From a87b7dc9f7fa7c87cbd575361553e8e9e4ab4473 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 20 Apr 2018 15:38:00 -0700 Subject: [PATCH] net/ipv6: Move rcu locking to callers of fib6_get_cookie_safe A later patch protects 'from' in rt6_info and this simplifies the locking needed by it. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- include/net/ip6_fib.h | 6 ++++-- net/ipv6/route.c | 13 ++++++++++--- 2 files changed, 14 insertions(+), 5 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index dd1481ed8bdb..dc3505fb62b3 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -234,7 +234,6 @@ static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, struct fib6_node *fn; bool status = false; - rcu_read_lock(); fn = rcu_dereference(f6i->fib6_node); if (fn) { @@ -244,7 +243,6 @@ static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, status = true; } - rcu_read_unlock(); return status; } @@ -252,10 +250,14 @@ static inline u32 rt6_get_cookie(const struct rt6_info *rt) { u32 cookie = 0; + rcu_read_lock(); + if (rt->rt6i_flags & RTF_PCPU || (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->from)) fib6_get_cookie_safe(rt->from, &cookie); + rcu_read_unlock(); + return cookie; } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index f8b22183b7fd..810a37ac043b 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2159,9 +2159,12 @@ static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie) static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) { + struct dst_entry *dst_ret; struct rt6_info *rt; - rt = (struct rt6_info *) dst; + rt = container_of(dst, struct rt6_info, dst); + + rcu_read_lock(); /* All IPV6 dsts are created with ->obsolete set to the value * DST_OBSOLETE_FORCE_CHK which forces validation calls down @@ -2170,9 +2173,13 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) if (rt->rt6i_flags & RTF_PCPU || (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->from)) - return rt6_dst_from_check(rt, cookie); + dst_ret = rt6_dst_from_check(rt, cookie); else - return rt6_check(rt, cookie); + dst_ret = rt6_check(rt, cookie); + + rcu_read_unlock(); + + return dst_ret; } static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) -- 2.30.2