kernel/linux.git/lib/vdso/gettimeofday.c, branch linux-7.0.y

vdso/gettimeofday: Force inlining of __cvdso_clock_getres_common()

2026-01-26T21:27:07+00:00

With CONFIG_CC_OPTIMIZE_FOR_SIZE=y, GCC may decide not to inline __cvdso_clock_getres_common(). This introduces spurious internal function calls in the vDSO fastpath. Furthermore, with automatic stack variable initialization (CONFIG_INIT_STACK_ALL_ZERO or CONFIG_INIT_STACK_ALL_PATTERN) GCC can emit a call to memset() which is not valid in the vDSO. Mark __cvdso_clock_getres_common() as __always_inline to avoid both issues. Paradoxically the inlining even reduces the size of the code: $ ./scripts/bloat-o-meter arch/powerpc/kernel/vdso/vgettimeofday-32.o.before arch/powerpc/kernel/vdso/vgettimeofday-32.o.after add/remove: 0/1 grow/shrink: 1/1 up/down: 52/-148 (-96) Function old new delta __c_kernel_clock_getres_time64 92 144 +52 __c_kernel_clock_getres 136 132 -4 __cvdso_clock_getres_common 144 - -144 Total: Before=2788, After=2692, chg -3.44% With CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE=y the functions are always inlined and therefore the behaviour stays the same. See also the equivalent change for clock_gettime() in commit b91c8c42ffdd ("lib/vdso: Force inlining of __cvdso_clock_gettime_common()"). Fixes: 21bbfd74044f ("x86/vdso: Provide clock_getres_time64() for x86-32") Fixes: 1149dcdfc9ef ("ARM: VDSO: Provide clock_getres_time64()") Fixes: f10c2e72b5de ("arm64: vdso32: Provide clock_getres_time64()") Fixes: bec06cd6a140 ("MIPS: vdso: Provide getres_time64() for 32-bit ABIs") Fixes: 759a1f97373f ("powerpc/vdso: Provide clock_getres_time64()") Reported-by: Sverdlin, Alexander Suggested-by: Christophe Leroy (CS GROUP) Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/lkml/230c749f-ebd6-4829-93ee-601d88000a45@kernel.org/ Link: https://patch.msgid.link/20260123-vdso-clock_getres-inline-v1-1-4d6203b90cd3@linutronix.de Closes: https://lore.kernel.org/lkml/f45316f65a46da638b3c6aa69effd8980e6677b9.camel@siemens.com/

vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE

2025-09-04T09:23:50+00:00

All users of the generic vDSO library also use the generic vDSO datastore. Remove the now unnecessary Kconfig symbol. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Acked-by: Catalin Marinas Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-9-d9b65750e49f@linutronix.de

vdso/gettimeofday: Remove !CONFIG_TIME_NS stubs

2025-09-04T09:23:49+00:00

All calls of these functions are already gated behind CONFIG_TIME_NS. The compiler will already optimize them away if time namespaces are disabled. Drop the unnecessary stubs. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-4-d9b65750e49f@linutronix.de

vdso/gettimeofday: Add support for auxiliary clocks

2025-07-18T12:09:39+00:00

Expose the auxiliary clocks through the vDSO. Architectures not using the generic vDSO time framework, namely SPARC64, are not supported. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250701-vdso-auxclock-v1-12-df7d9f87b9b8@linutronix.de

vdso/gettimeofday: Introduce vdso_get_timestamp()

2025-07-18T11:45:32+00:00

This code is duplicated and with the introduction of auxiliary clocks will be duplicated even more. Introduce a helper. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250701-vdso-auxclock-v1-9-df7d9f87b9b8@linutronix.de

vdso/gettimeofday: Introduce vdso_set_timespec()

2025-07-18T11:45:32+00:00

vdso/gettimeofday: Introduce vdso_clockid_valid()

2025-07-18T11:45:32+00:00

Move the clock ID validation check into a common helper. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250701-vdso-auxclock-v1-7-df7d9f87b9b8@linutronix.de

vdso/gettimeofday: Return bool from clock_gettime() helpers

2025-07-18T11:45:32+00:00

The internal helpers are effectively using boolean results, while pretending to use error numbers. Switch the return type to bool for more clarity. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250701-vdso-auxclock-v1-6-df7d9f87b9b8@linutronix.de

vdso/gettimeofday: Return bool from clock_getres() helpers

2025-07-09T09:52:34+00:00

vdso: Rework struct vdso_time_data and introduce struct vdso_clock

2025-03-08T13:37:41+00:00

To support multiple PTP clocks, the VDSO data structure needs to be reworked. All clock specific data will end up in struct vdso_clock and in struct vdso_time_data there will be an array of VDSO clocks. Now that all preparatory changes are in place: Split the clock related struct members into a separate struct vdso_clock. Make sure all users are aware, that vdso_time_data is no longer initialized as an array and vdso_clock is now the array inside vdso_data. Remove the vdso_clock define, which mapped it to vdso_time_data for the transition. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Nam Cao Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-19-c1b5c69a166f@linutronix.de