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| author | Eric Dumazet <edumazet@google.com> | 2022-06-23 04:34:43 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-06-24 11:34:37 +0100 |
| commit | db9eb7c8ae34c4acdb8a94c3566d1b4f4b5e7b1c (patch) | |
| tree | 1a2b95a4b465f9f65a5e1cff017b53396f9bc842 /net/ipv6/ip6mr.c | |
| parent | 638cf4a24a09d14c51415dd0964f978f97d54642 (diff) | |
| download | linux-stable-db9eb7c8ae34c4acdb8a94c3566d1b4f4b5e7b1c.tar.gz linux-stable-db9eb7c8ae34c4acdb8a94c3566d1b4f4b5e7b1c.tar.bz2 linux-stable-db9eb7c8ae34c4acdb8a94c3566d1b4f4b5e7b1c.zip | |
ip6mr: do not acquire mrt_lock before calling ip6mr_cache_unresolved
rcu_read_lock() protection is good enough.
ip6mr_cache_unresolved() uses a dedicated spinlock (mfc_unres_lock)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/ip6mr.c')
| -rw-r--r-- | net/ipv6/ip6mr.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index b4ad606e24bd..089c26af3120 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -730,7 +730,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, if (VIF_EXISTS(mrt, tmp)) break; } - mrt->maxvif = tmp + 1; + WRITE_ONCE(mrt->maxvif, tmp + 1); } write_unlock_bh(&mrt_lock); @@ -927,7 +927,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, WRITE_ONCE(mrt->mroute_reg_vif_num, vifi); #endif if (vifi + 1 > mrt->maxvif) - mrt->maxvif = vifi + 1; + WRITE_ONCE(mrt->maxvif, vifi + 1); write_unlock_bh(&mrt_lock); call_ip6mr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, dev, vifi, mrt->id); @@ -2099,11 +2099,13 @@ out_free: return 0; } +/* Called with mrt_lock or rcu_read_lock() */ static int ip6mr_find_vif(struct mr_table *mrt, struct net_device *dev) { int ct; - for (ct = mrt->maxvif - 1; ct >= 0; ct--) { + /* Pairs with WRITE_ONCE() in mif6_delete()/mif6_add() */ + for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) { if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev) break; } @@ -2249,7 +2251,6 @@ int ip6_mr_input(struct sk_buff *skb) return err; } - read_lock(&mrt_lock); cache = ip6mr_cache_find(mrt, &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr); if (!cache) { @@ -2270,15 +2271,14 @@ int ip6_mr_input(struct sk_buff *skb) vif = ip6mr_find_vif(mrt, dev); if (vif >= 0) { int err = ip6mr_cache_unresolved(mrt, vif, skb, dev); - read_unlock(&mrt_lock); return err; } - read_unlock(&mrt_lock); kfree_skb(skb); return -ENODEV; } + read_lock(&mrt_lock); ip6_mr_forward(net, mrt, dev, skb, cache); read_unlock(&mrt_lock); |