Re: [PATCH v8 1/3] devres: provide devm_krealloc()

From: Andy Shevchenko
Date: Fri Aug 21 2020 - 04:35:43 EST


On Thu, Aug 20, 2020 at 08:51:08PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> Implement the managed variant of krealloc(). This function works with
> all memory allocated by devm_kmalloc() (or devres functions using it
> implicitly like devm_kmemdup(), devm_kstrdup() etc.).
>
> Managed realloc'ed chunks can be manually released with devm_kfree().
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

...

> +static struct devres *to_devres(void *data)
> +{
> + return data - ALIGN(sizeof(struct devres), ARCH_KMALLOC_MINALIGN);
> +}
> +
> +static size_t devres_data_size(size_t total_size)
> +{
> + return total_size - ALIGN(sizeof(struct devres), ARCH_KMALLOC_MINALIGN);
> +}

I'm fine with above, but here is a side note, perhaps

offsetof(struct devres, data)

will be more practical (no duplication of alignment and hence slightly better
maintenance)? (Note, I didn't check if it provides the correct result)

Another side note: do we have existing users of these helpers?

--
With Best Regards,
Andy Shevchenko