[PATCH] pinctrl: single: Fix memleak in pcs_dt_node_to_map

[guomengqi (A)]

在 2023/7/4 17:18, Linus Walleij 写道:
> On Mon, Jul 3, 2023 at 10:24 AM Guo Mengqi <guomengqi3 at huawei.com> wrote:
>
>> In a reliability test which repeatedly load and remove a module,
>> I found some kmalloc-256 memory leaks in pinctrl-single.
>>
>> pcs_dt_node_to_map() will recognize a dt_node and
>> make a mapping for it. Along the way some pinctrl functions and groups
>> are registered in pinctrl-single controller. These functions/groups are
>> registered once and not removed during the system lifetime.
>>
>> When the client module loads again, pcs_dt_node_to_map() fail to consider
>> this situation, create the same set of resources, and does not release or
>> use them.
>>
>> To fix this, add a check at the start of pcs_parse_one_pinctrl_entry/
>> pcs_parse_bits_in_pinctrl_entry. If the target is found,
>> then all the resource allocation and parsing work can be skipped,
>> just set the mapping with existing function/group information.
>>
>> Fixes: 8b8b091bf07f ("pinctrl: Add one-register-per-pin type device tree
>> based pinctrl driver")
>>
>> Signed-off-by: Guo Mengqi <guomengqi3 at huawei.com>
> Good catch!
>
> I expect Tony to review the patch in-depth.

Thank you :)

>> -static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
>> +int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
>>                                          const char *function)
>>   {
>>          const struct pinmux_ops *ops = pctldev->desc->pmxops;
> It appears you need to add EXPORT_SYMBOL_GPL() for this function
> so the module can build. (This is why the build robot complains.)
Yes, it happens when config=M. I will send a v2 patch later to fix this.
> Yours,
> Linus Walleij
> .