On Sat, Aug 18, 2012 at 3:39 PM, Wolfram Sang <w.sang@xxxxxxxxxxxxxx> wrote: > On Thu, Aug 09, 2012 at 07:07:42PM +0530, Shubhrajyoti D wrote: >> Prevent the NULL pointer access by moving the platform_set_drvdata function >> after the access of the pdev. >> >> [ 654.961761] Unable to handle kernel NULL pointer dereference at virtual address 00000070 >> [ 654.970611] pgd = df254000 >> [ 654.973480] [00000070] *pgd=9f1da831, *pte=00000000, *ppte=00000000 >> [ 654.980163] Internal error: Oops: 17 [#1] SMP ARM >> [ 654.985076] Modules linked in: >> [ 654.988281] CPU: 1 Not tainted (3.6.0-rc1-00031-ge547de1-dirty #339) >> [ 654.995330] PC is at omap_i2c_runtime_resume+0x8/0x148 >> [ 655.000732] LR is at omap_i2c_runtime_resume+0x8/0x148 >> >> Signed-off-by: Shubhrajyoti D <shubhrajyoti@xxxxxx> >> --- >> drivers/i2c/busses/i2c-omap.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c >> index c8e3886..0c593d4 100644 >> --- a/drivers/i2c/busses/i2c-omap.c >> +++ b/drivers/i2c/busses/i2c-omap.c >> @@ -1217,8 +1217,6 @@ static int __devexit omap_i2c_remove(struct platform_device *pdev) >> struct omap_i2c_dev *dev = platform_get_drvdata(pdev); >> int ret; >> >> - platform_set_drvdata(pdev, NULL); >> - >> i2c_del_adapter(&dev->adapter); >> ret = pm_runtime_get_sync(&pdev->dev); >> if (IS_ERR_VALUE(ret)) >> @@ -1227,6 +1225,8 @@ static int __devexit omap_i2c_remove(struct platform_device *pdev) >> omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); >> pm_runtime_put(&pdev->dev); >> pm_runtime_disable(&pdev->dev); >> + platform_set_drvdata(pdev, NULL); >> + >> return 0; >> } > > I think this patch is correct, because drvdata is used in the PM code of > the driver and thus cleared too early. > > As such, this is a bugfix and should be not based on the big cleanup > since it should go into this rc series. > > I will pick it as soon as the comments on the other patches are > answered. BTW it was pointed out that the The platform_device object will be destroyed. Do you agree with http://www.spinics.net/lists/linux-omap/msg75553.html > > -- > Pengutronix e.K. | Wolfram Sang | > Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
