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From:   Yoshio Furuyama <ytc-mb-yfuruyama7@kioxia.com>
To:     miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com
Cc:     linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/2] Fix corner case in bad block table handling.
Date:   Tue,  6 Apr 2021 10:47:08 +0900
Message-Id: <774a92693f311e7de01e5935e720a179fb1b2468.1616635406.git.ytc-mb-yfuruyama7@kioxia.com>
In-Reply-To: <cover.1616635406.git.ytc-mb-yfuruyama7@kioxia.com>
References: <cover.1616635406.git.ytc-mb-yfuruyama7@kioxia.com>
Precedence: bulk

From: "Doyle, Patrick" <pdoyle@irobot.com>

In the unlikely event that both blocks 10 and 11 are marked as bad (on a
32 bit machine), then the process of marking block 10 as bad stomps on
cached entry for block 11.  There are (of course) other examples.

Signed-off-by: Patrick Doyle <pdoyle@irobot.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
---
 drivers/mtd/nand/bbt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c
index 044adf913854..64af6898131d 100644
--- a/drivers/mtd/nand/bbt.c
+++ b/drivers/mtd/nand/bbt.c
@@ -123,7 +123,7 @@ int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
 		unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
 
 		pos[1] &= ~GENMASK(rbits - 1, 0);
-		pos[1] |= val >> rbits;
+		pos[1] |= val >> (bits_per_block - rbits);
 	}
 
 	return 0;
-- 
2.25.1