From patchwork Wed Dec 16 00:37:17 2009
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Subject: OneNAND: Fix test of unsigned in onenand_otp_walk()
Date: Tue, 15 Dec 2009 14:37:17 -0000
From: roel kluin <roel.kluin@gmail.com>
X-Patchwork-Id: 41227
Message-Id: <4B282BBD.4050106@gmail.com>
To: Kyungmin Park <kyungmin.park@samsung.com>, linux-mtd@lists.infradead.org,
 Andrew Morton <akpm@linux-foundation.org>, 
 LKML <linux-kernel@vger.kernel.org>

mtd->writesize and len are unsigned so the test does not work.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>

---
you can test this with:

#include <stdio.h>

int main()
{
        int c = 1, d = 1;
        unsigned a = 30;
        unsigned b = 10;

        if ((b * c) - (d + a) < 0)
                printf("good\n");
        else
                printf("bad\n");
        return 0;
}

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index ff66e43..cbe2711 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -2725,7 +2725,7 @@ static int onenand_otp_walk(struct mtd_info *mtd, loff_t from, size_t len,
 	}
 
 	/* Check User/Factory boundary */
-	if (((mtd->writesize * otp_pages) - (from + len)) < 0)
+	if (mtd->writesize * otp_pages < from + len)
 		return 0;
 
 	onenand_get_device(mtd, FL_OTPING);