From: Marc Zyngier <maz@kernel.org>
To: Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
kernel-team@android.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/3] arm64: timers: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040
Date: Wed, 1 Jul 2020 17:18:24 +0100 [thread overview]
Message-ID: <20200701161824.1346732-4-maz@kernel.org> (raw)
In-Reply-To: <20200701161824.1346732-1-maz@kernel.org>
ARM64_WORKAROUND_1418040 requires that AArch32 EL0 accesses to
the virtual counter register are trapped and emulated by the kernel.
This makes the vdso pretty pointless, and in some cases livelock
prone.
Provide a workaround entry that limits the vdso to 64bit tasks.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/clocksource/arm_arch_timer.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index f828835c568f..9c61252e7d99 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -480,6 +480,14 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = {
.set_next_event_virt = erratum_set_next_event_tval_virt,
},
#endif
+#ifdef CONFIG_ARM64_ERRATUM_1418040
+ {
+ .match_type = ate_match_local_cap_id,
+ .id = (void *)ARM64_WORKAROUND_1418040,
+ .desc = "ARM erratum 1418040",
+ .vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT,
+ },
+#endif
};
typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,
--
2.27.0
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prev parent reply other threads:[~2020-07-01 16:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-01 16:18 [PATCH 0/3] arm64: Allow the compat vdso to be disabled at runtime Marc Zyngier
2020-07-01 16:18 ` [PATCH 1/3] arm64: Introduce a way to disable the 32bit vdso Marc Zyngier
2020-07-02 10:18 ` Mark Rutland
2020-07-01 16:18 ` [PATCH 2/3] arm64: arch_timer: Allow an workaround descriptor to provide vdso_clock_mode Marc Zyngier
2020-07-02 10:28 ` Mark Rutland
2020-07-02 13:52 ` Marc Zyngier
2020-07-01 16:18 ` Marc Zyngier [this message]
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