linux-kernel - [PATCH] sched/topology: replace kzalloc() with kcalloc() in sched_init

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Message-Id: <20250222-sched-kcalloc-v1-1-4dee15fd8241@ethancedwards.com>
Date: Sat, 22 Feb 2025 14:46:23 -0500
From: Ethan Carter Edwards <ethan@...ancedwards.com>
To: Markus Elfring <Markus.Elfring@....de>
Cc: Ingo Molnar <mingo@...hat.com>, Peter Zijlstra <peterz@...radead.org>, 
 Juri Lelli <juri.lelli@...hat.com>, 
 Vincent Guittot <vincent.guittot@...aro.org>, 
 Dietmar Eggemann <dietmar.eggemann@....com>, 
 Steven Rostedt <rostedt@...dmis.org>, Ben Segall <bsegall@...gle.com>, 
 Mel Gorman <mgorman@...e.de>, Valentin Schneider <vschneid@...hat.com>, 
 linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org, 
 Ethan Carter Edwards <ethan@...ancedwards.com>
Subject: [PATCH] sched/topology: replace kzalloc() with kcalloc() in
 sched_init_numa()

We are trying to get rid of all multiplications from allocation
functions to prevent integer overflows[1]. Here the multiplication is
obviously safe, but using kcalloc() is more appropriate and improves
readability. This patch has no effect on runtime behavior.

Link: https://github.com/KSPP/linux/issues/162 [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Signed-off-by: Ethan Carter Edwards <ethan@...ancedwards.com>
---
 kernel/sched/topology.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index c49aea8c10254dec985bba47b18f61be954d23f6..b4539b29fb36f6b2f0c5ca310620ebda29755e5c 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1918,7 +1918,7 @@ void sched_init_numa(int offline_node)
 	 */
 	sched_domains_numa_levels = 0;
 
-	masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL);
+	masks = kcalloc(nr_levels, sizeof(void *), GFP_KERNEL);
 	if (!masks)
 		return;
 
@@ -1927,7 +1927,7 @@ void sched_init_numa(int offline_node)
 	 * CPUs of nodes that are that many hops away from us.
 	 */
 	for (i = 0; i < nr_levels; i++) {
-		masks[i] = kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
+		masks[i] = kcalloc(nr_node_ids, sizeof(void *), GFP_KERNEL);
 		if (!masks[i])
 			return;
 

---
base-commit: 5cf80612d3f72c46ad53ef5042b4c609c393122f
change-id: 20250222-sched-kcalloc-1d5acea7249b

Best regards,
-- 
Ethan Carter Edwards <ethan@...ancedwards.com>