[PATCH] efi: fix handling error value in fdt_find_uefi_params

[PATCH] efi: fix handling error value in fdt_find_uefi_params

[Andrzej Hajda]

of_get_flat_dt_subnode_by_name can return negative value in case of error.

The problem has been detected using semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
---
 drivers/firmware/efi/efi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 5a2631a..7dd2e2d 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -657,9 +657,12 @@ static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
 		}
 
 		if (subnode) {
-			node = of_get_flat_dt_subnode_by_name(node, subnode);
-			if (node < 0)
+			int err = of_get_flat_dt_subnode_by_name(node, subnode);
+
+			if (err < 0)
 				return 0;
+
+			node = err;
 		}
 
 		return __find_uefi_params(node, info, dt_params[i].params);
-- 
1.9.1

Re: [PATCH] efi: fix handling error value in fdt_find_uefi_params

[Matt Fleming]

On Wed, 17 Aug, at 12:00:40PM, Andrzej Hajda wrote:
> of_get_flat_dt_subnode_by_name can return negative value in case of error.
> 
> The problem has been detected using semantic patch
> scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci
> 
> Signed-off-by: Andrzej Hajda <a.hajda-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> ---
>  drivers/firmware/efi/efi.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 5a2631a..7dd2e2d 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -657,9 +657,12 @@ static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
>  		}
>  
>  		if (subnode) {
> -			node = of_get_flat_dt_subnode_by_name(node, subnode);
> -			if (node < 0)
> +			int err = of_get_flat_dt_subnode_by_name(node, subnode);
> +
> +			if (err < 0)
>  				return 0;
> +
> +			node = err;
>  		}
>  
>  		return __find_uefi_params(node, info, dt_params[i].params);
> -- 
> 1.9.1
 
Looks good to me. Thanks, applied.