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From: Dawei Li <dawei.li@shingroup.cn>
To: tglx@linutronix.de,
	yury.norov@gmail.com
Cc: akpm@linux-foundation.org,
	maz@kernel.org,
	florian.fainelli@broadcom.com,
	chenhuacai@kernel.org,
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	samuel.holland@sifive.com,
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	linux-kernel@vger.kernel.org,
	Dawei Li <dawei.li@shingroup.cn>
Subject: [PATCH 3/6] irqchip/gic-v3-its: Avoid explicit cpumask allocation on stack
Date: Fri, 12 Apr 2024 18:58:36 +0800
Message-Id: <20240412105839.2896281-4-dawei.li@shingroup.cn>
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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.

Remove cpumask var on stack and use proper cpumask API to address it.

Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
---
 drivers/irqchip/irq-gic-v3-its.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index fca888b36680..a821396c4261 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3826,7 +3826,7 @@ static int its_vpe_set_affinity(struct irq_data *d,
 				bool force)
 {
 	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
-	struct cpumask common, *table_mask;
+	struct cpumask *table_mask;
 	unsigned long flags;
 	int from, cpu;
 
@@ -3850,8 +3850,11 @@ static int its_vpe_set_affinity(struct irq_data *d,
 	 * If we are offered another CPU in the same GICv4.1 ITS
 	 * affinity, pick this one. Otherwise, any CPU will do.
 	 */
-	if (table_mask && cpumask_and(&common, mask_val, table_mask))
-		cpu = cpumask_test_cpu(from, &common) ? from : cpumask_first(&common);
+	if (table_mask && cpumask_intersects(mask_val, table_mask)) {
+		cpu = cpumask_test_cpu(from, mask_val) &&
+		      cpumask_test_cpu(from, table_mask) ?
+		      from : cpumask_first_and(mask_val, table_mask);
+	}
 	else
 		cpu = cpumask_first(mask_val);
 
-- 
2.27.0