From: Marc Zyngier maz@kernel.org
mainline inclusion from mainline-v5.19-rc1 commit c48c8b829d2b966a6649827426bcdba082ccf922 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5F4TK CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Although setting the affinity of an interrupt to a set of CPUs that doesn't have any online CPU is generally frowned apon, there are a few limited cases where such affinity is set from a CPUHP notifier, setting the affinity to a CPU that isn't online yet.
The saving grace is that this is always done using the 'force' attribute, which gives a hint that the affinity setting can be outside of the online CPU mask and the callsite set this flag with the knowledge that the underlying interrupt controller knows to handle it.
This restores the expected behaviour on Marek's system.
Fixes: 33de0aa4bae9 ("genirq: Always limit the affinity to online CPUs") Reported-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Marek Szyprowski m.szyprowski@samsung.com Link: https://lore.kernel.org/r/4b7fc13c-887b-a664-26e8-45aed13f048a@samsung.com Link: https://lore.kernel.org/r/20220414140011.541725-1-maz@kernel.org Signed-off-by: Chen Jiahao chenjiahao16@huawei.com Reviewed-by: Zhang Jianhua chris.zjh@huawei.com Reviewed-by: Liao Chang liaochang1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- kernel/irq/manage.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 7ed0e452bbc7..8d3d49c0483e 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -267,10 +267,16 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, prog_mask = mask; }
- /* Make sure we only provide online CPUs to the irqchip */ + /* + * Make sure we only provide online CPUs to the irqchip, + * unless we are being asked to force the affinity (in which + * case we do as we are told). + */ cpumask_and(&tmp_mask, prog_mask, cpu_online_mask); - if (!cpumask_empty(&tmp_mask)) + if (!force && !cpumask_empty(&tmp_mask)) ret = chip->irq_set_affinity(data, &tmp_mask, force); + else if (force) + ret = chip->irq_set_affinity(data, mask, force); else ret = -EINVAL;