boot tagging: minor fixes

msgbufinit may be called multiple times as we initialize the msgbuf into a
progressively larger buffer. This doesn't happen as of now on head, but it
may happen in the future and we generally support this. As such, only print
the boot tag if we've just initialized the buffer for the first time.

The boot tag also now has a newline appended to it for better visibility,
and has been switched to a normal printf, by requesto f bde, after we've
denoted that the msgbuf is mapped.

1 files changed, 6 insertions, 2 deletions

diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c
index f1bc4c295a64..ef295f206227 100644
--- a/sys/kern/subr_prf.c
+++ b/sys/kern/subr_prf.c
@@ -1033,20 +1033,24 @@ void
 msgbufinit(void *ptr, int size)
 {
 	char *cp;
-	static struct msgbuf *oldp = NULL;
+	static struct msgbuf *oldp;
+	bool print_boot_tag;
 
+	oldp = NULL;
 	size -= sizeof(*msgbufp);
 	cp = (char *)ptr;
+	print_boot_tag = !msgbufmapped;
 	/* Attempt to fetch kern.boot_tag tunable on first mapping */
 	if (!msgbufmapped)
 		TUNABLE_STR_FETCH("kern.boot_tag", current_boot_tag,
 		    sizeof(current_boot_tag));
 	msgbufp = (struct msgbuf *)(cp + size);
 	msgbuf_reinit(msgbufp, cp, size);
-	msgbuf_addstr(msgbufp, -1, current_boot_tag, 0);
 	if (msgbufmapped && oldp != msgbufp)
 		msgbuf_copy(oldp, msgbufp);
 	msgbufmapped = true;
+	if (print_boot_tag)
+		printf("%s\n", current_boot_tag);
 	oldp = msgbufp;
 }