From fadf0464b83f91ba021a358c0238a0810c0d2a0b Mon Sep 17 00:00:00 2001 From: Jason Baron <jbaron@redhat.com> Date: Tue, 21 Feb 2012 15:02:53 -0500 Subject: 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 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/jump_label.c') diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 01d3b70fc98..ed9654fd7d2 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); -- cgit v1.2.3-70-g09d2