Re: [PATCH 1/7] drivers/macintosh/via-pmu-led.c: Add of_node_putto avoid memory leak

From: walter harms
Date: Tue Aug 31 2010 - 11:49:29 EST




Julia Lawall schrieb:
> Add a call to of_node_put in the error handling code following a call to
> of_find_node_by_path.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @r exists@
> local idexpression x;
> expression E,E1;
> statement S;
> @@
>
> *x =
> (of_find_node_by_path
> |of_find_node_by_name
> |of_find_node_by_phandle
> |of_get_parent
> |of_get_next_parent
> |of_get_next_child
> |of_find_compatible_node
> |of_match_node
> )(...);
> ...
> if (x == NULL) S
> <... when != x = E
> *if (...) {
> ... when != of_node_put(x)
> when != if (...) { ... of_node_put(x); ... }
> (
> return <+...x...+>;
> |
> * return ...;
> )
> }
> ...>
> of_node_put(x);
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@xxxxxxx>
>
> ---
> drivers/macintosh/via-pmu-led.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/macintosh/via-pmu-led.c b/drivers/macintosh/via-pmu-led.c
> index d242976..19c3718 100644
> --- a/drivers/macintosh/via-pmu-led.c
> +++ b/drivers/macintosh/via-pmu-led.c
> @@ -92,8 +92,10 @@ static int __init via_pmu_led_init(void)
> if (dt == NULL)
> return -ENODEV;
> model = of_get_property(dt, "model", NULL);
> - if (model == NULL)
> + if (model == NULL) {
> + of_node_put(dt);
> return -ENODEV;
> + }
> if (strncmp(model, "PowerBook", strlen("PowerBook")) != 0 &&
> strncmp(model, "iBook", strlen("iBook")) != 0 &&
> strcmp(model, "PowerMac7,2") != 0 &&
>

is there any rule that says when to use strncmp ? it seems perfecly valid to use strcpy here
(what is done in the last cmp).

re,
wh



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