blob: 5988debfc505c84c8c5f7abeb0b5fb1e2d88f1fc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/init/main.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * GK 2/5/95 - Changed to support mounting root fs via NFS
7 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
10 */
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/syscalls.h>
Ingo Molnar9b5609f2008-02-14 09:41:09 +010017#include <linux/stackprotector.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/string.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/smp_lock.h>
24#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040026#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/tty.h>
28#include <linux/gfp.h>
29#include <linux/percpu.h>
30#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070031#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010033#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020035#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <linux/workqueue.h>
37#include <linux/profile.h>
38#include <linux/rcupdate.h>
39#include <linux/moduleparam.h>
40#include <linux/kallsyms.h>
41#include <linux/writeback.h>
42#include <linux/cpu.h>
43#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070044#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080046#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080047#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070048#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070049#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <linux/unistd.h>
51#include <linux/rmap.h>
52#include <linux/mempolicy.h>
53#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070054#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070055#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070056#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070057#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070058#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010059#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080060#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080061#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070062#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010063#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080064#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070065#include <linux/idr.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040066#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080067#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020068#include <linux/kmemcheck.h>
Zhaolei02af61b2009-04-10 14:26:18 +080069#include <linux/kmemtrace.h>
Feng Tang6ae69962009-08-14 15:13:46 -040070#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020071#include <linux/shmem_fs.h>
Frederic Weisbecker3f5ec132008-11-11 23:21:31 +010072#include <trace/boot.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74#include <asm/io.h>
75#include <asm/bugs.h>
76#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070077#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080078#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Linus Torvalds1da177e2005-04-16 15:20:36 -070080#ifdef CONFIG_X86_LOCAL_APIC
81#include <asm/smp.h>
82#endif
83
Sam Ravnborgaae5f662007-02-26 16:45:41 +010084static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
86extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087extern void fork_init(unsigned long);
88extern void mca_init(void);
89extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090extern void prio_tree_init(void);
91extern void radix_tree_init(void);
92extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080093#ifndef CONFIG_DEBUG_RODATA
94static inline void mark_rodata_ro(void) { }
95#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97#ifdef CONFIG_TC
98extern void tc_init(void);
99#endif
100
Paul E. McKenneya6826042009-02-25 18:03:42 -0800101enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102EXPORT_SYMBOL(system_state);
103
104/*
105 * Boot command-line arguments
106 */
107#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
108#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
109
110extern void time_init(void);
111/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800112void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113extern void softirq_init(void);
114
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800115/* Untouched command line saved by arch-specific code. */
116char __initdata boot_command_line[COMMAND_LINE_SIZE];
117/* Untouched saved command line (eg. for /proc) */
118char *saved_command_line;
119/* Command line for parameter parsing */
120static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
122static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700123static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
Jan Beulich8b3b2952007-07-15 23:41:07 -0700125#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126/* Setup configured maximum number of CPUs to activate */
Andi Kleenca74a6f2008-01-30 13:33:17 +0100127unsigned int __initdata setup_max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700128
129/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 * Setup routine for controlling SMP activation
131 *
132 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
133 * activation entirely (the MPS table probe still happens, though).
134 *
135 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
136 * greater than 0, limits the maximum number of CPUs activated in
137 * SMP mode to <NUM>.
138 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100139
140void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142static int __init nosmp(char *str)
143{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100144 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100145 arch_disable_smp_support();
146
Jan Beulich8b3b2952007-07-15 23:41:07 -0700147 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148}
149
Jan Beulich8b3b2952007-07-15 23:41:07 -0700150early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
152static int __init maxcpus(char *str)
153{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100154 get_option(&str, &setup_max_cpus);
155 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100156 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400157
158 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159}
160
Hugh Dickins81340972007-08-27 16:02:12 +0100161early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700162#else
Ingo Molnar65a4e572009-01-31 03:36:17 +0100163const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700164#endif
165
166/*
167 * If set, this is an indication to the drivers that reset the underlying
168 * device before going ahead with the initialization otherwise driver might
169 * rely on the BIOS and skip the reset operation.
170 *
171 * This is useful if kernel is booting in an unreliable environment.
172 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
173 * skipped and devices will be in unknown state.
174 */
175unsigned int reset_devices;
176EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Vivek Goyal7e962872006-09-27 01:50:44 -0700178static int __init set_reset_devices(char *str)
179{
180 reset_devices = 1;
181 return 1;
182}
183
184__setup("reset_devices", set_reset_devices);
185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
187char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
188static const char *panic_later, *panic_param;
189
190extern struct obs_kernel_param __setup_start[], __setup_end[];
191
192static int __init obsolete_checksetup(char *line)
193{
194 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200195 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
197 p = __setup_start;
198 do {
199 int n = strlen(p->str);
200 if (!strncmp(line, p->str, n)) {
201 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200202 /* Already done in parse_early_param?
203 * (Needs exact match on param part).
204 * Keep iterating, as we can have early
205 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200207 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 } else if (!p->setup_func) {
209 printk(KERN_WARNING "Parameter %s is obsolete,"
210 " ignored\n", p->str);
211 return 1;
212 } else if (p->setup_func(line + n))
213 return 1;
214 }
215 p++;
216 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200217
218 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219}
220
221/*
222 * This should be approx 2 Bo*oMips to start (note initial shift), and will
223 * still work even if initially too large, it will just take slightly longer
224 */
225unsigned long loops_per_jiffy = (1<<12);
226
227EXPORT_SYMBOL(loops_per_jiffy);
228
229static int __init debug_kernel(char *str)
230{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800232 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233}
234
235static int __init quiet_kernel(char *str)
236{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800238 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
Yinghai Luf6f21c812008-02-08 04:21:58 -0800241early_param("debug", debug_kernel);
242early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244static int __init loglevel(char *str)
245{
246 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800247 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248}
249
Yinghai Luf6f21c812008-02-08 04:21:58 -0800250early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252/*
253 * Unknown boot options get handed to init, unless they look like
254 * failed parameters
255 */
256static int __init unknown_bootoption(char *param, char *val)
257{
258 /* Change NUL term back to "=", to make "param" the whole string. */
259 if (val) {
260 /* param=val or param="val"? */
261 if (val == param+strlen(param)+1)
262 val[-1] = '=';
263 else if (val == param+strlen(param)+2) {
264 val[-2] = '=';
265 memmove(val-1, val, strlen(val)+1);
266 val--;
267 } else
268 BUG();
269 }
270
271 /* Handle obsolete-style parameters */
272 if (obsolete_checksetup(param))
273 return 0;
274
275 /*
Simon Arlott211fee82007-10-20 01:28:29 +0200276 * Preemptive maintenance for "why didn't my misspelled command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 * line work?"
278 */
279 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
280 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
281 return 0;
282 }
283
284 if (panic_later)
285 return 0;
286
287 if (val) {
288 /* Environment option */
289 unsigned int i;
290 for (i = 0; envp_init[i]; i++) {
291 if (i == MAX_INIT_ENVS) {
292 panic_later = "Too many boot env vars at `%s'";
293 panic_param = param;
294 }
295 if (!strncmp(param, envp_init[i], val - param))
296 break;
297 }
298 envp_init[i] = param;
299 } else {
300 /* Command line option */
301 unsigned int i;
302 for (i = 0; argv_init[i]; i++) {
303 if (i == MAX_INIT_ARGS) {
304 panic_later = "Too many boot init vars at `%s'";
305 panic_param = param;
306 }
307 }
308 argv_init[i] = param;
309 }
310 return 0;
311}
312
Ingo Molnar12d6f212008-01-30 13:33:58 +0100313#ifdef CONFIG_DEBUG_PAGEALLOC
314int __read_mostly debug_pagealloc_enabled = 0;
315#endif
316
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317static int __init init_setup(char *str)
318{
319 unsigned int i;
320
321 execute_command = str;
322 /*
323 * In case LILO is going to boot us with default command line,
324 * it prepends "auto" before the whole cmdline which makes
325 * the shell think it should execute a script with such name.
326 * So we ignore all arguments entered _before_ init=... [MJ]
327 */
328 for (i = 1; i < MAX_INIT_ARGS; i++)
329 argv_init[i] = NULL;
330 return 1;
331}
332__setup("init=", init_setup);
333
Olof Johanssonffdfc402005-09-06 15:17:19 -0700334static int __init rdinit_setup(char *str)
335{
336 unsigned int i;
337
338 ramdisk_execute_command = str;
339 /* See "auto" comment in init_setup */
340 for (i = 1; i < MAX_INIT_ARGS; i++)
341 argv_init[i] = NULL;
342 return 1;
343}
344__setup("rdinit=", rdinit_setup);
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346#ifndef CONFIG_SMP
347
348#ifdef CONFIG_X86_LOCAL_APIC
349static void __init smp_init(void)
350{
351 APIC_init_uniprocessor();
352}
353#else
354#define smp_init() do { } while (0)
355#endif
356
Mike Travise0982e92008-03-26 14:23:48 -0700357static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358static inline void smp_prepare_cpus(unsigned int maxcpus) { }
359
360#else
361
Mike Travise0982e92008-03-26 14:23:48 -0700362/* Setup number of possible processor ids */
363int nr_cpu_ids __read_mostly = NR_CPUS;
364EXPORT_SYMBOL(nr_cpu_ids);
365
366/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
367static void __init setup_nr_cpu_ids(void)
368{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030369 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700370}
371
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372/* Called by boot processor to activate the rest. */
373static void __init smp_init(void)
374{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800375 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
Max Krasnyanskye761b772008-07-15 04:43:49 -0700377 /*
378 * Set up the current CPU as possible to migrate to.
379 * The other ones will be done by cpu_up/cpu_down()
380 */
Rusty Russell2b17fa52009-03-30 22:05:12 -0600381 set_cpu_active(smp_processor_id(), true);
Max Krasnyanskye761b772008-07-15 04:43:49 -0700382
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800384 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100385 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800387 if (!cpu_online(cpu))
388 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 }
390
391 /* Any cleanup work */
392 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100393 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394}
395
396#endif
397
398/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800399 * We need to store the untouched command line for future reference.
400 * We also need to store the touched command line since the parameter
401 * parsing is performed in place, and we should allow a component to
402 * store reference of name/value for future reference.
403 */
404static void __init setup_command_line(char *command_line)
405{
406 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
407 static_command_line = alloc_bootmem(strlen (command_line)+1);
408 strcpy (saved_command_line, boot_command_line);
409 strcpy (static_command_line, command_line);
410}
411
412/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 * We need to finalize in a non-__init function or else race conditions
414 * between the root thread and the init thread may cause start_kernel to
415 * be reaped by free_initmem before the root thread has proceeded to
416 * cpu_idle.
417 *
418 * gcc-3.4 accidentally inlines this function, so use noinline.
419 */
420
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800421static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 __releases(kernel_lock)
423{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700424 int pid;
425
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700426 rcu_scheduler_starting();
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100427 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700429 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700430 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200432
433 /*
434 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200435 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200436 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200437 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800438 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200439 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800440 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200441
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800442 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200444}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
446/* Check for early params. */
447static int __init do_early_param(char *param, char *val)
448{
449 struct obs_kernel_param *p;
450
451 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700452 if ((p->early && strcmp(param, p->str) == 0) ||
453 (strcmp(param, "console") == 0 &&
454 strcmp(p->str, "earlycon") == 0)
455 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 if (p->setup_func(val) != 0)
457 printk(KERN_WARNING
458 "Malformed early option '%s'\n", param);
459 }
460 }
461 /* We accept everything at this stage. */
462 return 0;
463}
464
Magnus Damm13977092009-03-30 14:37:25 -0700465void __init parse_early_options(char *cmdline)
466{
467 parse_args("early options", cmdline, NULL, 0, do_early_param);
468}
469
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470/* Arch code calls this early on, or if not, just before other parsing. */
471void __init parse_early_param(void)
472{
473 static __initdata int done = 0;
474 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
475
476 if (done)
477 return;
478
479 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800480 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700481 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 done = 1;
483}
484
485/*
486 * Activate the first processor.
487 */
488
Stas Sergeev44fd2292006-03-23 02:59:44 -0800489static void __init boot_cpu_init(void)
490{
491 int cpu = smp_processor_id();
492 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030493 set_cpu_online(cpu, true);
494 set_cpu_present(cpu, true);
495 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800496}
497
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000498void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700499{
500}
501
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000502void __init __weak thread_info_cache_init(void)
503{
504}
505
Pekka Enberg444f4782009-06-11 18:29:06 +0300506/*
507 * Set up kernel memory allocators
508 */
509static void __init mm_init(void)
510{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300511 /*
512 * page_cgroup requires countinous pages as memmap
513 * and it's bigger than MAX_ORDER unless SPARSEMEM.
514 */
515 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300516 mem_init();
517 kmem_cache_init();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000518 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300519 vmalloc_init();
520}
521
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522asmlinkage void __init start_kernel(void)
523{
524 char * command_line;
525 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700526
527 smp_setup_processor_id();
528
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700529 /*
530 * Need to run as early as possible, to initialize the
531 * lockdep hash:
532 */
533 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700534 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100535
536 /*
537 * Set up the the initial canary ASAP:
538 */
539 boot_init_stack_canary();
540
Paul Menageddbcc7e2007-10-18 23:39:30 -0700541 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700542
543 local_irq_disable();
544 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700545 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700546
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547/*
548 * Interrupts are still disabled. Do necessary setups, then
549 * enable them
550 */
551 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800552 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800553 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200555 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700557 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800558 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700559 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900560 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800561 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
Pekka Enberg83b519e2009-06-10 19:40:04 +0300563 build_all_zonelists();
564 page_alloc_init();
565
566 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
567 parse_early_param();
568 parse_args("Booting kernel", static_command_line, __start___param,
569 __stop___param - __start___param,
570 &unknown_bootoption);
571 /*
572 * These use large bootmem allocations and must precede
573 * kmem_cache_init()
574 */
575 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300576 vfs_caches_init_early();
577 sort_main_extable();
578 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300579 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 /*
581 * Set up the scheduler prior starting any interrupts (such as the
582 * timer interrupt). Full topology setup happens at smp_init()
583 * time - but meanwhile we still have a functioning scheduler.
584 */
585 sched_init();
586 /*
587 * Disable preemption - early bootup scheduling is extremely
588 * fragile until we cpu_idle() for the first time.
589 */
590 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800591 if (!irqs_disabled()) {
592 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
593 "enabled *very* early, fixing it\n");
594 local_irq_disable();
595 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 rcu_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800597 /* init some links before init_ISA_irqs() */
598 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100600 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800602 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700604 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700605 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700606 profile_init();
607 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030608 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
609 "enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700610 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700611 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000612
613 /* Interrupts are enabled now so all GFP allocations are safe. */
614 set_gfp_allowed_mask(__GFP_BITS_MASK);
615
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300616 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
618 /*
619 * HACK ALERT! This is early. We're enabling the console before
620 * we've done PCI setups etc, and console_init() must be aware of
621 * this. But we do want output early, in case something goes wrong.
622 */
623 console_init();
624 if (panic_later)
625 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700626
627 lockdep_info();
628
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700629 /*
630 * Need to run this when irqs are enabled, because it wants
631 * to self-test [hard/soft]-irqs on/off lock inversion bugs
632 * too:
633 */
634 locking_selftest();
635
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636#ifdef CONFIG_BLK_DEV_INITRD
637 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700638 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200640 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700641 page_to_pfn(virt_to_page((void *)initrd_start)),
642 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 initrd_start = 0;
644 }
645#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700646 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100647 enable_debug_pagealloc();
Eduard - Gabriel Munteanub9ce08c2008-08-10 20:14:03 +0300648 kmemtrace_init();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100649 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700650 debug_objects_mem_init();
Akinobu Mita199f0ca2008-04-29 01:03:13 -0700651 idr_init_cache();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700652 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 numa_policy_init();
654 if (late_time_init)
655 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200656 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 calibrate_delay();
658 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 anon_vma_init();
660#ifdef CONFIG_X86
661 if (efi_enabled)
662 efi_enter_virtual_mode();
663#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000664 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100665 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700666 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 proc_caches_init();
668 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 key_init();
670 security_init();
Jan Beulich44813742009-09-21 17:03:05 -0700671 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 radix_tree_init();
673 signals_init();
674 /* rootfs populating might need page-writeback */
675 page_writeback_init();
676#ifdef CONFIG_PROC_FS
677 proc_root_init();
678#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700679 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700681 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700682 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684 check_bugs();
685
686 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400687 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400689 ftrace_init();
690
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 /* Do the rest non-__init'ed, we're now alive */
692 rest_init();
693}
694
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700695/* Call all constructor functions linked into the kernel. */
696static void __init do_ctors(void)
697{
698#ifdef CONFIG_CONSTRUCTORS
699 ctor_fn_t *call = (ctor_fn_t *) __ctors_start;
700
701 for (; call < (ctor_fn_t *) __ctors_end; call++)
702 (*call)();
703#endif
704}
705
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800706int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500707core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200709static char msgbuf[64];
710static struct boot_trace_call call;
711static struct boot_trace_ret ret;
712
Arjan van de Ven59f94152008-07-30 12:49:02 -0700713int do_one_initcall(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700714{
715 int count = preempt_count();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100716 ktime_t calltime, delta, rettime;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700717
718 if (initcall_debug) {
Frederic Weisbecker74239072008-11-11 23:24:42 +0100719 call.caller = task_pid_nr(current);
720 printk("calling %pF @ %i\n", fn, call.caller);
721 calltime = ktime_get();
722 trace_boot_call(&call, fn);
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100723 enable_boot_trace();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700724 }
725
Frederic Weisbecker74239072008-11-11 23:24:42 +0100726 ret.result = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700727
728 if (initcall_debug) {
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100729 disable_boot_trace();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100730 rettime = ktime_get();
731 delta = ktime_sub(rettime, calltime);
Will Newton1d926f22008-11-21 14:08:59 -0800732 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Frederic Weisbecker74239072008-11-11 23:24:42 +0100733 trace_boot_ret(&ret, fn);
Tim Birdca538f62008-10-09 15:23:05 -0700734 printk("initcall %pF returned %d after %Ld usecs\n", fn,
Frederic Weisbecker74239072008-11-11 23:24:42 +0100735 ret.result, ret.duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700736 }
737
738 msgbuf[0] = 0;
739
Frederic Weisbecker74239072008-11-11 23:24:42 +0100740 if (ret.result && ret.result != -ENODEV && initcall_debug)
741 sprintf(msgbuf, "error code %d ", ret.result);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700742
743 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700744 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700745 preempt_count() = count;
746 }
747 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700748 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700749 local_irq_enable();
750 }
751 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700752 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700753 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700754
Frederic Weisbecker74239072008-11-11 23:24:42 +0100755 return ret.result;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700756}
757
758
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700759extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
761static void __init do_initcalls(void)
762{
763 initcall_t *call;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700765 for (call = __early_initcall_end; call < __initcall_end; call++)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700766 do_one_initcall(*call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
768 /* Make sure there is no pending stuff from the initcall sequence */
769 flush_scheduled_work();
770}
771
772/*
773 * Ok, the machine is now initialized. None of the devices
774 * have been touched yet, but the CPU subsystem is up and
775 * running, and memory and process management works.
776 *
777 * Now we can finally start doing some real work..
778 */
779static void __init do_basic_setup(void)
780{
Linus Torvalds4403b402008-10-25 19:53:38 -0700781 init_workqueues();
Lai Jiangshan759ee092009-03-25 17:06:30 +0800782 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 usermodehelper_init();
Kay Sievers2b2af542009-04-30 15:23:42 +0200784 init_tmpfs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800786 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700787 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 do_initcalls();
789}
790
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700791static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700792{
793 initcall_t *call;
794
795 for (call = __initcall_start; call < __early_initcall_end; call++)
796 do_one_initcall(*call);
797}
798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799static void run_init_process(char *init_filename)
800{
801 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700802 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803}
804
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100805/* This is a non __init function. Force it to be noinline otherwise gcc
806 * makes it inline to init() and it becomes part of init.text section
807 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800808static noinline int init_post(void)
Hannes Ederacdd0522009-03-31 15:23:50 -0700809 __releases(kernel_lock)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100810{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800811 /* need to finish all async __init code before freeing the memory */
812 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100813 free_initmem();
814 unlock_kernel();
815 mark_rodata_ro();
816 system_state = SYSTEM_RUNNING;
817 numa_default_policy();
818
819 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
820 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
821
822 (void) sys_dup(0);
823 (void) sys_dup(0);
824
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700825 current->signal->flags |= SIGNAL_UNKILLABLE;
826
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100827 if (ramdisk_execute_command) {
828 run_init_process(ramdisk_execute_command);
829 printk(KERN_WARNING "Failed to execute %s\n",
830 ramdisk_execute_command);
831 }
832
833 /*
834 * We try each of these until one succeeds.
835 *
836 * The Bourne shell can be used instead of init if we are
837 * trying to recover a really broken machine.
838 */
839 if (execute_command) {
840 run_init_process(execute_command);
841 printk(KERN_WARNING "Failed to execute %s. Attempting "
842 "defaults...\n", execute_command);
843 }
844 run_init_process("/sbin/init");
845 run_init_process("/etc/init");
846 run_init_process("/bin/init");
847 run_init_process("/bin/sh");
848
849 panic("No init found. Try passing init= option to kernel.");
850}
851
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100852static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853{
854 lock_kernel();
Miao Xie58568d22009-06-16 15:31:49 -0700855
856 /*
857 * init can allocate pages on any node
858 */
859 set_mems_allowed(node_possible_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 /*
861 * init can run on any cpu.
862 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600863 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 /*
865 * Tell the world that we're going to be the grim
866 * reaper of innocent orphaned children.
867 *
868 * We don't want people to have to make incorrect
869 * assumptions about where in the task array this
870 * can be found.
871 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800872 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700874 cad_pid = task_pid(current);
875
Andi Kleenca74a6f2008-01-30 13:33:17 +0100876 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877
878 do_pre_smp_initcalls();
Frédéric Weisbecker3bf77af2008-09-23 11:38:18 +0100879 start_boot_trace();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 smp_init();
882 sched_init_smp();
883
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 do_basic_setup();
885
886 /*
887 * check if there is an early userspace init. If yes, let it do all
888 * the work
889 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700890
891 if (!ramdisk_execute_command)
892 ramdisk_execute_command = "/init";
893
894 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
895 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700897 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 /*
900 * Ok, we have completed the initial bootup, and
901 * we're essentially up and running. Get rid of the
902 * initmem segments and start the user-mode stuff..
903 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100904
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100905 init_post();
906 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907}