From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 8 Mar 2022 05:02:21 -0500
Subject: mm: use vmalloc_array and vcalloc for array allocations
Git-commit: 3000f2e2fc855664c28d3e6a47e0373737974eb4
Patch-mainline: v5.18-rc1
References: bsc#1198110

Instead of using array_size or just a multiply, use a function that
takes care of both the multiplication and the overflow checks.

Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>
---
 mm/percpu-stats.c | 2 +-
 mm/swap_cgroup.c  | 4 +---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c
index c6bd092ff7a3..dd3590dfc23d 100644
--- a/mm/percpu-stats.c
+++ b/mm/percpu-stats.c
@@ -144,7 +144,7 @@ static int percpu_stats_show(struct seq_file *m, void *v)
 	spin_unlock_irq(&pcpu_lock);
 
 	/* there can be at most this many free and allocated fragments */
-	buffer = vmalloc(array_size(sizeof(int), (2 * max_nr_alloc + 1)));
+	buffer = vmalloc_array(2 * max_nr_alloc + 1, sizeof(int));
 	if (!buffer)
 		return -ENOMEM;
 
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index 7f34343c075a..5a9442979a18 100644
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -167,14 +167,12 @@ unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
 int swap_cgroup_swapon(int type, unsigned long max_pages)
 {
 	void *array;
-	unsigned long array_size;
 	unsigned long length;
 	struct swap_cgroup_ctrl *ctrl;
 
 	length = DIV_ROUND_UP(max_pages, SC_PER_PAGE);
-	array_size = length * sizeof(void *);
 
-	array = vzalloc(array_size);
+	array = vcalloc(length, sizeof(void *));
 	if (!array)
 		goto nomem;