From: Sean Christopherson <seanjc@google.com> mainline inclusion from mainline-v6.17 commit 5d7dbdce388b43cf3a9bc50c4132493de26aeba4 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9782 CVE: NA Reference: https://github.com/kvm-x86/linux/commit/5d7dbdce388b -------------------------------- Use the paired consumer/producer information to disconnect IRQ bypass producers/consumers in O(1) time (ignoring the cost of __disconnect()). Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/r/20250516230734.2564775-6-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Qiqi Li <liqiqi23@huawei.com> --- virt/lib/irqbypass.c | 48 ++++++++------------------------------------ 1 file changed, 8 insertions(+), 40 deletions(-) diff --git a/virt/lib/irqbypass.c b/virt/lib/irqbypass.c index fdbf7ecc0c21..6a183459dc44 100644 --- a/virt/lib/irqbypass.c +++ b/virt/lib/irqbypass.c @@ -138,32 +138,16 @@ EXPORT_SYMBOL_GPL(irq_bypass_register_producer); */ void irq_bypass_unregister_producer(struct irq_bypass_producer *producer) { - struct irq_bypass_producer *tmp; - struct irq_bypass_consumer *consumer; - if (!producer->eventfd) return; mutex_lock(&lock); - list_for_each_entry(tmp, &producers, node) { - if (tmp->eventfd != producer->eventfd) - continue; - - list_for_each_entry(consumer, &consumers, node) { - if (consumer->eventfd == producer->eventfd) { - WARN_ON_ONCE(producer->consumer != consumer); - __disconnect(producer, consumer); - break; - } - } - - producer->eventfd = NULL; - list_del(&producer->node); - break; - } + if (producer->consumer) + __disconnect(producer, producer->consumer); - WARN_ON_ONCE(producer->eventfd); + producer->eventfd = NULL; + list_del(&producer->node); mutex_unlock(&lock); } EXPORT_SYMBOL_GPL(irq_bypass_unregister_producer); @@ -228,32 +212,16 @@ EXPORT_SYMBOL_GPL(irq_bypass_register_consumer); */ void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer) { - struct irq_bypass_consumer *tmp; - struct irq_bypass_producer *producer; - if (!consumer->eventfd) return; mutex_lock(&lock); - list_for_each_entry(tmp, &consumers, node) { - if (tmp != consumer) - continue; - - list_for_each_entry(producer, &producers, node) { - if (producer->eventfd == consumer->eventfd) { - WARN_ON_ONCE(consumer->producer != producer); - __disconnect(producer, consumer); - break; - } - } - - consumer->eventfd = NULL; - list_del(&consumer->node); - break; - } + if (consumer->producer) + __disconnect(consumer->producer, consumer); - WARN_ON_ONCE(consumer->eventfd); + consumer->eventfd = NULL; + list_del(&consumer->node); mutex_unlock(&lock); } EXPORT_SYMBOL_GPL(irq_bypass_unregister_consumer); -- 2.43.0