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authorEric Dumazet <edumazet@google.com>2023-09-22 03:42:21 +0000
committerDavid S. Miller <davem@davemloft.net>2023-10-01 19:39:19 +0100
commit02715925222c137f418ecac417b68c7801e8f729 (patch)
tree9335c1b4160ce9a68755d89abc5746090a80116f /net/ipv4/ip_sockglue.c
parentc4480eb5504c9771f935cbca58a3b874bdd36af8 (diff)
inet: implement lockless getsockopt(IP_MULTICAST_IF)
Add missing annotations to inet->mc_index and inet->mc_addr to fix data-races. getsockopt(IP_MULTICAST_IF) can be lockless. setsockopt() side is left for later. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
-rw-r--r--net/ipv4/ip_sockglue.c25
1 files changed, 12 insertions, 13 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 1ee01ff64171..0b74ac49d6a6 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1168,8 +1168,8 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
if (!mreq.imr_ifindex) {
if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
- inet->mc_index = 0;
- inet->mc_addr = 0;
+ WRITE_ONCE(inet->mc_index, 0);
+ WRITE_ONCE(inet->mc_addr, 0);
err = 0;
break;
}
@@ -1194,8 +1194,8 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
midx != sk->sk_bound_dev_if)
break;
- inet->mc_index = mreq.imr_ifindex;
- inet->mc_addr = mreq.imr_address.s_addr;
+ WRITE_ONCE(inet->mc_index, mreq.imr_ifindex);
+ WRITE_ONCE(inet->mc_addr, mreq.imr_address.s_addr);
err = 0;
break;
}
@@ -1673,19 +1673,11 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
case IP_UNICAST_IF:
val = (__force int)htonl((__u32) READ_ONCE(inet->uc_index));
goto copyval;
- }
-
- if (needs_rtnl)
- rtnl_lock();
- sockopt_lock_sock(sk);
-
- switch (optname) {
case IP_MULTICAST_IF:
{
struct in_addr addr;
len = min_t(unsigned int, len, sizeof(struct in_addr));
- addr.s_addr = inet->mc_addr;
- sockopt_release_sock(sk);
+ addr.s_addr = READ_ONCE(inet->mc_addr);
if (copy_to_sockptr(optlen, &len, sizeof(int)))
return -EFAULT;
@@ -1693,6 +1685,13 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
return -EFAULT;
return 0;
}
+ }
+
+ if (needs_rtnl)
+ rtnl_lock();
+ sockopt_lock_sock(sk);
+
+ switch (optname) {
case IP_MSFILTER:
{
struct ip_msfilter msf;