[PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[Andreea-Cristina Bernat]

The "rcu_dereference()" call is used directly in a condition.
Since its return value is never dereferenced it is recommended to use
"rcu_access_pointer()" instead of "rcu_dereference()".
Therefore, this patch makes the replacement.

The following Coccinelle semantic patch was used:
@@
@@

(
 if(
 (<+...
- rcu_dereference
+ rcu_access_pointer
  (...)
  ...+>)) {...}
|
 while(
 (<+...
- rcu_dereference
+ rcu_access_pointer
  (...)
  ...+>)) {...}
)

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
---
 drivers/staging/rtl8188eu/core/rtw_mlme.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_mlme.c b/drivers/staging/rtl8188eu/core/rtw_mlme.c
index 155282e..8643003 100644
--- a/drivers/staging/rtl8188eu/core/rtw_mlme.c
+++ b/drivers/staging/rtl8188eu/core/rtw_mlme.c
@@ -1544,7 +1544,7 @@ void rtw_dynamic_check_timer_handlder(struct adapter *adapter)
 
 	rcu_read_lock();
 
-	if (rcu_dereference(adapter->pnetdev->rx_handler_data) &&
+	if (rcu_access_pointer(adapter->pnetdev->rx_handler_data) &&
 	    (check_fwstate(pmlmepriv, WIFI_STATION_STATE|WIFI_ADHOC_STATE) == true)) {
 		/*  expire NAT2.5 entry */
 		nat25_db_expire(adapter);
-- 
1.9.1

Re: [PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[Greg KH]

On Sun, Aug 17, 2014 at 02:43:37PM +0300, Andreea-Cristina Bernat wrote:
> The "rcu_dereference()" call is used directly in a condition.
> Since its return value is never dereferenced it is recommended to use
> "rcu_access_pointer()" instead of "rcu_dereference()".
> Therefore, this patch makes the replacement.
> 
> The following Coccinelle semantic patch was used:
> @@
> @@
> 
> (
>  if(
>  (<+...
> - rcu_dereference
> + rcu_access_pointer
>   (...)
>   ...+>)) {...}
> |
>  while(
>  (<+...
> - rcu_dereference
> + rcu_access_pointer
>   (...)
>   ...+>)) {...}
> )
> 
> Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
> ---
>  drivers/staging/rtl8188eu/core/rtw_mlme.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

This patch fails to apply to my tree, can you refresh it against the
staging-next branch of the staging.git tree on kernel.org and resend?

thanks,

greg k-h

Re: [PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[Andreea Bernat]

Hello,

I cloned this:
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git

and after moved to staging-next branch, but in both cases, in
those files I don't find any use of rcu_dereference() call (the call
which I am looking for to modify).

Thank you,
Andreea

2014-08-30 23:42 GMT+03:00 Greg KH <gregkh@linuxfoundation.org>:
> On Sun, Aug 17, 2014 at 02:43:37PM +0300, Andreea-Cristina Bernat wrote:
>> The "rcu_dereference()" call is used directly in a condition.
>> Since its return value is never dereferenced it is recommended to use
>> "rcu_access_pointer()" instead of "rcu_dereference()".
>> Therefore, this patch makes the replacement.
>>
>> The following Coccinelle semantic patch was used:
>> @@
>> @@
>>
>> (
>>  if(
>>  (<+...
>> - rcu_dereference
>> + rcu_access_pointer
>>   (...)
>>   ...+>)) {...}
>> |
>>  while(
>>  (<+...
>> - rcu_dereference
>> + rcu_access_pointer
>>   (...)
>>   ...+>)) {...}
>> )
>>
>> Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
>> ---
>>  drivers/staging/rtl8188eu/core/rtw_mlme.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> This patch fails to apply to my tree, can you refresh it against the
> staging-next branch of the staging.git tree on kernel.org and resend?
>
> thanks,
>
> greg k-h

Re: [PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[Larry Finger]

On 09/04/2014 03:58 PM, Andreea Bernat wrote:
> Hello,
>
> I cloned this:
> git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
>
> and after moved to staging-next branch, but in both cases, in
> those files I don't find any use of rcu_dereference() call (the call
> which I am looking for to modify).

The rcu_dereference() call in core/rtw_mlme.c is no longer there in mainline 
3.17, thus it was removed some time ago.

There is a similar reference in os_dep/recv_linux.c. Perhaps it should be removed.

This problem shows the importance of working with the latest pull of the staging 
repo when working with staging code. Even then patches may suffer mid-air 
collisions if multiple devs are working on a particular piece of code.

Larry

Re: [PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[Greg KH]

On Thu, Sep 04, 2014 at 11:58:36PM +0300, Andreea Bernat wrote:
> Hello,
> 
> I cloned this:
> git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
> 
> and after moved to staging-next branch, but in both cases, in
> those files I don't find any use of rcu_dereference() call (the call
> which I am looking for to modify).

Then there's nothing left to be done here, right?  :)

thanks,

greg k-h

Re: [PATCH] rtl8188eu: Replace rcu_dereference() with rcu_access_pointer()

[Andreea Bernat]

2014-09-05 0:38 GMT+03:00 Greg KH <gregkh@linuxfoundation.org>:
> On Thu, Sep 04, 2014 at 11:58:36PM +0300, Andreea Bernat wrote:
>> Hello,
>>
>> I cloned this:
>> git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
>>
>> and after moved to staging-next branch, but in both cases, in
>> those files I don't find any use of rcu_dereference() call (the call
>> which I am looking for to modify).
>
> Then there's nothing left to be done here, right?  :)

Yes :-)

Thank you,
Andreea

>
> thanks,
>
> greg k-h