linux/drivers/staging/rtl8723bs
Gustavo A. R. Silva bc8392e33d staging: rtl8723bs: Replace one-element array with flexible-array member in struct ndis_80211_var_ie
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Refactor the code according to the use of a flexible-array member in
struct ndis_80211_var_ie, instead of a one-element array.

Also, this helps with the ongoing efforts to enable -Warray-bounds and
fix the following warnings:

  CC [M]  drivers/staging/rtl8723bs/core/rtw_wlan_util.o
In file included from ./drivers/staging/rtl8723bs/include/drv_types.h:20,
                 from drivers/staging/rtl8723bs/core/rtw_wlan_util.c:9:
drivers/staging/rtl8723bs/core/rtw_wlan_util.c: In function ‘HT_caps_handler’:
./drivers/staging/rtl8723bs/include/basic_types.h:108:11: warning: array subscript 1 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
  108 |  (EF1BYTE(*((u8 *)(__pstart))))
      |           ^
./drivers/staging/rtl8723bs/include/basic_types.h:42:8: note: in definition of macro ‘EF1BYTE’
   42 |  ((u8)(_val))
      |        ^~~~
./drivers/staging/rtl8723bs/include/basic_types.h:127:4: note: in expansion of macro ‘LE_P1BYTE_TO_HOST_1BYTE’
  127 |   (LE_P1BYTE_TO_HOST_1BYTE(__pstart) >> (__bitoffset)) & \
      |    ^~~~~~~~~~~~~~~~~~~~~~~
./drivers/staging/rtl8723bs/include/rtw_ht.h:97:55: note: in expansion of macro ‘LE_BITS_TO_1BYTE’
   97 | #define GET_HT_CAPABILITY_ELE_RX_STBC(_pEleStart)     LE_BITS_TO_1BYTE((_pEleStart)+1, 0, 2)
      |                                                       ^~~~~~~~~~~~~~~~
drivers/staging/rtl8723bs/core/rtw_wlan_util.c:1104:58: note: in expansion of macro ‘GET_HT_CAPABILITY_ELE_RX_STBC’
 1104 |   if (TEST_FLAG(phtpriv->stbc_cap, STBC_HT_ENABLE_TX) && GET_HT_CAPABILITY_ELE_RX_STBC(pIE->data)) {
      |                                                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/staging/rtl8723bs/core/rtw_wlan_util.c:1051:75: warning: array subscript 2 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
 1051 |    if ((pmlmeinfo->HT_caps.u.HT_cap_element.AMPDU_para & 0x3) > (pIE->data[i] & 0x3))
      |                                                                  ~~~~~~~~~^~~
drivers/staging/rtl8723bs/core/rtw_wlan_util.c: In function ‘check_assoc_AP’:
drivers/staging/rtl8723bs/core/rtw_wlan_util.c:1606:19: warning: array subscript 4 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
 1606 |      if (pIE->data[4] == 1)
      |          ~~~~~~~~~^~~
drivers/staging/rtl8723bs/core/rtw_wlan_util.c:1609:20: warning: array subscript 5 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
 1609 |       if (pIE->data[5] & RT_HT_CAP_USE_92SE)
      |           ~~~~~~~~~^~~
drivers/staging/rtl8723bs/core/rtw_wlan_util.c:1613:19: warning: array subscript 5 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
 1613 |      if (pIE->data[5] & RT_HT_CAP_USE_SOFTAP)
      |          ~~~~~~~~~^~~
drivers/staging/rtl8723bs/core/rtw_wlan_util.c:1617:20: warning: array subscript 6 is above array bounds of ‘u8[1]’ {aka ‘unsigned char[1]’} [-Warray-bounds]
 1617 |       if (pIE->data[6] & RT_HT_CAP_USE_JAGUAR_BCUT) {
      |           ~~~~~~~~~^~~

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/602434b8.jc5DoXJ0bmHoxgIL%25lkp@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20210210224937.GA11922@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-11 12:13:53 +01:00
..
core Staging: rtl8723bs/core: fix braces coding style issues 2020-12-28 15:08:29 +01:00
hal staging: rtl8723bs: remove typedefs from rtl8723b_recv.h 2021-02-09 18:42:16 +01:00
include staging: rtl8723bs: Replace one-element array with flexible-array member in struct ndis_80211_var_ie 2021-02-11 12:13:53 +01:00
os_dep staging: rtl8723bs: fix braces for os_dep/mlme_linux.c 2021-02-09 09:28:19 +01:00
Kconfig staging: rtl8723bs: use help instead of ---help--- in Kconfig 2019-05-20 10:49:08 +02:00
Makefile staging: rtl8723bs: Remove debugging information exposed via procfs 2019-08-14 13:20:12 +02:00
TODO staging: rtl8723bs: Remove myself from CC: 2019-06-20 14:32:07 +02:00