Re: [PATCH net] rds: Fix endian annotations across various assignments
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2025-08-10 17:47:11
Also in:
linux-rdma, lkml
On Sun, Aug 10, 2025 at 10:41:55PM +0530, Ujwal Kundur wrote:
quoted hunk ↗ jump to hunk
diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c index 086a13170e09..9cd5905d916a 100644 --- a/net/rds/af_rds.c +++ b/net/rds/af_rds.c@@ -242,7 +242,7 @@ static __poll_t rds_poll(struct file *file, struct socket *sock, if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) mask |= (EPOLLOUT | EPOLLWRNORM); if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) - mask |= POLLERR; + mask |= (__force __poll_t)POLLERR;
EPOLLERR.
quoted hunk ↗ jump to hunk
read_unlock_irqrestore(&rs->rs_recv_lock, flags); /* clear state any time we wake a seen-congested socket */diff --git a/net/rds/connection.c b/net/rds/connection.c index d62f486ab29f..0047b76c3c0b 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c@@ -62,13 +62,13 @@ static struct hlist_head *rds_conn_bucket(const struct in6_addr *laddr, net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret)); net_get_random_once(&rds6_hash_secret, sizeof(rds6_hash_secret)); - lhash = (__force u32)laddr->s6_addr32[3]; + lhash = (__force __u32)laddr->s6_addr32[3]; #if IS_ENABLED(CONFIG_IPV6) fhash = __ipv6_addr_jhash(faddr, rds6_hash_secret); #else - fhash = (__force u32)faddr->s6_addr32[3]; + fhash = (__force __u32)(faddr->s6_addr32[3]); #endif - hash = __inet_ehashfn(lhash, 0, fhash, 0, rds_hash_secret); + hash = __inet_ehashfn((__force __be32)lhash, 0, (__force __be32)fhash, 0, rds_hash_secret);
what the... You have lhash and fhash set to __be32 values, then feed them to function that expects __be32 argument. Just turn these two variables into __be32 and lose the pointless casts.
quoted hunk ↗ jump to hunk
diff --git a/net/rds/rds.h b/net/rds/rds.h index dc360252c515..c2fb47e1fe07 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h@@ -93,7 +93,7 @@ enum { /* Max number of multipaths per RDS connection. Must be a power of 2 */ #define RDS_MPATH_WORKERS 8 -#define RDS_MPATH_HASH(rs, n) (jhash_1word((rs)->rs_bound_port, \ +#define RDS_MPATH_HASH(rs, n) (jhash_1word((__force __u16)(rs)->rs_bound_port, \ (rs)->rs_hash_initval) & ((n) - 1))
Reasonable.
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#define IS_CANONICAL(laddr, faddr) (htonl(laddr) < htonl(faddr))diff --git a/net/rds/recv.c b/net/rds/recv.c index 5627f80013f8..7fc7a3850a7b 100644 --- a/net/rds/recv.c +++ b/net/rds/recv.c@@ -216,10 +216,10 @@ static void rds_recv_hs_exthdrs(struct rds_header *hdr, switch (type) { case RDS_EXTHDR_NPATHS: conn->c_npaths = min_t(int, RDS_MPATH_WORKERS, - be16_to_cpu(buffer.rds_npaths)); + (__force __u16)buffer.rds_npaths);
No. It will break on little-endian. That's over-the-wire data you are dealing with; it's *NOT* going to be host-endian. Fix the buggered annotations instead.
break; case RDS_EXTHDR_GEN_NUM: - new_peer_gen_num = be32_to_cpu(buffer.rds_gen_num); + new_peer_gen_num = (__force __u32)buffer.rds_gen_num; break;
Ditto.
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diff --git a/net/rds/send.c b/net/rds/send.c index 42d991bc8543..0d79455c9721 100644 --- a/net/rds/send.c +++ b/net/rds/send.c@@ -1454,8 +1454,8 @@ rds_send_probe(struct rds_conn_path *cp, __be16 sport, if (RDS_HS_PROBE(be16_to_cpu(sport), be16_to_cpu(dport)) && cp->cp_conn->c_trans->t_mp_capable) { - u16 npaths = cpu_to_be16(RDS_MPATH_WORKERS); - u32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num); + u16 npaths = (__force __u16)RDS_MPATH_WORKERS; + u32 my_gen_num = (__force __u32)cp->cp_conn->c_my_gen_num;
Again, over-the-wire data; you are breaking it on l-e.
rds_message_add_extension(&rm->m_inc.i_hdr, RDS_EXTHDR_NPATHS, &npaths,