Module Name:    src
Committed By:   martin
Date:           Mon Apr 27 14:56:22 UTC 2020

Modified Files:
        src/sys/dev/nvmm [netbsd-9]: nvmm.c

Log Message:
Pull up following revision(s) (requested by maxv in ticket #857):

        sys/dev/nvmm/nvmm.c: revision 1.26

In nvmm_open(), make sure an implementation was found. This fixes an
initialization bug triggerable in certain conditions.

If you build nvmm inside the kernel, AND have a cpu that is not supported,
AND run nvmmctl (or qemu-nvmm, both being the only binaries in the "nvmm"
group), you get a page fault.

This is because when nvmm is built inside the kernel, the kernel registers
nvmm_cdevsw behind nvmm's back. The ioctl is therefore always accessible,
and will hit NULL pointers if nvmm_init() failed.

Problem reported by Andrei M. on netbsd-users@, thanks.


To generate a diff of this commit:
cvs rdiff -u -r1.22.2.1 -r1.22.2.2 src/sys/dev/nvmm/nvmm.c

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/nvmm/nvmm.c
diff -u src/sys/dev/nvmm/nvmm.c:1.22.2.1 src/sys/dev/nvmm/nvmm.c:1.22.2.2
--- src/sys/dev/nvmm/nvmm.c:1.22.2.1	Sun Nov 10 12:58:30 2019
+++ src/sys/dev/nvmm/nvmm.c	Mon Apr 27 14:56:22 2020
@@ -1,4 +1,4 @@
-/*	$NetBSD: nvmm.c,v 1.22.2.1 2019/11/10 12:58:30 martin Exp $	*/
+/*	$NetBSD: nvmm.c,v 1.22.2.2 2020/04/27 14:56:22 martin Exp $	*/
 
 /*
  * Copyright (c) 2018-2019 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nvmm.c,v 1.22.2.1 2019/11/10 12:58:30 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nvmm.c,v 1.22.2.2 2020/04/27 14:56:22 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1040,6 +1040,8 @@ nvmm_open(dev_t dev, int flags, int type
 	struct file *fp;
 	int error, fd;
 
+	if (__predict_false(nvmm_impl == NULL))
+		return ENXIO;
 	if (minor(dev) != 0)
 		return EXDEV;
 	if (!(flags & O_CLOEXEC))

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