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| author | Arnd Bergmann <arnd@arndb.de> | 2018-08-18 01:43:36 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-18 02:20:27 +0300 |
| commit | e36488c83b6d871b35dd555afb2d434bd61687cf (patch) | |
| tree | d16922681b3317ec836315159382501f87a7c7dc /include/linux/bitfield.h | |
| parent | 6ed191ca9045e595d02cdf206fd7d494a1573bdd (diff) | |
| download | linux-e36488c83b6d871b35dd555afb2d434bd61687cf.tar.xz | |
bitfield: avoid gcc-8 -Wint-in-bool-context warning
Passing an enum into FIELD_GET() produces a long but harmless warning on
newer compilers:
from include/linux/linkage.h:7,
from include/linux/kernel.h:7,
from include/linux/skbuff.h:17,
from include/linux/if_ether.h:23,
from include/linux/etherdevice.h:25,
from drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c:63:
drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c: In function 'iwl_mvm_rx_mpdu_mq':
include/linux/bitfield.h:56:20: error: enum constant in boolean context [-Werror=int-in-bool-context]
BUILD_BUG_ON_MSG(!(_mask), _pfx "mask is zero"); \
^
...
include/linux/bitfield.h:103:3: note: in expansion of macro '__BF_FIELD_CHECK'
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^~~~~~~~~~~~~~~~
drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c:1025:21: note: in expansion of macro 'FIELD_GET'
le16_encode_bits(FIELD_GET(IWL_RX_HE_PHY_SIBG_SYM_OR_USER_NUM_MASK,
The problem here is that the caller has no idea how the macro gets
expanding, leading to a false-positive. It can be trivially avoided by
doing a comparison against zero.
This only recently started appearing as the iwlwifi driver was patched
to use FIELD_GET.
Link: http://lkml.kernel.org/r/20180813220950.194841-1-arnd@arndb.de
Fixes: 514c30696fbc ("iwlwifi: add support for IEEE802.11ax")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/bitfield.h')
| -rw-r--r-- | include/linux/bitfield.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h index 65a6981eef7b..3f1ef4450a7c 100644 --- a/include/linux/bitfield.h +++ b/include/linux/bitfield.h @@ -53,7 +53,7 @@ ({ \ BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \ _pfx "mask is not constant"); \ - BUILD_BUG_ON_MSG(!(_mask), _pfx "mask is zero"); \ + BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero"); \ BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ? \ ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \ _pfx "value too large for the field"); \ |