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authorPaolo Bonzini <pbonzini@redhat.com>2017-08-01 18:24:05 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-10 13:28:56 +0300
commit7a34bcb8b272b1300f0125c93a54f0c98812acdd (patch)
tree0b83ca55e6f18f63b995a4b1af68d800823f4204 /Documentation/static-keys.txt
parent1dbb6704de91b169a58d0c8221624afd6a95cfc7 (diff)
downloadlinux-7a34bcb8b272b1300f0125c93a54f0c98812acdd.tar.xz
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>
Diffstat (limited to 'Documentation/static-keys.txt')
-rw-r--r--Documentation/static-keys.txt5
1 files changed, 5 insertions, 0 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);