Messages in this thread | | | Subject | Re: [PATCH] pinctrl: imx: reset group index on probe | From | Vladimir Zapolskiy <> | Date | Wed, 19 Oct 2016 01:40:10 +0300 |
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Hi Stefan,
On 19.10.2016 00:09, Stefan Agner wrote: > Group index is incremented on every new group parsed. Since the > field is part of struct imx_pinctrl_soc_info, which is typically > a global variable passed by the individual pinctrl-imx.c based > driver, it does not get cleared automatically when re-probing the > driver. This lead imx_pinctrl_parse_functions passing a group > pointer which is outside of the allocated group space on second > probe and onwards. Typically this ended up in a NULL pointer > dereference when accessing the name field like this: > Unable to handle kernel NULL pointer dereference at virtual address 00000000 > ... > PC is at strcmp+0x18/0x44 > LR is at imx_dt_node_to_map+0xc4/0x290 > > Avoid this by setting group_index to 0 on probe. > > This has been observed when using DEBUG_TEST_DRIVER_REMOVE. > > Signed-off-by: Stefan Agner <stefan@agner.ch>
I've recently developed a pinctrl driver for the last remaining i.MX31 platform from the SoC series (not published yet), it does not fit well under any of the 3 existing drivers, and instead of adding 1.5K lines of code with half of them almost copy-pasted from the rest drivers I started to work on generalization of the i.MX/Vybrid pinctrl/pinmux drivers.
This task is large and I'm not sure when I complete and share the results, but your change conflicts with one of the changes in my backlog... Let me share it with you right now, because it deals with info->group_index from another point of view and it (unlikely) may have an impact on Vybrid platform, which I can not test.
> --- > drivers/pinctrl/freescale/pinctrl-imx.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pinctrl/freescale/pinctrl-imx.c b/drivers/pinctrl/freescale/pinctrl-imx.c > index 4761320..79c4e14 100644 > --- a/drivers/pinctrl/freescale/pinctrl-imx.c > +++ b/drivers/pinctrl/freescale/pinctrl-imx.c > @@ -687,6 +687,7 @@ static int imx_pinctrl_probe_dt(struct platform_device *pdev, > if (!info->functions) > return -ENOMEM; > > + info->group_index = 0; > if (flat_funcs) { > info->ngroups = of_get_child_count(np); > } else { >
-- With best wishes, Vladimir
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