The sync.c file has a number of calls to BUG_ON(), which panics the kernel, which is not a good strategy for devices (like embedded) that don't have a way to capture console output. This commit therefore changes these BUG_ON() calls to WARN_ON_ONCE(), but does so quite naively.
Reported-by: Linus Torvalds <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Acked-by: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> --- kernel/rcu/sync.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c index 3f943efcf61c..a6ba446a9693 100644 --- a/kernel/rcu/sync.c +++ b/kernel/rcu/sync.c @@ -125,8 +125,7 @@ void rcu_sync_enter(struct rcu_sync *rsp) rsp->gp_state = GP_PENDING; spin_unlock_irq(&rsp->rss_lock); - BUG_ON(need_wait && need_sync); - + WARN_ON_ONCE(need_wait && need_sync); if (need_sync) { gp_ops[rsp->gp_type].sync(); rsp->gp_state = GP_PASSED; @@ -139,7 +138,7 @@ void rcu_sync_enter(struct rcu_sync *rsp) * Nobody has yet been allowed the 'fast' path and thus we can * avoid doing any sync(). The callback will get 'dropped'. */ - BUG_ON(rsp->gp_state != GP_PASSED); + WARN_ON_ONCE(rsp->gp_state != GP_PASSED); } } @@ -166,8 +165,8 @@ static void rcu_sync_func(struct rcu_head *rhp) struct rcu_sync *rsp = container_of(rhp, struct rcu_sync, cb_head); unsigned long flags; - BUG_ON(rsp->gp_state != GP_PASSED); - BUG_ON(rsp->cb_state == CB_IDLE); + WARN_ON_ONCE(rsp->gp_state != GP_PASSED); + WARN_ON_ONCE(rsp->cb_state == CB_IDLE); spin_lock_irqsave(&rsp->rss_lock, flags); if (rsp->gp_count) { @@ -225,7 +224,7 @@ void rcu_sync_dtor(struct rcu_sync *rsp) { int cb_state; - BUG_ON(rsp->gp_count); + WARN_ON_ONCE(rsp->gp_count); spin_lock_irq(&rsp->rss_lock); if (rsp->cb_state == CB_REPLAY) @@ -235,6 +234,6 @@ void rcu_sync_dtor(struct rcu_sync *rsp) if (cb_state != CB_IDLE) { gp_ops[rsp->gp_type].wait(); - BUG_ON(rsp->cb_state != CB_IDLE); + WARN_ON_ONCE(rsp->cb_state != CB_IDLE); } } -- 2.17.1
