Change the callout to supply -1 to indicate we are not changing

CPU, also add protection against invalid CPU's as well as
split c_flags and c_iflags so that if a user plays with the active
flag (the one expected to be played with by callers in MPSAFE) without
a lock, it won't adversely affect the callout system by causing a corrupt
list. This also means that all callers need to use the macros and *not*
play with the falgs directly (like netgraph used to).

Differential Revision: htts://reviews.freebsd.org/D1894
Reviewed by: .. timed out but looked at by jhb, imp, adrian hselasky
             tested by hiren and netflix.
Sponsored by:	Netflix Inc.

1 files changed, 2 insertions, 1 deletions

diff --git a/sys/sys/_callout.h b/sys/sys/_callout.h
index e186aec..1ad5f51 100644
--- a/sys/sys/_callout.h
+++ b/sys/sys/_callout.h
@@ -57,7 +57,8 @@ struct callout {
 	void	*c_arg;				/* function argument */
 	void	(*c_func)(void *);		/* function to call */
 	struct lock_object *c_lock;		/* lock to handle */
-	int	c_flags;			/* state of this entry */
+	int	c_flags;			/* User State */
+	int	c_iflags;			/* Internal State */
 	volatile int c_cpu;			/* CPU we're scheduled on */
 };