Commit-ID: 042d4c70a203998697b34eaad1a99f6f09d09e4d
Gitweb: https://git.kernel.org/tip/042d4c70a203998697b34eaad1a99f6f09d09e4d
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
AuthorDate: Mon, 22 Oct 2018 07:43:22 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
CommitDate: Thu, 8 Nov 2018 21:41:57 -0800
rcu: Eliminate BUG_ON() for sync.c
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 <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
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);
}
}
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