From c1fbec4ac0d701f350a581941d35643d5a9cd184 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 6 Jul 2020 17:38:00 +0100
Subject: [PATCH] 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: Marc Zyngier <maz@kernel.org>
Acked-by: Mark 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: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/arch_timer.h | 1 +
drivers/clocksource/arm_arch_timer.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h
index 7ae54d7d333a5..9f0ec21d6327f 100644
--- a/arch/arm64/include/asm/arch_timer.h
+++ b/arch/arm64/include/asm/arch_timer.h
@@ -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 *,
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index ecf7b7db2d050..a8e4fb429f52b 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -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;
}
}
--
2.30.2