From 4b661d6133c5d3a7c9aca0b4ee5a78c7766eff3f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 6 Jul 2020 17:38:01 +0100 Subject: arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040 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 Acked-by: Mark Rutland Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200706163802.1836732-4-maz@kernel.org Signed-off-by: Will Deacon --- drivers/clocksource/arm_arch_timer.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/clocksource') diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index a8e4fb429f52..6c3e84180146 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", + .disable_compat_vdso = true, + }, +#endif }; typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *, -- cgit v1.2.3