2009-12-16 00:35:32

by Roel Kluin

Subject: [PATCH] OneNAND: Fix test of unsigned in onenand_otp_walk()

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

Signed-off-by: Roel Kluin <[email protected]>
---
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);

2009-12-16 01:20:34

by Kyungmin Park

Subject: RE: [PATCH] OneNAND: Fix test of unsigned in onenand_otp_walk()

Acked-by: Kyungmin Park <[email protected]>

> -----Original Message-----
> From: Roel Kluin [mailto:[email protected]]
> Sent: Wednesday, December 16, 2009 9:37 AM
> To: Kyungmin Park; [email protected]; Andrew Morton; LKML
> Subject: [PATCH] OneNAND: Fix test of unsigned in onenand_otp_walk()
>
> mtd->writesize and len are unsigned so the test does not work.
>
> Signed-off-by: Roel Kluin <[email protected]>
> ---
> 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);