From 2a66a666d3e202dec5b1a4309447e32d5f292871 Mon Sep 17 00:00:00 2001
From: liuchao173 <55137861+liuchao173@users.noreply.github.com>
Date: Tue, 24 Aug 2021 20:50:18 +0800
Subject: [PATCH] fix unsigned integer subtraction sign overflow

Min_load, adjustment_load  and load are unsigned integers, so it overflows when (lb_info->min_load + info->load) < (lb_info->adjustment_load - info->load). The result will be greater than zero. Therefore the irq cannot be selected to rebalanced.
---
 irqlist.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/irqlist.c b/irqlist.c
index 9ab321a..4dd4a83 100644
--- a/irqlist.c
+++ b/irqlist.c
@@ -97,7 +97,7 @@ static void move_candidate_irqs(struct irq_info *info, void *data)
 	}
 
 	/* If we can migrate an irq without swapping the imbalance do it. */
-	if ((lb_info->min_load + info->load) - (lb_info->adjustment_load - info->load) < delta_load) {
+	if ((lb_info->min_load + info->load) < delta_load + (lb_info->adjustment_load - info->load)) {
 		lb_info->adjustment_load -= info->load;
 		lb_info->min_load += info->load;
 		if (lb_info->min_load > lb_info->adjustment_load) {