Merge tag 'x86-urgent-2020-08-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit 5a30a78924ec · 2020-08-02T13:10:42.000-07:00
Pull x86 fix from Ingo Molnar:
 "A single fix for a potential deadlock when printing a message about
  spurious interrupts"

* tag 'x86-urgent-2020-08-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/i8259: Use printk_deferred() to prevent deadlock
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
@@ -207,7 +207,7 @@ static void mask_and_ack_8259A(struct irq_data *data)
 		 * lets ACK and report it. [once per IRQ]
 		 */
 		if (!(spurious_irq_mask & irqmask)) {
-			printk(KERN_DEBUG
+			printk_deferred(KERN_DEBUG
 			       "spurious 8259A interrupt: IRQ%d.\n", irq);
 			spurious_irq_mask |= irqmask;
 		}

Original file line number	Diff line number	Diff line change
`@@ -207,7 +207,7 @@ static void mask_and_ack_8259A(struct irq_data *data)`
`207`	`207`	`* lets ACK and report it. [once per IRQ]`
`208`	`208`	`*/`
`209`	`209`	`if (!(spurious_irq_mask & irqmask)) {`
`210`		`- printk(KERN_DEBUG`
	`210`	`+ printk_deferred(KERN_DEBUG`
`211`	`211`	`"spurious 8259A interrupt: IRQ%d.\n", irq);`
`212`	`212`	`spurious_irq_mask \|= irqmask;`
`213`	`213`	`}`