Messages in this thread Patch in this message | | | From | Paolo Bonzini <> | Subject | [PATCH 2/3] jump_labels: do not use unserialized static_key_enabled | Date | Tue, 1 Aug 2017 17:24:05 +0200 |
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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.
Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- 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 ef419fd0897f..181998852961 100644 --- a/Documentation/static-keys.txt +++ b/Documentation/static-keys.txt @@ -142,6 +142,11 @@ 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 1d6219bf2d6b..74b7810df9fc 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1644,8 +1644,7 @@ 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 75703fda23e7..1a96233622b7 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -564,8 +564,7 @@ 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); -- 1.8.3.1
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