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: Marc Zyngier maz@kernel.org --- arch/arm64/include/asm/arch_timer.h | 1 + drivers/clocksource/arm_arch_timer.c | 3 +++ 2 files changed, 4 insertions(+)
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 7ae54d7d333a..9f0ec21d6327 100644 --- 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 *, diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 909fe093249e..fd2a75f0af77 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -562,6 +562,9 @@ void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa if (wa->read_cntvct_el0) { clocksource_counter.archdata.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.archdata.clock_mode = vdso_default; } }