| Message ID | 20200706163802.1836732-4-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Allow the compat vdso to be disabled at runtime | expand |
On Mon, Jul 06, 2020 at 05:38:01PM +0100, Marc Zyngier wrote: > 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. > > Cc: stable@vger.kernel.org > Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > 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 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 *, > -- > 2.27.0 >
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 *,
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. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org> --- drivers/clocksource/arm_arch_timer.c | 8 ++++++++ 1 file changed, 8 insertions(+)