Introduce a new lock, hostname_mtx, and use it to synchronize access

to global hostname and domainname variables.  Where necessary, copy
to or from a stack-local buffer before performing copyin() or
copyout().  A few uses, such as in cd9660 and daemon_saver, remain
under-synchronized and will require further updates.

Correct a bug in which a failed copyin() of domainname would leave
domainname potentially corrupted.

MFC after:	3 weeks

1 files changed, 2 insertions, 0 deletions

diff --git a/sys/dev/syscons/daemon/daemon_saver.c b/sys/dev/syscons/daemon/daemon_saver.c
index b15e04c..2afc4c0 100644
--- a/sys/dev/syscons/daemon/daemon_saver.c
+++ b/sys/dev/syscons/daemon/daemon_saver.c
@@ -350,6 +350,8 @@ daemon_saver(video_adapter_t *adp, int blank)
 static int
 daemon_init(video_adapter_t *adp)
 {
+
+	/* XXXRW: Locking -- these can change! */
 	messagelen = strlen(hostname) + 3 + strlen(ostype) + 1 + 
 	    strlen(osrelease);
 	message = malloc(messagelen + 1, M_DEVBUF, M_WAITOK);