[PATCH 2/3] drivers/video/imxfb.c: Fix resource size off by 1 error

[PATCH 2/3] drivers/video/imxfb.c: Fix resource size off by 1 error

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

In the first case, the change is not semantics-preserving, but
resource_size is used at the corresponding call to request_mem_region in
the same function.

In the second case, the change is semantics-preserving.

The problem was found using the following semantic patch:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
struct resource *res;
@@

- (res->end - res->start) + 1
+ resource_size(res)

@@
struct resource *res;
@@

- res->end - res->start
+ BAD(resource_size(res))
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 drivers/video/imxfb.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -u -p a/drivers/video/imxfb.c b/drivers/video/imxfb.c
--- a/drivers/video/imxfb.c 2009-04-13 16:04:25.000000000 +0200
+++ b/drivers/video/imxfb.c 2009-07-04 21:37:48.000000000 +0200
@@ -754,7 +754,7 @@ failed_map:
 failed_getclock:
 	iounmap(fbi->regs);
 failed_ioremap:
-	release_mem_region(res->start, res->end - res->start);
+	release_mem_region(res->start, resource_size(res));
 failed_req:
 	kfree(info->pseudo_palette);
 failed_init:
@@ -785,7 +785,7 @@ static int __devexit imxfb_remove(struct
 	framebuffer_release(info);
 
 	iounmap(fbi->regs);
-	release_mem_region(res->start, res->end - res->start + 1);
+	release_mem_region(res->start, resource_size(res));
 	clk_disable(fbi->clk);
 	clk_put(fbi->clk);
 

Re: [PATCH 2/3] drivers/video/imxfb.c: Fix resource size off by 1 error

[Sascha Hauer]

Hi Julia,

On Sat, Jul 04, 2009 at 11:32:29PM +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> In the first case, the change is not semantics-preserving, but
> resource_size is used at the corresponding call to request_mem_region in
> the same function.
> 
> In the second case, the change is semantics-preserving.
> 
> The problem was found using the following semantic patch:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @@
> struct resource *res;
> @@
> 
> - (res->end - res->start) + 1
> + resource_size(res)
> 
> @@
> struct resource *res;
> @@
> 
> - res->end - res->start
> + BAD(resource_size(res))
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
>  drivers/video/imxfb.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff -u -p a/drivers/video/imxfb.c b/drivers/video/imxfb.c
> --- a/drivers/video/imxfb.c 2009-04-13 16:04:25.000000000 +0200
> +++ b/drivers/video/imxfb.c 2009-07-04 21:37:48.000000000 +0200
> @@ -754,7 +754,7 @@ failed_map:
>  failed_getclock:
>  	iounmap(fbi->regs);
>  failed_ioremap:
> -	release_mem_region(res->start, res->end - res->start);
> +	release_mem_region(res->start, resource_size(res));
>  failed_req:
>  	kfree(info->pseudo_palette);
>  failed_init:
> @@ -785,7 +785,7 @@ static int __devexit imxfb_remove(struct
>  	framebuffer_release(info);
>  
>  	iounmap(fbi->regs);
> -	release_mem_region(res->start, res->end - res->start + 1);
> +	release_mem_region(res->start, resource_size(res));
>  	clk_disable(fbi->clk);
>  	clk_put(fbi->clk);

I already have a patch queued for this issue in imxfb.c

Sascha

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