On 11/04/2013 11:07 AM, Wang, Xiaoming wrote: > Dear Choi > > -----Original Message----- > From: Chanwoo Choi [mailto:[email protected]] > Sent: Monday, November 04, 2013 9:43 AM > To: Wang, Xiaoming > Cc: [email protected]; [email protected]; Liu, Chuansheng; > Zhang, Dongxing > Subject: Re: [PATCH] [extcon]:remove freed groups caused the panic or warning > in unregister flow > > Hi Wang, > >> drivers/extcon/extcon-class.c | 3 ++- >> 1 files changed, 2 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/extcon/extcon-class.c >> b/drivers/extcon/extcon-class.c index 148382f..48f4669 100644 >> --- a/drivers/extcon/extcon-class.c >> +++ b/drivers/extcon/extcon-class.c >> @@ -794,6 +794,8 @@ void extcon_dev_unregister(struct extcon_dev *edev) >> return; >> } >> >> + device_unregister(edev->dev); >> + >> if (edev->mutually_exclusive && edev->max_supported) { >> for (index = 0; edev->mutually_exclusive[index]; >> index++) >> @@ -814,7 +816,6 @@ void extcon_dev_unregister(struct extcon_dev *edev) >> if (switch_class) >> class_compat_remove_link(switch_class, edev->dev, NULL); #endif >> - device_unregister(edev->dev); >> put_device(edev->dev); >> } >> EXPORT_SYMBOL_GPL(extcon_dev_unregister); >> > > I think we could only apply following patch instead of moving the position of > device_unregister(). > > diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c > index 148382f..ff27b19 100644 > --- a/drivers/extcon/extcon-class.c > +++ b/drivers/extcon/extcon-class.c > @@ -805,10 +805,8 @@ void extcon_dev_unregister(struct extcon_dev *edev) > for (index = 0; index < edev->max_supported; index++) > kfree(edev->cables[index].attr_g.name); > > - if (edev->max_supported) { > - kfree(edev->extcon_dev_type.groups); > + if (edev->max_supported) > kfree(edev->cables); > - } > > #if defined(CONFIG_ANDROID) > if (switch_class) > > Thanks, > Chanwoo Choi > > I don't agree with you. > Why do not you want moving the position of device_unregister()? > It will cause the memory leak if has not kfree > edev->extcon_dev_type.groups as your patch do firstly. And if you think kfree > edev->extcon_dev_type.groups is meaningless well then kfree > edev->extcon_dev_type.groups in function exton_dev_register (line 756)also > should be removed I think. What do you think? >
As you comment, my opinion has memory leak problem. My mistake. But, I prefer to call 'device_unregister' at the end of extcon_dev_unregister(). To resolve kernel panic, I think we could use 'devm_kzalloc' instead of kzalloc/kfree. What is your opinion about my approach? Thanks, Chanwoo Choi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
