Commit e0e8eb54 authored Mar 16, 2006 by Eric W. Biederman Committed by Linus Torvalds Mar 17, 2006

[PATCH] unshare: Use rcu_assign_pointer when setting sighand



The sighand pointer only needs the rcu_read_lock on the
read side.  So only depending on task_lock protection
when setting this pointer is not enough.  We also need
a memory barrier to ensure the initialization is seen first.

Use rcu_assign_pointer as it does this for us, and clearly
documents that we are setting an rcu readable pointer.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 232a347a

kernel/fork.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1569,7 +1569,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)

		if (new_sigh) {
		sigh = current->sighand;
		current->sighand = new_sigh;
		rcu_assign_pointer(current->sighand, new_sigh);
		new_sigh = sigh;
		}

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