[PATCH] staging: wlags49_h2: Replace kmalloc+memset by kzalloc and add error handling.

[santosh prasad nayak]

On Fri, Mar 23, 2012 at 8:26 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Fri, Mar 23, 2012 at 03:11:45PM +0530, santosh nayak wrote:
>> From: Santosh Nayak <santoshprasadnayak at gmail.com>
>>
>> Replace kmalloc+memset pair by kzalloc() in 'wl_wds_device_alloc()'.
>> Add error handling to avoid null derefernce.
>>
>> Signed-off-by: Santosh Nayak <santoshprasadnayak at gmail.com>
>> ---
>>  drivers/staging/wlags49_h2/wl_netdev.c |    8 ++++++--
>>  1 files changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/wlags49_h2/wl_netdev.c b/drivers/staging/wlags49_h2/wl_netdev.c
>> index 9c16f54..426ba04 100644
>> --- a/drivers/staging/wlags49_h2/wl_netdev.c
>> +++ b/drivers/staging/wlags49_h2/wl_netdev.c
>> @@ -1511,8 +1511,12 @@ void wl_wds_device_alloc( struct wl_private *lp )
>>      for( count = 0; count < NUM_WDS_PORTS; count++ ) {
>>          struct net_device *dev_wds = NULL;
>>
>> -        dev_wds = kmalloc( sizeof( struct net_device ), GFP_KERNEL );
>> -        memset( dev_wds, 0, sizeof( struct net_device ));
>> +     dev_wds = kzalloc(sizeof(struct net_device), GFP_KERNEL);
>> +     if (unlikely(!dev_wds)) {
>
> NEVER use unlikely unless you are working on scheduler code, or
> something else equally time critical.  So, take this into consideration,
> and Dan's comments, and please redo this, I can't take it as-is.
>

Greg,

I will include your suggestion and resend it.

Can you please explain whats the disadvantage of having 'unlikely()' here ?
I have seen it at several places in driver side.

regards
Santosh

> thanks,
>
> greg k-h