MFC r197518:

  lindev(4) [1] is supposed to be a collection of linux-specific pseudo
  devices that we also support, just not by default (thus only LINT or
  module builds by default).

  While currently there is only "/dev/full" [2], we are planning to see more
  in the future.  We may decide to change the module/dependency logic in the
  future should the list grow too long.

  This is not part of linux.ko as also non-linux binaries like kFreeBSD
  userland or ports can make use of this as well.

Suggested by:	rwatson [1] (name)
Submitted by:	ed [2]
Discussed with:	markm, ed, rwatson, kib (weeks ago)
Reviewed by:	rwatson, brueffer (prev. version)
PR:		kern/68961

14 files changed, 314 insertions, 0 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index c46f4b9..50b707c 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -173,6 +173,7 @@ MAN=	aac.4 \
 	le.4 \
 	led.4 \
 	lge.4 \
+	${_lindev.4} \
 	${_linux.4} \
 	lmc.4 \
 	lo.4 \
@@ -624,6 +625,7 @@ _if_urtw.4=	if_urtw.4
 _if_wpi.4=	if_wpi.4
 _ipmi.4=	ipmi.4
 _io.4=		io.4
+_lindev.4=	lindev.4
 _linux.4=	linux.4
 _ndis.4=	ndis.4
 _nfe.4=		nfe.4
@@ -635,6 +637,8 @@ _speaker.4=	speaker.4
 _spkr.4=	spkr.4
 _urtw.4=	urtw.4
 _wpi.4=		wpi.4
+
+MLINKS+=lindev.4 full.4
 .endif
 
 .if exists(${.CURDIR}/man4.${MACHINE_ARCH})
diff --git a/share/man/man4/lindev.4 b/share/man/man4/lindev.4
new file mode 100644
index 0000000..b2dc60e
--- /dev/null
+++ b/share/man/man4/lindev.4
@@ -0,0 +1,73 @@
+.\"-
+.\" Copyright (c) 2009 "Bjoern A. Zeeb" <bz@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd September 26, 2009
+.Dt LINDEV 4
+.Os
+.Sh NAME
+.Nm lindev
+.Nd the lindev module
+.Sh SYNOPSIS
+To compile this collection of linux-specific pseudo devices into the kernel,
+place the following line in your kernel configuration file:
+.Bd -ragged -offset indent
+.Cd "device lindev"
+.Ed
+.Pp
+Alternatively, to load the driver as a module at boot time,
+place the following line in
+.Xr loader.conf 5 :
+.Bd -literal -offset indent
+lindev_load="YES"
+.Ed
+.Sh DESCRIPTION
+The
+.Nm
+module provides a collection of linux-specific pseudo devices.
+.Sh DEVICES
+.Bl -tag -width /dev/full
+.It Pa /dev/full
+The
+.Xr full
+device always returns
+.Er ENOSPC
+on write attempts.
+For reads it emulates
+.Xr zero 4 .
+.El
+.Sh FILES
+.Bl -tag -width /dev/full
+.It Pa /dev/full
+.El
+.Sh SEE ALSO
+.Xr null 4 ,
+.Xr zero 4
+.Sh HISTORY
+The
+.Nm
+module first appeared in
+.Fx 9.0 .
diff --git a/sys/amd64/conf/NOTES b/sys/amd64/conf/NOTES
index 27fe068..5361224 100644
--- a/sys/amd64/conf/NOTES
+++ b/sys/amd64/conf/NOTES
@@ -503,3 +503,6 @@ options 	VM_KMEM_SIZE_SCALE
 # Enable NDIS binary driver support
 options 	NDISAPI
 device		ndis
+
+# Linux-specific pseudo devices support
+device		lindev
diff --git a/sys/boot/forth/loader.conf b/sys/boot/forth/loader.conf
index 862e86f..44eef5f 100644
--- a/sys/boot/forth/loader.conf
+++ b/sys/boot/forth/loader.conf
@@ -179,6 +179,7 @@ screensave_name="green_saver"	# Set to the name of the screensaver module
 ibcs2_load="NO"			# IBCS2 (SCO) emulation
 ibcs2_coff_load="NO"
 linux_load="NO"			# Linux emulation
+lindev_load="NO"		# Linux-specific pseudo devices (see lindev(4))
 svr4_load="NO"			# SystemV R4 emulation
 streams_load="NO"		# System V streams module
 
diff --git a/sys/conf/files.amd64 b/sys/conf/files.amd64
index be1aff58..c22a213 100644
--- a/sys/conf/files.amd64
+++ b/sys/conf/files.amd64
@@ -205,6 +205,8 @@ dev/hwpmc/hwpmc_piv.c		optional	hwpmc
 dev/hwpmc/hwpmc_tsc.c		optional	hwpmc
 dev/hwpmc/hwpmc_x86.c		optional	hwpmc
 dev/kbd/kbd.c			optional	atkbd | sc | ukbd | usb2_input_kbd
+dev/lindev/full.c		optional	lindev
+dev/lindev/lindev.c		optional	lindev
 dev/mem/memutil.c		optional	mem
 dev/nfe/if_nfe.c		optional	nfe pci
 dev/nve/if_nve.c		optional	nve pci
diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index 88bd1f1..91d42a1 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -198,6 +198,8 @@ dev/ipmi/ipmi_pci.c		optional ipmi pci
 dev/ipmi/ipmi_linux.c		optional ipmi compat_linux
 dev/kbd/kbd.c			optional atkbd | sc | ukbd | usb2_input_kbd
 dev/le/if_le_isa.c		optional le isa
+dev/lindev/full.c		optional lindev
+dev/lindev/lindev.c		optional lindev
 dev/mem/memutil.c		optional mem
 dev/mse/mse.c			optional mse
 dev/mse/mse_isa.c		optional mse isa
diff --git a/sys/conf/files.pc98 b/sys/conf/files.pc98
index 7aedb38..7f2afc5 100644
--- a/sys/conf/files.pc98
+++ b/sys/conf/files.pc98
@@ -107,6 +107,8 @@ dev/hwpmc/hwpmc_x86.c		optional hwpmc
 dev/io/iodev.c			optional io
 dev/kbd/kbd.c			optional pckbd | sc | ukbd | usb2_input_kbd
 dev/le/if_le_cbus.c		optional le isa
+dev/lindev/full.c		optional lindev
+dev/lindev/lindev.c		optional lindev
 dev/mem/memutil.c		optional mem
 dev/mse/mse.c			optional mse
 dev/mse/mse_cbus.c		optional mse isa
diff --git a/sys/dev/lindev/full.c b/sys/dev/lindev/full.c
new file mode 100644
index 0000000..294094c
--- /dev/null
+++ b/sys/dev/lindev/full.c
@@ -0,0 +1,103 @@
+/*-
+ * Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/conf.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/systm.h>
+#include <sys/uio.h>
+
+#include <dev/lindev/lindev.h>
+
+static struct cdev *full_dev;
+
+static d_read_t full_read;
+static d_write_t full_write;
+
+static struct cdevsw full_cdevsw = {
+	.d_version =	D_VERSION,
+	.d_read =	full_read,
+	.d_write =	full_write,
+	.d_name =	"full",
+};
+
+static void *zbuf;
+
+/* ARGSUSED */
+static int
+full_read(struct cdev *dev __unused, struct uio *uio, int flags __unused)
+{
+	int error = 0;
+
+	while (uio->uio_resid > 0 && error == 0)
+		error = uiomove(zbuf, MIN(uio->uio_resid, PAGE_SIZE), uio);
+
+	return (error);
+}
+
+/* ARGSUSED */
+static int
+full_write(struct cdev *dev __unused, struct uio *uio __unused,
+    int flags __unused)
+{
+
+	return (ENOSPC);
+}
+
+/* ARGSUSED */
+int
+lindev_modevent_full(module_t mod __unused, int type, void *data __unused)
+{
+
+	switch(type) {
+	case MOD_LOAD:
+		zbuf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK | M_ZERO);
+		full_dev = make_dev(&full_cdevsw, 0, UID_ROOT, GID_WHEEL,
+		    0666, "full");
+		if (bootverbose)
+			printf("full: <full device>\n");
+		break;
+
+	case MOD_UNLOAD:
+		destroy_dev(full_dev);
+		free(zbuf, M_TEMP);
+		break;
+
+	case MOD_SHUTDOWN:
+		break;
+
+	default:
+		return (EOPNOTSUPP);
+	}
+
+	return (0);
+}
+
diff --git a/sys/dev/lindev/lindev.c b/sys/dev/lindev/lindev.c
new file mode 100644
index 0000000..cf87604
--- /dev/null
+++ b/sys/dev/lindev/lindev.c
@@ -0,0 +1,73 @@
+/*-
+ * Copyright (c) 2009 "Bjoern A. Zeeb" <bz@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * "lindev" is supposed to be a collection of linux-specific devices
+ * that we also support, just not by default.
+ * While currently there is only "/dev/full", we are planning to see
+ * more in the future.
+ * This file is only the container to load/unload all supported devices;
+ * the implementation of each should go into its own file.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/conf.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+
+#include <dev/lindev/lindev.h>
+
+/* ARGSUSED */
+static int
+lindev_modevent(module_t mod, int type, void *data)
+{
+	int error;
+
+	switch(type) {
+	case MOD_LOAD:
+		error = lindev_modevent_full(mod, type, data);
+		break;
+
+	case MOD_UNLOAD:
+		error = lindev_modevent_full(mod, type, data);
+		break;
+
+	case MOD_SHUTDOWN:
+		error = lindev_modevent_full(mod, type, data);
+		break;
+
+	default:
+		return (EOPNOTSUPP);
+	}
+
+	return (error);
+}
+
+DEV_MODULE(lindev, lindev_modevent, NULL);
+MODULE_VERSION(lindev, 1);
diff --git a/sys/dev/lindev/lindev.h b/sys/dev/lindev/lindev.h
new file mode 100644
index 0000000..9b0be82
--- /dev/null
+++ b/sys/dev/lindev/lindev.h
@@ -0,0 +1,34 @@
+/*-
+ * Copyright (c) 2009 "Bjoern A. Zeeb" <bz@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	_DEV_LINDEV_LINDEV_H
+#define	_DEV_LINDEV_LINDEV_H
+
+int lindev_modevent_full(module_t, int, void *);
+
+#endif /* _DEV_LINDEV_LINDEV_H */
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index 4c71a81..b7f2409 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -876,6 +876,9 @@ device		streams		# STREAMS network driver (required for svr4).
 options 	NDISAPI
 device		ndis
 
+# Linux-specific pseudo devices support
+device		lindev
+
 
 #####################################################################
 # VM OPTIONS
diff --git a/sys/modules/Makefile b/sys/modules/Makefile
index 089450a..eca7b6b 100644
--- a/sys/modules/Makefile
+++ b/sys/modules/Makefile
@@ -150,6 +150,7 @@ SUBDIR=	${_3dfx} \
 	libiconv \
 	libmbpool \
 	libmchain \
+	${_lindev} \
 	${_linprocfs} \
 	${_linsysfs} \
 	${_linux} \
@@ -370,6 +371,7 @@ _ie=		ie
 _if_ndis=	if_ndis
 _igb=		igb
 _io=		io
+_lindev=	lindev
 _linprocfs=	linprocfs
 _linsysfs=	linsysfs
 _linux=		linux
@@ -505,6 +507,7 @@ _ipwfw=		ipwfw
 _iwn=		iwn
 _iwnfw=		iwnfw
 _ixgb=		ixgb
+_lindev=	lindev
 _linprocfs=	linprocfs
 _linsysfs=	linsysfs
 _linux=		linux
diff --git a/sys/modules/lindev/Makefile b/sys/modules/lindev/Makefile
new file mode 100644
index 0000000..704cac3
--- /dev/null
+++ b/sys/modules/lindev/Makefile
@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../dev/lindev
+
+KMOD=	lindev
+SRCS=	full.c lindev.c
+
+.include <bsd.kmod.mk>
diff --git a/sys/pc98/conf/NOTES b/sys/pc98/conf/NOTES
index 9ab70b9..990fc94 100644
--- a/sys/pc98/conf/NOTES
+++ b/sys/pc98/conf/NOTES
@@ -565,6 +565,9 @@ options 	COMPAT_SVR4	# build emulator statically
 options 	DEBUG_SVR4	# enable verbose debugging
 device		streams		# STREAMS network driver (required for svr4).
 
+# Linux-specific pseudo devices support
+device		lindev
+
 
 #####################################################################
 # VM OPTIONS