lkml.org 
[lkml]   [2018]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH] rtc: sunxi: fix possible race condition
    Date
    The IRQ is requested before the struct rtc is allocated and registered, but
    this struct is used in the IRQ handler. This may lead to a NULL pointer
    dereference.

    Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
    before requesting the IRQ.

    Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
    ---
    drivers/rtc/rtc-sunxi.c | 23 +++++++++--------------
    1 file changed, 9 insertions(+), 14 deletions(-)

    diff --git a/drivers/rtc/rtc-sunxi.c b/drivers/rtc/rtc-sunxi.c
    index dadbf8b324ad..21865d3d8fe8 100644
    --- a/drivers/rtc/rtc-sunxi.c
    +++ b/drivers/rtc/rtc-sunxi.c
    @@ -445,6 +445,10 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
    platform_set_drvdata(pdev, chip);
    chip->dev = &pdev->dev;

    + chip->rtc = devm_rtc_allocate_device(&pdev->dev);
    + if (IS_ERR(chip->rtc))
    + return PTR_ERR(chip->rtc);
    +
    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    chip->base = devm_ioremap_resource(&pdev->dev, res);
    if (IS_ERR(chip->base))
    @@ -481,11 +485,12 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
    writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +
    SUNXI_ALRM_IRQ_STA);

    - chip->rtc = rtc_device_register("rtc-sunxi", &pdev->dev,
    - &sunxi_rtc_ops, THIS_MODULE);
    - if (IS_ERR(chip->rtc)) {
    + chip->rtc->ops = &sunxi_rtc_ops;
    +
    + ret = rtc_register_device(chip->rtc);
    + if (ret) {
    dev_err(&pdev->dev, "unable to register device\n");
    - return PTR_ERR(chip->rtc);
    + return ret;
    }

    dev_info(&pdev->dev, "RTC enabled\n");
    @@ -493,18 +498,8 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
    return 0;
    }

    -static int sunxi_rtc_remove(struct platform_device *pdev)
    -{
    - struct sunxi_rtc_dev *chip = platform_get_drvdata(pdev);
    -
    - rtc_device_unregister(chip->rtc);
    -
    - return 0;
    -}
    -
    static struct platform_driver sunxi_rtc_driver = {
    .probe = sunxi_rtc_probe,
    - .remove = sunxi_rtc_remove,
    .driver = {
    .name = "sunxi-rtc",
    .of_match_table = sunxi_rtc_dt_ids,
    --
    2.17.1
    \
     
     \ /
      Last update: 2018-06-04 14:07    [W:3.363 / U:0.488 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site