[PATCH] mm: fix invalid loop for poison_init_mem

[Nicolas Pitre]

On Wed, 3 Aug 2011, Jamie Iles wrote:

> poison_init_mem() used a loop of:
> 
> 	while ((count = count - 4))
> 
> which has 2 problems - an off by one error so that we do one less word
> than we should, and the other is that if count == 0 then we loop forever
> and poison too much.  On a platform with HAVE_TCM=y but nothing in the
> TCM's, this caused corruption and the platform failed to boot.
> 
> Cc: Stephen Boyd <sboyd at codeaurora.org>
> Cc: Nicolas Pitre <nicolas.pitre at linaro.org>
> Cc: Russell King <rmk+kernel at arm.linux.org.uk>
> Signed-off-by: Jamie Iles <jamie at jamieiles.com>

Acked-by: Nicolas Pitre <nicolas.pitre at linaro.org>


> ---
>  arch/arm/mm/init.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 2fee782..91bca35 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -441,7 +441,7 @@ static inline int free_area(unsigned long pfn, unsigned long end, char *s)
>  static inline void poison_init_mem(void *s, size_t count)
>  {
>  	u32 *p = (u32 *)s;
> -	while ((count = count - 4))
> +	for (; count != 0; count -= 4)
>  		*p++ = 0xe7fddef0;
>  }
>  
> -- 
> 1.7.4.1
>