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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /lib/vdso/gettimeofday.c
downloadlinux-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.c513
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 */