diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /lib/vdso/gettimeofday.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'lib/vdso/gettimeofday.c')
| -rw-r--r-- | lib/vdso/gettimeofday.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c new file mode 100644 index 000000000..f7a591aba --- /dev/null +++ b/lib/vdso/gettimeofday.c @@ -0,0 +1,513 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic userspace implementations of gettimeofday() and similar. + */ +#include <vdso/auxclock.h> +#include <vdso/clocksource.h> +#include <vdso/datapage.h> +#include <vdso/helpers.h> +#include <vdso/ktime.h> +#include <vdso/limits.h> +#include <vdso/math64.h> +#include <vdso/time32.h> +#include <vdso/time64.h> + +#include <uapi/linux/unistd.h> + +/* + * The generic vDSO implementation requires that gettimeofday.h + * provides: + * - __arch_get_hw_counter(): to get the hw counter based on the + * clock_mode. + * - gettimeofday_fallback(): fallback for gettimeofday. + * - clock_gettime_fallback(): fallback for clock_gettime. + * - clock_getres_fallback(): fallback for clock_getres. + */ +#include <asm/vdso/gettimeofday.h> + +#include <linux/build_bug.h> + +/* Bring in default accessors */ +#include <vdso/vsyscall.h> + +#ifndef vdso_calc_ns + +#ifdef VDSO_DELTA_NOMASK +# define VDSO_DELTA_MASK(vd) ULLONG_MAX +#else +# define VDSO_DELTA_MASK(vd) (vd->mask) +#endif + +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT +static __always_inline bool vdso_delta_ok(const struct vdso_clock *vc, u64 delta) +{ + return delta < vc->max_cycles; +} +#else +static __always_inline bool vdso_delta_ok(const struct vdso_clock *vc, u64 delta) +{ + return true; +} +#endif + +#ifndef vdso_shift_ns +static __always_inline u64 vdso_shift_ns(u64 ns, u32 shift) +{ + return ns >> shift; +} +#endif + +/* + * Default implementation which works for all sane clocksources. That + * obviously excludes x86/TSC. + */ +static __always_inline u64 vdso_calc_ns(const struct vdso_clock *vc, u64 cycles, u64 base) +{ + u64 delta = (cycles - vc->cycle_last) & VDSO_DELTA_MASK(vc); + + if (likely(vdso_delta_ok(vc, delta))) + return vdso_shift_ns((delta * vc->mult) + base, vc->shift); + + return mul_u64_u32_add_u64_shr(delta, vc->mult, base, vc->shift); +} +#endif /* vdso_calc_ns */ + +#ifndef __arch_vdso_hres_capable +static inline bool __arch_vdso_hres_capable(void) +{ + return true; +} +#endif + +#ifndef vdso_clocksource_ok +static inline bool vdso_clocksource_ok(const struct vdso_clock *vc) +{ + return vc->clock_mode != VDSO_CLOCKMODE_NONE; +} +#endif + +#ifndef vdso_cycles_ok +static inline bool vdso_cycles_ok(u64 cycles) +{ + return true; +} +#endif + +static __always_inline bool vdso_clockid_valid(clockid_t clock) +{ + /* Check for negative values or invalid clocks */ + return likely((u32) clock <= CLOCK_AUX_LAST); +} + +/* + * Must not be invoked within the sequence read section as a race inside + * that loop could result in __iter_div_u64_rem() being extremely slow. + */ +static __always_inline void vdso_set_timespec(struct __kernel_timespec *ts, u64 sec, u64 ns) +{ + ts->tv_sec = sec + __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns); + ts->tv_nsec = ns; +} + +static __always_inline +bool vdso_get_timestamp(const struct vdso_time_data *vd, const struct vdso_clock *vc, + unsigned int clkidx, u64 *sec, u64 *ns) +{ + const struct vdso_timestamp *vdso_ts = &vc->basetime[clkidx]; + u64 cycles; + + if (unlikely(!vdso_clocksource_ok(vc))) + return false; + + cycles = __arch_get_hw_counter(vc->clock_mode, vd); + if (unlikely(!vdso_cycles_ok(cycles))) + return false; + + *ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec); + *sec = vdso_ts->sec; + + return true; +} + +static __always_inline +const struct vdso_time_data *vdso_timens_data(const struct vdso_time_data *vd) +{ + return (void *)vd + PAGE_SIZE; +} + +static __always_inline +bool do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, + clockid_t clk, struct __kernel_timespec *ts) +{ + const struct vdso_time_data *vd = vdso_timens_data(vdns); + const struct timens_offset *offs = &vcns->offset[clk]; + const struct vdso_clock *vc = vd->clock_data; + u32 seq; + s64 sec; + u64 ns; + + if (clk != CLOCK_MONOTONIC_RAW) + vc = &vc[CS_HRES_COARSE]; + else + vc = &vc[CS_RAW]; + + do { + seq = vdso_read_begin(vc); + + if (!vdso_get_timestamp(vd, vc, clk, &sec, &ns)) + return false; + } while (vdso_read_retry(vc, seq)); + + /* Add the namespace offset */ + sec += offs->sec; + ns += offs->nsec; + + vdso_set_timespec(ts, sec, ns); + + return true; +} + +static __always_inline +bool do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc, + clockid_t clk, struct __kernel_timespec *ts) +{ + u64 sec, ns; + u32 seq; + + /* Allows to compile the high resolution parts out */ + if (!__arch_vdso_hres_capable()) + return false; + + do { + if (vdso_read_begin_timens(vc, &seq)) + return do_hres_timens(vd, vc, clk, ts); + + if (!vdso_get_timestamp(vd, vc, clk, &sec, &ns)) + return false; + } while (vdso_read_retry(vc, seq)); + + vdso_set_timespec(ts, sec, ns); + + return true; +} + +static __always_inline +bool do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns, + clockid_t clk, struct __kernel_timespec *ts) +{ + const struct vdso_time_data *vd = vdso_timens_data(vdns); + const struct timens_offset *offs = &vcns->offset[clk]; + const struct vdso_clock *vc = vd->clock_data; + const struct vdso_timestamp *vdso_ts; + u64 nsec; + s64 sec; + s32 seq; + + vdso_ts = &vc->basetime[clk]; + + do { + seq = vdso_read_begin(vc); + sec = vdso_ts->sec; + nsec = vdso_ts->nsec; + } while (vdso_read_retry(vc, seq)); + + /* Add the namespace offset */ + sec += offs->sec; + nsec += offs->nsec; + + vdso_set_timespec(ts, sec, nsec); + + return true; +} + +static __always_inline +bool do_coarse(const struct vdso_time_data *vd, const struct vdso_clock *vc, + clockid_t clk, struct __kernel_timespec *ts) +{ + const struct vdso_timestamp *vdso_ts = &vc->basetime[clk]; + u32 seq; + + do { + if (vdso_read_begin_timens(vc, &seq)) + return do_coarse_timens(vd, vc, clk, ts); + + ts->tv_sec = vdso_ts->sec; + ts->tv_nsec = vdso_ts->nsec; + } while (vdso_read_retry(vc, seq)); + + return true; +} + +static __always_inline +bool do_aux(const struct vdso_time_data *vd, clockid_t clock, struct __kernel_timespec *ts) +{ + const struct vdso_clock *vc; + u32 seq, idx; + u64 sec, ns; + + if (!IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS)) + return false; + + idx = clock - CLOCK_AUX; + vc = &vd->aux_clock_data[idx]; + + do { + while (vdso_read_begin_timens(vc, &seq)) { + /* Re-read from the real time data page, reload seq by looping */ + vd = vdso_timens_data(vd); + vc = &vd->aux_clock_data[idx]; + } + + /* Auxclock disabled? */ + if (vc->clock_mode == VDSO_CLOCKMODE_NONE) + return false; + + if (!vdso_get_timestamp(vd, vc, VDSO_BASE_AUX, &sec, &ns)) + return false; + } while (vdso_read_retry(vc, seq)); + + vdso_set_timespec(ts, sec, ns); + + return true; +} + +static __always_inline bool +__cvdso_clock_gettime_common(const struct vdso_time_data *vd, clockid_t clock, + struct __kernel_timespec *ts) +{ + const struct vdso_clock *vc = vd->clock_data; + u32 msk; + + if (!vdso_clockid_valid(clock)) + return false; + + /* + * 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 & VDSO_HRES)) + vc = &vc[CS_HRES_COARSE]; + else if (msk & VDSO_COARSE) + return do_coarse(vd, &vc[CS_HRES_COARSE], clock, ts); + else if (msk & VDSO_RAW) + vc = &vc[CS_RAW]; + else if (msk & VDSO_AUX) + return do_aux(vd, clock, ts); + else + return false; + + return do_hres(vd, vc, clock, ts); +} + +static int +__cvdso_clock_gettime_data(const struct vdso_time_data *vd, clockid_t clock, + struct __kernel_timespec *ts) +{ + bool ok; + + ok = __cvdso_clock_gettime_common(vd, clock, ts); + + if (unlikely(!ok)) + return clock_gettime_fallback(clock, ts); + return 0; +} + +static __maybe_unused int +__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime_data(__arch_get_vdso_u_time_data(), clock, ts); +} + +#ifdef BUILD_VDSO32 +static int +__cvdso_clock_gettime32_data(const struct vdso_time_data *vd, clockid_t clock, + struct old_timespec32 *res) +{ + struct __kernel_timespec ts; + bool ok; + + BUILD_BUG_ON(!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)); + + ok = __cvdso_clock_gettime_common(vd, clock, &ts); + + if (unlikely(!ok)) + return clock_gettime32_fallback(clock, res); + + /* For ok == true */ + res->tv_sec = ts.tv_sec; + res->tv_nsec = ts.tv_nsec; + + return 0; +} + +static __maybe_unused int +__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res) +{ + return __cvdso_clock_gettime32_data(__arch_get_vdso_u_time_data(), clock, res); +} +#endif /* BUILD_VDSO32 */ + +static int +__cvdso_gettimeofday_data(const struct vdso_time_data *vd, + struct __kernel_old_timeval *tv, struct timezone *tz) +{ + const struct vdso_clock *vc = vd->clock_data; + +#ifndef __NR_gettimeofday + BUILD_BUG(); +#endif + + BUILD_BUG_ON(sizeof(tv->tv_sec) != 8 && !IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)); + + if (likely(tv != NULL)) { + struct __kernel_timespec ts; + + if (!do_hres(vd, &vc[CS_HRES_COARSE], CLOCK_REALTIME, &ts)) + return gettimeofday_fallback(tv, tz); + + tv->tv_sec = ts.tv_sec; + tv->tv_usec = (u32)ts.tv_nsec / NSEC_PER_USEC; + } + + if (unlikely(tz != NULL)) { + if (vdso_is_timens_clock(vc)) + vd = vdso_timens_data(vd); + + tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest; + tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime; + } + + return 0; +} + +static __maybe_unused int +__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) +{ + return __cvdso_gettimeofday_data(__arch_get_vdso_u_time_data(), tv, tz); +} + +#ifdef VDSO_HAS_TIME +static __kernel_old_time_t +__cvdso_time_data(const struct vdso_time_data *vd, __kernel_old_time_t *time) +{ + const struct vdso_clock *vc = vd->clock_data; + __kernel_old_time_t t; + +#ifndef __NR_time + BUILD_BUG(); +#endif + + BUILD_BUG_ON(sizeof(*time) != 8 && !IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)); + + if (vdso_is_timens_clock(vc)) { + vd = vdso_timens_data(vd); + vc = vd->clock_data; + } + + t = READ_ONCE(vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec); + + if (time) + *time = t; + + return t; +} + +static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time) +{ + return __cvdso_time_data(__arch_get_vdso_u_time_data(), time); +} +#endif /* VDSO_HAS_TIME */ + +#ifdef VDSO_HAS_CLOCK_GETRES +static __always_inline +bool __cvdso_clock_getres_common(const struct vdso_time_data *vd, clockid_t clock, + struct __kernel_timespec *res) +{ + const struct vdso_clock *vc = vd->clock_data; + u32 msk; + u64 ns; + + if (!vdso_clockid_valid(clock)) + return false; + + if (vdso_is_timens_clock(vc)) + vd = vdso_timens_data(vd); + + /* + * Convert the clockid to a bitmask and use it to check which + * clocks are handled in the VDSO directly. + */ + msk = 1U << clock; + if (msk & (VDSO_HRES | VDSO_RAW)) { + /* + * Preserves the behaviour of posix_get_hrtimer_res(). + */ + ns = READ_ONCE(vd->hrtimer_res); + } else if (msk & VDSO_COARSE) { + /* + * Preserves the behaviour of posix_get_coarse_res(). + */ + ns = LOW_RES_NSEC; + } else if (msk & VDSO_AUX) { + ns = aux_clock_resolution_ns(); + } else { + return false; + } + + if (likely(res)) { + res->tv_sec = 0; + res->tv_nsec = ns; + } + return true; +} + +static +int __cvdso_clock_getres_data(const struct vdso_time_data *vd, clockid_t clock, + struct __kernel_timespec *res) +{ + bool ok; + + ok = __cvdso_clock_getres_common(vd, clock, res); + + if (unlikely(!ok)) + return clock_getres_fallback(clock, res); + return 0; +} + +static __maybe_unused +int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res) +{ + return __cvdso_clock_getres_data(__arch_get_vdso_u_time_data(), clock, res); +} + +#ifdef BUILD_VDSO32 +static int +__cvdso_clock_getres_time32_data(const struct vdso_time_data *vd, clockid_t clock, + struct old_timespec32 *res) +{ + struct __kernel_timespec ts; + bool ok; + + BUILD_BUG_ON(!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)); + + ok = __cvdso_clock_getres_common(vd, clock, &ts); + + if (unlikely(!ok)) + return clock_getres32_fallback(clock, res); + + if (likely(res)) { + res->tv_sec = ts.tv_sec; + res->tv_nsec = ts.tv_nsec; + } + return 0; +} + +static __maybe_unused int +__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) +{ + return __cvdso_clock_getres_time32_data(__arch_get_vdso_u_time_data(), + clock, res); +} +#endif /* BUILD_VDSO32 */ +#endif /* VDSO_HAS_CLOCK_GETRES */ |
