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-rw-r--r--lib/vdso/gettimeofday.c239
1 files changed, 141 insertions, 98 deletions
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index ce2f69552003..93ef801a97ef 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -5,15 +5,26 @@
#include <vdso/datapage.h>
#include <vdso/helpers.h>
-#ifndef vdso_calc_delta
-/*
- * Default implementation which works for all sane clocksources. That
- * obviously excludes x86/TSC.
- */
-static __always_inline
-u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
+/* 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 ((cycles - last) & mask) * mult;
+ return delta < vc->max_cycles;
+}
+#else
+static __always_inline bool vdso_delta_ok(const struct vdso_clock *vc, u64 delta)
+{
+ return true;
}
#endif
@@ -24,6 +35,21 @@ static __always_inline u64 vdso_shift_ns(u64 ns, u32 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)
{
@@ -32,9 +58,9 @@ static inline bool __arch_vdso_hres_capable(void)
#endif
#ifndef vdso_clocksource_ok
-static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+static inline bool vdso_clocksource_ok(const struct vdso_clock *vc)
{
- return vd->clock_mode != VDSO_CLOCKMODE_NONE;
+ return vc->clock_mode != VDSO_CLOCKMODE_NONE;
}
#endif
@@ -46,39 +72,45 @@ static inline bool vdso_cycles_ok(u64 cycles)
#endif
#ifdef CONFIG_TIME_NS
-static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
- struct __kernel_timespec *ts)
+
+#ifdef CONFIG_GENERIC_VDSO_DATA_STORE
+static __always_inline
+const struct vdso_time_data *__arch_get_vdso_u_timens_data(const struct vdso_time_data *vd)
+{
+ return (void *)vd + PAGE_SIZE;
+}
+#endif /* CONFIG_GENERIC_VDSO_DATA_STORE */
+
+static __always_inline
+int do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns,
+ clockid_t clk, struct __kernel_timespec *ts)
{
- const struct vdso_data *vd;
- const struct timens_offset *offs = &vdns->offset[clk];
+ const struct vdso_time_data *vd = __arch_get_vdso_u_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 cycles, last, ns;
+ u64 cycles, ns;
u32 seq;
s64 sec;
- vd = vdns - (clk == CLOCK_MONOTONIC_RAW ? CS_RAW : CS_HRES_COARSE);
- vd = __arch_get_timens_vdso_data(vd);
if (clk != CLOCK_MONOTONIC_RAW)
- vd = &vd[CS_HRES_COARSE];
+ vc = &vc[CS_HRES_COARSE];
else
- vd = &vd[CS_RAW];
- vdso_ts = &vd->basetime[clk];
+ vc = &vc[CS_RAW];
+ vdso_ts = &vc->basetime[clk];
do {
- seq = vdso_read_begin(vd);
+ seq = vdso_read_begin(vc);
- if (unlikely(!vdso_clocksource_ok(vd)))
+ if (unlikely(!vdso_clocksource_ok(vc)))
return -1;
- cycles = __arch_get_hw_counter(vd->clock_mode, vd);
+ cycles = __arch_get_hw_counter(vc->clock_mode, vd);
if (unlikely(!vdso_cycles_ok(cycles)))
return -1;
- ns = vdso_ts->nsec;
- last = vd->cycle_last;
- ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
- ns = vdso_shift_ns(ns, vd->shift);
+ ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec);
sec = vdso_ts->sec;
- } while (unlikely(vdso_read_retry(vd, seq)));
+ } while (unlikely(vdso_read_retry(vc, seq)));
/* Add the namespace offset */
sec += offs->sec;
@@ -95,23 +127,25 @@ static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_
}
#else
static __always_inline
-const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
+const struct vdso_time_data *__arch_get_vdso_u_timens_data(const struct vdso_time_data *vd)
{
return NULL;
}
-static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
- struct __kernel_timespec *ts)
+static __always_inline
+int do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns,
+ clockid_t clk, struct __kernel_timespec *ts)
{
return -EINVAL;
}
#endif
-static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
- struct __kernel_timespec *ts)
+static __always_inline
+int do_hres(const struct vdso_time_data *vd, const struct vdso_clock *vc,
+ clockid_t clk, struct __kernel_timespec *ts)
{
- const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
- u64 cycles, last, sec, ns;
+ const struct vdso_timestamp *vdso_ts = &vc->basetime[clk];
+ u64 cycles, sec, ns;
u32 seq;
/* Allows to compile the high resolution parts out */
@@ -120,36 +154,33 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
do {
/*
- * Open coded to handle VDSO_CLOCKMODE_TIMENS. Time namespace
- * enabled tasks have a special VVAR page installed which
- * has vd->seq set to 1 and vd->clock_mode set to
- * VDSO_CLOCKMODE_TIMENS. For non time namespace affected tasks
- * this does not affect performance because if vd->seq is
- * odd, i.e. a concurrent update is in progress the extra
- * check for vd->clock_mode is just a few extra
- * instructions while spin waiting for vd->seq to become
+ * Open coded function vdso_read_begin() to handle
+ * VDSO_CLOCKMODE_TIMENS. Time namespace enabled tasks have a
+ * special VVAR page installed which has vc->seq set to 1 and
+ * vc->clock_mode set to VDSO_CLOCKMODE_TIMENS. For non time
+ * namespace affected tasks this does not affect performance
+ * because if vc->seq is odd, i.e. a concurrent update is in
+ * progress the extra check for vc->clock_mode is just a few
+ * extra instructions while spin waiting for vc->seq to become
* even again.
*/
- while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) {
+ while (unlikely((seq = READ_ONCE(vc->seq)) & 1)) {
if (IS_ENABLED(CONFIG_TIME_NS) &&
- vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
- return do_hres_timens(vd, clk, ts);
+ vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+ return do_hres_timens(vd, vc, clk, ts);
cpu_relax();
}
smp_rmb();
- if (unlikely(!vdso_clocksource_ok(vd)))
+ if (unlikely(!vdso_clocksource_ok(vc)))
return -1;
- cycles = __arch_get_hw_counter(vd->clock_mode, vd);
+ cycles = __arch_get_hw_counter(vc->clock_mode, vd);
if (unlikely(!vdso_cycles_ok(cycles)))
return -1;
- ns = vdso_ts->nsec;
- last = vd->cycle_last;
- ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
- ns = vdso_shift_ns(ns, vd->shift);
+ ns = vdso_calc_ns(vc, cycles, vdso_ts->nsec);
sec = vdso_ts->sec;
- } while (unlikely(vdso_read_retry(vd, seq)));
+ } while (unlikely(vdso_read_retry(vc, seq)));
/*
* Do this outside the loop: a race inside the loop could result
@@ -162,21 +193,25 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
}
#ifdef CONFIG_TIME_NS
-static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
- struct __kernel_timespec *ts)
+static __always_inline
+int do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns,
+ clockid_t clk, struct __kernel_timespec *ts)
{
- const struct vdso_data *vd = __arch_get_timens_vdso_data(vdns);
- const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
- const struct timens_offset *offs = &vdns->offset[clk];
+ const struct vdso_time_data *vd = __arch_get_vdso_u_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(vd);
+ seq = vdso_read_begin(vc);
sec = vdso_ts->sec;
nsec = vdso_ts->nsec;
- } while (unlikely(vdso_read_retry(vd, seq)));
+ } while (unlikely(vdso_read_retry(vc, seq)));
/* Add the namespace offset */
sec += offs->sec;
@@ -191,43 +226,46 @@ static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clocki
return 0;
}
#else
-static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
- struct __kernel_timespec *ts)
+static __always_inline
+int do_coarse_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns,
+ clockid_t clk, struct __kernel_timespec *ts)
{
return -1;
}
#endif
-static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk,
- struct __kernel_timespec *ts)
+static __always_inline
+int 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 = &vd->basetime[clk];
+ const struct vdso_timestamp *vdso_ts = &vc->basetime[clk];
u32 seq;
do {
/*
- * Open coded to handle VDSO_CLOCK_TIMENS. See comment in
- * do_hres().
+ * Open coded function vdso_read_begin() to handle
+ * VDSO_CLOCK_TIMENS. See comment in do_hres().
*/
- while ((seq = READ_ONCE(vd->seq)) & 1) {
+ while ((seq = READ_ONCE(vc->seq)) & 1) {
if (IS_ENABLED(CONFIG_TIME_NS) &&
- vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
- return do_coarse_timens(vd, clk, ts);
+ vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+ return do_coarse_timens(vd, vc, clk, ts);
cpu_relax();
}
smp_rmb();
ts->tv_sec = vdso_ts->sec;
ts->tv_nsec = vdso_ts->nsec;
- } while (unlikely(vdso_read_retry(vd, seq)));
+ } while (unlikely(vdso_read_retry(vc, seq)));
return 0;
}
static __always_inline int
-__cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock,
+__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;
/* Check for negative values or invalid clocks */
@@ -240,19 +278,19 @@ __cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock,
*/
msk = 1U << clock;
if (likely(msk & VDSO_HRES))
- vd = &vd[CS_HRES_COARSE];
+ vc = &vc[CS_HRES_COARSE];
else if (msk & VDSO_COARSE)
- return do_coarse(&vd[CS_HRES_COARSE], clock, ts);
+ return do_coarse(vd, &vc[CS_HRES_COARSE], clock, ts);
else if (msk & VDSO_RAW)
- vd = &vd[CS_RAW];
+ vc = &vc[CS_RAW];
else
return -1;
- return do_hres(vd, clock, ts);
+ return do_hres(vd, vc, clock, ts);
}
static __maybe_unused int
-__cvdso_clock_gettime_data(const struct vdso_data *vd, clockid_t clock,
+__cvdso_clock_gettime_data(const struct vdso_time_data *vd, clockid_t clock,
struct __kernel_timespec *ts)
{
int ret = __cvdso_clock_gettime_common(vd, clock, ts);
@@ -265,12 +303,12 @@ __cvdso_clock_gettime_data(const struct vdso_data *vd, clockid_t clock,
static __maybe_unused int
__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
{
- return __cvdso_clock_gettime_data(__arch_get_vdso_data(), clock, ts);
+ return __cvdso_clock_gettime_data(__arch_get_vdso_u_time_data(), clock, ts);
}
#ifdef BUILD_VDSO32
static __maybe_unused int
-__cvdso_clock_gettime32_data(const struct vdso_data *vd, clockid_t clock,
+__cvdso_clock_gettime32_data(const struct vdso_time_data *vd, clockid_t clock,
struct old_timespec32 *res)
{
struct __kernel_timespec ts;
@@ -291,19 +329,20 @@ __cvdso_clock_gettime32_data(const struct vdso_data *vd, clockid_t clock,
static __maybe_unused int
__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
{
- return __cvdso_clock_gettime32_data(__arch_get_vdso_data(), clock, res);
+ return __cvdso_clock_gettime32_data(__arch_get_vdso_u_time_data(), clock, res);
}
#endif /* BUILD_VDSO32 */
static __maybe_unused int
-__cvdso_gettimeofday_data(const struct vdso_data *vd,
+__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;
if (likely(tv != NULL)) {
struct __kernel_timespec ts;
- if (do_hres(&vd[CS_HRES_COARSE], CLOCK_REALTIME, &ts))
+ if (do_hres(vd, &vc[CS_HRES_COARSE], CLOCK_REALTIME, &ts))
return gettimeofday_fallback(tv, tz);
tv->tv_sec = ts.tv_sec;
@@ -312,8 +351,8 @@ __cvdso_gettimeofday_data(const struct vdso_data *vd,
if (unlikely(tz != NULL)) {
if (IS_ENABLED(CONFIG_TIME_NS) &&
- vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
- vd = __arch_get_timens_vdso_data(vd);
+ vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+ vd = __arch_get_vdso_u_timens_data(vd);
tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime;
@@ -325,20 +364,23 @@ __cvdso_gettimeofday_data(const struct vdso_data *vd,
static __maybe_unused int
__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
{
- return __cvdso_gettimeofday_data(__arch_get_vdso_data(), tv, tz);
+ return __cvdso_gettimeofday_data(__arch_get_vdso_u_time_data(), tv, tz);
}
#ifdef VDSO_HAS_TIME
static __maybe_unused __kernel_old_time_t
-__cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
+__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;
if (IS_ENABLED(CONFIG_TIME_NS) &&
- vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
- vd = __arch_get_timens_vdso_data(vd);
+ vc->clock_mode == VDSO_CLOCKMODE_TIMENS) {
+ vd = __arch_get_vdso_u_timens_data(vd);
+ vc = vd->clock_data;
+ }
- t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
+ t = READ_ONCE(vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
if (time)
*time = t;
@@ -348,15 +390,16 @@ __cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time)
{
- return __cvdso_time_data(__arch_get_vdso_data(), time);
+ return __cvdso_time_data(__arch_get_vdso_u_time_data(), time);
}
#endif /* VDSO_HAS_TIME */
#ifdef VDSO_HAS_CLOCK_GETRES
static __maybe_unused
-int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
+int __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;
@@ -365,8 +408,8 @@ int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
return -1;
if (IS_ENABLED(CONFIG_TIME_NS) &&
- vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
- vd = __arch_get_timens_vdso_data(vd);
+ vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+ vd = __arch_get_vdso_u_timens_data(vd);
/*
* Convert the clockid to a bitmask and use it to check which
@@ -377,7 +420,7 @@ int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
/*
* Preserves the behaviour of posix_get_hrtimer_res().
*/
- ns = READ_ONCE(vd[CS_HRES_COARSE].hrtimer_res);
+ ns = READ_ONCE(vd->hrtimer_res);
} else if (msk & VDSO_COARSE) {
/*
* Preserves the behaviour of posix_get_coarse_res().
@@ -395,7 +438,7 @@ int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
}
static __maybe_unused
-int __cvdso_clock_getres_data(const struct vdso_data *vd, clockid_t clock,
+int __cvdso_clock_getres_data(const struct vdso_time_data *vd, clockid_t clock,
struct __kernel_timespec *res)
{
int ret = __cvdso_clock_getres_common(vd, clock, res);
@@ -408,12 +451,12 @@ int __cvdso_clock_getres_data(const struct vdso_data *vd, clockid_t clock,
static __maybe_unused
int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
{
- return __cvdso_clock_getres_data(__arch_get_vdso_data(), clock, res);
+ return __cvdso_clock_getres_data(__arch_get_vdso_u_time_data(), clock, res);
}
#ifdef BUILD_VDSO32
static __maybe_unused int
-__cvdso_clock_getres_time32_data(const struct vdso_data *vd, clockid_t clock,
+__cvdso_clock_getres_time32_data(const struct vdso_time_data *vd, clockid_t clock,
struct old_timespec32 *res)
{
struct __kernel_timespec ts;
@@ -434,7 +477,7 @@ __cvdso_clock_getres_time32_data(const struct vdso_data *vd, clockid_t clock,
static __maybe_unused int
__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
{
- return __cvdso_clock_getres_time32_data(__arch_get_vdso_data(),
+ return __cvdso_clock_getres_time32_data(__arch_get_vdso_u_time_data(),
clock, res);
}
#endif /* BUILD_VDSO32 */
generated by cgit (git 2.34.1) at 2025-07-30 18:51:54 +0000