Re: [PATCH] pinctrl: imx: reset group index on probe
From: Vladimir Zapolskiy <vz@mleia.com>
Date: 2016-10-18 22:40:18
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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.
quoted hunk ↗ jump to hunk
--- 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