Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   sxwjean@me.com
To:     cl@linux.com, penberg@kernel.org, rientjes@google.com,
        iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz,
        roman.gushchin@linux.dev, 42.hyeyoo@gmail.com,
        keescook@chromium.org
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org,
        Xiongwei Song <xiongwei.song@windriver.com>
Subject: [PATCH 5/5] slub: Don't read nr_slabs and total_objects directly
Date:   Thu, 13 Apr 2023 22:34:52 +0800
Message-Id: <20230413143452.211250-6-sxwjean@me.com>
In-Reply-To: <20230413143452.211250-1-sxwjean@me.com>
References: <20230413143452.211250-1-sxwjean@me.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Xiongwei Song <xiongwei.song@windriver.com>

We have node_nr_slabs() to read nr_slabs, node_nr_objs() to read
total_objects in a kmem_cache_node, so no need to access the two
members directly.

Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com>
---
 mm/slub.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 33b4fec6bc7a..2c3af399d9d6 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5157,9 +5157,9 @@ static int validate_slab_node(struct kmem_cache *s,
 		validate_slab(s, slab, obj_map);
 		count++;
 	}
-	if (count != atomic_long_read(&n->nr_slabs)) {
+	if (count != node_nr_slabs(n)) {
 		pr_err("SLUB: %s %ld slabs counted but counter=%ld\n",
-		       s->name, count, atomic_long_read(&n->nr_slabs));
+		       s->name, count, node_nr_slabs(n));
 		slab_add_kunit_errors();
 	}
 
@@ -5443,12 +5443,11 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
 		for_each_kmem_cache_node(s, node, n) {
 
 			if (flags & SO_TOTAL)
-				x = atomic_long_read(&n->total_objects);
+				x = node_nr_objs(n);
 			else if (flags & SO_OBJECTS)
-				x = atomic_long_read(&n->total_objects) -
-					count_partial(n, count_free);
+				x = node_nr_objs(n) - count_partial(n, count_free);
 			else
-				x = atomic_long_read(&n->nr_slabs);
+				x = node_nr_slabs(n);
 			total += x;
 			nodes[node] += x;
 		}
@@ -6387,7 +6386,7 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep)
 		unsigned long flags;
 		struct slab *slab;
 
-		if (!atomic_long_read(&n->nr_slabs))
+		if (!node_nr_slabs(n))
 			continue;
 
 		spin_lock_irqsave(&n->list_lock, flags);
-- 
2.30.2