Commit bb169f80 authored by Nuno Das Neves's avatar Nuno Das Neves Committed by Wei Liu
Browse files

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: e39397d1 ("x86/hyperv: implement an MSI domain for root partition")
Reported-by: default avatarMichael Kelley <mhklinux@outlook.com>
Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB4157639630F8AD2D8FD8F52FD475A@SN6PR02MB4157.namprd02.prod.outlook.com/


Suggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarNuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: default avatarMichael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
Message-ID: <1751582677-30930-4-git-send-email-nunodasneves@linux.microsoft.com>
parent f84b21da

arch/x86/hyperv/irqdomain.c

+1 −3
Original line number Diff line number Diff line
@@ -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) {

		/*