From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
syzbot <syzkaller@googlegroups.com>
Subject: [PATCH net] net: annotate accesses to sk->sk_incoming_cpu
Date: Wed, 30 Oct 2019 13:00:04 -0700 [thread overview]
Message-ID: <20191030200004.234357-1-edumazet@google.com> (raw)
This socket field can be read and written by concurrent cpus.
Use READ_ONCE() and WRITE_ONCE() annotations to document this,
and avoid some compiler 'optimizations'.
KCSAN reported :
BUG: KCSAN: data-race in tcp_v4_rcv / tcp_v4_rcv
write to 0xffff88812220763c of 4 bytes by interrupt on cpu 0:
sk_incoming_cpu_update include/net/sock.h:953 [inline]
tcp_v4_rcv+0x1b3c/0x1bb0 net/ipv4/tcp_ipv4.c:1934
ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
__netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
process_backlog+0x1d3/0x420 net/core/dev.c:5955
napi_poll net/core/dev.c:6392 [inline]
net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
__do_softirq+0x115/0x33f kernel/softirq.c:292
do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337
do_softirq kernel/softirq.c:329 [inline]
__local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189
read to 0xffff88812220763c of 4 bytes by interrupt on cpu 1:
sk_incoming_cpu_update include/net/sock.h:952 [inline]
tcp_v4_rcv+0x181a/0x1bb0 net/ipv4/tcp_ipv4.c:1934
ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
__netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
process_backlog+0x1d3/0x420 net/core/dev.c:5955
napi_poll net/core/dev.c:6392 [inline]
net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
__do_softirq+0x115/0x33f kernel/softirq.c:292
run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
include/net/sock.h | 4 ++--
net/core/sock.c | 4 ++--
net/ipv4/inet_hashtables.c | 2 +-
net/ipv4/udp.c | 2 +-
net/ipv6/inet6_hashtables.c | 2 +-
net/ipv6/udp.c | 2 +-
6 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index c31a9ed86d5a58be7f1ca9933c48c40f12d0e57f..8f9adcfac41bea7e46062851a25c042261323679 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -954,8 +954,8 @@ static inline void sk_incoming_cpu_update(struct sock *sk)
{
int cpu = raw_smp_processor_id();
- if (unlikely(sk->sk_incoming_cpu != cpu))
- sk->sk_incoming_cpu = cpu;
+ if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
+ WRITE_ONCE(sk->sk_incoming_cpu, cpu);
}
static inline void sock_rps_record_flow_hash(__u32 hash)
diff --git a/net/core/sock.c b/net/core/sock.c
index b8e758bcb6ad65c93e93fb64f70a61e353a5737e..ac78a570e43add1ce263841212b3759dbbfd8eae 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1127,7 +1127,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
break;
}
case SO_INCOMING_CPU:
- sk->sk_incoming_cpu = val;
+ WRITE_ONCE(sk->sk_incoming_cpu, val);
break;
case SO_CNX_ADVICE:
@@ -1476,7 +1476,7 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
break;
case SO_INCOMING_CPU:
- v.val = sk->sk_incoming_cpu;
+ v.val = READ_ONCE(sk->sk_incoming_cpu);
break;
case SO_MEMINFO:
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 97824864e40d13bac71510920ae125c6a89fef1d..83fb00153018f16678e71695134f7ae4d30ee0a3 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -240,7 +240,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
return -1;
score = sk->sk_family == PF_INET ? 2 : 1;
- if (sk->sk_incoming_cpu == raw_smp_processor_id())
+ if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
score++;
}
return score;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index d1ed160af202c054839387201abd3f13b55d00e9..1d58ce829dcae476a7a32a6ab5fa8bb91ec8ae67 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -388,7 +388,7 @@ static int compute_score(struct sock *sk, struct net *net,
return -1;
score += 4;
- if (sk->sk_incoming_cpu == raw_smp_processor_id())
+ if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
score++;
return score;
}
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index cf60fae9533b230455d89007a9ac45af958f2efe..fbe9d4295eac38d247aca362d6006cdec2d7f7da 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -105,7 +105,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
return -1;
score = 1;
- if (sk->sk_incoming_cpu == raw_smp_processor_id())
+ if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
score++;
}
return score;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 6324d3a8cb53dd76ea0deaf4358e33e529ce56ec..9fec580c968e0d331fcaf54289364526ebd902c2 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -135,7 +135,7 @@ static int compute_score(struct sock *sk, struct net *net,
return -1;
score++;
- if (sk->sk_incoming_cpu == raw_smp_processor_id())
+ if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
score++;
return score;
--
2.24.0.rc0.303.g954a862665-goog
next reply other threads:[~2019-10-30 20:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-30 20:00 Eric Dumazet [this message]
2019-10-30 20:27 ` [PATCH net] net: annotate accesses to sk->sk_incoming_cpu David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191030200004.234357-1-edumazet@google.com \
--to=edumazet@google.com \
--cc=davem@davemloft.net \
--cc=eric.dumazet@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=syzkaller@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox