diff options
| -rw-r--r-- | kernel/rcu.h | 10 | ||||
| -rw-r--r-- | kernel/rcutree.c | 14 |
2 files changed, 20 insertions, 4 deletions
diff --git a/kernel/rcu.h b/kernel/rcu.h index 0a90ccc65bfb..77131966c4ad 100644 --- a/kernel/rcu.h +++ b/kernel/rcu.h @@ -67,12 +67,15 @@ extern struct debug_obj_descr rcuhead_debug_descr; -static inline void debug_rcu_head_queue(struct rcu_head *head) +static inline int debug_rcu_head_queue(struct rcu_head *head) { - debug_object_activate(head, &rcuhead_debug_descr); + int r1; + + r1 = debug_object_activate(head, &rcuhead_debug_descr); debug_object_active_state(head, &rcuhead_debug_descr, STATE_RCU_HEAD_READY, STATE_RCU_HEAD_QUEUED); + return r1; } static inline void debug_rcu_head_unqueue(struct rcu_head *head) @@ -83,8 +86,9 @@ static inline void debug_rcu_head_unqueue(struct rcu_head *head) debug_object_deactivate(head, &rcuhead_debug_descr); } #else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ -static inline void debug_rcu_head_queue(struct rcu_head *head) +static inline int debug_rcu_head_queue(struct rcu_head *head) { + return 0; } static inline void debug_rcu_head_unqueue(struct rcu_head *head) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index a7bf517b0482..91840566e294 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -2305,6 +2305,13 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp, } /* + * RCU callback function to leak a callback. + */ +static void rcu_leak_callback(struct rcu_head *rhp) +{ +} + +/* * Helper function for call_rcu() and friends. The cpu argument will * normally be -1, indicating "currently running CPU". It may specify * a CPU only if that CPU is a no-CBs CPU. Currently, only _rcu_barrier() @@ -2318,7 +2325,12 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), struct rcu_data *rdp; WARN_ON_ONCE((unsigned long)head & 0x3); /* Misaligned rcu_head! */ - debug_rcu_head_queue(head); + if (debug_rcu_head_queue(head)) { + /* Probable double call_rcu(), so leak the callback. */ + ACCESS_ONCE(head->func) = rcu_leak_callback; + WARN_ONCE(1, "__call_rcu(): Leaked duplicate callback\n"); + return; + } head->func = func; head->next = NULL; |