Hi Biju,
On Tue, Aug 15, 2023 at 3:16 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> Fix the below random NULL pointer crash during boot by serializing
> pinctrl group and function creation/remove calls in
> rzg2l_dt_subnode_to_map() with mutex lock.
>
> Crash logs:
> pc : __pi_strcmp+0x20/0x140
> lr : pinmux_func_name_to_selector+0x68/0xa4
> Call trace:
> __pi_strcmp+0x20/0x140
> pinmux_generic_add_function+0x34/0xcc
> rzg2l_dt_subnode_to_map+0x314/0x44c
> rzg2l_dt_node_to_map+0x164/0x194
> pinctrl_dt_to_map+0x218/0x37c
> create_pinctrl+0x70/0x3d8
>
> While at it, add comments for bitmap_lock and lock.
>
> Fixes: c4c4637eb57f ("pinctrl: renesas: Add RZ/G2L pin and gpio controller driver")
> Cc: stable@xxxxxxxxxx
> Tested-by: Chris Paterson <Chris.Paterson2@xxxxxxxxxxx>
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
> v2->v3:
> * Added comment for bitmap_lock and lock.
> * Moved map allocation down to reduce lock section.
> * Added locks for maps and pinctrl group and function creation/remove
> calls
> * Added unlock_and_done label for lock error path.
Thanks for the update!
Upon closer look, I noticed that I had missed that the map allocation
is not global, but local to a specific DT node, so it does not
need protection by a lock. If no one objects, I will back out that
change myself, queue this patch in renesas-pinctrl-for-v6.6, and send
a PR tomorrow.
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
