From 7ef43ebaa538e0cc9063cbf84593a05091bcace2 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 12 May 2008 15:42:28 -0700 Subject: tipc: Fix race condition when creating socket or native port This patch eliminates the (very remote) chance of a crash resulting from a partially initialized socket or native port unexpectedly receiving a message. Now, during the creation of a socket or native port, the underlying generic port's lock is not released until all initialization required to handle incoming messages has been done. Signed-off-by: Allan Stephens Signed-off-by: David S. Miller --- net/tipc/ref.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'net/tipc/ref.c') diff --git a/net/tipc/ref.c b/net/tipc/ref.c index 89cbab24d08..a101de86824 100644 --- a/net/tipc/ref.c +++ b/net/tipc/ref.c @@ -142,9 +142,13 @@ void tipc_ref_table_stop(void) /** * tipc_ref_acquire - create reference to an object * - * Return a unique reference value which can be translated back to the pointer - * 'object' at a later time. Also, pass back a pointer to the lock protecting - * the object, but without locking it. + * Register an object pointer in reference table and lock the object. + * Returns a unique reference value that is used from then on to retrieve the + * object pointer, or to determine that the object has been deregistered. + * + * Note: The object is returned in the locked state so that the caller can + * register a partially initialized object, without running the risk that + * the object will be accessed before initialization is complete. */ u32 tipc_ref_acquire(void *object, spinlock_t **lock) @@ -178,13 +182,13 @@ u32 tipc_ref_acquire(void *object, spinlock_t **lock) ref = (next_plus_upper & ~index_mask) + index; entry->ref = ref; entry->object = object; - spin_unlock_bh(&entry->lock); *lock = &entry->lock; } else if (tipc_ref_table.init_point < tipc_ref_table.capacity) { index = tipc_ref_table.init_point++; entry = &(tipc_ref_table.entries[index]); spin_lock_init(&entry->lock); + spin_lock_bh(&entry->lock); ref = tipc_ref_table.start_mask + index; entry->ref = ref; entry->object = object; -- cgit v1.2.3