From: Marc Zyngier Date: Mon, 6 Jul 2020 16:38:01 +0000 (+0100) Subject: arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040 X-Git-Tag: Ubuntu-5.10.0-12.13~2427^2~6 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=4b661d6133c5d3a7c9aca0b4ee5a78c7766eff3f;p=mirror_ubuntu-hirsute-kernel.git 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 --- 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 *,