Re: [PATCH] regmap: debugfs: potentially duplicate the name string of the config

[Dafna Hirschfeld]

Hi, thank you for the fast review,

Am 08.09.20 um 17:35 schrieb Mark Brown:
> On Tue, Sep 08, 2020 at 05:28:59PM +0200, Dafna Hirschfeld wrote:
> > In function regmap_debugfs_init the name of the regmap_config is assigned
> > in a node of regmap_debugfs_early_list to be used later after regmap
> > is initialized. It is unknown how and when the name is allocated and freed.
> > Therefore the name should be copied to the node using 'kstrdup_const'.
>
> It does not follow that the name should be copied, it equally follows
> (and is expected by the API given that the common case is that the name
> is a static string assigned at build time) that the caller should not
> free the string while the regmap is active.

I see that the same copy is already done in function __regmap_init in drivers/base/regmap/regmap.c
added in patch 8253bb3f82554 "regmap: potentially duplicate the name string stored in regmap"
so I thought I'll do the same.

> > This fixes an error
> > "debugfs: Directory 'dummy-' with parent 'regmap' already present!"
> > where the name was freed in function of_syscon_register before
> > it was accessed.
>
> Fix the caller.  It is *very* much unclear to me why a syscon would be
> assigning a name for a regmap it creates in the first place.

I'll have a deeper look.

Thanks,
Dafna

>