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authorEric Dumazet <edumazet@google.com>2023-09-18 14:23:21 +0000
committerPaolo Abeni <pabeni@redhat.com>2023-09-19 18:21:44 +0200
commitfa17a6d8a5bd0cd7565b613cb804242cd0f6b7ab (patch)
tree47b212f49ee830235b382165cf734328cdff2e00 /include
parent6a23c555f7eb436d6799533675ffa179db3d5834 (diff)
ipv6: lockless IPV6_ADDR_PREFERENCES implementation
We have data-races while reading np->srcprefs Switch the field to a plain byte, add READ_ONCE() and WRITE_ONCE() annotations where needed, and IPV6_ADDR_PREFERENCES setsockopt() can now be lockless. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230918142321.1794107-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ipv6.h2
-rw-r--r--include/net/ip6_route.h5
-rw-r--r--include/net/ipv6.h20
3 files changed, 10 insertions, 17 deletions
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 09253825c99c..e400ff757f13 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -243,7 +243,7 @@ struct ipv6_pinfo {
} rxopt;
/* sockopt flags */
- __u8 srcprefs:3; /* 001: prefer temporary address
+ __u8 srcprefs; /* 001: prefer temporary address
* 010: prefer public address
* 100: prefer care-of address
*/
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index b1ea49900b4a..28b065790261 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -53,13 +53,12 @@ struct route_info {
*/
static inline int rt6_srcprefs2flags(unsigned int srcprefs)
{
- /* No need to bitmask because srcprefs have only 3 bits. */
- return srcprefs << 3;
+ return (srcprefs & IPV6_PREFER_SRC_MASK) << 3;
}
static inline unsigned int rt6_flags2srcprefs(int flags)
{
- return (flags >> 3) & 7;
+ return (flags >> 3) & IPV6_PREFER_SRC_MASK;
}
static inline bool rt6_need_strict(const struct in6_addr *daddr)
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index bd115980809f..b3444c8a6f74 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1306,10 +1306,13 @@ static inline void ip6_sock_set_recverr(struct sock *sk)
inet6_set_bit(RECVERR6, sk);
}
-static inline int __ip6_sock_set_addr_preferences(struct sock *sk, int val)
+#define IPV6_PREFER_SRC_MASK (IPV6_PREFER_SRC_TMP | IPV6_PREFER_SRC_PUBLIC | \
+ IPV6_PREFER_SRC_COA)
+
+static inline int ip6_sock_set_addr_preferences(struct sock *sk, int val)
{
+ unsigned int prefmask = ~IPV6_PREFER_SRC_MASK;
unsigned int pref = 0;
- unsigned int prefmask = ~0;
/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
switch (val & (IPV6_PREFER_SRC_PUBLIC |
@@ -1359,20 +1362,11 @@ static inline int __ip6_sock_set_addr_preferences(struct sock *sk, int val)
return -EINVAL;
}
- inet6_sk(sk)->srcprefs = (inet6_sk(sk)->srcprefs & prefmask) | pref;
+ WRITE_ONCE(inet6_sk(sk)->srcprefs,
+ (READ_ONCE(inet6_sk(sk)->srcprefs) & prefmask) | pref);
return 0;
}
-static inline int ip6_sock_set_addr_preferences(struct sock *sk, int val)
-{
- int ret;
-
- lock_sock(sk);
- ret = __ip6_sock_set_addr_preferences(sk, val);
- release_sock(sk);
- return ret;
-}
-
static inline void ip6_sock_set_recvpktinfo(struct sock *sk)
{
lock_sock(sk);