From 7a34bcb8b272b1300f0125c93a54f0c98812acdd Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 1 Aug 2017 17:24:05 +0200 Subject: [PATCH] jump_label: Do not use unserialized static_key_enabled() Any use of key->enabled (that is static_key_enabled and static_key_count) outside jump_label_lock should handle its own serialization. The only two that are not doing so are the UDP encapsulation static keys. Change them to use static_key_enable, which now correctly tests key->enabled under the jump label lock. Signed-off-by: Paolo Bonzini Signed-off-by: Peter Zijlstra (Intel) Cc: Eric Dumazet Cc: Jason Baron Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1501601046-35683-3-git-send-email-pbonzini@redhat.com Signed-off-by: Ingo Molnar --- Documentation/static-keys.txt | 5 +++++ net/ipv4/udp.c | 3 +-- net/ipv6/udp.c | 3 +-- 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/Documentation/static-keys.txt b/Documentation/static-keys.txt index b83dfa1c0602..870b4be3cb11 100644 --- a/Documentation/static-keys.txt +++ b/Documentation/static-keys.txt @@ -149,6 +149,11 @@ static_branch_inc(), will change the branch back to true. Likewise, if the key is initialized false, a 'static_branch_inc()', will change the branch to true. And then a 'static_branch_dec()', will again make the branch false. +The state and the reference count can be retrieved with 'static_key_enabled()' +and 'static_key_count()'. In general, if you use these functions, they +should be protected with the same mutex used around the enable/disable +or increment/decrement function. + Where an array of keys is required, it can be defined as:: DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index e6276fa3750b..3037339ed8b8 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1809,8 +1809,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) static struct static_key udp_encap_needed __read_mostly; void udp_encap_enable(void) { - if (!static_key_enabled(&udp_encap_needed)) - static_key_slow_inc(&udp_encap_needed); + static_key_enable(&udp_encap_needed); } EXPORT_SYMBOL(udp_encap_enable); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 578142b7ca3e..96d240798c38 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -574,8 +574,7 @@ static __inline__ void udpv6_err(struct sk_buff *skb, static struct static_key udpv6_encap_needed __read_mostly; void udpv6_encap_enable(void) { - if (!static_key_enabled(&udpv6_encap_needed)) - static_key_slow_inc(&udpv6_encap_needed); + static_key_enable(&udpv6_encap_needed); } EXPORT_SYMBOL(udpv6_encap_enable); -- 2.20.1