linux-kernel - [patch 31/46] genirq/manage: Rework irq_update_affinity

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250313155915.997259133@linutronix.de>
Date: Thu, 13 Mar 2025 17:00:35 +0100 (CET)
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Peter Zijlstra <peterz@...radead.org>,
 Jiri Slaby <jirislaby@...nel.org>
Subject: [patch 31/46] genirq/manage: Rework irq_update_affinity_desc()

Use the new guards to get and lock the interrupt descriptor and tidy up the
code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 kernel/irq/manage.c |   76 +++++++++++++++++++++-------------------------------
 1 file changed, 32 insertions(+), 44 deletions(-)

--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -393,14 +393,8 @@ int irq_set_affinity_locked(struct irq_d
  * an interrupt which is already started or which has already been configured
  * as managed will also fail, as these mean invalid init state or double init.
  */
-int irq_update_affinity_desc(unsigned int irq,
-			     struct irq_affinity_desc *affinity)
+int irq_update_affinity_desc(unsigned int irq, struct irq_affinity_desc *affinity)
 {
-	struct irq_desc *desc;
-	unsigned long flags;
-	bool activated;
-	int ret = 0;
-
 	/*
 	 * Supporting this with the reservation scheme used by x86 needs
 	 * some more thought. Fail it for now.
@@ -408,44 +402,38 @@ int irq_update_affinity_desc(unsigned in
 	if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
 		return -EOPNOTSUPP;
 
-	desc = irq_get_desc_buslock(irq, &flags, 0);
-	if (!desc)
-		return -EINVAL;
-
-	/* Requires the interrupt to be shut down */
-	if (irqd_is_started(&desc->irq_data)) {
-		ret = -EBUSY;
-		goto out_unlock;
-	}
-
-	/* Interrupts which are already managed cannot be modified */
-	if (irqd_affinity_is_managed(&desc->irq_data)) {
-		ret = -EBUSY;
-		goto out_unlock;
+	scoped_irqdesc_get_and_buslock(irq, 0) {
+		struct irq_desc *desc = scoped_irqdesc;
+		bool activated;
+
+		/* Requires the interrupt to be shut down */
+		if (irqd_is_started(&desc->irq_data))
+			return -EBUSY;
+
+		/* Interrupts which are already managed cannot be modified */
+		if (irqd_affinity_is_managed(&desc->irq_data))
+			return -EBUSY;
+		/*
+		 * Deactivate the interrupt. That's required to undo
+		 * anything an earlier activation has established.
+		 */
+		activated = irqd_is_activated(&desc->irq_data);
+		if (activated)
+			irq_domain_deactivate_irq(&desc->irq_data);
+
+		if (affinity->is_managed) {
+			irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
+			irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
+		}
+
+		cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
+
+		/* Restore the activation state */
+		if (activated)
+			irq_domain_activate_irq(&desc->irq_data, false);
+		return 0;
 	}
-
-	/*
-	 * Deactivate the interrupt. That's required to undo
-	 * anything an earlier activation has established.
-	 */
-	activated = irqd_is_activated(&desc->irq_data);
-	if (activated)
-		irq_domain_deactivate_irq(&desc->irq_data);
-
-	if (affinity->is_managed) {
-		irqd_set(&desc->irq_data, IRQD_AFFINITY_MANAGED);
-		irqd_set(&desc->irq_data, IRQD_MANAGED_SHUTDOWN);
-	}
-
-	cpumask_copy(desc->irq_common_data.affinity, &affinity->mask);
-
-	/* Restore the activation state */
-	if (activated)
-		irq_domain_activate_irq(&desc->irq_data, false);
-
-out_unlock:
-	irq_put_desc_busunlock(desc, flags);
-	return ret;
+	return -EINVAL;
 }
 
 static int __irq_set_affinity(unsigned int irq, const struct cpumask *mask,