2018-08-27 12:39 GMT+02:00 Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>:
> On Mon, Aug 27, 2018 at 10:21:01AM +0200, Bartosz Golaszewski wrote:
>> Use devm_kstrdup_const() in the pmc-atom driver. This mostly serves as
>> an example of how to use this new routine to shrink driver code.
>>
>> While we're at it: replace a call to kcalloc() with devm_kcalloc().
>>
>> Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
>> ---
>> drivers/clk/x86/clk-pmc-atom.c | 19 ++++---------------
>> 1 file changed, 4 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/clk/x86/clk-pmc-atom.c b/drivers/clk/x86/clk-pmc-atom.c
>> index 08ef69945ffb..daa2192e6568 100644
>> --- a/drivers/clk/x86/clk-pmc-atom.c
>> +++ b/drivers/clk/x86/clk-pmc-atom.c
>> @@ -253,14 +253,6 @@ static void plt_clk_unregister_fixed_rate_loop(struct clk_plt_data *data,
>> plt_clk_unregister_fixed_rate(data->parents[i]);
>> }
>>
>> -static void plt_clk_free_parent_names_loop(const char **parent_names,
>> - unsigned int i)
>> -{
>> - while (i--)
>> - kfree_const(parent_names[i]);
>> - kfree(parent_names);
>> -}
>> -
>> static void plt_clk_unregister_loop(struct clk_plt_data *data,
>> unsigned int i)
>> {
>> @@ -286,8 +278,8 @@ static const char **plt_clk_register_parents(struct platform_device *pdev,
>> if (!data->parents)
>> return ERR_PTR(-ENOMEM);
>>
>> - parent_names = kcalloc(nparents, sizeof(*parent_names),
>> - GFP_KERNEL);
>> + parent_names = devm_kcalloc(&pdev->dev, nparents,
>> + sizeof(*parent_names), GFP_KERNEL);
>> if (!parent_names)
>> return ERR_PTR(-ENOMEM);
>>
>> @@ -300,7 +292,8 @@ static const char **plt_clk_register_parents(struct platform_device *pdev,
>> err = PTR_ERR(data->parents[i]);
>> goto err_unreg;
>> }
>> - parent_names[i] = kstrdup_const(clks[i].name, GFP_KERNEL);
>> + parent_names[i] = devm_kstrdup_const(&pdev->dev,
>> + clks[i].name, GFP_KERNEL);
>> }
>>
>> data->nparents = nparents;
>> @@ -308,7 +301,6 @@ static const char **plt_clk_register_parents(struct platform_device *pdev,
>>
>> err_unreg:
>> plt_clk_unregister_fixed_rate_loop(data, i);
>> - plt_clk_free_parent_names_loop(parent_names, i);
>
> What happens if clks[i].name is not a part of RO data? The devm_kstrdup_const
> will allocate memory and nothing will ever free it...
>
I'm looking at it and trying to see if I'm missing something, but
AFAIK the whole concept of devm_* is to leave out the resource
management part.
devm_kstrdup_const() will internally call devm_kstrdup() for strings
that are not in .rodata and once the device is detached, the string
will be freed (or not if it's in .rodata).
BR
Bart
> And, please don't drop kfree(parent_names) here.
>
>> return ERR_PTR(err);
>> }
>>
>> @@ -351,15 +343,12 @@ static int plt_clk_probe(struct platform_device *pdev)
>> goto err_unreg_clk_plt;
>> }
>>
>> - plt_clk_free_parent_names_loop(parent_names, data->nparents);
>> -
>> platform_set_drvdata(pdev, data);
>> return 0;
>>
>> err_unreg_clk_plt:
>> plt_clk_unregister_loop(data, i);
>> plt_clk_unregister_parents(data);
>> - plt_clk_free_parent_names_loop(parent_names, data->nparents);
>
> Ditto.
>
>> return err;
>> }
>>
>> --
>> 2.18.0
>>
>
> --
> Sincerely yours,
> Mike.
>
