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authorArnd Bergmann2023-02-14 14:20:21 +0100
committerGreg Kroah-Hartman2023-03-10 09:33:05 +0100
commit2a0200daeccf95d05bfcc5b4ce9c668f72cd1f8a (patch)
treeea63f1dd987c33a191085d75e2f8c6f21115117f
parent1ee0a1d7fb3b1fc0eb78c70b03cbc9f915f3fc7f (diff)
wifi: mac80211: avoid u32_encode_bits() warning
[ Upstream commit 1d8d4af4347420d657be448f8be4c39c558f3b5d ] gcc-9 triggers a false-postive warning in ieee80211_mlo_multicast_tx() for u32_encode_bits(ffs(links) - 1, ...), since ffs() can return zero on an empty bitmask, and the negative argument to u32_encode_bits() is then out of range: In file included from include/linux/ieee80211.h:21, from include/net/cfg80211.h:23, from net/mac80211/tx.c:23: In function 'u32_encode_bits', inlined from 'ieee80211_mlo_multicast_tx' at net/mac80211/tx.c:4437:17, inlined from 'ieee80211_subif_start_xmit' at net/mac80211/tx.c:4485:3: include/linux/bitfield.h:177:3: error: call to '__field_overflow' declared with attribute error: value doesn't fit into mask 177 | __field_overflow(); \ | ^~~~~~~~~~~~~~~~~~ include/linux/bitfield.h:197:2: note: in expansion of macro '____MAKE_OP' 197 | ____MAKE_OP(u##size,u##size,,) | ^~~~~~~~~~~ include/linux/bitfield.h:200:1: note: in expansion of macro '__MAKE_OP' 200 | __MAKE_OP(32) | ^~~~~~~~~ Newer compiler versions do not cause problems with the zero argument because they do not consider this a __builtin_constant_p(). It's also harmless since the hweight16() check already guarantees that this cannot be 0. Replace the ffs() with an equivalent find_first_bit() check that matches the later for_each_set_bit() style and avoids the warning. Fixes: 963d0e8d08d9 ("wifi: mac80211: optionally implement MLO multicast TX") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20230214132025.1532147-1-arnd@kernel.org Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--net/mac80211/tx.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6409097a56c7..55220e764de6 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -4395,7 +4395,7 @@ static void ieee80211_mlo_multicast_tx(struct net_device *dev,
u32 ctrl_flags = IEEE80211_TX_CTRL_MCAST_MLO_FIRST_TX;
if (hweight16(links) == 1) {
- ctrl_flags |= u32_encode_bits(ffs(links) - 1,
+ ctrl_flags |= u32_encode_bits(find_first_bit(&links, 16) - 1,
IEEE80211_TX_CTRL_MLO_LINK);
__ieee80211_subif_start_xmit(skb, sdata->dev, 0, ctrl_flags,