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Diffstat (limited to 'include/linux/rcupdate_trace.h')
-rw-r--r--include/linux/rcupdate_trace.h13
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h
index d9015aac78c6..3e7919fc5f34 100644
--- a/include/linux/rcupdate_trace.h
+++ b/include/linux/rcupdate_trace.h
@@ -50,6 +50,7 @@ static inline void rcu_read_lock_trace(void)
struct task_struct *t = current;
WRITE_ONCE(t->trc_reader_nesting, READ_ONCE(t->trc_reader_nesting) + 1);
+ barrier();
if (IS_ENABLED(CONFIG_TASKS_TRACE_RCU_READ_MB) &&
t->trc_reader_special.b.need_mb)
smp_mb(); // Pairs with update-side barriers
@@ -72,6 +73,9 @@ static inline void rcu_read_unlock_trace(void)
rcu_lock_release(&rcu_trace_lock_map);
nesting = READ_ONCE(t->trc_reader_nesting) - 1;
+ barrier(); // Critical section before disabling.
+ // Disable IPI-based setting of .need_qs.
+ WRITE_ONCE(t->trc_reader_nesting, INT_MIN);
if (likely(!READ_ONCE(t->trc_reader_special.s)) || nesting) {
WRITE_ONCE(t->trc_reader_nesting, nesting);
return; // We assume shallow reader nesting.
@@ -82,7 +86,14 @@ static inline void rcu_read_unlock_trace(void)
void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func);
void synchronize_rcu_tasks_trace(void);
void rcu_barrier_tasks_trace(void);
-
+#else
+/*
+ * The BPF JIT forms these addresses even when it doesn't call these
+ * functions, so provide definitions that result in runtime errors.
+ */
+static inline void call_rcu_tasks_trace(struct rcu_head *rhp, rcu_callback_t func) { BUG(); }
+static inline void rcu_read_lock_trace(void) { BUG(); }
+static inline void rcu_read_unlock_trace(void) { BUG(); }
#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
#endif /* __LINUX_RCUPDATE_TRACE_H */