[PATCH -next] drivers/base/power: fix build error without SYSFS

[PATCH -next] drivers/base/power: fix build error without SYSFS

[Hongbo Yao]

If CONFIG_SYSFS=n, the following error is seen while building 
drivers/base/power/sysfs.c:

drivers/base/power/sysfs.c: In function dpm_sysfs_change_owner:
drivers/base/power/sysfs.c:708:44: error: passing argument 2 of
sysfs_group_change_owner from incompatible pointer type
[-Werror=incompatible-pointer-types]
  rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
                                            ^
In file included from ./include/linux/kobject.h:20:0,
                 from ./include/linux/device.h:17,
                 from drivers/base/power/sysfs.c:3:
./include/linux/sysfs.h:564:19: note: expected const struct
attribute_group ** but argument is of type const struct attribute_group *

dpm_sysfs_change_owner() should only used when CONFIG_SYSFS is
defined.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 3b52fc5d7876 ("drivers/base/power: add dpm_sysfs_change_owner()")
Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
---
 drivers/base/power/power.h | 10 +++++++++-
 drivers/base/power/sysfs.c |  2 ++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index 54292cdd7808..4bd88f696be9 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -74,7 +74,6 @@ extern int pm_qos_sysfs_add_flags(struct device *dev);
 extern void pm_qos_sysfs_remove_flags(struct device *dev);
 extern int pm_qos_sysfs_add_latency_tolerance(struct device *dev);
 extern void pm_qos_sysfs_remove_latency_tolerance(struct device *dev);
-extern int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
 
 #else /* CONFIG_PM */
 
@@ -89,6 +88,15 @@ static inline void pm_runtime_remove(struct device *dev) {}
 
 static inline int dpm_sysfs_add(struct device *dev) { return 0; }
 static inline void dpm_sysfs_remove(struct device *dev) {}
+
+#endif
+
+#if defined(CONFIG_PM) && defined(CONFIG_SYSFS)
+
+extern int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
+
+#else
+
 static inline int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid,
 					 kgid_t kgid) { return 0; }
 
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index 2b99fe1eb207..d6749f374ded 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -698,6 +698,7 @@ int dpm_sysfs_add(struct device *dev)
 	return rc;
 }
 
+#ifdef CONFIG_SYSFS
 int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
 {
 	int rc;
@@ -736,6 +737,7 @@ int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
 	}
 	return 0;
 }
+#endif
 
 int wakeup_sysfs_add(struct device *dev)
 {
-- 
2.17.1

Re: [PATCH -next] drivers/base/power: fix build error without SYSFS

[Greg KH]

On Mon, Mar 02, 2020 at 05:29:18PM +0800, Hongbo Yao wrote:
> If CONFIG_SYSFS=n, the following error is seen while building 
> drivers/base/power/sysfs.c:
> 
> drivers/base/power/sysfs.c: In function dpm_sysfs_change_owner:
> drivers/base/power/sysfs.c:708:44: error: passing argument 2 of
> sysfs_group_change_owner from incompatible pointer type
> [-Werror=incompatible-pointer-types]
>   rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
>                                             ^
> In file included from ./include/linux/kobject.h:20:0,
>                  from ./include/linux/device.h:17,
>                  from drivers/base/power/sysfs.c:3:
> ./include/linux/sysfs.h:564:19: note: expected const struct
> attribute_group ** but argument is of type const struct attribute_group *
> 
> dpm_sysfs_change_owner() should only used when CONFIG_SYSFS is
> defined.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: 3b52fc5d7876 ("drivers/base/power: add dpm_sysfs_change_owner()")
> Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
> ---
>  drivers/base/power/power.h | 10 +++++++++-
>  drivers/base/power/sysfs.c |  2 ++

You shouldn't have to add #ifdefs to a .c file here, it should all be
able to be fixed in the .h file by putting proper "empty" functions.

thanks,

greg k-h

Re: [PATCH -next] drivers/base/power: fix build error without SYSFS

[Hongbo Yao]

On 2020/3/2 17:23, Greg KH wrote:
> On Mon, Mar 02, 2020 at 05:29:18PM +0800, Hongbo Yao wrote:
>> If CONFIG_SYSFS=n, the following error is seen while building 
>> drivers/base/power/sysfs.c:
>>
>> drivers/base/power/sysfs.c: In function dpm_sysfs_change_owner:
>> drivers/base/power/sysfs.c:708:44: error: passing argument 2 of
>> sysfs_group_change_owner from incompatible pointer type
>> [-Werror=incompatible-pointer-types]
>>   rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
>>                                             ^
>> In file included from ./include/linux/kobject.h:20:0,
>>                  from ./include/linux/device.h:17,
>>                  from drivers/base/power/sysfs.c:3:
>> ./include/linux/sysfs.h:564:19: note: expected const struct
>> attribute_group ** but argument is of type const struct attribute_group *
>>
>> dpm_sysfs_change_owner() should only used when CONFIG_SYSFS is
>> defined.
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Fixes: 3b52fc5d7876 ("drivers/base/power: add dpm_sysfs_change_owner()")
>> Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
>> ---
>>  drivers/base/power/power.h | 10 +++++++++-
>>  drivers/base/power/sysfs.c |  2 ++
> 
> You shouldn't have to add #ifdefs to a .c file here, it should all be
> able to be fixed in the .h file by putting proper "empty" functions.

  I think it's a little difficult to fix this without changing the .c file,
  unless changing the Kconfig.

  This function was implemeted when CONFIG_PM=y, and if CONFIG_PM=n, this
  function would be "empty".

  However, I found this function should depends on CONFIG_SYSFS, if
  CONFIG_SYSFS=n, this function should also be empty, so only changing the
  dependency of the header file will cause redefinition.

  thanks,
  Hongbo.

> thanks,
> 
> greg k-h
> 
> .
> 

Re: [PATCH -next] drivers/base/power: fix build error without SYSFS

[Christian Brauner]

On Mon, Mar 02, 2020 at 05:29:18PM +0800, Hongbo Yao wrote:
> If CONFIG_SYSFS=n, the following error is seen while building 
> drivers/base/power/sysfs.c:
> 
> drivers/base/power/sysfs.c: In function dpm_sysfs_change_owner:
> drivers/base/power/sysfs.c:708:44: error: passing argument 2 of
> sysfs_group_change_owner from incompatible pointer type
> [-Werror=incompatible-pointer-types]
>   rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
>                                             ^
> In file included from ./include/linux/kobject.h:20:0,
>                  from ./include/linux/device.h:17,
>                  from drivers/base/power/sysfs.c:3:
> ./include/linux/sysfs.h:564:19: note: expected const struct
> attribute_group ** but argument is of type const struct attribute_group *
> 
> dpm_sysfs_change_owner() should only used when CONFIG_SYSFS is
> defined.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: 3b52fc5d7876 ("drivers/base/power: add dpm_sysfs_change_owner()")
> Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>

Thanks for catching this!
An organizational comment first. The series this belongs to is sitting
in Dave Miller's net-next tree. So this fix needs to go through his tree
to. This just means, you should Cc the netdev kernel mailing list and
append make the subject
[PATCH net-next] drivers/base/power: fix build error without SYSFS
.

But about the fix. It strikes me as odd that this fails in pm_attr_group
since dpm_sysfs_add() doesn't but also unconditionally accesses pm_attr_group.

Christian

Re: [PATCH -next] drivers/base/power: fix build error without SYSFS

[Hongbo Yao]

On 2020/3/2 17:31, Christian Brauner wrote:
> On Mon, Mar 02, 2020 at 05:29:18PM +0800, Hongbo Yao wrote:
>> If CONFIG_SYSFS=n, the following error is seen while building 
>> drivers/base/power/sysfs.c:
>>
>> drivers/base/power/sysfs.c: In function dpm_sysfs_change_owner:
>> drivers/base/power/sysfs.c:708:44: error: passing argument 2 of
>> sysfs_group_change_owner from incompatible pointer type
>> [-Werror=incompatible-pointer-types]
>>   rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
>>                                             ^
>> In file included from ./include/linux/kobject.h:20:0,
>>                  from ./include/linux/device.h:17,
>>                  from drivers/base/power/sysfs.c:3:
>> ./include/linux/sysfs.h:564:19: note: expected const struct
>> attribute_group ** but argument is of type const struct attribute_group *
>>
>> dpm_sysfs_change_owner() should only used when CONFIG_SYSFS is
>> defined.
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Fixes: 3b52fc5d7876 ("drivers/base/power: add dpm_sysfs_change_owner()")
>> Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
> 
> Thanks for catching this!
> An organizational comment first. The series this belongs to is sitting
> in Dave Miller's net-next tree. So this fix needs to go through his tree
> to. This just means, you should Cc the netdev kernel mailing list and
> append make the subject
> [PATCH net-next] drivers/base/power: fix build error without SYSFS
> .

  Thanks, I'll resend it with this tag .


> But about the fix. It strikes me as odd that this fails in pm_attr_group
> since dpm_sysfs_add() doesn't but also unconditionally accesses pm_attr_group.

  The two functions have different parameter types when CONFIG_SYSFS=n.

> Christian
> 
> .
>