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From: Brian Norris <computersforpeace@gmail.com>
To: <linux-mtd@lists.infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>,
	Maxim Levitsky <maximlevitsky@gmail.com>
Subject: [PATCH 6/6] mtd: nand: r852: correct write_buf loop bounds
Date: Tue, 20 May 2014 23:17:03 -0700	[thread overview]
Message-ID: <1400653023-25757-7-git-send-email-computersforpeace@gmail.com> (raw)
In-Reply-To: <1400653023-25757-1-git-send-email-computersforpeace@gmail.com>

The two loops in r852_write_buf() are designed to handle 4-byte-aligned
and then 1-byte-aligned portions, respectively. However, there are two
issues:

(1) The first loop will only terminate if 'len' is a multiple of 4
(2) The second loop will never terminate if it runs at least once

Rewrite these loops as they were probably intended. Compile tested only.

Issues pointed out by Coverity Scan.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
---
 drivers/mtd/nand/r852.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/r852.c b/drivers/mtd/nand/r852.c
index 325930db3f04..baea83f4dea8 100644
--- a/drivers/mtd/nand/r852.c
+++ b/drivers/mtd/nand/r852.c
@@ -245,7 +245,7 @@ static void r852_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
 	}
 
 	/* write DWORD chinks - faster */
-	while (len) {
+	while (len >= 4) {
 		reg = buf[0] | buf[1] << 8 | buf[2] << 16 | buf[3] << 24;
 		r852_write_reg_dword(dev, R852_DATALINE, reg);
 		buf += 4;
@@ -254,8 +254,10 @@ static void r852_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
 	}
 
 	/* write rest */
-	while (len)
+	while (len > 0) {
 		r852_write_reg(dev, R852_DATALINE, *buf++);
+		len--;
+	}
 }
 
 /*
-- 
1.7.9.5

  parent reply	other threads:[~2014-05-21  6:17 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-21  6:16 [PATCH 0/6] mtd: small cleanups Brian Norris
2014-05-21  6:16 ` [PATCH 1/6] mtd: pfow: remove unused variable Brian Norris
2014-05-21  6:16 ` [PATCH 2/6] mtd: slram: fix unused variable warning Brian Norris
2014-05-21  6:17 ` [PATCH 3/6] mtd: maps: sc520cdp: fix warnings Brian Norris
2014-05-21  6:17 ` [PATCH 4/6] mtd: nand_bbt: remove unused variable Brian Norris
2014-05-21  6:17 ` [PATCH 5/6] mtd: nand_bbt: handle error case for nand_create_badblock_pattern() Brian Norris
2014-05-21  6:17 ` Brian Norris [this message]
2014-05-28  7:07 ` [PATCH 0/6] mtd: small cleanups Brian Norris

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