X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Frcupdate.c;h=72a8dc9567f5825ee24bb52174b67953ca372b63;hb=1f522509c77a5dea8dc384b735314f03908a6415;hp=7bfa004572b1c25ba16871f3761387d11221931a;hpb=d9f1bb6ad7fc53c406706f47858dd5ff030b14a3;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 7bfa004..72a8dc9 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -44,7 +44,7 @@
 #include <linux/cpu.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
-#include <linux/kernel_stat.h>
+#include <linux/hardirq.h>
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key rcu_lock_key;
@@ -63,22 +63,34 @@ struct lockdep_map rcu_sched_lock_map =
 EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
 #endif
 
-int rcu_scheduler_active __read_mostly;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
 
-/*
- * This function is invoked towards the end of the scheduler's initialization
- * process.  Before this is called, the idle task might contain
- * RCU read-side critical sections (during which time, this idle
- * task is booting the system).  After this function is called, the
- * idle tasks are prohibited from containing RCU read-side critical
- * sections.
+int debug_lockdep_rcu_enabled(void)
+{
+	return rcu_scheduler_active && debug_locks &&
+	       current->lockdep_recursion == 0;
+}
+EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
+
+/**
+ * rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section?
+ *
+ * Check for bottom half being disabled, which covers both the
+ * CONFIG_PROVE_RCU and not cases.  Note that if someone uses
+ * rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
+ * will show the situation.
+ *
+ * Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
  */
-void rcu_scheduler_starting(void)
+int rcu_read_lock_bh_held(void)
 {
-	WARN_ON(num_online_cpus() != 1);
-	WARN_ON(nr_context_switches() > 0);
-	rcu_scheduler_active = 1;
+	if (!debug_lockdep_rcu_enabled())
+		return 1;
+	return in_softirq();
 }
+EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+
+#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
 
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
@@ -91,3 +103,14 @@ void wakeme_after_rcu(struct rcu_head  *head)
 	rcu = container_of(head, struct rcu_synchronize, head);
 	complete(&rcu->completion);
 }
+
+#ifdef CONFIG_PROVE_RCU
+/*
+ * wrapper function to avoid #include problems.
+ */
+int rcu_my_thread_group_empty(void)
+{
+	return thread_group_empty(current);
+}
+EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty);
+#endif /* #ifdef CONFIG_PROVE_RCU */