Commit 6f78c2a7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-apic-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 apic update from Thomas Gleixner:
 "A single commit to make the vector allocation code more resilent
  against an accidental allocation attempt for IRQ2"

* tag 'x86-apic-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vector: Add a sanity check to prevent IRQ2 allocations
parents 87dcebff 9a98bc2c

arch/x86/kernel/apic/vector.c

+13 −0
Original line number Diff line number Diff line
@@ -543,6 +543,14 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq, 
	if ((info->flags & X86_IRQ_ALLOC_CONTIGUOUS_VECTORS) && nr_irqs > 1)

		return -ENOSYS;



	/*

	 * Catch any attempt to touch the cascade interrupt on a PIC

	 * equipped system.

	 */

	if (WARN_ON_ONCE(info->flags & X86_IRQ_ALLOC_LEGACY &&

			 virq == PIC_CASCADE_IR))

		return -EINVAL;



	for (i = 0; i < nr_irqs; i++) {

		irqd = irq_domain_get_irq_data(domain, virq + i);

		BUG_ON(!irqd);
@@ -745,6 +753,11 @@ void __init lapic_assign_system_vectors(void) 


	/* Mark the preallocated legacy interrupts */

	for (i = 0; i < nr_legacy_irqs(); i++) {

		/*

		 * Don't touch the cascade interrupt. It's unusable

		 * on PIC equipped machines. See the large comment

		 * in the IO/APIC code.

		 */

		if (i != PIC_CASCADE_IR)

			irq_matrix_assign(vector_matrix, ISA_IRQ_VECTOR(i));

	}