Commit Graph

5 Commits

Author SHA1 Message Date
Thomas Gleixner c7a18100bd lib/vdso: Avoid highres update if clocksource is not VDSO capable
If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de
2020-02-17 20:12:17 +01:00
Thomas Gleixner f86fd32db7 lib/vdso: Cleanup clock mode storage leftovers
Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de
2020-02-17 20:12:17 +01:00
Thomas Gleixner 9a6b55ac4a lib/vdso: Make __arch_update_vdso_data() logic understandable
The function name suggests that this is a boolean checking whether the
architecture asks for an update of the VDSO data, but it works the other
way round. To spare further confusion invert the logic.

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200114185946.656652824@linutronix.de
2020-01-17 15:53:50 +01:00
Huacai Chen 52338415cf timekeeping/vsyscall: Update VDSO data unconditionally
The update of the VDSO data is depending on __arch_use_vsyscall() returning
True. This is a leftover from the attempt to map the features of various
architectures 1:1 into generic code.

The usage of __arch_use_vsyscall() in the actual vsyscall implementations
got dropped and replaced by the requirement for the architecture code to
return U64_MAX if the global clocksource is not usable in the VDSO.

But the __arch_use_vsyscall() check in the update code stayed which causes
the VDSO data to be stale or invalid when an architecture actually
implements that function and returns False when the current clocksource is
not usable in the VDSO.

As a consequence the VDSO implementations of clock_getres(), time(),
clock_gettime(CLOCK_.*_COARSE) operate on invalid data and return bogus
information.

Remove the __arch_use_vsyscall() check from the VDSO update function and
update the VDSO data unconditionally.

[ tglx: Massaged changelog and removed the now useless implementations in
  	asm-generic/ARM64/MIPS ]

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1571887709-11447-1-git-send-email-chenhc@lemote.com
2019-11-04 23:02:53 +01:00
Vincenzo Frascino 44f57d788e timekeeping: Provide a generic update_vsyscall() implementation
The new generic VDSO library allows to unify the update_vsyscall[_tz]()
implementations.

Provide a generic implementation based on the x86 code and the bindings
which need to be implemented in architecture specific code.

[ tglx: Moved it into kernel/time where it belongs. Removed the pointless
  	line breaks in the stub functions. Massaged changelog ]

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shijith Thotton <sthotton@marvell.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Huw Davies <huw@codeweavers.com>
Link: https://lkml.kernel.org/r/20190621095252.32307-4-vincenzo.frascino@arm.com
2019-06-22 21:21:06 +02:00