linux-kernel - [PATCH] cacheinfo: Decrement refcount in cache_setup_of

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Message-Id: <20221026185954.991547-1-pierre.gondois@arm.com>
Date:   Wed, 26 Oct 2022 20:59:54 +0200
From:   Pierre Gondois <pierre.gondois@....com>
To:     linux-kernel@...r.kernel.org
Cc:     Rob.Herring@....com, sudeep.holla@....com,
        Pierre Gondois <pierre.gondois@....com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>
Subject: [PATCH] cacheinfo: Decrement refcount in cache_setup_of_node()

Refcounts to DT nodes are only incremented in the function
and never decremented. Decrease the refcounts when necessary.

Signed-off-by: Pierre Gondois <pierre.gondois@....com>
---
 drivers/base/cacheinfo.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 1448a329f66d..10ddb05a6e39 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -196,7 +196,7 @@ static void cache_of_set_props(struct cacheinfo *this_leaf,
 
 static int cache_setup_of_node(unsigned int cpu)
 {
-	struct device_node *np;
+	struct device_node *np, *prev;
 	struct cacheinfo *this_leaf;
 	unsigned int index = 0;
 
@@ -206,19 +206,24 @@ static int cache_setup_of_node(unsigned int cpu)
 		return -ENOENT;
 	}
 
+	prev = np;
+
 	while (index < cache_leaves(cpu)) {
 		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
-		if (this_leaf->level != 1)
+		if (this_leaf->level != 1) {
 			np = of_find_next_cache_node(np);
-		else
-			np = of_node_get(np);/* cpu node itself */
-		if (!np)
-			break;
+			of_node_put(prev);
+			prev = np;
+			if (!np)
+				break;
+		}
 		cache_of_set_props(this_leaf, np);
 		this_leaf->fw_token = np;
 		index++;
 	}
 
+	of_node_put(np);
+
 	if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 		return -ENOENT;
 
-- 
2.25.1