Re: [PATCH RESEND] mfd: mc13xxx: Fix null pointer dereference in mc13xxx_common_init

Lee Jones
2013-12-02T10:54:40Z

On Sat, 30 Nov 2013, Alexander Shiyan wrote:

> If this driver being loaded from devicetree, the pdata is NULL.
> This cause kernel Oops when "fsl,mc13xxx-uses-codec" and/or
> "fsl,mc13xxx-uses-touch" properties is specified.

<snip>

The original code is pretty gross. This stuff shouldn't be identifying
_support_ in Device Tree, then dragging in configuration from platform
code.

Rather than patch it up with little plasters (band aids), can we fix
it properly please?

> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
>
> Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
> ---
> drivers/mfd/mc13xxx-core.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
> index dbbf8ee..625633a 100644
> --- a/drivers/mfd/mc13xxx-core.c
> +++ b/drivers/mfd/mc13xxx-core.c
> @@ -682,14 +682,14 @@ err_revision:
> if (mc13xxx->flags & MC13XXX_USE_ADC)
> mc13xxx_add_subdevice(mc13xxx, "%s-adc");
>
> - if (mc13xxx->flags & MC13XXX_USE_CODEC)
> + if ((mc13xxx->flags & MC13XXX_USE_CODEC) && pdata)
> mc13xxx_add_subdevice_pdata(mc13xxx, "%s-codec",
> pdata->codec, sizeof(*pdata->codec));
>
> if (mc13xxx->flags & MC13XXX_USE_RTC)
> mc13xxx_add_subdevice(mc13xxx, "%s-rtc");
>
> - if (mc13xxx->flags & MC13XXX_USE_TOUCHSCREEN)
> + if ((mc13xxx->flags & MC13XXX_USE_TOUCHSCREEN) && pdata)
> mc13xxx_add_subdevice_pdata(mc13xxx, "%s-ts",
> &pdata->touch, sizeof(pdata->touch));
>
> @@ -701,6 +701,10 @@ err_revision:
> mc13xxx_add_subdevice_pdata(mc13xxx, "%s-pwrbutton",
> pdata->buttons, sizeof(*pdata->buttons));
> } else {
> + if (mc13xxx->flags & MC13XXX_USE_CODEC)
> + mc13xxx_add_subdevice(mc13xxx, "%s-codec");
> + if (mc13xxx->flags & MC13XXX_USE_TOUCHSCREEN)
> + mc13xxx_add_subdevice(mc13xxx, "%s-ts");
> mc13xxx_add_subdevice(mc13xxx, "%s-regulator");
> mc13xxx_add_subdevice(mc13xxx, "%s-led");
> mc13xxx_add_subdevice(mc13xxx, "%s-pwrbutton");

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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