linux-kernel - [tip: irq/core] irqchip/irq-bcm6345-l1: Avoid explicit cpumask allocation on stack

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Date: Wed, 24 Apr 2024 20:04:07 -0000
From: "tip-bot2 for Dawei Li" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Dawei Li <dawei.li@...ngroup.cn>, Thomas Gleixner <tglx@...utronix.de>,
 x86@...nel.org, linux-kernel@...r.kernel.org, maz@...nel.org
Subject: [tip: irq/core] irqchip/irq-bcm6345-l1: Avoid explicit cpumask
 allocation on stack

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     6a9a52f74e3b82ff3f5398810c1b23ad497e2df5
Gitweb:        https://git.kernel.org/tip/6a9a52f74e3b82ff3f5398810c1b23ad497e2df5
Author:        Dawei Li <dawei.li@...ngroup.cn>
AuthorDate:    Tue, 16 Apr 2024 16:54:49 +08:00
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Wed, 24 Apr 2024 21:23:49 +02:00

irqchip/irq-bcm6345-l1: Avoid explicit cpumask allocation on stack

In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_first_and_and() to avoid the need for a temporary cpumask on
the stack.

Signed-off-by: Dawei Li <dawei.li@...ngroup.cn>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Link: https://lore.kernel.org/r/20240416085454.3547175-3-dawei.li@shingroup.cn

---
 drivers/irqchip/irq-bcm6345-l1.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-bcm6345-l1.c b/drivers/irqchip/irq-bcm6345-l1.c
index eb02d20..90daa27 100644
--- a/drivers/irqchip/irq-bcm6345-l1.c
+++ b/drivers/irqchip/irq-bcm6345-l1.c
@@ -192,14 +192,10 @@ static int bcm6345_l1_set_affinity(struct irq_data *d,
 	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 	unsigned int old_cpu = cpu_for_irq(intc, d);
 	unsigned int new_cpu;
-	struct cpumask valid;
 	unsigned long flags;
 	bool enabled;
 
-	if (!cpumask_and(&valid, &intc->cpumask, dest))
-		return -EINVAL;
-
-	new_cpu = cpumask_any_and(&valid, cpu_online_mask);
+	new_cpu = cpumask_first_and_and(&intc->cpumask, dest, cpu_online_mask);
 	if (new_cpu >= nr_cpu_ids)
 		return -EINVAL;