diff options
| -rw-r--r-- | kernel/rcupdate.c | 26 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 2 |
2 files changed, 22 insertions, 6 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index f3240e987928..b54d6d18258c 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -142,7 +142,14 @@ static int rcuhead_fixup_init(void *addr, enum debug_obj_state state) * Ensure that queued callbacks are all executed. * If we detect that we are nested in a RCU read-side critical * section, we should simply fail, otherwise we would deadlock. + * In !PREEMPT configurations, there is no way to tell if we are + * in a RCU read-side critical section or not, so we never + * attempt any fixup and just print a warning. */ +#ifndef CONFIG_PREEMPT + WARN_ON(1); + return 0; +#endif if (rcu_preempt_depth() != 0 || preempt_count() != 0 || irqs_disabled()) { WARN_ON(1); @@ -184,7 +191,14 @@ static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state) * Ensure that queued callbacks are all executed. * If we detect that we are nested in a RCU read-side critical * section, we should simply fail, otherwise we would deadlock. + * In !PREEMPT configurations, there is no way to tell if we are + * in a RCU read-side critical section or not, so we never + * attempt any fixup and just print a warning. */ +#ifndef CONFIG_PREEMPT + WARN_ON(1); + return 0; +#endif if (rcu_preempt_depth() != 0 || preempt_count() != 0 || irqs_disabled()) { WARN_ON(1); @@ -214,12 +228,14 @@ static int rcuhead_fixup_free(void *addr, enum debug_obj_state state) * Ensure that queued callbacks are all executed. * If we detect that we are nested in a RCU read-side critical * section, we should simply fail, otherwise we would deadlock. - * Note that the machinery to reliably determine whether - * or not we are in an RCU read-side critical section - * exists only in the preemptible RCU implementations - * (TINY_PREEMPT_RCU and TREE_PREEMPT_RCU), which is why - * DEBUG_OBJECTS_RCU_HEAD is disallowed if !PREEMPT. + * In !PREEMPT configurations, there is no way to tell if we are + * in a RCU read-side critical section or not, so we never + * attempt any fixup and just print a warning. */ +#ifndef CONFIG_PREEMPT + WARN_ON(1); + return 0; +#endif if (rcu_preempt_depth() != 0 || preempt_count() != 0 || irqs_disabled()) { WARN_ON(1); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 93ce6de3300d..3aa278046d78 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -337,7 +337,7 @@ config DEBUG_OBJECTS_WORK config DEBUG_OBJECTS_RCU_HEAD bool "Debug RCU callbacks objects" - depends on DEBUG_OBJECTS && PREEMPT + depends on DEBUG_OBJECTS help Enable this to turn on debugging of RCU list heads (call_rcu() usage). |