Commit c1fbec4a authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: arch_timer: Allow an workaround descriptor to disable compat vdso 



As we are about to disable the vdso for compat tasks in some circumstances,
let's allow a workaround descriptor to express exactly that.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200706163802.1836732-3-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 97884ca8

arch/arm64/include/asm/arch_timer.h

+1 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ struct arch_timer_erratum_workaround { 
	u64 (*read_cntvct_el0)(void);

	int (*set_next_event_phys)(unsigned long, struct clock_event_device *);

	int (*set_next_event_virt)(unsigned long, struct clock_event_device *);

	bool disable_compat_vdso;

};



DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *,

drivers/clocksource/arm_arch_timer.c

+3 −0
Original line number Diff line number Diff line
@@ -566,6 +566,9 @@ void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa 
	if (wa->read_cntvct_el0) {

		clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE;

		vdso_default = VDSO_CLOCKMODE_NONE;

	} else if (wa->disable_compat_vdso && vdso_default != VDSO_CLOCKMODE_NONE) {

		vdso_default = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT;

		clocksource_counter.vdso_clock_mode = vdso_default;

	}

}

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