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From:   Bartosz Golaszewski <bgolaszewski@baylibre.com>
Date:   Mon, 30 Nov 2020 17:42:43 +0100
Message-ID: <CAMpxmJUnao=KXTRORF5z2X4BHojDW2UCosHjZi_K9jCtVVtGMQ@mail.gmail.com>
Subject: Re: [PATCH v2] gpio: dwapb: fix NULL pointer dereference at dwapb_gpio_suspend()
To:     Luo Jiaxing <luojiaxing@huawei.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Sergey.Semin@baikalelectronics.ru,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-gpio <linux-gpio@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, linuxarm@huawei.com
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On Fri, Nov 27, 2020 at 9:50 AM Luo Jiaxing <luojiaxing@huawei.com> wrote:
>
> Following Calltrace is found when running echo freeze > /sys/power/state.
>
> [  272.755506] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
> [  272.755585] Call trace:
> [  272.755587]  dwapb_gpio_suspend+0x18/0x318
> [  272.755588]  pm_generic_suspend+0x2c/0x48
> [  272.755595]  acpi_subsys_suspend+0x60/0x70
> [  272.755599]  dpm_run_callback.isra.18+0x40/0xe0
> [  272.755601]  __device_suspend+0xf4/0x360
>
> The reason is platform_set_drvdata() is deleted, and dwapb_gpio_suspend()
> get *gpio by dev_get_drvdata().
>
> Fixes: feeaefd378ca ("gpio: dwapb: Use resource managed GPIO-chip add data method")
> Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
> Acked-by: Serge Semin <fancer.lancer@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
>
> ---
>    v1->v2:
>           1. reduce calltrace log
>           2. delete blank line in tag block
> ---
> ---
>  drivers/gpio/gpio-dwapb.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index 2a9046c..4275c18 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -724,6 +724,8 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
>                         return err;
>         }
>
> +       platform_set_drvdata(pdev, gpio);
> +
>         return 0;
>  }
>
> --
> 2.7.4
>

Applied, thanks!

Bartosz