From bb169f80ed5a156ec3405e0e49c6b8e9ae264718 Mon Sep 17 00:00:00 2001 From: Nuno Das Neves Date: Thu, 3 Jul 2025 15:44:34 -0700 Subject: [PATCH] x86/hyperv: Fix usage of cpu_online_mask to get valid cpu Accessing cpu_online_mask here is problematic because the cpus read lock is not held in this context. However, cpu_online_mask isn't needed here since the effective affinity mask is guaranteed to be valid in this callback. So, just use cpumask_first() to get the cpu instead of ANDing it with cpus_online_mask unnecessarily. Fixes: e39397d1fd68 ("x86/hyperv: implement an MSI domain for root partition") Reported-by: Michael Kelley Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB4157639630F8AD2D8FD8F52FD475A@SN6PR02MB4157.namprd02.prod.outlook.com/ Suggested-by: Thomas Gleixner Signed-off-by: Nuno Das Neves Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com> --- arch/x86/hyperv/irqdomain.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c index f7627bc8fe495..de883ac76445b 100644 --- a/arch/x86/hyperv/irqdomain.c +++ b/arch/x86/hyperv/irqdomain.c @@ -193,7 +193,6 @@ static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) struct pci_dev *dev; struct hv_interrupt_entry out_entry, *stored_entry; struct irq_cfg *cfg = irqd_cfg(data); - const cpumask_t *affinity; int cpu; u64 status; @@ -205,8 +204,7 @@ static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) return; } - affinity = irq_data_get_effective_affinity_mask(data); - cpu = cpumask_first_and(affinity, cpu_online_mask); + cpu = cpumask_first(irq_data_get_effective_affinity_mask(data)); if (data->chip_data) { /* -- 2.47.2