The sparse commit 6002ded74587 ("add a flag to warn on casts to/from bitwise pointers") introduced a check for non-direct casts from/to restricted datatypes (when -Wbitwise-pointer is enabled).
This triggered various warnings in batman-adv when some (already big endian) buffer content was casted to/from the corresponding big endian integer data types. But these were correct and can therefore be marked with __force to signalize sparse an intended cast from/to a bitwise type.
Signed-off-by: Sven Eckelmann sven@narfation.org --- net/batman-adv/bridge_loop_avoidance.c | 2 +- net/batman-adv/distributed-arp-table.c | 8 +++++--- 2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 663a53b6..0eff3358 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -844,7 +844,7 @@ static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr,
/* handle as ANNOUNCE frame */ backbone_gw->lasttime = jiffies; - crc = ntohs(*((__be16 *)(&an_addr[4]))); + crc = ntohs(*((__force __be16 *)(&an_addr[4])));
batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n", diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index b0af3a11..5004e38f 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -246,7 +246,7 @@ static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) */ static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) { - return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); + return *(__force __be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); }
/** @@ -270,7 +270,9 @@ static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) */ static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) { - return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); + u8 *dst = batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4; + + return *(__force __be32 *)dst; }
/** @@ -287,7 +289,7 @@ static u32 batadv_hash_dat(const void *data, u32 size) const unsigned char *key; u32 i;
- key = (const unsigned char *)&dat->ip; + key = (__force const unsigned char *)&dat->ip; for (i = 0; i < sizeof(dat->ip); i++) { hash += key[i]; hash += (hash << 10);