoseconds part). - * @seq_count: Counter to synchronise updates (odd = updating). - * @cs_shift: Clocksource shift value. - * @clock_mode: Clocksource to use for time functions. - * @cs_mult: Clocksource multiplier value. - * @cs_cycle_last: Clock cycle value at last update. - * @cs_mask: Clocksource mask value. - * @tz_minuteswest: Minutes west of Greenwich (from timezone). - * @tz_dsttime: Type of DST correction (from timezone). - * - * This structure contains data needed by functions within the VDSO. It is - * populated by the kernel and mapped read-only into user memory. The time - * fields are mirrors of internal data from the timekeeping infrastructure. - * - * Note: Care should be taken when modifying as the layout must remain the same - * for both 64- and 32-bit (for 32-bit userland on 64-bit kernel). - */ union mips_vdso_data { - struct { - u64 xtime_sec; - u64 xtime_nsec; - u64 wall_to_mono_sec; - u64 wall_to_mono_nsec; - u32 seq_count; - u32 cs_shift; - u8 clock_mode; - u32 cs_mult; - u64 cs_cycle_last; - u64 cs_mask; - s32 tz_minuteswest; - s32 tz_dsttime; - }; - + struct vdso_data data[CS_BASES]; u8 page[PAGE_SIZE]; };

-static inline u32 vdso_data_read_begin(const union mips_vdso_data *data) -{ - u32 seq; - - while (true) { - seq = READ_ONCE(data->seq_count); - if (likely(!(seq & 1))) { - /* Paired with smp_wmb() in vdso_data_write_*(). */ - smp_rmb(); - return seq; - } - - cpu_relax(); - } -} - -static inline bool vdso_data_read_retry(const union mips_vdso_data *data, - u32 start_seq) -{ - /* Paired with smp_wmb() in vdso_data_write_*(). */ - smp_rmb(); - return unlikely(data->seq_count != start_seq); -} - -static inline void vdso_data_write_begin(union mips_vdso_data *data) -{ - ++data->seq_count; - - /* Ensure sequence update is written before other data page values. */ - smp_wmb(); -} - -static inline void vdso_data_write_end(union mips_vdso_data *data) -{ - /* Ensure data values are written before updating sequence again. */ - smp_wmb(); - ++data->seq_count; -} - #endif /* __ASM_VDSO_H */ diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h new file mode 100644 index 000000000000..a9fb871fb096 --- /dev/null +++ b/arch/mips/include/asm/vdso/gettimeofday.h @@ -0,0 +1,175 @@ +/* + * Copyright (C) 2018 ARM Limited + * Copyright (C) 2015 Imagination Technologies + * Author: Alex Smith alex.smith@imgtec.com + * + * 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; either version 2 of the License, or (at your + * option) any later version. + */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include <linux/compiler.h> +#include <linux/time.h> + +#include <asm/vdso/vdso.h> +#include <asm/clocksource.h> +#include <asm/io.h> +#include <asm/unistd.h> +#include <asm/vdso.h> + +#ifdef CONFIG_MIPS_CLOCK_VSYSCALL + +static __always_inline notrace long gettimeofday_fallback( + struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + register struct timezone *tz asm("a1") = _tz; + register struct __kernel_old_timeval *tv asm("a0") = _tv; + register long ret asm("v0"); + register long nr asm("v0") = __NR_gettimeofday; + register long error asm("a3"); + + asm volatile( + " syscall\n" + : "=r" (ret), "=r" (error) + : "r" (tv), "r" (tz), "r" (nr) + : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", + "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + + return error ? -ret : ret; +} + +#else + +static __always_inline notrace long gettimeofday_fallback( + struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + return -1; +} + +#endif + +static __always_inline notrace long clock_gettime_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("a1") = _ts; + register clockid_t clkid asm("a0") = _clkid; + register long ret asm("v0"); +#if _MIPS_SIM == _MIPS_SIM_ABI64 + register long nr asm("v0") = __NR_clock_gettime; +#else + register long nr asm("v0") = __NR_clock_gettime64; +#endif + register long error asm("a3"); + + asm volatile( + " syscall\n" + : "=r" (ret), "=r" (error) + : "r" (clkid), "r" (ts), "r" (nr) + : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", + "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + + return error ? -ret : ret; +} + +static __always_inline notrace int clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("a1") = _ts; + register clockid_t clkid asm("a0") = _clkid; + register long ret asm("v0"); +#if _MIPS_SIM == _MIPS_SIM_ABI64 + register long nr asm("v0") = __NR_clock_getres; +#else + register long nr asm("v0") = __NR_clock_getres_time64; +#endif + register long error asm("a3"); + + asm volatile( + " syscall\n" + : "=r" (ret), "=r" (error) + : "r" (clkid), "r" (ts), "r" (nr) + : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", + "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + + return error ? -ret : ret; +} + +#ifdef CONFIG_CSRC_R4K + +static __always_inline u64 read_r4k_count(void) +{ + unsigned int count; + + __asm__ __volatile__( + " .set push\n" + " .set mips32r2\n" + " rdhwr %0, $2\n" + " .set pop\n" + : "=r" (count)); + + return count; +} + +#endif + +#ifdef CONFIG_CLKSRC_MIPS_GIC + +static __always_inline u64 read_gic_count(const struct vdso_data *data) +{ + void __iomem *gic = get_gic(data); + u32 hi, hi2, lo; + + do { + hi = __raw_readl(gic + sizeof(lo)); + lo = __raw_readl(gic); + hi2 = __raw_readl(gic + sizeof(lo)); + } while (hi2 != hi); + + return (((u64)hi) << 32) + lo; +} + +#endif + +static __always_inline notrace u64 __arch_get_hw_counter(s32 clock_mode) +{ +#ifdef CONFIG_CLKSRC_MIPS_GIC + const struct vdso_data *data = get_vdso_data(); +#endif + u64 cycle_now; + + switch (clock_mode) { +#ifdef CONFIG_CSRC_R4K + case VDSO_CLOCK_R4K: + cycle_now = read_r4k_count(); + break; +#endif +#ifdef CONFIG_CLKSRC_MIPS_GIC + case VDSO_CLOCK_GIC: + cycle_now = read_gic_count(data); + break; +#endif + default: + cycle_now = 0; + break; + } + + return cycle_now; +} + +static __always_inline notrace const struct vdso_data *__arch_get_vdso_data(void) +{ + return get_vdso_data(); +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/mips/vdso/vdso.h b/arch/mips/include/asm/vdso/vdso.h similarity index 90% rename from arch/mips/vdso/vdso.h rename to arch/mips/include/asm/vdso/vdso.h index cfb1be441dec..048d12fbb925 100644 --- a/arch/mips/vdso/vdso.h +++ b/arch/mips/include/asm/vdso/vdso.h @@ -72,14 +72,14 @@ static inline unsigned long get_vdso_base(void) return addr; }

-static inline const union mips_vdso_data *get_vdso_data(void) +static inline const struct vdso_data *get_vdso_data(void) { - return (const union mips_vdso_data *)(get_vdso_base() - PAGE_SIZE); + return (const struct vdso_data *)(get_vdso_base() - PAGE_SIZE); }

#ifdef CONFIG_CLKSRC_MIPS_GIC

-static inline void __iomem *get_gic(const union mips_vdso_data *data) +static inline void __iomem *get_gic(const struct vdso_data *data) { return (void __iomem *)data - PAGE_SIZE; } diff --git a/arch/mips/include/asm/vdso/vsyscall.h b/arch/mips/include/asm/vdso/vsyscall.h new file mode 100644 index 000000000000..195314732233 --- /dev/null +++ b/arch/mips/include/asm/vdso/vsyscall.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSO_VSYSCALL_H +#define __ASM_VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include <linux/timekeeper_internal.h> +#include <vdso/datapage.h> + +extern struct vdso_data *vdso_data; + +/* + * Update the vDSO data page to keep in sync with kernel timekeeping. + */ +static __always_inline +struct vdso_data *__mips_get_k_vdso_data(void) +{ + return vdso_data; +} +#define __arch_get_k_vdso_data __mips_get_k_vdso_data + +static __always_inline +int __mips_get_clock_mode(struct timekeeper *tk) +{ + u32 clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode; + + return clock_mode; +} +#define __arch_get_clock_mode __mips_get_clock_mode + +static __always_inline +int __mips_use_vsyscall(struct vdso_data *vdata) +{ + return (vdata[CS_HRES_COARSE].clock_mode != VDSO_CLOCK_NONE); +} +#define __arch_use_vsyscall __mips_use_vsyscall + +/* The asm-generic header needs to be included after the definitions above */ +#include <asm-generic/vdso/vsyscall.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_VSYSCALL_H */ diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c index 9df3ebdc7b0f..157ee8045035 100644 --- a/arch/mips/kernel/vdso.c +++ b/arch/mips/kernel/vdso.c @@ -24,9 +24,12 @@ #include <asm/mips-cps.h> #include <asm/page.h> #include <asm/vdso.h> +#include <vdso/helpers.h> +#include <vdso/vsyscall.h>

/* Kernel-provided data used by the VDSO. */ -static union mips_vdso_data vdso_data __page_aligned_data; +static union mips_vdso_data mips_vdso_data __page_aligned_data; +struct vdso_data *vdso_data = mips_vdso_data.data;

/* * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as @@ -70,34 +73,6 @@ static int __init init_vdso(void) } subsys_initcall(init_vdso);

-void update_vsyscall(struct timekeeper *tk) -{ - vdso_data_write_begin(&vdso_data); - - vdso_data.xtime_sec = tk->xtime_sec; - vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec; - vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec; - vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec; - vdso_data.cs_shift = tk->tkr_mono.shift; - - vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode; - if (vdso_data.clock_mode != VDSO_CLOCK_NONE) { - vdso_data.cs_mult = tk->tkr_mono.mult; - vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last; - vdso_data.cs_mask = tk->tkr_mono.mask; - } - - vdso_data_write_end(&vdso_data); -} - -void update_vsyscall_tz(void) -{ - if (vdso_data.clock_mode != VDSO_CLOCK_NONE) { - vdso_data.tz_minuteswest = sys_tz.tz_minuteswest; - vdso_data.tz_dsttime = sys_tz.tz_dsttime; - } -} - static unsigned long vdso_base(void) { unsigned long base; @@ -167,7 +142,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) */ if (cpu_has_dc_aliases) { base = __ALIGN_MASK(base, shm_align_mask); - base += ((unsigned long)&vdso_data - gic_size) & shm_align_mask; + base += ((unsigned long)vdso_data - gic_size) & shm_align_mask; }

data_addr = base + gic_size; @@ -193,7 +168,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)

/* Map data page. */ ret = remap_pfn_range(vma, data_addr, - virt_to_phys(&vdso_data) >> PAGE_SHIFT, + virt_to_phys(vdso_data) >> PAGE_SHIFT, PAGE_SIZE, PAGE_READONLY); if (ret) goto out; diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index 7221df24cb23..96420357d5bf 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -1,6 +1,12 @@ # SPDX-License-Identifier: GPL-2.0 # Objects to go into the VDSO. -obj-vdso-y := elf.o gettimeofday.o sigreturn.o + +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_MIPS_JUMP_SLOT|R_MIPS_GLOB_DAT +include $(srctree)/lib/vdso/Makefile + +obj-vdso-y := elf.o vgettimeofday.o sigreturn.o

# Common compiler flags between ABIs. ccflags-vdso := \ @@ -15,15 +21,23 @@ ifdef CONFIG_CC_IS_CLANG ccflags-vdso += $(filter --target=%,$(KBUILD_CFLAGS)) endif

+# +# The -fno-jump-tables flag only prevents the compiler from generating +# jump tables but does not prevent the compiler from emitting absolute +# offsets. cflags-vdso := $(ccflags-vdso) \ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ - -O2 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ - -DDISABLE_BRANCH_PROFILING \ + -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ + -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ $(call cc-option, -fno-asynchronous-unwind-tables) \ $(call cc-option, -fno-stack-protector) aflags-vdso := $(ccflags-vdso) \ -D__ASSEMBLY__ -Wa,-gdwarf-2

+ifneq ($(c-gettimeofday-y),) +CFLAGS_vgettimeofday.o = -include $(c-gettimeofday-y) +endif + # # For the pre-R6 code in arch/mips/vdso/vdso.h for locating # the base address of VDSO, the linker will emit a R_MIPS_PC32 @@ -48,6 +62,8 @@ VDSO_LDFLAGS := \ $(addprefix -Wl$(comma),$(filter -E%,$(KBUILD_CFLAGS))) \ -nostdlib -shared -Wl,--hash-style=sysv -Wl,--build-id

+CFLAGS_REMOVE_vdso.o = -pg + GCOV_PROFILE := n UBSAN_SANITIZE := n

@@ -96,6 +112,7 @@ $(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi)

$(obj)/vdso.so.dbg.raw: $(obj)/vdso.lds $(obj-vdso) FORCE $(call if_changed,vdsold) + $(call if_changed,vdso_check)

$(obj)/vdso-image.c: $(obj)/vdso.so.dbg.raw $(obj)/vdso.so.raw \ $(obj)/genvdso FORCE @@ -134,6 +151,7 @@ $(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE

$(obj)/vdso-o32.so.dbg.raw: $(obj)/vdso-o32.lds $(obj-vdso-o32) FORCE $(call if_changed,vdsold) + $(call if_changed,vdso_check)

$(obj)/vdso-o32-image.c: VDSO_NAME := o32 $(obj)/vdso-o32-image.c: $(obj)/vdso-o32.so.dbg.raw $(obj)/vdso-o32.so.raw \ @@ -174,6 +192,7 @@ $(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE

$(obj)/vdso-n32.so.dbg.raw: $(obj)/vdso-n32.lds $(obj-vdso-n32) FORCE $(call if_changed,vdsold) + $(call if_changed,vdso_check)

$(obj)/vdso-n32-image.c: VDSO_NAME := n32 $(obj)/vdso-n32-image.c: $(obj)/vdso-n32.so.dbg.raw $(obj)/vdso-n32.so.raw \ diff --git a/arch/mips/vdso/elf.S b/arch/mips/vdso/elf.S index 428a1917afc6..c0c85d126094 100644 --- a/arch/mips/vdso/elf.S +++ b/arch/mips/vdso/elf.S @@ -8,7 +8,7 @@ * option) any later version. */

-#include "vdso.h" +#include <asm/vdso/vdso.h>

#include <asm/isa-rev.h>

diff --git a/arch/mips/vdso/gettimeofday.c b/arch/mips/vdso/gettimeofday.c deleted file mode 100644 index e22b422f282c..000000000000 --- a/arch/mips/vdso/gettimeofday.c +++ /dev/null @@ -1,273 +0,0 @@ -/* - * Copyright (C) 2015 Imagination Technologies - * Author: Alex Smith alex.smith@imgtec.com - * - * 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; either version 2 of the License, or (at your - * option) any later version. - */ - -#include "vdso.h" - -#include <linux/compiler.h> -#include <linux/time.h> - -#include <asm/clocksource.h> -#include <asm/io.h> -#include <asm/unistd.h> -#include <asm/vdso.h> - -#ifdef CONFIG_MIPS_CLOCK_VSYSCALL - -static __always_inline long gettimeofday_fallback(struct timeval *_tv, - struct timezone *_tz) -{ - register struct timezone *tz asm("a1") = _tz; - register struct timeval *tv asm("a0") = _tv; - register long ret asm("v0"); - register long nr asm("v0") = __NR_gettimeofday; - register long error asm("a3"); - - asm volatile( - " syscall\n" - : "=r" (ret), "=r" (error) - : "r" (tv), "r" (tz), "r" (nr) - : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); - - return error ? -ret : ret; -} - -#endif - -static __always_inline long clock_gettime_fallback(clockid_t _clkid, - struct timespec *_ts) -{ - register struct timespec *ts asm("a1") = _ts; - register clockid_t clkid asm("a0") = _clkid; - register long ret asm("v0"); - register long nr asm("v0") = __NR_clock_gettime; - register long error asm("a3"); - - asm volatile( - " syscall\n" - : "=r" (ret), "=r" (error) - : "r" (clkid), "r" (ts), "r" (nr) - : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); - - return error ? -ret : ret; -} - -static __always_inline int do_realtime_coarse(struct timespec *ts, - const union mips_vdso_data *data) -{ - u32 start_seq; - - do { - start_seq = vdso_data_read_begin(data); - - ts->tv_sec = data->xtime_sec; - ts->tv_nsec = data->xtime_nsec >> data->cs_shift; - } while (vdso_data_read_retry(data, start_seq)); - - return 0; -} - -static __always_inline int do_monotonic_coarse(struct timespec *ts, - const union mips_vdso_data *data) -{ - u32 start_seq; - u64 to_mono_sec; - u64 to_mono_nsec; - - do { - start_seq = vdso_data_read_begin(data); - - ts->tv_sec = data->xtime_sec; - ts->tv_nsec = data->xtime_nsec >> data->cs_shift; - - to_mono_sec = data->wall_to_mono_sec; - to_mono_nsec = data->wall_to_mono_nsec; - } while (vdso_data_read_retry(data, start_seq)); - - ts->tv_sec += to_mono_sec; - timespec_add_ns(ts, to_mono_nsec); - - return 0; -} - -#ifdef CONFIG_CSRC_R4K - -static __always_inline u64 read_r4k_count(void) -{ - unsigned int count; - - __asm__ __volatile__( - " .set push\n" - " .set mips32r2\n" - " rdhwr %0, $2\n" - " .set pop\n" - : "=r" (count)); - - return count; -} - -#endif - -#ifdef CONFIG_CLKSRC_MIPS_GIC - -static __always_inline u64 read_gic_count(const union mips_vdso_data *data) -{ - void __iomem *gic = get_gic(data); - u32 hi, hi2, lo; - - do { - hi = __raw_readl(gic + sizeof(lo)); - lo = __raw_readl(gic); - hi2 = __raw_readl(gic + sizeof(lo)); - } while (hi2 != hi); - - return (((u64)hi) << 32) + lo; -} - -#endif - -static __always_inline u64 get_ns(const union mips_vdso_data *data) -{ - u64 cycle_now, delta, nsec; - - switch (data->clock_mode) { -#ifdef CONFIG_CSRC_R4K - case VDSO_CLOCK_R4K: - cycle_now = read_r4k_count(); - break; -#endif -#ifdef CONFIG_CLKSRC_MIPS_GIC - case VDSO_CLOCK_GIC: - cycle_now = read_gic_count(data); - break; -#endif - default: - return 0; - } - - delta = (cycle_now - data->cs_cycle_last) & data->cs_mask; - - nsec = (delta * data->cs_mult) + data->xtime_nsec; - nsec >>= data->cs_shift; - - return nsec; -} - -static __always_inline int do_realtime(struct timespec *ts, - const union mips_vdso_data *data) -{ - u32 start_seq; - u64 ns; - - do { - start_seq = vdso_data_read_begin(data); - - if (data->clock_mode == VDSO_CLOCK_NONE) - return -ENOSYS; - - ts->tv_sec = data->xtime_sec; - ns = get_ns(data); - } while (vdso_data_read_retry(data, start_seq)); - - ts->tv_nsec = 0; - timespec_add_ns(ts, ns); - - return 0; -} - -static __always_inline int do_monotonic(struct timespec *ts, - const union mips_vdso_data *data) -{ - u32 start_seq; - u64 ns; - u64 to_mono_sec; - u64 to_mono_nsec; - - do { - start_seq = vdso_data_read_begin(data); - - if (data->clock_mode == VDSO_CLOCK_NONE) - return -ENOSYS; - - ts->tv_sec = data->xtime_sec; - ns = get_ns(data); - - to_mono_sec = data->wall_to_mono_sec; - to_mono_nsec = data->wall_to_mono_nsec; - } while (vdso_data_read_retry(data, start_seq)); - - ts->tv_sec += to_mono_sec; - ts->tv_nsec = 0; - timespec_add_ns(ts, ns + to_mono_nsec); - - return 0; -} - -#ifdef CONFIG_MIPS_CLOCK_VSYSCALL - -/* - * This is behind the ifdef so that we don't provide the symbol when there's no - * possibility of there being a usable clocksource, because there's nothing we - * can do without it. When libc fails the symbol lookup it should fall back on - * the standard syscall path. - */ -int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) -{ - const union mips_vdso_data *data = get_vdso_data(); - struct timespec ts; - int ret; - - ret = do_realtime(&ts, data); - if (ret) - 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 = data->tz_minuteswest; - tz->tz_dsttime = data->tz_dsttime; - } - - return 0; -} - -#endif /* CONFIG_MIPS_CLOCK_VSYSCALL */ - -int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts) -{ - const union mips_vdso_data *data = get_vdso_data(); - int ret = -1; - - switch (clkid) { - case CLOCK_REALTIME_COARSE: - ret = do_realtime_coarse(ts, data); - break; - case CLOCK_MONOTONIC_COARSE: - ret = do_monotonic_coarse(ts, data); - break; - case CLOCK_REALTIME: - ret = do_realtime(ts, data); - break; - case CLOCK_MONOTONIC: - ret = do_monotonic(ts, data); - break; - default: - break; - } - - if (ret) - ret = clock_gettime_fallback(clkid, ts); - - return ret; -} diff --git a/arch/mips/vdso/sigreturn.S b/arch/mips/vdso/sigreturn.S index 30c6219912ac..c2b05956e4cb 100644 --- a/arch/mips/vdso/sigreturn.S +++ b/arch/mips/vdso/sigreturn.S @@ -8,7 +8,7 @@ * option) any later version. */

-#include "vdso.h" +#include <asm/vdso/vdso.h>

#include <uapi/asm/unistd.h>

diff --git a/arch/mips/vdso/vdso.lds.S b/arch/mips/vdso/vdso.lds.S index 8df7dd53e8e0..659fe0c3750a 100644 --- a/arch/mips/vdso/vdso.lds.S +++ b/arch/mips/vdso/vdso.lds.S @@ -99,6 +99,10 @@ VERSION global: __vdso_clock_gettime; __vdso_gettimeofday; + __vdso_clock_getres; +#if _MIPS_SIM != _MIPS_SIM_ABI64 + __vdso_clock_gettime64; +#endif #endif local: *; }; diff --git a/arch/mips/vdso/vgettimeofday.c b/arch/mips/vdso/vgettimeofday.c new file mode 100644 index 000000000000..41b6a21cd1d1 --- /dev/null +++ b/arch/mips/vdso/vgettimeofday.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MIPS64 and compat userspace implementations of gettimeofday() + * and similar. + * + * Copyright (C) 2018 ARM Limited + * + */ +#include <linux/time.h> +#include <linux/types.h> + +#if _MIPS_SIM != _MIPS_SIM_ABI64 +notrace int __vdso_clock_gettime(clockid_t clock, + struct old_timespec32 *ts) +{ + return __cvdso_clock_gettime32(clock, ts); +} + +notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +notrace int __vdso_clock_getres(clockid_t clock_id, + struct old_timespec32 *res) +{ + return __cvdso_clock_getres_time32(clock_id, res); +} + +notrace int __vdso_clock_gettime_time64(clockid_t clock, + struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +#else + +notrace int __vdso_clock_gettime(clockid_t clock, + struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +notrace int __vdso_clock_getres(clockid_t clock_id, + struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock_id, res); +} + +#endif

The x86 vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library.

Introduce the following changes: - Modification of vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday

Cc: Thomas Gleixner tglx@linutronix.de Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- arch/x86/Kconfig | 3 + arch/x86/entry/vdso/Makefile | 9 + arch/x86/entry/vdso/vclock_gettime.c | 251 +++++------------------ arch/x86/entry/vdso/vdso.lds.S | 2 + arch/x86/entry/vdso/vdso32/vdso32.lds.S | 2 + arch/x86/entry/vdso/vdsox32.lds.S | 1 + arch/x86/entry/vsyscall/Makefile | 2 - arch/x86/entry/vsyscall/vsyscall_gtod.c | 83 -------- arch/x86/include/asm/mshyperv-tsc.h | 76 +++++++ arch/x86/include/asm/mshyperv.h | 70 +------ arch/x86/include/asm/pvclock.h | 2 +- arch/x86/include/asm/vdso/gettimeofday.h | 203 ++++++++++++++++++ arch/x86/include/asm/vdso/vsyscall.h | 44 ++++ arch/x86/include/asm/vgtod.h | 75 +------ arch/x86/include/asm/vvar.h | 7 +- arch/x86/kernel/pvclock.c | 1 + 16 files changed, 396 insertions(+), 435 deletions(-) delete mode 100644 arch/x86/entry/vsyscall/vsyscall_gtod.c create mode 100644 arch/x86/include/asm/mshyperv-tsc.h create mode 100644 arch/x86/include/asm/vdso/gettimeofday.h create mode 100644 arch/x86/include/asm/vdso/vsyscall.h

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2bbbd4d1ba31..51a98d6eae8e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -17,6 +17,7 @@ config X86_32 select HAVE_DEBUG_STACKOVERFLOW select MODULES_USE_ELF_REL select OLD_SIGACTION + select GENERIC_VDSO_32

config X86_64 def_bool y @@ -121,6 +122,7 @@ 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 @@ -202,6 +204,7 @@ 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 42fe42e82baf..39106111be86 100644 --- a/arch/x86/entry/vdso/Makefile +++ b/arch/x86/entry/vdso/Makefile @@ -3,6 +3,12 @@ # 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 @@ -51,6 +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 @@ -121,6 +128,7 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE

$(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 @@ -160,6 +168,7 @@ $(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 98c7d12b945c..39268f941878 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -1,240 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * 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 2019 ARM Limited + * Copyright 2006 Andi Kleen, SUSE Labs. * 32 Bit compat layer by Stefani Seibold stefani@seibold.net * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany - * - * The code should have no internal unresolved relocations. - * Check with readelf after changing. */ - -#include <uapi/linux/time.h> -#include <asm/vgtod.h> -#include <asm/vvar.h> -#include <asm/unistd.h> -#include <asm/msr.h> -#include <asm/pvclock.h> -#include <asm/mshyperv.h> -#include <linux/math64.h> #include <linux/time.h> -#include <linux/kernel.h> +#include <linux/types.h>

-#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) -{ - long ret; - asm ("syscall" : "=a" (ret), "=m" (*ts) : - "0" (__NR_clock_gettime), "D" (clock), "S" (ts) : - "rcx", "r11"); - return ret; -} - -#else - -notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) +notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) { - 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) - : "edx"); - return ret; + return __cvdso_gettimeofday(tv, tz); } +int gettimeofday(struct __kernel_old_timeval *, struct timezone *) + __attribute__((weak, alias("__vdso_gettimeofday")));

-#endif - -#ifdef CONFIG_PARAVIRT_CLOCK -static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void) +notrace time_t __vdso_time(time_t *t) { - return (const struct pvclock_vsyscall_time_info *)&pvclock_page; + return __cvdso_time(t); } +time_t time(time_t *t) + __attribute__((weak, alias("__vdso_time")));

-static notrace 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 notrace 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 +#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); +extern int __vdso_clock_getres(clockid_t clock, struct __kernel_timespec *res);

-notrace static inline u64 vgetcyc(int mode) +notrace int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) { - if (mode == VCLOCK_TSC) - return (u64)rdtsc_ordered(); -#ifdef CONFIG_PARAVIRT_CLOCK - else if (mode == VCLOCK_PVCLOCK) - return vread_pvclock(); -#endif -#ifdef CONFIG_HYPERV_TSCPAGE - else if (mode == VCLOCK_HVCLOCK) - return vread_hvclock(); -#endif - return U64_MAX; + return __cvdso_clock_gettime(clock, ts); } +int clock_gettime(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_gettime")));

-notrace static int do_hres(clockid_t clk, struct timespec *ts) +notrace int __vdso_clock_getres(clockid_t clock, + struct __kernel_timespec *res) { - struct vgtod_ts *base = &gtod->basetime[clk]; - u64 cycles, last, sec, ns; - unsigned int seq; - - do { - seq = gtod_read_begin(gtod); - cycles = vgetcyc(gtod->vclock_mode); - ns = base->nsec; - last = gtod->cycle_last; - if (unlikely((s64)cycles < 0)) - return vdso_fallback_gettime(clk, ts); - if (cycles > last) - ns += (cycles - last) * gtod->mult; - ns >>= gtod->shift; - sec = base->sec; - } while (unlikely(gtod_read_retry(gtod, seq))); - - /* - * Do this outside the loop: a race inside the loop could result - * in __iter_div_u64_rem() being extremely slow. - */ - ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); - ts->tv_nsec = ns; - - return 0; + return __cvdso_clock_getres(clock, res); } +int clock_getres(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_getres")));

-notrace static void do_coarse(clockid_t clk, struct timespec *ts) -{ - struct vgtod_ts *base = &gtod->basetime[clk]; - unsigned int seq; - - do { - seq = gtod_read_begin(gtod); - ts->tv_sec = base->sec; - ts->tv_nsec = base->nsec; - } while (unlikely(gtod_read_retry(gtod, seq))); -} +#else +/* i386 only */ +extern int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts); +extern int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts); +extern int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res);

-notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) +notrace int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts) { - unsigned int msk; - - /* Sort out negative (CPU/FD) and invalid clocks */ - if (unlikely((unsigned int) clock >= MAX_CLOCKS)) - return vdso_fallback_gettime(clock, ts); - - /* - * Convert the clockid to a bitmask and use it to check which - * clocks are handled in the VDSO directly. - */ - msk = 1U << clock; - if (likely(msk & VGTOD_HRES)) { - return do_hres(clock, ts); - } else if (msk & VGTOD_COARSE) { - do_coarse(clock, ts); - return 0; - } - return vdso_fallback_gettime(clock, ts); + return __cvdso_clock_gettime32(clock, ts); } - -int clock_gettime(clockid_t, struct timespec *) +int clock_gettime(clockid_t, struct old_timespec32 *) __attribute__((weak, alias("__vdso_clock_gettime")));

-notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) +notrace int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts) { - if (likely(tv != NULL)) { - struct timespec *ts = (struct timespec *) tv; - - do_hres(CLOCK_REALTIME, ts); - tv->tv_usec /= 1000; - } - if (unlikely(tz != NULL)) { - tz->tz_minuteswest = gtod->tz_minuteswest; - tz->tz_dsttime = gtod->tz_dsttime; - } - - return 0; + return __cvdso_clock_gettime(clock, ts); } -int gettimeofday(struct timeval *, struct timezone *) - __attribute__((weak, alias("__vdso_gettimeofday"))); +int clock_gettime64(clockid_t, struct __kernel_timespec *) + __attribute__((weak, alias("__vdso_clock_gettime64")));

-/* - * This will break when the xtime seconds get inaccurate, but that is - * unlikely - */ -notrace time_t __vdso_time(time_t *t) +notrace int __vdso_clock_getres(clockid_t clock, + struct old_timespec32 *res) { - /* This is atomic on x86 so we don't need any locks. */ - time_t result = READ_ONCE(gtod->basetime[CLOCK_REALTIME].sec); - - if (t) - *t = result; - return result; + return __cvdso_clock_getres_time32(clock, res); } -time_t time(time_t *t) - __attribute__((weak, alias("__vdso_time"))); +int clock_getres(clockid_t, struct old_timespec32 *) + __attribute__((weak, alias("__vdso_clock_getres"))); +#endif diff --git a/arch/x86/entry/vdso/vdso.lds.S b/arch/x86/entry/vdso/vdso.lds.S index d3a2dce4cfa9..36b644e16272 100644 --- a/arch/x86/entry/vdso/vdso.lds.S +++ b/arch/x86/entry/vdso/vdso.lds.S @@ -25,6 +25,8 @@ VERSION { __vdso_getcpu; time; __vdso_time; + clock_getres; + __vdso_clock_getres; local: *; }; } diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S index 422764a81d32..c7720995ab1a 100644 --- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S +++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S @@ -26,6 +26,8 @@ VERSION __vdso_clock_gettime; __vdso_gettimeofday; __vdso_time; + __vdso_clock_getres; + __vdso_clock_gettime64; };

LINUX_2.5 { 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 1ac4dd116c26..93c1b3e949a7 100644 --- a/arch/x86/entry/vsyscall/Makefile +++ b/arch/x86/entry/vsyscall/Makefile @@ -2,7 +2,5 @@ # # 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 cfcdba082feb..000000000000 --- a/arch/x86/entry/vsyscall/vsyscall_gtod.c +++ /dev/null @@ -1,83 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (C) 2001 Andrea Arcangeli andrea@suse.de SuSE - * Copyright 2003 Andi Kleen, SuSE Labs. - * - * Modified for x86 32 bit architecture by - * Stefani Seibold stefani@seibold.net - * 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 <linux/timekeeper_internal.h> -#include <asm/vgtod.h> -#include <asm/vvar.h> - -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; - struct vgtod_ts *base; - u64 nsec; - - /* 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; - - base = &vdata->basetime[CLOCK_REALTIME]; - base->sec = tk->xtime_sec; - base->nsec = tk->tkr_mono.xtime_nsec; - - base = &vdata->basetime[CLOCK_TAI]; - base->sec = tk->xtime_sec + (s64)tk->tai_offset; - base->nsec = tk->tkr_mono.xtime_nsec; - - base = &vdata->basetime[CLOCK_MONOTONIC]; - base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; - nsec = tk->tkr_mono.xtime_nsec; - nsec += ((u64)tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift); - while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { - nsec -= ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift; - base->sec++; - } - base->nsec = nsec; - - base = &vdata->basetime[CLOCK_REALTIME_COARSE]; - base->sec = tk->xtime_sec; - base->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; - - base = &vdata->basetime[CLOCK_MONOTONIC_COARSE]; - base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; - nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; - nsec += tk->wall_to_monotonic.tv_nsec; - while (nsec >= NSEC_PER_SEC) { - nsec -= NSEC_PER_SEC; - base->sec++; - } - base->nsec = nsec; - - gtod_write_end(vdata); -} diff --git a/arch/x86/include/asm/mshyperv-tsc.h b/arch/x86/include/asm/mshyperv-tsc.h new file mode 100644 index 000000000000..99c98ccea0bf --- /dev/null +++ b/arch/x86/include/asm/mshyperv-tsc.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_MSHYPER_TSCPAGE_H +#define _ASM_X86_MSHYPER_TSCPAGE_H + +#include <asm/hyperv-tlfs.h> + +#ifdef CONFIG_HYPERV_TSCPAGE +struct ms_hyperv_tsc_page *hv_get_tsc_page(void); +static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, + u64 *cur_tsc) +{ + u64 scale, offset; + u32 sequence; + + /* + * The protocol for reading Hyper-V TSC page is specified in Hypervisor + * Top-Level Functional Specification ver. 3.0 and above. To get the + * reference time we must do the following: + * - READ ReferenceTscSequence + * A special '0' value indicates the time source is unreliable and we + * need to use something else. The currently published specification + * versions (up to 4.0b) contain a mistake and wrongly claim '-1' + * instead of '0' as the special value, see commit c35b82ef0294. + * - ReferenceTime = + * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset + * - READ ReferenceTscSequence again. In case its value has changed + * since our first reading we need to discard ReferenceTime and repeat + * the whole sequence as the hypervisor was updating the page in + * between. + */ + do { + sequence = READ_ONCE(tsc_pg->tsc_sequence); + if (!sequence) + return U64_MAX; + /* + * Make sure we read sequence before we read other values from + * TSC page. + */ + smp_rmb(); + + scale = READ_ONCE(tsc_pg->tsc_scale); + offset = READ_ONCE(tsc_pg->tsc_offset); + *cur_tsc = rdtsc_ordered(); + + /* + * Make sure we read sequence after we read all other values + * from TSC page. + */ + smp_rmb(); + + } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence); + + return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset; +} + +static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) +{ + u64 cur_tsc; + + return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc); +} + +#else +static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) +{ + return NULL; +} + +static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, + u64 *cur_tsc) +{ + BUG(); + return U64_MAX; +} +#endif +#endif diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index cc60e617931c..db095a992f3e 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -7,6 +7,7 @@ #include <linux/nmi.h> #include <asm/io.h> #include <asm/hyperv-tlfs.h> +#include <asm/mshyperv-tsc.h> #include <asm/nospec-branch.h>

#define VP_INVAL U32_MAX @@ -387,73 +388,4 @@ static inline int hyperv_flush_guest_mapping_range(u64 as, } #endif /* CONFIG_HYPERV */

-#ifdef CONFIG_HYPERV_TSCPAGE -struct ms_hyperv_tsc_page *hv_get_tsc_page(void); -static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, - u64 *cur_tsc) -{ - u64 scale, offset; - u32 sequence; - - /* - * The protocol for reading Hyper-V TSC page is specified in Hypervisor - * Top-Level Functional Specification ver. 3.0 and above. To get the - * reference time we must do the following: - * - READ ReferenceTscSequence - * A special '0' value indicates the time source is unreliable and we - * need to use something else. The currently published specification - * versions (up to 4.0b) contain a mistake and wrongly claim '-1' - * instead of '0' as the special value, see commit c35b82ef0294. - * - ReferenceTime = - * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset - * - READ ReferenceTscSequence again. In case its value has changed - * since our first reading we need to discard ReferenceTime and repeat - * the whole sequence as the hypervisor was updating the page in - * between. - */ - do { - sequence = READ_ONCE(tsc_pg->tsc_sequence); - if (!sequence) - return U64_MAX; - /* - * Make sure we read sequence before we read other values from - * TSC page. - */ - smp_rmb(); - - scale = READ_ONCE(tsc_pg->tsc_scale); - offset = READ_ONCE(tsc_pg->tsc_offset); - *cur_tsc = rdtsc_ordered(); - - /* - * Make sure we read sequence after we read all other values - * from TSC page. - */ - smp_rmb(); - - } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence); - - return mul_u64_u64_shr(*cur_tsc, scale, 64) + offset; -} - -static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) -{ - u64 cur_tsc; - - return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc); -} - -#else -static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) -{ - return NULL; -} - -static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, - u64 *cur_tsc) -{ - BUG(); - return U64_MAX; -} -#endif #endif 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 <linux/clocksource.h> +#include <asm/clocksource.h> #include <asm/pvclock-abi.h>

/* 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..45608b1d6ff8 --- /dev/null +++ b/arch/x86/include/asm/vdso/gettimeofday.h @@ -0,0 +1,203 @@ +/* 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 stefani@seibold.net + * sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany + */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include <uapi/linux/time.h> +#include <asm/vgtod.h> +#include <asm/vvar.h> +#include <asm/unistd.h> +#include <asm/msr.h> +#include <asm/pvclock.h> +#include <asm/mshyperv-tsc.h> + +#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 notrace 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 notrace 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; +} + +static __always_inline notrace long clock_getres_fallback( + clockid_t _clkid, + struct __kernel_timespec *_ts) +{ + long ret; + asm ("syscall" : "=a" (ret), "=m" (*_ts) : + "0" (__NR_clock_getres), "D" (_clkid), "S" (_ts) : + "rcx", "r11"); + return ret; +} + +#else + +static __always_inline notrace 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_gettime64), [clock] "g" (_clkid), "c" (_ts) + : "edx"); + return ret; +} + +static __always_inline notrace 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; +} + +static __always_inline notrace long clock_getres_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_getres_time64), [clock] "g" (_clkid), "c" (_ts) + : "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(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 notrace 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 + +notrace static inline u64 __arch_get_hw_counter(s32 clock_mode) +{ + if (clock_mode == VCLOCK_TSC) + return (u64)rdtsc_ordered(); +#ifdef CONFIG_PARAVIRT_CLOCK + else if (clock_mode == VCLOCK_PVCLOCK) + return vread_pvclock(); +#endif +#ifdef CONFIG_HYPERV_TSCPAGE + else if (clock_mode == VCLOCK_HVCLOCK) + return vread_hvclock(); +#endif + return U64_MAX; +} + +static __always_inline notrace 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 <linux/hrtimer.h> +#include <linux/timekeeper_internal.h> +#include <vdso/datapage.h> +#include <asm/vgtod.h> +#include <asm/vvar.h> + +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 <asm-generic/vdso/vsyscall.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_VSYSCALL_H */ diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 913a133f8e6f..a2638c6124ed 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -3,7 +3,9 @@ #define _ASM_X86_VGTOD_H

#include <linux/compiler.h> -#include <linux/clocksource.h> +#include <asm/clocksource.h> +#include <vdso/datapage.h> +#include <vdso/helpers.h>

#include <uapi/linux/time.h>

@@ -13,81 +15,10 @@ typedef u64 gtod_long_t; typedef unsigned long gtod_long_t; #endif

-/* - * There is one of these objects in the vvar page for each - * vDSO-accelerated clockid. For high-resolution clocks, this encodes - * the time corresponding to vsyscall_gtod_data.cycle_last. For coarse - * clocks, this encodes the actual time. - * - * To confuse the reader, for high-resolution clocks, nsec is left-shifted - * by vsyscall_gtod_data.shift. - */ -struct vgtod_ts { - u64 sec; - u64 nsec; -}; - -#define VGTOD_BASES (CLOCK_TAI + 1) -#define VGTOD_HRES (BIT(CLOCK_REALTIME) | BIT(CLOCK_MONOTONIC) | BIT(CLOCK_TAI)) -#define VGTOD_COARSE (BIT(CLOCK_REALTIME_COARSE) | BIT(CLOCK_MONOTONIC_COARSE)) - -/* - * 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 int seq; - - int vclock_mode; - u64 cycle_last; - u64 mask; - u32 mult; - u32 shift; - - struct vgtod_ts basetime[VGTOD_BASES]; - - 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) { return READ_ONCE(vclocks_used) & (1 << vclock); }

-static inline unsigned int gtod_read_begin(const struct vsyscall_gtod_data *s) -{ - unsigned int 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 int 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 0ff3e294d0e5..10125358b9c4 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -3,6 +3,7 @@

*/

+#include <linux/clocksource.h> #include <linux/kernel.h> #include <linux/percpu.h> #include <linux/notifier.h>

The current version of the multiarch vDSO selftest verifies only gettimeofday.

Extend the vDSO selftest to the other library functions: - time - clock_getres - clock_gettime

The extension has been used to verify the unified vdso library on the supported architectures.

Cc: Shuah Khan shuah@kernel.org Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- tools/testing/selftests/vDSO/Makefile | 2 + tools/testing/selftests/vDSO/vdso_full_test.c | 261 ++++++++++++++++++ 2 files changed, 263 insertions(+) create mode 100644 tools/testing/selftests/vDSO/vdso_full_test.c

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile index 9e03d61f52fd..68e9b4a1cdcf 100644 --- a/tools/testing/selftests/vDSO/Makefile +++ b/tools/testing/selftests/vDSO/Makefile @@ -5,6 +5,7 @@ uname_M := $(shell uname -m 2>/dev/null || echo not) ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)

TEST_GEN_PROGS := $(OUTPUT)/vdso_test +TEST_GEN_PROGS += $(OUTPUT)/vdso_full_test ifeq ($(ARCH),x86) TEST_GEN_PROGS += $(OUTPUT)/vdso_standalone_test_x86 endif @@ -18,6 +19,7 @@ endif

all: $(TEST_GEN_PROGS) $(OUTPUT)/vdso_test: parse_vdso.c vdso_test.c +$(OUTPUT)/vdso_full_test: parse_vdso.c vdso_full_test.c $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c $(CC) $(CFLAGS) $(CFLAGS_vdso_standalone_test_x86) \ vdso_standalone_test_x86.c parse_vdso.c \ diff --git a/tools/testing/selftests/vDSO/vdso_full_test.c b/tools/testing/selftests/vDSO/vdso_full_test.c new file mode 100644 index 000000000000..62001d3d241b --- /dev/null +++ b/tools/testing/selftests/vDSO/vdso_full_test.c @@ -0,0 +1,261 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * vdso_full_test.c: Sample code to test all the timers. + * Copyright (c) 2019 Arm Ltd. + * + * Compile with: + * gcc -std=gnu99 vdso_full_test.c parse_vdso.c + * + * Tested on ARM, ARM64, MIPS32 and x86 (32-bit and 64-bit). + * Might work on other architectures. + */ + +#include <stdint.h> +#include <elf.h> +#include <stdio.h> +#include <time.h> +#include <sys/auxv.h> +#include <sys/time.h> +#define _GNU_SOURCE +#include <unistd.h> +#include <sys/syscall.h> + +#include "../kselftest.h" + +extern void *vdso_sym(const char *version, const char *name); +extern void vdso_init_from_sysinfo_ehdr(uintptr_t base); +extern void vdso_init_from_auxv(void *auxv); + +/* + * ARM64's vDSO exports its vDSO implementation with different names and + * a different version from other architectures, so we need to handle it + * as a special case. + */ +#if defined(__aarch64__) +const char *version = "LINUX_2.6.39"; +const char *name[4] = { + "__kernel_gettimeofday", + "__kernel_clock_gettime", + "__kernel_time", + "__kernel_clock_getres", +}; +#else +/* Tested on x86, arm, mips */ +const char *version = "LINUX_2.6"; +const char *name[4] = { + "__vdso_gettimeofday", + "__vdso_clock_gettime", + "__vdso_time", + "__vdso_clock_getres", +}; +#endif + +typedef long (*vdso_gettimeofday_t)(struct timeval *tv, struct timezone *tz); +typedef long (*vdso_clock_gettime_t)(clockid_t clk_id, struct timespec *ts); +typedef long (*vdso_clock_getres_t)(clockid_t clk_id, struct timespec *ts); +typedef time_t (*vdso_time_t)(time_t *t); + +static int vdso_test_gettimeofday(void) +{ + /* Find gettimeofday. */ + vdso_gettimeofday_t vdso_gettimeofday = + (vdso_gettimeofday_t)vdso_sym(version, name[0]); + + if (!vdso_gettimeofday) { + printf("Could not find %s\n", name[0]); + return KSFT_SKIP; + } + + struct timeval tv; + long ret = vdso_gettimeofday(&tv, 0); + + if (ret == 0) { + printf("The time is %lld.%06lld\n", + (long long)tv.tv_sec, (long long)tv.tv_usec); + } else { + printf("%s failed\n", name[0]); + return KSFT_FAIL; + } + + return KSFT_PASS; +} + +static int vdso_test_clock_gettime(clockid_t clk_id) +{ + /* Find clock_gettime. */ + vdso_clock_gettime_t vdso_clock_gettime = + (vdso_clock_gettime_t)vdso_sym(version, name[1]); + + if (!vdso_clock_gettime) { + printf("Could not find %s\n", name[1]); + return KSFT_SKIP; + } + + struct timespec ts; + long ret = vdso_clock_gettime(clk_id, &ts); + + if (ret == 0) { + printf("The time is %lld.%06lld\n", + (long long)ts.tv_sec, (long long)ts.tv_nsec); + } else { + printf("%s failed\n", name[1]); + return KSFT_FAIL; + } + + return KSFT_PASS; +} + +static int vdso_test_time(void) +{ + /* Find time. */ + vdso_time_t vdso_time = + (vdso_time_t)vdso_sym(version, name[2]); + + if (!vdso_time) { + printf("Could not find %s\n", name[2]); + return KSFT_SKIP; + } + + long ret = vdso_time(NULL); + + if (ret > 0) { + printf("The time in hours since January 1, 1970 is %lld\n", + (long long)(ret / 3600)); + } else { + printf("%s failed\n", name[2]); + return KSFT_FAIL; + } + + return KSFT_PASS; +} + +static int vdso_test_clock_getres(clockid_t clk_id) +{ + /* Find clock_getres. */ + vdso_clock_getres_t vdso_clock_getres = + (vdso_clock_getres_t)vdso_sym(version, name[3]); + + if (!vdso_clock_getres) { + printf("Could not find %s\n", name[3]); + return KSFT_SKIP; + } + + struct timespec ts, sys_ts; + long ret = vdso_clock_getres(clk_id, &ts); + + if (ret == 0) { + printf("The resolution is %lld %lld\n", + (long long)ts.tv_sec, (long long)ts.tv_nsec); + } else { + printf("%s failed\n", name[3]); + return KSFT_FAIL; + } + + ret = syscall(SYS_clock_getres, clk_id, &sys_ts); + + if ((sys_ts.tv_sec != ts.tv_sec) || (sys_ts.tv_nsec != ts.tv_nsec)) { + printf("%s failed\n", name[3]); + return KSFT_FAIL; + } + + return KSFT_PASS; +} + +const char *vdso_clock_name[12] = { + "CLOCK_REALTIME", + "CLOCK_MONOTONIC", + "CLOCK_PROCESS_CPUTIME_ID", + "CLOCK_THREAD_CPUTIME_ID", + "CLOCK_MONOTONIC_RAW", + "CLOCK_REALTIME_COARSE", + "CLOCK_MONOTONIC_COARSE", + "CLOCK_BOOTTIME", + "CLOCK_REALTIME_ALARM", + "CLOCK_BOOTTIME_ALARM", + "CLOCK_SGI_CYCLE", + "CLOCK_TAI", +}; + +/* + * This function calls vdso_test_clock_gettime and vdso_test_clock_getres + * with different values for clock_id. + */ +static inline int vdso_test_clock(clockid_t clock_id) +{ + int ret0, ret1; + + ret0 = vdso_test_clock_gettime(clock_id); + /* A skipped test is considered passed */ + if (ret0 == KSFT_SKIP) + ret0 = KSFT_PASS; + + ret1 = vdso_test_clock_getres(clock_id); + /* A skipped test is considered passed */ + if (ret1 == KSFT_SKIP) + ret1 = KSFT_PASS; + + ret0 += ret1; + + printf("clock_id: %s", vdso_clock_name[clock_id]); + + if (ret0 > 0) + printf(" [FAIL]\n"); + else + printf(" [PASS]\n"); + + return ret0; +} + +int main(int argc, char **argv) +{ + unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR); + int ret; + + if (!sysinfo_ehdr) { + printf("AT_SYSINFO_EHDR is not present!\n"); + return KSFT_SKIP; + } + + vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR)); + + ret = vdso_test_gettimeofday(); + +#if _POSIX_TIMERS > 0 + +#ifdef CLOCK_REALTIME + ret += vdso_test_clock(CLOCK_REALTIME); +#endif + +#ifdef CLOCK_BOOTTIME + ret += vdso_test_clock(CLOCK_BOOTTIME); +#endif + +#ifdef CLOCK_TAI + ret += vdso_test_clock(CLOCK_TAI); +#endif + +#ifdef CLOCK_REALTIME_COARSE + ret += vdso_test_clock(CLOCK_REALTIME_COARSE); +#endif + +#ifdef CLOCK_MONOTONIC + ret += vdso_test_clock(CLOCK_MONOTONIC); +#endif + +#ifdef CLOCK_MONOTONIC_RAW + ret += vdso_test_clock(CLOCK_MONOTONIC_RAW); +#endif + +#ifdef CLOCK_MONOTONIC_COARSE + ret += vdso_test_clock(CLOCK_MONOTONIC_COARSE); +#endif + +#endif + + ret += vdso_test_time(); + + if (ret > 0) + return KSFT_FAIL; + + return KSFT_PASS; +}