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vdso: Remove remnants of architecture-specific time storage

Browse source 
All users of the time releated parts of the vDSO are now using the generic
storage implementation. Remove the therefore unnecessary compatibility
accessor functions and symbols.

Co-developed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-18-13a4669dfc8c@linutronix.de
This commit is contained in:
Thomas Weißschuh 2025-02-04 13:05:50 +01:00 • committed by Thomas Gleixner
parent 998a8a2608
commit ac1a42f4e4
8 changed files with 53 additions and 89 deletions
Download patch file Download diff file Expand all files Collapse all files

20
include/asm-generic/vdso/vsyscall.h
View file

@ -20,31 +20,19 @@ static __always_inline const struct vdso_rng_data *__arch_get_vdso_u_rng_data(vo
}
#endif
#else /* !CONFIG_GENERIC_VDSO_DATA_STORE */
#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 */
#define vdso_k_time_data __arch_get_k_vdso_data()
#define __arch_get_vdso_u_time_data __arch_get_vdso_data
#endif /* CONFIG_GENERIC_VDSO_DATA_STORE */
#ifndef __arch_update_vsyscall
static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata)
static __always_inline void __arch_update_vsyscall(struct vdso_time_data *vdata)
{
}
#endif /* __arch_update_vsyscall */
#ifndef __arch_sync_vdso_data
static __always_inline void __arch_sync_vdso_data(struct vdso_data *vdata)
#ifndef __arch_sync_vdso_time_data
static __always_inline void __arch_sync_vdso_time_data(struct vdso_time_data *vdata)
{
}
#endif /* __arch_sync_vdso_data */
#endif /* __arch_sync_vdso_time_data */
#endif /* !__ASSEMBLY__ */

3
include/linux/time_namespace.h
View file

@ -8,7 +8,6 @@
#include <linux/ns_common.h>
#include <linux/err.h>
#include <linux/time64.h>
#include <vdso/datapage.h>
struct user_namespace;
extern struct user_namespace init_user_ns;
@ -166,6 +165,4 @@ static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim)
}
#endif
struct vdso_data *arch_get_vdso_data(void *vvar_page);
#endif /* _LINUX_TIMENS_H */

19
include/vdso/datapage.h
View file

@ -128,8 +128,6 @@ struct vdso_time_data {
struct arch_vdso_time_data arch_data;
};
#define vdso_data vdso_time_data
/**
* struct vdso_rng_data - vdso RNG state information
* @generation: counter representing the number of RNG reseeds
@ -149,10 +147,7 @@ struct vdso_rng_data {
* With the hidden visibility, the compiler simply generates a PC-relative
* relocation, and this is what we need.
*/
#ifndef CONFIG_GENERIC_VDSO_DATA_STORE
extern struct vdso_time_data _vdso_data[CS_BASES] __attribute__((visibility("hidden")));
extern struct vdso_time_data _timens_data[CS_BASES] __attribute__((visibility("hidden")));
#else
#ifdef CONFIG_GENERIC_VDSO_DATA_STORE
extern struct vdso_time_data vdso_u_time_data[CS_BASES] __attribute__((visibility("hidden")));
extern struct vdso_rng_data vdso_u_rng_data __attribute__((visibility("hidden")));
extern struct vdso_arch_data vdso_u_arch_data __attribute__((visibility("hidden")));
@ -160,17 +155,6 @@ extern struct vdso_arch_data vdso_u_arch_data __attribute__((visibility("hidden"
extern struct vdso_time_data *vdso_k_time_data;
extern struct vdso_rng_data *vdso_k_rng_data;
extern struct vdso_arch_data *vdso_k_arch_data;
#endif
/**
* union vdso_data_store - Generic vDSO data page
*/
union vdso_data_store {
struct vdso_time_data data[CS_BASES];
u8 page[1U << CONFIG_PAGE_SHIFT];
};
#ifdef CONFIG_GENERIC_VDSO_DATA_STORE
#define VDSO_ARCH_DATA_SIZE ALIGN(sizeof(struct vdso_arch_data), PAGE_SIZE)
#define VDSO_ARCH_DATA_PAGES (VDSO_ARCH_DATA_SIZE >> PAGE_SHIFT)
@ -189,7 +173,6 @@ enum vdso_pages {
/*
* The generic vDSO implementation requires that gettimeofday.h
* provides:
* - __arch_get_vdso_data(): to get the vdso datapage.
* - __arch_get_hw_counter(): to get the hw counter based on the
* clock_mode.
* - gettimeofday_fallback(): fallback for gettimeofday.

8
include/vdso/helpers.h
View file

@ -7,7 +7,7 @@
#include <asm/barrier.h>
#include <vdso/datapage.h>
static __always_inline u32 vdso_read_begin(const struct vdso_data *vd)
static __always_inline u32 vdso_read_begin(const struct vdso_time_data *vd)
{
u32 seq;
@ -18,7 +18,7 @@ static __always_inline u32 vdso_read_begin(const struct vdso_data *vd)
return seq;
}
static __always_inline u32 vdso_read_retry(const struct vdso_data *vd,
static __always_inline u32 vdso_read_retry(const struct vdso_time_data *vd,
u32 start)
{
u32 seq;
@ -28,7 +28,7 @@ static __always_inline u32 vdso_read_retry(const struct vdso_data *vd,
return seq != start;
}
static __always_inline void vdso_write_begin(struct vdso_data *vd)
static __always_inline void vdso_write_begin(struct vdso_time_data *vd)
{
/*
* WRITE_ONCE() is required otherwise the compiler can validly tear
@ -40,7 +40,7 @@ static __always_inline void vdso_write_begin(struct vdso_data *vd)
smp_wmb();
}
static __always_inline void vdso_write_end(struct vdso_data *vd)
static __always_inline void vdso_write_end(struct vdso_time_data *vd)
{
smp_wmb();
/*

12
kernel/time/namespace.c
View file

@ -165,18 +165,18 @@ static struct timens_offset offset_from_ts(struct timespec64 off)
* HVCLOCK
* VVAR
*
* The check for vdso_data->clock_mode is in the unlikely path of
* The check for vdso_time_data->clock_mode is in the unlikely path of
* the seq begin magic. So for the non-timens case most of the time
* 'seq' is even, so the branch is not taken.
*
* If 'seq' is odd, i.e. a concurrent update is in progress, the extra check
* for vdso_data->clock_mode is a non-issue. The task is spin waiting for the
* for vdso_time_data->clock_mode is a non-issue. The task is spin waiting for the
* update to finish and for 'seq' to become even anyway.
*
* Timens page has vdso_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which
* Timens page has vdso_time_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which
* enforces the time namespace handling path.
*/
static void timens_setup_vdso_data(struct vdso_data *vdata,
static void timens_setup_vdso_data(struct vdso_time_data *vdata,
struct time_namespace *ns)
{
struct timens_offset *offset = vdata->offset;
@ -219,7 +219,7 @@ static DEFINE_MUTEX(offset_lock);
static void timens_set_vvar_page(struct task_struct *task,
struct time_namespace *ns)
{
struct vdso_data *vdata;
struct vdso_time_data *vdata;
unsigned int i;
if (ns == &init_time_ns)
@ -235,7 +235,7 @@ static void timens_set_vvar_page(struct task_struct *task,
goto out;
ns->frozen_offsets = true;
vdata = arch_get_vdso_data(page_address(ns->vvar_page));
vdata = page_address(ns->vvar_page);
for (i = 0; i < CS_BASES; i++)
timens_setup_vdso_data(&vdata[i], ns);

19
kernel/time/vsyscall.c
View file

@ -15,8 +15,7 @@
#include "timekeeping_internal.h"
static inline void update_vdso_data(struct vdso_data *vdata,
struct timekeeper *tk)
static inline void update_vdso_time_data(struct vdso_time_data *vdata, struct timekeeper *tk)
{
struct vdso_timestamp *vdso_ts;
u64 nsec, sec;
@ -77,7 +76,7 @@ static inline void update_vdso_data(struct vdso_data *vdata,
void update_vsyscall(struct timekeeper *tk)
{
struct vdso_data *vdata = vdso_k_time_data;
struct vdso_time_data *vdata = vdso_k_time_data;
struct vdso_timestamp *vdso_ts;
s32 clock_mode;
u64 nsec;
@ -117,23 +116,23 @@ void update_vsyscall(struct timekeeper *tk)
* update of the high resolution parts.
*/
if (clock_mode != VDSO_CLOCKMODE_NONE)
update_vdso_data(vdata, tk);
update_vdso_time_data(vdata, tk);
__arch_update_vsyscall(vdata);
vdso_write_end(vdata);
__arch_sync_vdso_data(vdata);
__arch_sync_vdso_time_data(vdata);
}
void update_vsyscall_tz(void)
{
struct vdso_data *vdata = vdso_k_time_data;
struct vdso_time_data *vdata = vdso_k_time_data;
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);
__arch_sync_vdso_time_data(vdata);
}
/**
@ -150,7 +149,7 @@ void update_vsyscall_tz(void)
*/
unsigned long vdso_update_begin(void)
{
struct vdso_data *vdata = vdso_k_time_data;
struct vdso_time_data *vdata = vdso_k_time_data;
unsigned long flags = timekeeper_lock_irqsave();
vdso_write_begin(vdata);
@ -167,9 +166,9 @@ unsigned long vdso_update_begin(void)
*/
void vdso_update_end(unsigned long flags)
{
struct vdso_data *vdata = vdso_k_time_data;
struct vdso_time_data *vdata = vdso_k_time_data;
vdso_write_end(vdata);
__arch_sync_vdso_data(vdata);
__arch_sync_vdso_time_data(vdata);
timekeeper_unlock_irqrestore(flags);
}

10
lib/vdso/datastore.c
View file

@ -12,7 +12,10 @@
* The vDSO data page.
*/
#ifdef CONFIG_HAVE_GENERIC_VDSO
static union vdso_data_store vdso_time_data_store __page_aligned_data;
static union {
struct vdso_time_data data[CS_BASES];
u8 page[PAGE_SIZE];
} vdso_time_data_store __page_aligned_data;
struct vdso_time_data *vdso_k_time_data = vdso_time_data_store.data;
static_assert(sizeof(vdso_time_data_store) == PAGE_SIZE);
#endif /* CONFIG_HAVE_GENERIC_VDSO */
@ -123,9 +126,4 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
return 0;
}
struct vdso_time_data *arch_get_vdso_data(void *vvar_page)
{
return (struct vdso_time_data *)vvar_page;
}
#endif

51
lib/vdso/gettimeofday.c
View file

@ -17,12 +17,12 @@
#endif
#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT
static __always_inline bool vdso_delta_ok(const struct vdso_data *vd, u64 delta)
static __always_inline bool vdso_delta_ok(const struct vdso_time_data *vd, u64 delta)
{
return delta < vd->max_cycles;
}
#else
static __always_inline bool vdso_delta_ok(const struct vdso_data *vd, u64 delta)
static __always_inline bool vdso_delta_ok(const struct vdso_time_data *vd, u64 delta)
{
return true;
}
@ -39,7 +39,7 @@ static __always_inline u64 vdso_shift_ns(u64 ns, u32 shift)
* Default implementation which works for all sane clocksources. That
* obviously excludes x86/TSC.
*/
static __always_inline u64 vdso_calc_ns(const struct vdso_data *vd, u64 cycles, u64 base)
static __always_inline u64 vdso_calc_ns(const struct vdso_time_data *vd, u64 cycles, u64 base)
{
u64 delta = (cycles - vd->cycle_last) & VDSO_DELTA_MASK(vd);
@ -58,7 +58,7 @@ 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_time_data *vd)
{
return vd->clock_mode != VDSO_CLOCKMODE_NONE;
}
@ -79,21 +79,20 @@ const struct vdso_time_data *__arch_get_vdso_u_timens_data(const struct vdso_tim
{
return (void *)vd + PAGE_SIZE;
}
#define __arch_get_timens_vdso_data(vd) __arch_get_vdso_u_timens_data(vd)
#endif /* CONFIG_GENERIC_VDSO_DATA_STORE */
static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
static __always_inline int do_hres_timens(const struct vdso_time_data *vdns, clockid_t clk,
struct __kernel_timespec *ts)
{
const struct timens_offset *offs = &vdns->offset[clk];
const struct vdso_timestamp *vdso_ts;
const struct vdso_data *vd;
const struct vdso_time_data *vd;
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);
vd = __arch_get_vdso_u_timens_data(vd);
if (clk != CLOCK_MONOTONIC_RAW)
vd = &vd[CS_HRES_COARSE];
else
@ -128,19 +127,19 @@ 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,
static __always_inline int do_hres_timens(const struct vdso_time_data *vdns, clockid_t clk,
struct __kernel_timespec *ts)
{
return -EINVAL;
}
#endif
static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
static __always_inline int do_hres(const struct vdso_time_data *vd, clockid_t clk,
struct __kernel_timespec *ts)
{
const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
@ -192,10 +191,10 @@ 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,
static __always_inline int do_coarse_timens(const struct vdso_time_data *vdns, clockid_t clk,
struct __kernel_timespec *ts)
{
const struct vdso_data *vd = __arch_get_timens_vdso_data(vdns);
const struct vdso_time_data *vd = __arch_get_vdso_u_timens_data(vdns);
const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
const struct timens_offset *offs = &vdns->offset[clk];
u64 nsec;
@ -221,14 +220,14 @@ 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,
static __always_inline int do_coarse_timens(const struct vdso_time_data *vdns, clockid_t clk,
struct __kernel_timespec *ts)
{
return -1;
}
#endif
static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk,
static __always_inline int do_coarse(const struct vdso_time_data *vd, clockid_t clk,
struct __kernel_timespec *ts)
{
const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
@ -255,7 +254,7 @@ static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk,
}
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)
{
u32 msk;
@ -282,7 +281,7 @@ __cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock,
}
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);
@ -300,7 +299,7 @@ __cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *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;
@ -326,7 +325,7 @@ __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *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)
{
@ -343,7 +342,7 @@ __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);
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;
@ -360,13 +359,13 @@ __cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *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)
{
__kernel_old_time_t t;
if (IS_ENABLED(CONFIG_TIME_NS) &&
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
vd = __arch_get_timens_vdso_data(vd);
vd = __arch_get_vdso_u_timens_data(vd);
t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
@ -384,7 +383,7 @@ static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *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)
{
u32 msk;
@ -396,7 +395,7 @@ int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
if (IS_ENABLED(CONFIG_TIME_NS) &&
vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
vd = __arch_get_timens_vdso_data(vd);
vd = __arch_get_vdso_u_timens_data(vd);
/*
* Convert the clockid to a bitmask and use it to check which
@ -425,7 +424,7 @@ 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);
@ -443,7 +442,7 @@ int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *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;