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From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>,
	Minchan Kim <minchan@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	linux-block@vger.kernel.org,
	Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCH 08/14] zram: check that backends array has at least one backend
Date: Fri,  3 May 2024 18:17:33 +0900
Message-ID: <20240503091823.3616962-9-senozhatsky@chromium.org>
In-Reply-To: <20240503091823.3616962-1-senozhatsky@chromium.org>
References: <20240503091823.3616962-1-senozhatsky@chromium.org>
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Make sure that backends array has anything apart from the
sentinel NULL value.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 drivers/block/zram/zcomp.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 9fc5477a6259..fdf06fc6b364 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -205,6 +205,14 @@ struct zcomp *zcomp_create(const char *alg)
 	struct zcomp *comp;
 	int error;
 
+	/*
+	 * The backends array has a sentinel NULL value, so the minimum
+	 * size is 1. In order to be valid the array, apart from the
+	 * sentinel NULL element, should have at least one compression
+	 * backend selected.
+	 */
+	BUILD_BUG_ON(ARRAY_SIZE(backends) <= 1);
+
 	comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL);
 	if (!comp)
 		return ERR_PTR(-ENOMEM);
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog