Re: [PATCH 2/4] Staging: rtl8712: Use ether_addr_equal() over memcmp()

[punit vara]

On Sun, Oct 11, 2015 at 6:07 AM, kbuild test robot <lkp@xxxxxxxxx> wrote:
> Hi Punit,
>
> [auto build test WARNING on v4.3-rc4 -- if it's inappropriate base, please ignore]
>
> reproduce:
>         # apt-get install sparse
>         make ARCH=x86_64 allmodconfig
>         make C=1 CF=-D__CHECK_ENDIAN__
>
>
> sparse warnings: (new ones prefixed by >>)
>
>    drivers/staging/rtl8712/rtl871x_ioctl_linux.c:227:15: sparse: cast to restricted __le16
>>> drivers/staging/rtl8712/rtl871x_ioctl_linux.c:2010:54: sparse: incorrect type in argument 2 (different base types)
>    drivers/staging/rtl8712/rtl871x_ioctl_linux.c:2010:54:    expected unsigned char const [usertype] *addr2
>    drivers/staging/rtl8712/rtl871x_ioctl_linux.c:2010:54:    got struct wlan_bssid_ex network
>    drivers/staging/rtl8712/rtl871x_ioctl_linux.c: In function 'r871x_get_ap_info':
>    drivers/staging/rtl8712/rtl871x_ioctl_linux.c:2010:32: error: incompatible type for argument 2 of 'ether_addr_equal'
>       if (!ether_addr_equal(bssid, pnetwork->network)) {
>                                    ^
>    In file included from drivers/staging/rtl8712/osdep_service.h:39:0,
>                     from drivers/staging/rtl8712/rtl871x_ioctl_linux.c:32:
>    include/linux/etherdevice.h:310:20: note: expected 'const u8 * {aka const unsigned char *}' but argument is of type 'struct wlan_bssid_ex'
>     static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
>                        ^
>
> vim +2010 drivers/staging/rtl8712/rtl871x_ioctl_linux.c
>
>   1994                   return -EINVAL;
>   1995          spin_lock_irqsave(&(pmlmepriv->scanned_queue.lock), irqL);
>   1996          phead = &queue->queue;
>   1997          plist = phead->next;
>   1998          while (1) {
>   1999                  if (end_of_queue_search(phead, plist) == true)
>   2000                          break;
>   2001                  pnetwork = LIST_CONTAINOR(plist, struct wlan_network, list);
>   2002                  if (hwaddr_aton_i(data, bssid)) {
>   2003                          netdev_info(dev, "r8712u: Invalid BSSID '%s'.\n",
>   2004                                      (u8 *)data);
>   2005                          spin_unlock_irqrestore(&(pmlmepriv->scanned_queue.lock),
>   2006                                                 irqL);
>   2007                          return -EINVAL;
>   2008                  }
>   2009                  netdev_info(dev, "r8712u: BSSID:%pM\n", bssid);
>> 2010                  if (!ether_addr_equal(bssid, pnetwork->network)) {
>   2011                          /* BSSID match, then check if supporting wpa/wpa2 */
>   2012                          pbuf = r8712_get_wpa_ie(&pnetwork->network.IEs[12],
>   2013                                 &wpa_ielen, pnetwork->network.IELength-12);
>   2014                          if (pbuf && (wpa_ielen > 0)) {
>   2015                                  pdata->flags = 1;
>   2016                                  break;
>   2017                          }
>   2018                          pbuf = r8712_get_wpa2_ie(&pnetwork->network.IEs[12],
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation


That error is because I forgot MacAddress that I have already mention.
Julia I have used pahole as you suggested me
following are the two structure need to be consider for alignment.

struct iw_pmksa {
__u32                      cmd;                     /*     0     4 */
struct sockaddr            bssid;                /*     4    16 */
__u8                       pmkid[16];              /*    20    16 */

/* size: 36, cachelines: 1, members: 3 */
/* last cacheline: 36 bytes */
};

struct wlan_bssid_ex {
u32                        Length;                           /*     0     4 */
unsigned char              MacAddress[6];        /*     4     6 */
u8                         Reserved[2];                    /*    10     2 */
struct ndis_802_11_ssid    Ssid;                  /*    12    36 */
u32                        Privacy;                          /*    48     4 */
s32                        Rssi;                               /*    52     4 */
enum NDIS_802_11_NETWORK_TYPE NetworkTypeInUse;  /*    56     4 */
struct NDIS_802_11_CONFIGURATION Configuration;           /*    60    32 */
/* --- cacheline 1 boundary (64 bytes) was 28 bytes ago --- */
enum NDIS_802_11_NETWORK_INFRASTRUCTURE InfrastructureMode; /*    92     4 */
u8                         rates[16];              /*    96    16 */
u32                        IELength;             /*   112     4 */
u8                         IEs[768];               /*   116   768 */
/* --- cacheline 13 boundary (832 bytes) was 52 bytes ago --- */

/* size: 884, cachelines: 14, members: 12 */
/* last cacheline: 52 bytes */
};


As I understood both are not aligned to u16 so
ether_addr_equal_unaligned() should be used.

Here ether_addr_equal_unaligned() return true if both  address are equal.

so here correct answer would be
if(ether_addr_equal_unaligned(bssid, pnetwork->network.MacAddress))  ??

If I am getting wrong any feedback are welcome  otherwise I will
resend patch with correct modification.
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