Re: [PATCH] Input: gpio-keys - fix crash when disabliing GPIO-less buttons

[Tony Lindgren]

* Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> [210407 05:30]:
> My brain-damaged adjustments to Paul's patch caused crashes in
> gpio_keys_disable_button() when driver is used in GPIO-less (i.e.
> purely interrupt-driven) setups, because I mixed together debounce and
> release timers when they are in fact separate:
> 
> Unable to handle kernel NULL pointer dereference at virtual address 0000000c
> ...
> PC is at hrtimer_active+0xc/0x98
> LR is at hrtimer_try_to_cancel+0x24/0x140
> ...
> [<c01c43b8>] (hrtimer_active) from [<c01c50f4>] (hrtimer_try_to_cancel+0x24/0x140)
> [<c01c50f4>] (hrtimer_try_to_cancel) from [<c01c5224>] (hrtimer_cancel+0x14/0x4c)
> [<c01c5224>] (hrtimer_cancel) from [<bf1cae24>] (gpio_keys_attr_store_helper+0x1b8/0x1d8 [gpio_keys])
> [<bf1cae24>] (gpio_keys_attr_store_helper [gpio_keys]) from [<bf1cae80>] (gpio_keys_store_disabled_keys+0x18/0x24 [gpio_keys])
> [<bf1cae80>] (gpio_keys_store_disabled_keys [gpio_keys]) from [<c038ec7c>] (kernfs_fop_write_iter+0x10c/0x1cc)
> [<c038ec7c>] (kernfs_fop_write_iter) from [<c02df858>] (vfs_write+0x2ac/0x404)
> [<c02df858>] (vfs_write) from [<c02dfaf4>] (ksys_write+0x64/0xdc)
> [<c02dfaf4>] (ksys_write) from [<c0100080>] (ret_fast_syscall+0x0/0x58)
> 
> Let's fix it up.
> 
> Fixes: c9efb0ba281e ("Input: gpio-keys - use hrtimer for software debounce, if possible")
> Reported-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
> 
> Tony, could you please try this patch and see if it fixes the crash you
> observed?

Yes great, thanks this works for me:

Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>