From: Marc Zyngier maz@kernel.org
commit c1fbec4ac0d701f350a581941d35643d5a9cd184 upstream.
As we are about to disable the vdso for compat tasks in some circumstances, let's allow a workaround descriptor to express exactly that.
Signed-off-by: Marc Zyngier maz@kernel.org Acked-by: Mark Rutland mark.rutland@arm.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200706163802.1836732-3-maz@kernel.org Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/include/asm/arch_timer.h | 1 + drivers/clocksource/arm_arch_timer.c | 3 +++ 2 files changed, 4 insertions(+)
--- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -58,6 +58,7 @@ struct arch_timer_erratum_workaround { u64 (*read_cntvct_el0)(void); int (*set_next_event_phys)(unsigned long, struct clock_event_device *); int (*set_next_event_virt)(unsigned long, struct clock_event_device *); + bool disable_compat_vdso; };
DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *, --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -566,6 +566,9 @@ void arch_timer_enable_workaround(const if (wa->read_cntvct_el0) { clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE; vdso_default = VDSO_CLOCKMODE_NONE; + } else if (wa->disable_compat_vdso && vdso_default != VDSO_CLOCKMODE_NONE) { + vdso_default = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT; + clocksource_counter.vdso_clock_mode = vdso_default; } }