I'm able to reproduce a lockdep splat when CONFIG_PROVE_LOCKING=y and CONFIG_PREEMPTIRQ_EVENTS=y.
$ echo 1 > /d/tracing/events/preemptirq/preempt_enable/enable Cc: Steven Rostedt <[email protected]> Cc: Peter Zilstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Tom Zanussi <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Thomas Glexiner <[email protected]> Cc: Boqun Feng <[email protected]> Cc: Paul McKenney <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Fenguang Wu <[email protected]> Cc: Baohong Liu <[email protected]> Cc: Vedang Patel <[email protected]> Cc: [email protected] Signed-off-by: Joel Fernandes <[email protected]> --- kernel/softirq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 24d243ef8e71..47e2f61938c0 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -139,9 +139,13 @@ static void __local_bh_enable(unsigned int cnt) { lockdep_assert_irqs_disabled(); + if (preempt_count() == cnt) + trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip()); + if (softirq_count() == (cnt & SOFTIRQ_MASK)) trace_softirqs_on(_RET_IP_); - preempt_count_sub(cnt); + + __preempt_count_sub(cnt); } /* -- 2.17.0.441.gb46fe60e1d-goog
