From: Marc Zyngier maz@kernel.org
commit 33de0aa4bae982ed6f7c777f86b5af3e627ac937 upstream.
[ Fixed small conflicts due to the HK_FLAG_MANAGED_IRQ flag been renamed on upstream ]
When booting with maxcpus=<small number> (or even loading a driver while most CPUs are offline), it is pretty easy to observe managed affinities containing a mix of online and offline CPUs being passed to the irqchip driver.
This means that the irqchip cannot trust the affinity passed down from the core code, which is a bit annoying and requires (at least in theory) all drivers to implement some sort of affinity narrowing.
In order to address this, always limit the cpumask to the set of online CPUs.
Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/20220405185040.206297-3-maz@kernel.org
Signed-off-by: Luiz Capitulino luizcap@amazon.com --- kernel/irq/manage.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 0c3c26fb054f..a1727cdaebed 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -222,11 +222,16 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, { struct irq_desc *desc = irq_data_to_desc(data); struct irq_chip *chip = irq_data_get_irq_chip(data); + const struct cpumask *prog_mask; int ret;
+ static DEFINE_RAW_SPINLOCK(tmp_mask_lock); + static struct cpumask tmp_mask; + if (!chip || !chip->irq_set_affinity) return -EINVAL;
+ raw_spin_lock(&tmp_mask_lock); /* * If this is a managed interrupt and housekeeping is enabled on * it check whether the requested affinity mask intersects with @@ -248,24 +253,28 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, */ if (irqd_affinity_is_managed(data) && housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) { - const struct cpumask *hk_mask, *prog_mask; - - static DEFINE_RAW_SPINLOCK(tmp_mask_lock); - static struct cpumask tmp_mask; + const struct cpumask *hk_mask;
hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ);
- raw_spin_lock(&tmp_mask_lock); cpumask_and(&tmp_mask, mask, hk_mask); if (!cpumask_intersects(&tmp_mask, cpu_online_mask)) prog_mask = mask; else prog_mask = &tmp_mask; - ret = chip->irq_set_affinity(data, prog_mask, force); - raw_spin_unlock(&tmp_mask_lock); } else { - ret = chip->irq_set_affinity(data, mask, force); + prog_mask = mask; } + + /* Make sure we only provide online CPUs to the irqchip */ + cpumask_and(&tmp_mask, prog_mask, cpu_online_mask); + if (!cpumask_empty(&tmp_mask)) + ret = chip->irq_set_affinity(data, &tmp_mask, force); + else + ret = -EINVAL; + + raw_spin_unlock(&tmp_mask_lock); + switch (ret) { case IRQ_SET_MASK_OK: case IRQ_SET_MASK_OK_DONE: