Module Name: src
Committed By: riastradh
Date: Mon Oct 3 19:12:29 UTC 2022
Modified Files:
src/sys/dev: cons.c cons.h
Log Message:
cons(9): New function cn_set_tab.
Increment of progress toward eliminating bare access to cn_tab so we
can make more things MP-safe without the kernel lock (and maybe some
day better formalize console detection and switching).
To generate a diff of this commit:
cvs rdiff -u -r1.79 -r1.80 src/sys/dev/cons.c
cvs rdiff -u -r1.28 -r1.29 src/sys/dev/cons.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/cons.c
diff -u src/sys/dev/cons.c:1.79 src/sys/dev/cons.c:1.80
--- src/sys/dev/cons.c:1.79 Mon Aug 22 00:20:56 2022
+++ src/sys/dev/cons.c Mon Oct 3 19:12:29 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: cons.c,v 1.79 2022/08/22 00:20:56 riastradh Exp $ */
+/* $NetBSD: cons.c,v 1.80 2022/10/03 19:12:29 riastradh Exp $ */
/*
* Copyright (c) 1988 University of Utah.
@@ -39,7 +39,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.79 2022/08/22 00:20:56 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.80 2022/10/03 19:12:29 riastradh Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@@ -87,6 +87,22 @@ struct tty *constty = NULL; /* virtual c
struct consdev *cn_tab; /* physical console device info */
struct vnode *cn_devvp[2]; /* vnode for underlying device. */
+void
+cn_set_tab(struct consdev *tab)
+{
+
+ /*
+ * This is a point that we should have KASSERT(cold) or add
+ * synchronization in case this can happen after cold boot.
+ * However, cn_tab initialization is so critical to any
+ * diagnostics or debugging that we need to tread carefully
+ * about introducing new ways to crash. So let's put the
+ * assertion in only after we've audited most or all of the
+ * cn_tab updates.
+ */
+ cn_tab = tab;
+}
+
int
cnopen(dev_t dev, int flag, int mode, struct lwp *l)
{
Index: src/sys/dev/cons.h
diff -u src/sys/dev/cons.h:1.28 src/sys/dev/cons.h:1.29
--- src/sys/dev/cons.h:1.28 Sun Aug 28 09:52:43 2022
+++ src/sys/dev/cons.h Mon Oct 3 19:12:29 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: cons.h,v 1.28 2022/08/28 09:52:43 riastradh Exp $ */
+/* $NetBSD: cons.h,v 1.29 2022/10/03 19:12:29 riastradh Exp $ */
/*
* Copyright (c) 1988 University of Utah.
@@ -76,6 +76,8 @@ struct consdev {
extern struct consdev constab[];
extern struct consdev *cn_tab;
+void cn_set_tab(struct consdev *);
+
void cninit(void);
int cngetc(void);
int cngetsn(char *, int);
