From 6f5211c079b88056f655749594f2ab29471adc5d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 6 Jul 2020 17:38:01 +0100 Subject: [PATCH] UPSTREAM: arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040 commit 4b661d6133c5d3a7c9aca0b4ee5a78c7766eff3f upstream. 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 Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman Signed-off-by: Marc Zyngier Change-Id: Ic7358a5cc152dce9d72e5a08085748a1dfc2f903 (cherry picked from commit 4b661d6133c5d3a7c9aca0b4ee5a78c7766eff3f) Signed-off-by: Greg Kroah-Hartman --- 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 d997b90beebd..981e22fe6d81 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -476,6 +476,14 @@ 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 *,