diff options
| author | Marc Zyngier <maz@kernel.org> | 2024-08-18 19:16:25 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-08-20 16:57:13 +0200 |
| commit | f97fd458763a4801d04dbb4a79d9ca6282d293ec (patch) | |
| tree | 526fdd4253a7f14c81ce9a55829a675c9a2b2760 /drivers/irqchip/irq-gic-v3-its.c | |
| parent | irqchip/sifive-plic: Probe plic driver early for Allwinner D1 platform (diff) | |
| download | linux-f97fd458763a4801d04dbb4a79d9ca6282d293ec.tar.xz linux-f97fd458763a4801d04dbb4a79d9ca6282d293ec.zip | |
irqchip/gic-v4: Fix ordering between vmapp and vpe locks
The recently established lock ordering mandates that the per-VM
vmapp_lock is acquired before taking the per-VPE lock.
As it turns out, its_vpe_set_affinity() takes the VPE lock, and
then calls into its_send_vmovp(), which itself takes the vmapp
lock. Obviously, this is a lock order violation.
As its_send_vmovp() is only called from its_vpe_set_affinity(),
hoist the vmapp locking from the former into the latter, restoring
the expected order.
Fixes: f0eb154c39471 ("irqchip/gic-v4: Substitute vmovp_lock for a per-VM lock")
Reported-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240818171625.3030584-1-maz@kernel.org
Diffstat (limited to 'drivers/irqchip/irq-gic-v3-its.c')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 9b34596b3542..fdec478ba5e7 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -1330,12 +1330,6 @@ static void its_send_vmovp(struct its_vpe *vpe) } /* - * Protect against concurrent updates of the mapping state on - * individual VMs. - */ - guard(raw_spinlock_irqsave)(&vpe->its_vm->vmapp_lock); - - /* * Yet another marvel of the architecture. If using the * its_list "feature", we need to make sure that all ITSs * receive all VMOVP commands in the same order. The only way @@ -3824,7 +3818,14 @@ static int its_vpe_set_affinity(struct irq_data *d, * protect us, and that we must ensure nobody samples vpe->col_idx * during the update, hence the lock below which must also be * taken on any vLPI handling path that evaluates vpe->col_idx. + * + * Finally, we must protect ourselves against concurrent updates of + * the mapping state on this VM should the ITS list be in use (see + * the shortcut in its_send_vmovp() otherewise). */ + if (its_list_map) + raw_spin_lock(&vpe->its_vm->vmapp_lock); + from = vpe_to_cpuid_lock(vpe, &flags); table_mask = gic_data_rdist_cpu(from)->vpe_table_mask; @@ -3854,6 +3855,9 @@ out: irq_data_update_effective_affinity(d, cpumask_of(cpu)); vpe_to_cpuid_unlock(vpe, flags); + if (its_list_map) + raw_spin_unlock(&vpe->its_vm->vmapp_lock); + return IRQ_SET_MASK_OK_DONE; } |