Re: memory leak and other oddness in pinctrl-mvebu.c

From: Jason Cooper
Date: Sat Mar 09 2013 - 19:07:18 EST


Added LinusW, Gregory and Ezequiel to the email. Guys, can you give
this a Tested-by before I apply (or Ack for LinusW)?

thx,

Jason.

On Sat, Mar 09, 2013 at 11:39:31PM +0000, David Woodhouse wrote:
> On Sat, 2013-03-09 at 17:53 -0500, Jason Cooper wrote:
> > > + if (!nr_funcs)
> >
> > shouldn't this be:
> >
> > if (nr_funcs <= 0)
>
> Hm, no. But the loop should terminate if nr_funcs ever reaches zero,
> otherwise funcs->num_groups will be off the end of the original array:
>
> diff --git a/drivers/pinctrl/mvebu/pinctrl-mvebu.c b/drivers/pinctrl/mvebu/pinctrl-mvebu.c
> index c689c04..8bbc607 100644
> --- a/drivers/pinctrl/mvebu/pinctrl-mvebu.c
> +++ b/drivers/pinctrl/mvebu/pinctrl-mvebu.c
> @@ -478,16 +478,21 @@ static struct pinctrl_ops mvebu_pinctrl_ops = {
> .dt_free_map = mvebu_pinctrl_dt_free_map,
> };
>
> -static int _add_function(struct mvebu_pinctrl_function *funcs, const char *name)
> +static int _add_function(struct mvebu_pinctrl_function *funcs, int nr_funcs,
> + const char *name)
> {
> - while (funcs->num_groups) {
> + while (nr_funcs && funcs->num_groups) {
> /* function already there */
> if (strcmp(funcs->name, name) == 0) {
> funcs->num_groups++;
> return -EEXIST;
> }
> funcs++;
> + nr_funcs--;
> }
> + if (!nr_funcs)
> + return -EOVERFLOW;
> +
> funcs->name = name;
> funcs->num_groups = 1;
> return 0;
> @@ -501,7 +506,7 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
> int n, s;
>
> /* we allocate functions for number of pins and hope
> - * there are less unique functions than pins available */
> + * there are fewer unique functions than pins available */
> funcs = devm_kzalloc(&pdev->dev, pctl->desc.npins *
> sizeof(struct mvebu_pinctrl_function), GFP_KERNEL);
> if (!funcs)
> @@ -510,26 +515,27 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev,
> for (n = 0; n < pctl->num_groups; n++) {
> struct mvebu_pinctrl_group *grp = &pctl->groups[n];
> for (s = 0; s < grp->num_settings; s++) {
> + int ret;
> +
> /* skip unsupported settings on this variant */
> if (pctl->variant &&
> !(pctl->variant & grp->settings[s].variant))
> continue;
>
> /* check for unique functions and count groups */
> - if (_add_function(funcs, grp->settings[s].name))
> + ret = _add_function(funcs, pctl->desc.npins,
> + grp->settings[s].name);
> + if (ret == -EOVERFLOW)
> + dev_err(&pdev->dev,
> + "More functions than pins(%d)\n",
> + pctl->desc.npins);
> + if (ret)
> continue;
>
> num++;
> }
> }
>
> - /* with the number of unique functions and it's groups known,
> - reallocate functions and assign group names */
> - funcs = krealloc(funcs, num * sizeof(struct mvebu_pinctrl_function),
> - GFP_KERNEL);
> - if (!funcs)
> - return -ENOMEM;
> -
> pctl->num_functions = num;
> pctl->functions = funcs;
>
>
> --
> dwmw2
>


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