linux.git/kernel/time/time.c, branch v7.3-rc2

Merge tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-08-18T23:56:25+00:00

Pull VDSO updates from Thomas Gleixner:

 - Consolidate the VDSO datastore further and provide support for
   mlock_all() and prefaulting.

 - Provide 32-bit legacy time related functionality only if
   CONFIG_COMPAT_32BIT_TIME is enabled. The config switch exists,
   but architecture code still exposes the legacy functionality even
   disabled.

   Clean this up by adding the missing guards and validating at build
   time that the VDSO is legacy free if disabled.

 - Consolidate the VDSO related config options in core and drivers,
   which removes some non-sensical dependencies and quite an amount of
   #ifdeffery.

 - Clean up the PAGE_SIZE definition maze

* tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  random: vDSO: Drop custom PAGE_SIZE definitions
  LoongArch: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/timer-riscv: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/arm_arch_timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/mips-gic-timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  MIPS: csrc-r4k: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  vDSO: Make clockmode constants available without CONFIG_GENERIC_GETTIMEOFDAY
  kbuild: Support generated asm-headers in subdirectories
  vdso: Rename HAVE_GENERIC_VDSO to VDSO_DATASTORE
  vdso: Drop HAVE_GENERIC_VDSO from architecture kconfig files
  vdso: Automatically select HAVE_GENERIC_VDSO if necessary
  MIPS: vdso: Stop using CONFIG_HAVE_GENERIC_VDSO
  vdso: Remove the dependency on HAVE_GENERIC_VDSO from ARCH_HAS_VDSO_ARCH_DATA
  futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCK
  vdso/gettimeofday: Verify COMPAT_32BIT_TIME interactions
  sparc: vdso: Respect COMPAT_32BIT_TIME
  MIPS: VDSO: Respect COMPAT_32BIT_TIME
  powerpc/vdso: Respect COMPAT_32BIT_TIME
  ARM: VDSO: Respect COMPAT_32BIT_TIME
  arm64: vdso32: Respect COMPAT_32BIT_TIME
  ...

time: Respect COMPAT_32BIT_TIME for old time type functions

2026-07-07T21:52:53+00:00

The "old" time types use 32-bit seconds which are not y2038-safe.
Respect COMPAT_32BIT_TIME for functions using those types.
time(), stime() and gettimeofday() are disabled completely.

settimeofday() is kept as it is required to do the initial timewarping
after boot. However the 'tv' argument will be rejected.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Arnd Bergmann 
Link: https://lore.kernel.org/lkml/e9487ebe-3730-438a-9c23-e45f75986ecc@app.fastmail.com/
Link: https://patch.msgid.link/20260702-vdso-compat_32bit_time-v3-1-db9f36d8d432@linutronix.de

timekeeping: Move the vDSO update declarations into a private header

2026-07-07T21:48:08+00:00

All architectures are now fully using the generic vDSO infrastructure.
They don't need these declarations anymore to implement the functions
in architecture-specific code.

Move them to the private header.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Thomas Gleixner 
Link: https://patch.msgid.link/20260707-timekeeping-header-cleanup-v1-2-e85ad96409a9@linutronix.de

time: Fix off-by-one in compat settimeofday() usec validation

2026-06-22T11:20:20+00:00

The compat version of settimeofday() uses '>' instead of '>=' when
validating tv_usec against USEC_PER_SEC, allowing the value 1000000 to pass
the check. After the subsequent conversion to nanoseconds (tv_nsec *=
NSEC_PER_USEC), this results in tv_nsec == NSEC_PER_SEC, which violates the
timespec invariant that tv_nsec must be strictly less than NSEC_PER_SEC.

The native settimeofday() was already fixed in commit ce4abda5e126 ("time:
Fix off-by-one in settimeofday() usec validation"), but the compat
counterpart was missed.

Fix it by using '>=' to reject tv_usec values outside the valid range [0,
USEC_PER_SEC - 1].

Fixes: 5e0fb1b57bea ("y2038: time: avoid timespec usage in settimeofday()")
Signed-off-by: Wang Yan 
Signed-off-by: Thomas Gleixner 
Acked-by: Arnd Bergmann 
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260622103348.120255-1-wangyan01@kylinos.cn

time: Fix off-by-one in settimeofday() usec validation

2026-06-02T19:07:55+00:00

The validation check uses '>' instead of '>=' when comparing tv_usec
against USEC_PER_SEC, allowing the value 1000000 through. After
conversion to nanoseconds (*= 1000), this produces tv_nsec ==
NSEC_PER_SEC, violating the timespec invariant that tv_nsec must be
less than NSEC_PER_SEC.

Use '>=' to reject tv_usec values that are not in the valid range of
0 to 999999.

Fixes: 5e0fb1b57bea ("y2038: time: avoid timespec usage in settimeofday()")
Signed-off-by: Naveen Kumar Chaudhary 
Signed-off-by: Thomas Gleixner 
Acked-by: John Stultz 
Link: https://patch.msgid.link/4rikk44zew3s6577dugmx4jyblz7o5c57niuap6ct3td5yfm6w@gh7pcumg7qor

time/jiffies: Mark jiffies_64_to_clock_t() notrace

2026-03-11T09:33:12+00:00

The trace_clock_jiffies() function that handles the "uptime" clock for
tracing calls jiffies_64_to_clock_t(). This causes the function tracer to
constantly recurse when the tracing clock is set to "uptime". Mark it
notrace to prevent unnecessary recursion when using the "uptime" clock.

Fixes: 58d4e21e50ff3 ("tracing: Fix wraparound problems in "uptime" trace clock")
Signed-off-by: Steven Rostedt (Google) 
Signed-off-by: Thomas Gleixner 
Link: https://patch.msgid.link/20260306212403.72270bb2@robin

time/jiffies: Inline jiffies_to_msecs() and jiffies_to_usecs()

2026-02-11T07:55:52+00:00

For common cases (HZ=100, 250 or 1000), these helpers are at most one
multiply, so there is no point calling a tiny function.

Keep them out of line for HZ=300 and others.

This saves cycles in TCP fast path, among other things.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/8 grow/shrink: 25/89 up/down: 530/-3474 (-2944)
...
nla_put_msecs                                193       -    -193
message_stats_print                         2131     920   -1211
Total: Before=25365208, After=25362264, chg -0.01%

Signed-off-by: Eric Dumazet 
Signed-off-by: Thomas Gleixner 
Link: https://patch.msgid.link/20260210170226.57209-1-edumazet@google.com

time: export timespec64_add_safe() symbol

2025-09-03T23:51:08+00:00

Export the timespec64_add_safe() symbol so that this function can be used
in modules where computation of time related is done.

Signed-off-by: Gatien Chevallier 
Acked-by: Thomas Gleixner 
Link: https://patch.msgid.link/20250901-relative_flex_pps-v4-1-b874971dfe85@foss.st.com
Signed-off-by: Jakub Kicinski

time: Fix references to _msecs_to_jiffies() handling of values

2024-10-25T17:50:10+00:00

The details about the handling of the "normal" values were moved
to the _msecs_to_jiffies() helpers in commit ca42aaf0c861 ("time:
Refactor msecs_to_jiffies"). However, the same commit still mentioned
__msecs_to_jiffies() in the added documentation.

Thus point to _msecs_to_jiffies() instead.

Fixes: ca42aaf0c861 ("time: Refactor msecs_to_jiffies")
Signed-off-by: Miguel Ojeda 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241025110141.157205-2-ojeda@kernel.org

time: Partially revert cleanup on msecs_to_jiffies() documentation

2024-10-25T17:49:16+00:00

The documentation's intention is to compare msecs_to_jiffies() (first
sentence) with __msecs_to_jiffies() (second sentence), which is what the
original documentation did. One of the cleanups in commit f3cb80804b82
("time: Fix various kernel-doc problems") may have thought the paragraph
was talking about the latter since that is what it is being documented.

Thus revert that part of the change.

Fixes: f3cb80804b82 ("time: Fix various kernel-doc problems")
Signed-off-by: Miguel Ojeda 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241025110141.157205-1-ojeda@kernel.org