From 39cbe3e63d93d10e2c2929d7621ff895b0f1776b Mon Sep 17 00:00:00 2001 From: Dawei Li Date: Wed, 12 Mar 2025 22:51:00 +0900 Subject: [PATCH] irqchip/gic-v3-its: Avoid explicit cpumask allocation on stack BugLink: https://bugs.launchpad.net/bugs/2102118 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 cpumask_any_and() to address it. Signed-off-by: Dawei Li Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20240416085454.3547175-4-dawei.li@shingroup.cn (cherry picked from commit fcb8af4cbcd122e33ceeadd347b8866d32035af7) [koichiroden: pulled in prereq commit from mainline (v6.10-rc1~185^2~5)] Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- drivers/irqchip/irq-gic-v3-its.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 1fd135e3dec5..8b66300674ad 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3812,9 +3812,9 @@ 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; + unsigned int from, cpu = nr_cpu_ids; + struct cpumask *table_mask; unsigned long flags; - int from, cpu; /* * Check if we're racing against a VPE being destroyed, for @@ -3843,10 +3843,15 @@ 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); - else + if (table_mask) + cpu = cpumask_any_and(mask_val, table_mask); + if (cpu < nr_cpu_ids) { + if (cpumask_test_cpu(from, mask_val) && + cpumask_test_cpu(from, table_mask)) + cpu = from; + } else { cpu = cpumask_first(mask_val); + } if (from == cpu) goto out;