Linux Kernel Programming

by Magnus, Robert; Verworner, Dirk; Beck, Michael; Bohme, Harald; Dziadzka, Mirko; Kunitz, Ulrich

• ISBN13: 9780201331431
• ISBN10: 0201331438
• Edition: 2nd
• Format: Paperback w/CD
• Copyright: 2002-01-01
• Publisher: Addison-Wesley Professional

Summary

Since the introduction of Linux version 1.2 in March 1995, a whole community has evolved of programmers from all over the world who were attracted by the reliability and flexibility of this completely free operating system. Now at version 2.0, Linux is no longer only the operating system of choice for hackers, but is being successfully employed in commercial software development, by Internet providers and in research and teaching. This book is written for anybody who wants to learn more about Linux. It explains the inner mechanisms of Linux from process scheduling to memory management and file systems, and will tell you all you need to know about the structure of the kernel, the heart of the Linux operating system. The accompanying CD-ROM contains the Slackware distribution 3.1 together with its complete source code, the Linux kernel sources up to version 2.1.21, the PC speaker driver, and a wealth of documentation, as well as the program for generating the source-oriented index. This second edition of Linux Kernel Internals: has been thoroughly updated throughout to cover Linux 2. shows you how the Linux operating system actually works so that you can start to program the Linux kernel for yoursel introduces the kernel sources and describes basic algorithms and data structures, such as scheduling and task structur helps you to understand file systems, networking and how systems boot

Table of Contents

Foreword	vii	(2)
Preface	ix
1 LINUX -- the operating system	1	(5)
1.1 Main characteristics	3	(2)
1.2 Linux distributions	5	(1)
2 Compiling the kernel	6	(9)
2.1 Where is everything?	6	(3)
2.2 Compiling	9	(2)
2.3 Additional configuration facilities	11	(4)
3 Introduction to the kernel	15	(55)
3.1 Important data structures	20	(17)
3.1.1 The task structure	20	(9)
3.1.2 The process table	29	(2)
3.1.3 Files and inodes	31	(2)
3.1.4 Dynamics memory management	33	(1)
3.1.5 Queues and semaphores	34	(2)
3.1.6 System time and timers	36	(1)
3.2 Main algorithms	37	(14)
3.2.1 Signals	37	(2)
3.2.2 Interrupts	39	(2)
3.2.3 Booting the system	41	(3)
3.2.4 Timer interrupt	44	(3)
3.2.5 The scheduler	47	(4)
3.3 Implementing system calls	51	(19)
3.3.1 How do system calls actually work?	51	(2)
3.3.2 Examples of simple system calls	53	(2)
3.3.3 Examples of more complex system calls	55	(10)
3.3.4 Implementing a new system call	65	(5)
4 Memory management	70	(38)
4.1 The architecture-independent memory model in LINUX	72	(7)
4.1.1 Pages of memory	72	(1)
4.1.2 Virtual address space	72	(1)
4.1.3 Converting the linear address	73	(1)
4.1.4 The page directory	74	(1)
4.1.5 The page middle directory	75	(1)
4.1.6 The page table	76	(3)
4.2 The virtual address space for a process	79	(13)
4.2.1 The user segment	79	(2)
4.2.2 Virtual memory areas	81	(4)
4.2.3 The system call brk	85	(1)
4.2.4 Mapping functions	86	(1)
4.2.5 The kernel segment	86	(2)
4.2.6 Static memory allocation in the kernel segment	88	(1)
4.2.7 Dynamic memory allocation in the kernel segment	88	(4)
4.3 Block device caching	92	(6)
4.3.1 Block buffering	92	(2)
4.3.2 The update and bdflush processes	94	(1)
4.3.3 List structures for the buffer cache	95	(1)
4.3.4 Using the buffer cache	96	(2)
4.4 Paging under LINUX	98	(10)
4.4.1 Page cache and management	100	(1)
4.4.2 Finding a free page	101	(5)
4.4.3 Page errors and reloading a page	106	(2)
5 Inter-process communication	108	(40)
5.1 Synchronization in the kernel	110	(4)
5.2 Communication via files	114	(5)
5.2.1 Locking entire files	115	(1)
5.2.2 Locking file areas	116	(3)
5.3 Pipes	119	(2)
5.4 Debugging using ptrace	121	(4)
5.5 System V IPC	125	(13)
5.5.1 Access permissions, numbers and keys	125	(1)
5.5.2 Semaphores	126	(4)
5.5.3 Message queues	130	(3)
5.5.4 Shared memory	133	(4)
5.5.5 The ipcs and ipcrm commands	137	(1)
5.6 IPC with sockets	138	(10)
5.6.1 A simple example	139	(4)
5.6.2 The implementation of UNIX domain sockets	143	(5)
6 The LINUX file system	148	(38)
6.1 Basic principles	149	(3)
6.2 The representation of file systems in the kernel	152	(21)
6.2.1 Mounting	153	(2)
6.2.2 Superblock operations	155	(3)
6.2.3 The inode	158	(3)
6.2.4 Inode operations	161	(4)
6.2.5 The file structure	165	(1)
6.2.6 File operations	165	(4)
6.2.7 Opening a file	169	(3)
6.2.8 The directory cache	172	(1)
6.3 The Proc file system	173	(6)
6.4 The Ext2 file system	179	(7)
6.4.1 The structure of the Ext2 file system	180	(2)
6.4.2 Directories in the Ext2 file system	182	(1)
6.4.3 Block allocation in the Ext2 file system	183	(1)
6.4.4 Extensions of the Ext2 file system	184	(2)
7 Device drivers under LINUX	186	(41)
7.1 Character and block devices	188	(2)
7.2 Polling and interrupts	190	(10)
7.2.1 Polling mode	190	(1)
7.2.2 Interrupt mode	191	(2)
7.2.3 Interrupt sharing	193	(1)
7.2.4 Bottom halves	194	(2)
7.2.5 Task queues	196	(2)
7.2.6 DMA mode	198	(2)
7.3 The hardware	200	(7)
7.3.1 Hardware detection	203	(2)
7.3.2 Automatic interrupt detection	205	(2)
7.4 Implementing a driver	207	(14)
7.4.1 The setup function	209	(1)
7.4.2 init	210	(2)
7.4.3 open and release	212	(2)
7.4.4 read and write	214	(3)
7.4.5 IOCTL	217	(2)
7.4.6 select	219	(1)
7.4.7 lseek	220	(1)
7.4.8 mmap	220	(1)
7.4.9 readdir, fsync and fasync	221	(1)
7.4.10 check_media_change and revalidate	221	(1)
7.5 An example of DMA operation	221	(6)
8 Network implementation	227	(52)
8.1 Introductory summary	228	(6)
8.1.1 The layer model of the network implementation	229	(1)
8.1.2 Getting the data from A to B	230	(4)
8.2 Important structures	234	(13)
8.2.1 The socket structure	234	(1)
8.2.2 The sk_buff structure -- buffer management in the network	235	(4)
8.2.3 The INET socket -- a special part of a socket	239	(4)
8.2.4 Protocol operations in the proto structure	243	(3)
8.2.5 The general structure of a socket address	246	(1)
8.3 Network devices under LINUX	247	(9)
8.3.1 Ethernet	254	(1)
8.3.2 SLIP and PLIP	255	(1)
8.3.3 The loopback device	255	(1)
8.3.4 The dummy device	255	(1)
8.4 ARP -- the Address Resolution Protocol	256	(3)
8.5 IP	259	(10)
8.5.1 IP -- general introduction	259	(1)
8.5.2 IP functions	260	(3)
8.5.3 Routing	263	(2)
8.5.4 IP multicasting and IGPM	265	(2)
8.5.5 IP packet filters	267	(1)
8.5.6 IP accounting and IP firewalling	268	(1)
8.6 UDP	269	(2)
8.6.1 Functions of UDP	269	(2)
8.6.2 Other functions	271	(1)
8.7 TCP	271	(6)
8.7.1 General notes on TCP	271	(1)
8.7.2 The TCP communication end-point -- a finite state machine	272	(1)
8.7.3 Functions of TCP	273	(4)
8.8 The packet interface -- an alternative?	277	(2)
9 Modules and debugging	279	(14)
9.1 What are modules?	279	(1)
9.2 Implementation in the kernel	280	(3)
9.2.1 Signatures of symbols	283	(1)
9.3 What can be implemented as a module?	283	(2)
9.4 Parameter passing	285	(1)
9.5 The kernel daemon	285	(2)
9.6 An example module	287	(2)
9.7 Debugging	289	(4)
9.7.1 Changes are the beginning of the end	289	(1)
9.7.2 The best debugger -- printk()	290	(1)
9.7.3 Debugging with gdb	291	(2)
10 Multi-processing	293	(8)
10.1 The Intel multi-processor specification	293	(2)
10.2 Problems with multi-processor systems	295	(1)
10.3 Changes to the kernel	296	(4)
10.3.1 Kernel initialization	296	(1)
10.3.2 Scheduling	297	(1)
10.3.3 Message exchange between processors	298	(1)
10.3.4 Entering kernel mode	298	(1)
10.3.5 Interrupt handling	299	(1)
10.4 Compiling LINUX SMP	300	(1)
APPENDIX A -- System calls	301	(79)
A.1 Process management	302	(37)
A.2 The file system	339	(31)
A.3 Communication	370	(3)
A.4 Memory management	373	(5)
A.5 Initialization	378	(1)
A.6 All that remains	379	(1)
APPENDIX B -- Kernel-related commands	380	(35)
B.1 free -- synopsis of the system memory	380	(1)
B.2 ps -- display of process statistics	381	(5)
B.3 Additional kernel configuration	386	(1)
B.4 top -- the CPU charts	387	(2)
B.5 init -- primus inter pares	389	(6)
B.6 shutdown -- shutting down the system	395	(1)
B.7 strace -- monitoring a process	396	(4)
B.8 Configuring the network interface	400	(1)
B.9 traceroute -- Ariadne's thread in the Internet	400	(3)
B.10 Configuring a serial interface	403	(2)
B.11 Configuring a parallel interface	405	(2)
B.12 mount	407	(8)
APPENDIX C -- The Proc file system	415	(13)
C.1 The /proc/ directory	415	(6)
C.2 The net/ directory	421	(1)
C.3 The self/ directory	422	(4)
C.4 The sys/ directory	426	(2)
APPENDIX D -- The boot process	428	(13)
D.1 Carrying out the boot process	428	(3)
D.2 LILO -- the Linux loader	431	(10)
D.2.1 LILO started by MS-DOS MBR	431	(1)
D.2.2 LILO started by a boot manager	431	(1)
D.2.3 LILO in the master boot record	432	(1)
D.2.4 LILO files	432	(5)
D.2.5 LILO boot parameters	437	(2)
D.2.6 LILO start-up messages	439	(1)
D.2.7 Error messages	439	(2)
APPENDIX E -- Useful kernel functions	441	(16)
References	457	(4)
Index	461