Sun Dec 12 22:11:03 2010 UTC ()
Split "filesystem", and remove superfluous Pp.


(wiz)
diff -r1.1 -r1.2 src/share/man/man4/module.4
cvs diff -r1.1 -r1.2 src/share/man/man4/Attic/module.4 (expand / switch to unified diff)

--- src/share/man/man4/Attic/module.4 2010/12/12 19:29:01 1.1
+++ src/share/man/man4/Attic/module.4 2010/12/12 22:11:02 1.2
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1.\" $NetBSD: module.4,v 1.1 2010/12/12 19:29:01 pgoyette Exp $ 1.\" $NetBSD: module.4,v 1.2 2010/12/12 22:11:02 wiz Exp $
2.\" 2.\"
3.\" Copyright (c) 1993 Christopher G. Demetriou 3.\" Copyright (c) 1993 Christopher G. Demetriou
4.\" All rights reserved. 4.\" All rights reserved.
5.\" 5.\"
6.\" Redistribution and use in source and binary forms, with or without 6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions 7.\" modification, are permitted provided that the following conditions
8.\" are met: 8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright 9.\" 1. Redistributions of source code must retain the above copyright
10.\" notice, this list of conditions and the following disclaimer. 10.\" notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\" notice, this list of conditions and the following disclaimer in the 12.\" notice, this list of conditions and the following disclaimer in the
13.\" documentation and/or other materials provided with the distribution. 13.\" documentation and/or other materials provided with the distribution.
14.\" 3. All advertising materials mentioning features or use of this software 14.\" 3. All advertising materials mentioning features or use of this software
@@ -40,27 +40,27 @@ @@ -40,27 +40,27 @@
40.Nd Kernel Modules interface 40.Nd Kernel Modules interface
41.Sh SYNOPSIS 41.Sh SYNOPSIS
42.Cd "options MODULAR" 42.Cd "options MODULAR"
43.Sh DESCRIPTION 43.Sh DESCRIPTION
44Kernel modules allow the system administrator to 44Kernel modules allow the system administrator to
45dynamically add and remove functionality from a running system. 45dynamically add and remove functionality from a running system.
46This ability also helps software developers to develop 46This ability also helps software developers to develop
47new parts of the kernel without constantly rebooting to 47new parts of the kernel without constantly rebooting to
48test their changes. 48test their changes.
49.Pp 49.Pp
50Additionally, the kernel may automatically load software modules as 50Additionally, the kernel may automatically load software modules as
51needed to perform requested operations. 51needed to perform requested operations.
52For example, an xyzfs module can be loaded automatically when an 52For example, an xyzfs module can be loaded automatically when an
53attempt is made to mount an xyzfs filesystem. 53attempt is made to mount an xyzfs file system.
54Modules can also depend on other modules, and dependant modules are 54Modules can also depend on other modules, and dependant modules are
55automatically loaded. 55automatically loaded.
56When a module is no longer needed, it can be automatically unloaded. 56When a module is no longer needed, it can be automatically unloaded.
57.Pp 57.Pp
58An in-kernel linker resolves symbol references between the module 58An in-kernel linker resolves symbol references between the module
59and the rest of the kernel. 59and the rest of the kernel.
60.Pp 60.Pp
61The 61The
62.Nm 62.Nm
63interface is accessed with the 63interface is accessed with the
64.Xr modctl 2 64.Xr modctl 2
65system call. 65system call.
66Normally all operations involving 66Normally all operations involving
@@ -96,27 +96,26 @@ emulation module also be loaded. @@ -96,27 +96,26 @@ emulation module also be loaded.
96.Ss Miscellaneous modules 96.Ss Miscellaneous modules
97Miscellaneous modules are modules for which there are not currently 97Miscellaneous modules are modules for which there are not currently
98well-defined or well-used interfaces for extension. 98well-defined or well-used interfaces for extension.
99They are provided for extension, and the user-provided module 99They are provided for extension, and the user-provided module
100initialization routine is expected to install the necessary "hooks" 100initialization routine is expected to install the necessary "hooks"
101into the rest of the operating system. 101into the rest of the operating system.
102An example of a "miscellaneous module" might be a loader for 102An example of a "miscellaneous module" might be a loader for
103card-specific VGA drivers or alternate terminal emulations in 103card-specific VGA drivers or alternate terminal emulations in
104an appropriately layered console driver. 104an appropriately layered console driver.
105.Ss Security-Model modules 105.Ss Security-Model modules
106Alternate system security models may loaded using the 106Alternate system security models may loaded using the
107.Nm 107.Nm
108facility. 108facility.
109.Pp 
110.Sh NOTES 109.Sh NOTES
111.Ss Security considerations 110.Ss Security considerations
112Kernel modules can do anything with kernel structures. 111Kernel modules can do anything with kernel structures.
113There is no memory protection between modules and the rest of the kernel. 112There is no memory protection between modules and the rest of the kernel.
114Hence, a potential attacker with access to the 113Hence, a potential attacker with access to the
115.Xr modctl 2 114.Xr modctl 2
116system call can acquire complete and total control over the system. 115system call can acquire complete and total control over the system.
117.Pp 116.Pp
118To avoid associated security risks, new modules can only be loaded when 117To avoid associated security risks, new modules can only be loaded when
119.Pa securelevel 118.Pa securelevel
120is less than or equal to zero, or if the kernel was built with 119is less than or equal to zero, or if the kernel was built with
121.Cd options INSECURE . 120.Cd options INSECURE .
122.Ss Module might crash system 121.Ss Module might crash system
@@ -125,42 +124,42 @@ system. @@ -125,42 +124,42 @@ system.
125Since the module becomes part of kernel, a code error is much more 124Since the module becomes part of kernel, a code error is much more
126fatal than for userland programs. 125fatal than for userland programs.
127.Ss Modules need to be updated when the kernel is updated 126.Ss Modules need to be updated when the kernel is updated
128Kernel modules are built to operate only with a specific version of the 127Kernel modules are built to operate only with a specific version of the
129Operating System kernel. 128Operating System kernel.
130When you update the kernel to a new version, you should also update the 129When you update the kernel to a new version, you should also update the
131contents of the 130contents of the
132.Pa /stand/${ARCH}/${VERSION}/modules/ 131.Pa /stand/${ARCH}/${VERSION}/modules/
133directory with all required modules. 132directory with all required modules.
134(This location has been the subject of much discussion, and may change 133(This location has been the subject of much discussion, and may change
135in future versions of the 134in future versions of the
136.Nx 135.Nx
137operating system.) 136operating system.)
138.Ss Missing filesystem modules may prevent the system from booting 137.Ss Missing file system modules may prevent the system from booting
139If you attempt to boot the operating system from a filesystem for 138If you attempt to boot the operating system from a file system for
140which the module is not built into the kernel, the boot may fail 139which the module is not built into the kernel, the boot may fail
141with the message 140with the message
142.Dq "Cannot mount root, error 79" . 141.Dq "Cannot mount root, error 79" .
143On certain architectures (currently, i386 and amd64), you may be able to 142On certain architectures (currently, i386 and amd64), you may be able to
144recover from this error by using the 143recover from this error by using the
145.Dq "load xxxfs" 144.Dq "load xxxfs"
146command before trying to boot. 145command before trying to boot.
147This command is only available on newer bootloaders. 146This command is only available on newer bootloaders.
148.Pp 147.Pp
149Since the absence of required modules, or the inability of the bootloader 148Since the absence of required modules, or the inability of the bootloader
150to load the modules, is a common reason for a 149to load the modules, is a common reason for a
151.Dv MODULAR 150.Dv MODULAR
152kernel's failure to boot, you might want to maintain a non-MODULAR 151kernel's failure to boot, you might want to maintain a non-MODULAR
153kernel in the root filesystem for recovery purposes. 152kernel in the root file system for recovery purposes.
154.Sh SEE ALSO 153.Sh SEE ALSO
155.Xr modctl 2 , 154.Xr modctl 2 ,
156.Xr modload 8 , 155.Xr modload 8 ,
157.Xr modstat 8 , 156.Xr modstat 8 ,
158.Xr modunload 8 , 157.Xr modunload 8 ,
159.Xr module 9 158.Xr module 9
160.Sh HISTORY 159.Sh HISTORY
161The 160The
162.Nm 161.Nm
163facility was designed to be similar in functionality 162facility was designed to be similar in functionality
164to the loadable kernel modules facility provided by 163to the loadable kernel modules facility provided by
165.Tn "SunOS 4.1.3" . 164.Tn "SunOS 4.1.3" .
166The current 165The current