Messages in this thread Patch in this message | | | Date | Wed, 29 Feb 2012 02:13:40 -0800 | From | tip-bot for Jason Baron <> | Subject | [tip:perf/core] jump label: Add a WARN() if jump label key count goes negative |
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Commit-ID: fadf0464b83f91ba021a358c0238a0810c0d2a0b Gitweb: http://git.kernel.org/tip/fadf0464b83f91ba021a358c0238a0810c0d2a0b Author: Jason Baron <jbaron@redhat.com> AuthorDate: Tue, 21 Feb 2012 15:02:53 -0500 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 22 Feb 2012 07:59:39 +0100
jump label: Add a WARN() if jump label key count goes negative
The count on a jump label key should never go negative. Add a WARN() to check for this condition.
Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: davem@davemloft.net Cc: ddaney.cavm@gmail.com Cc: a.p.zijlstra@chello.nl Link: http://lkml.kernel.org/r/3c68556121be4d1920417a3fe367da1ec38246b4.1329851692.git.jbaron@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> --- kernel/jump_label.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 01d3b70..ed9654f 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -76,8 +76,11 @@ EXPORT_SYMBOL_GPL(jump_label_inc); static void __jump_label_dec(struct jump_label_key *key, unsigned long rate_limit, struct delayed_work *work) { - if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) + if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) { + WARN(atomic_read(&key->enabled) < 0, + "jump label: negative count!\n"); return; + } if (rate_limit) { atomic_inc(&key->enabled);
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