Message ID | 20180710090710.9066-2-Denis.Osterland@diehl.com |
---|---|
State | Superseded |
Headers | show |
Series | rtc: isl1208: fixes, documentation and isl1219 support | expand |
Hello, On 10/07/2018 09:44:15+0000, Denis OSTERLAND wrote: > From: Denis Osterland <Denis.Osterland@diehl.com> > > This patches addresses following problem: > rtc_allocate_device > devm_device_add_group <-- kernel oops / null pointer, because > sysfs entry does not yet exist > rtc_register_device > rc = devm_device_add_group > if (rc) > return rc; <-- forbidden to return error code > after device register > > In case groups were not yet registered (kobj.state_in_sysfs == 0) > rtc_add_group just addes given group to dev.groups, > otherwise it uses devm_device_add_group. > > Signed-off-by: Denis Osterland <Denis.Osterland@diehl.com> > --- > drivers/rtc/rtc-core.h | 6 ++++++ > drivers/rtc/rtc-sysfs.c | 39 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 45 insertions(+) > > diff --git a/drivers/rtc/rtc-core.h b/drivers/rtc/rtc-core.h > index 0abf98983e13..81d1c3ce7a96 100644 > --- a/drivers/rtc/rtc-core.h > +++ b/drivers/rtc/rtc-core.h > @@ -40,9 +40,15 @@ static inline void rtc_proc_del_device(struct rtc_device *rtc) > > #ifdef CONFIG_RTC_INTF_SYSFS > const struct attribute_group **rtc_get_dev_attribute_groups(void); > +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp); > #else > static inline const struct attribute_group **rtc_get_dev_attribute_groups(void) > { > return NULL; > } > +static inline > +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) > +{ > + return 0; > +} > #endif > diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c > index 454da38c6012..9a177b8f761b 100644 > --- a/drivers/rtc/rtc-sysfs.c > +++ b/drivers/rtc/rtc-sysfs.c > @@ -317,3 +317,42 @@ const struct attribute_group **rtc_get_dev_attribute_groups(void) > { > return rtc_attr_groups; > } > + > +static size_t rtc_group_count(struct rtc_device *rtc) > +{ I don't feel this function is necessary, you can include it in __rtc_add_group > + const struct attribute_group **groups = rtc->dev.groups; > + size_t cnt = 0; > + > + if (groups) > + for (; *groups; groups++) > + cnt++; > + > + return cnt; > +} > + > +static inline int > +__rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) > +{ > + size_t cnt = rtc_group_count(rtc); > + const struct attribute_group **groups, **old; > + > + groups = devm_kzalloc(&rtc->dev, (cnt+2)*sizeof(*groups), GFP_KERNEL); Please use devm_kcalloc > + if (IS_ERR_OR_NULL(groups)) > + return PTR_ERR(groups); > + memcpy(groups, rtc->dev.groups, cnt*sizeof(*groups)); > + groups[cnt] = grp; > + > + old = rtc->dev.groups; > + rtc->dev.groups = groups; > + if (old != rtc_attr_groups) > + devm_kfree(&rtc->dev, old); > + > + return 0; > +} > + > +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) > +{ > + return rtc->dev.kobj.state_in_sysfs ? > + devm_device_add_group(&rtc->dev, grp) : > + __rtc_add_group(rtc, grp); Using devm_device_add_group after RTC registration is racy and should not be allowed. I would merge __rtc_add_group in rtc_add_group and return an error if rtc->registered is true.
Hello, thanks for your comments. Am Mittwoch, den 18.07.2018, 09:25 +0200 schrieb Alexandre Belloni: > Hello, > > On 10/07/2018 09:44:15+0000, Denis OSTERLAND wrote: > > > > + > > +static size_t rtc_group_count(struct rtc_device *rtc) > > +{ > I don't feel this function is necessary, you can include it in __rtc_add_group I think that it is easier to read, but sure I can include it. > > > > > + > > +static inline int > > +__rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) > > +{ > > + size_t cnt = rtc_group_count(rtc); > > + const struct attribute_group **groups, **old; > > + > > + groups = devm_kzalloc(&rtc->dev, (cnt+2)*sizeof(*groups), GFP_KERNEL); > Please use devm_kcalloc okay > > > > > + if (IS_ERR_OR_NULL(groups)) > > + return PTR_ERR(groups); > > + memcpy(groups, rtc->dev.groups, cnt*sizeof(*groups)); > > + groups[cnt] = grp; > > + > > + old = rtc->dev.groups; > > + rtc->dev.groups = groups; > > + if (old != rtc_attr_groups) > > + devm_kfree(&rtc->dev, old); > > + > > + return 0; > > +} > > + > > +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) > > +{ > > + return rtc->dev.kobj.state_in_sysfs ? > > + devm_device_add_group(&rtc->dev, grp) : > > + __rtc_add_group(rtc, grp); > Using devm_device_add_group after RTC registration is racy and should > not be allowed. I would merge __rtc_add_group in rtc_add_group and > return an error if rtc->registered is true. You are right. An error in this case is better. > > Regards Denis Diehl Connectivity Solutions GmbH Geschäftsführung: Horst Leonberger Sitz der Gesellschaft: Nürnberg - Registergericht: Amtsgericht Nürnberg: HRB 32315
diff --git a/drivers/rtc/rtc-core.h b/drivers/rtc/rtc-core.h index 0abf98983e13..81d1c3ce7a96 100644 --- a/drivers/rtc/rtc-core.h +++ b/drivers/rtc/rtc-core.h @@ -40,9 +40,15 @@ static inline void rtc_proc_del_device(struct rtc_device *rtc) #ifdef CONFIG_RTC_INTF_SYSFS const struct attribute_group **rtc_get_dev_attribute_groups(void); +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp); #else static inline const struct attribute_group **rtc_get_dev_attribute_groups(void) { return NULL; } +static inline +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) +{ + return 0; +} #endif diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c index 454da38c6012..9a177b8f761b 100644 --- a/drivers/rtc/rtc-sysfs.c +++ b/drivers/rtc/rtc-sysfs.c @@ -317,3 +317,42 @@ const struct attribute_group **rtc_get_dev_attribute_groups(void) { return rtc_attr_groups; } + +static size_t rtc_group_count(struct rtc_device *rtc) +{ + const struct attribute_group **groups = rtc->dev.groups; + size_t cnt = 0; + + if (groups) + for (; *groups; groups++) + cnt++; + + return cnt; +} + +static inline int +__rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) +{ + size_t cnt = rtc_group_count(rtc); + const struct attribute_group **groups, **old; + + groups = devm_kzalloc(&rtc->dev, (cnt+2)*sizeof(*groups), GFP_KERNEL); + if (IS_ERR_OR_NULL(groups)) + return PTR_ERR(groups); + memcpy(groups, rtc->dev.groups, cnt*sizeof(*groups)); + groups[cnt] = grp; + + old = rtc->dev.groups; + rtc->dev.groups = groups; + if (old != rtc_attr_groups) + devm_kfree(&rtc->dev, old); + + return 0; +} + +int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp) +{ + return rtc->dev.kobj.state_in_sysfs ? + devm_device_add_group(&rtc->dev, grp) : + __rtc_add_group(rtc, grp); +}