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| author |   Paolo Bonzini <pbonzini@redhat.com> | 2017-08-01 17:24:05 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2017-08-10 12:28:56 +0200 |
| commit | 7a34bcb8b272b1300f0125c93a54f0c98812acdd (patch) | |
| tree | 0b83ca55e6f18f63b995a4b1af68d800823f4204 | |
| parent | jump_label: Fix concurrent static_key_enable/disable() (diff) | |
| download | linux-dev-7a34bcb8b272b1300f0125c93a54f0c98812acdd.tar.xz linux-dev-7a34bcb8b272b1300f0125c93a54f0c98812acdd.zip | |
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 <pbonzini@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1501601046-35683-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | Documentation/static-keys.txt | 5 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 3 | ||||
| -rw-r--r-- | 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); |