leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

irqchip/gic-v4.1: Ensure accessing the correct RD when writing INVALLR

Browse Source 
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 f3a059219b ("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: f3a059219b ("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
This commit is contained in:
Zenghui Yu 2020-07-20 17:23:28 +08:00 committed by Marc Zyngier
parent 9808357ff2
commit 3af9571cd5
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/irqchip/irq-gic-v3-its.c
View File

@ -4079,18 +4079,22 @@ static void its_vpe_4_1_deschedule(struct its_vpe *vpe,
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)