From: Zenghui Yu yuzenghui@huawei.com
commit 3af9571cd585efafc2facbd8dbd407317ff898cf upstream.
The GICv4.1 spec tells us that it's CONSTRAINED UNPREDICTABLE to issue a register-based invalidation operation for a vPEID not mapped to that RD, or another RD within the same CommonLPIAff group.
To follow this rule, commit f3a059219bc7 ("irqchip/gic-v4.1: Ensure mutual exclusion between vPE affinity change and RD access") tried to address the race between the RD accesses and the vPE affinity change, but somehow forgot to take GICR_INVALLR into account. Let's take the vpe_lock before evaluating vpe->col_idx to fix it.
Fixes: f3a059219bc7 ("irqchip/gic-v4.1: Ensure mutual exclusion between vPE affinity change and RD access") Signed-off-by: Zenghui Yu yuzenghui@huawei.com Signed-off-by: Marc Zyngier maz@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200720092328.708-1-yuzenghui@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/irqchip/irq-gic-v3-its.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3974,18 +3974,22 @@ static void its_vpe_4_1_deschedule(struc static void its_vpe_4_1_invall(struct its_vpe *vpe) { void __iomem *rdbase; + unsigned long flags; u64 val; + int cpu;
val = GICR_INVALLR_V; val |= FIELD_PREP(GICR_INVALLR_VPEID, vpe->vpe_id);
/* Target the redistributor this vPE is currently known on */ - raw_spin_lock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock); - rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base; + cpu = vpe_to_cpuid_lock(vpe, &flags); + raw_spin_lock(&gic_data_rdist_cpu(cpu)->rd_lock); + rdbase = per_cpu_ptr(gic_rdists->rdist, cpu)->rd_base; gic_write_lpir(val, rdbase + GICR_INVALLR);
wait_for_syncr(rdbase); - raw_spin_unlock(&gic_data_rdist_cpu(vpe->col_idx)->rd_lock); + raw_spin_unlock(&gic_data_rdist_cpu(cpu)->rd_lock); + vpe_to_cpuid_unlock(vpe, flags); }
static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)