Re: [PATCH] sm501: unsigned ptr cannot be negative

From: Andrew Morton
Date: Tue Dec 02 2008 - 17:06:30 EST


On Sat, 29 Nov 2008 06:49:20 -0500
roel kluin <roel.kluin@xxxxxxxxx> wrote:

> unsigned ptr cannot be negative
>
> Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
> ---
> diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
> index f94ae84..dcd9879 100644
> --- a/drivers/video/sm501fb.c
> +++ b/drivers/video/sm501fb.c
> @@ -159,6 +159,9 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem,
> break;
>
> case SM501_MEMF_PANEL:
> + if (size > inf->fbmem_len)
> + return -ENOMEM;
> +
> ptr = inf->fbmem_len - size;
> fbi = inf->fb[HEAD_CRT];
>
> @@ -172,9 +175,6 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem,
> if (fbi && ptr < fbi->fix.smem_len)
> return -ENOMEM;
>
> - if (ptr < 0)
> - return -ENOMEM;
> -
> break;
>
> case SM501_MEMF_CRT:

Looks OK.

Also this:

if (ptr > 0)
ptr &= ~(PAGE_SIZE - 1);

could just be

ptr = PAGE_ALIGN(ptr);
--
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