summaryrefslogtreecommitdiffstats
path: root/arch/um/kernel/um_arch.c
blob: 73747ac197748d6deb1649f0b59b4b1aad1d7051 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
/*
 * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
 * Licensed under the GPL
 */

#include "linux/config.h"
#include "linux/kernel.h"
#include "linux/sched.h"
#include "linux/notifier.h"
#include "linux/mm.h"
#include "linux/types.h"
#include "linux/tty.h"
#include "linux/init.h"
#include "linux/bootmem.h"
#include "linux/spinlock.h"
#include "linux/utsname.h"
#include "linux/sysrq.h"
#include "linux/seq_file.h"
#include "linux/delay.h"
#include "linux/module.h"
#include "asm/page.h"
#include "asm/pgtable.h"
#include "asm/ptrace.h"
#include "asm/elf.h"
#include "asm/user.h"
#include "asm/setup.h"
#include "ubd_user.h"
#include "asm/current.h"
#include "user_util.h"
#include "kern_util.h"
#include "kern.h"
#include "mem_user.h"
#include "mem.h"
#include "umid.h"
#include "initrd.h"
#include "init.h"
#include "os.h"
#include "choose-mode.h"
#include "mode_kern.h"
#include "mode.h"
#ifdef UML_CONFIG_MODE_SKAS
#include "skas.h"
#endif

#define DEFAULT_COMMAND_LINE "root=98:0"

/* Changed in linux_main and setup_arch, which run before SMP is started */
static char command_line[COMMAND_LINE_SIZE] = { 0 };

static void add_arg(char *arg)
{
	if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
		printf("add_arg: Too many command line arguments!\n");
		exit(1);
	}
	if(strlen(command_line) > 0)
		strcat(command_line, " ");
	strcat(command_line, arg);
}

struct cpuinfo_um boot_cpu_data = { 
	.loops_per_jiffy	= 0,
	.ipi_pipe		= { -1, -1 }
};

unsigned long thread_saved_pc(struct task_struct *task)
{
	return(os_process_pc(CHOOSE_MODE_PROC(thread_pid_tt, thread_pid_skas,
					      task)));
}

static int show_cpuinfo(struct seq_file *m, void *v)
{
	int index = 0;

#ifdef CONFIG_SMP
	index = (struct cpuinfo_um *) v - cpu_data;
	if (!cpu_online(index))
		return 0;
#endif

	seq_printf(m, "processor\t: %d\n", index);
	seq_printf(m, "vendor_id\t: User Mode Linux\n");
	seq_printf(m, "model name\t: UML\n");
	seq_printf(m, "mode\t\t: %s\n", CHOOSE_MODE("tt", "skas"));
	seq_printf(m, "host\t\t: %s\n", host_info);
	seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
		   loops_per_jiffy/(500000/HZ),
		   (loops_per_jiffy/(5000/HZ)) % 100);

	return(0);
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
	return *pos < NR_CPUS ? cpu_data + *pos : NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
	++*pos;
	return c_start(m, pos);
}

static void c_stop(struct seq_file *m, void *v)
{
}

struct seq_operations cpuinfo_op = {
	.start	= c_start,
	.next	= c_next,
	.stop	= c_stop,
	.show	= show_cpuinfo,
};

/* Set in linux_main */
unsigned long host_task_size;
unsigned long task_size;

unsigned long uml_start;

/* Set in early boot */
unsigned long uml_physmem;
unsigned long uml_reserved;
unsigned long start_vm;
unsigned long end_vm;
int ncpus = 1;

#ifdef CONFIG_CMDLINE_ON_HOST
/* Pointer set in linux_main, the array itself is private to each thread,
 * and changed at address space creation time so this poses no concurrency
 * problems.
 */
static char *argv1_begin = NULL;
static char *argv1_end = NULL;
#endif

/* Set in early boot */
static int have_root __initdata = 0;
long long physmem_size = 32 * 1024 * 1024;

void set_cmdline(char *cmd)
{
#ifdef CONFIG_CMDLINE_ON_HOST
	char *umid, *ptr;

	if(CHOOSE_MODE(honeypot, 0)) return;

	umid = get_umid();
	if(*umid != '\0'){
		snprintf(argv1_begin, 
			 (argv1_end - argv1_begin) * sizeof(*ptr), 
			 "(%s) ", umid);
		ptr = &argv1_begin[strlen(argv1_begin)];
	}
	else ptr = argv1_begin;

	snprintf(ptr, (argv1_end - ptr) * sizeof(*ptr), "[%s]", cmd);
	memset(argv1_begin + strlen(argv1_begin), '\0', 
	       argv1_end - argv1_begin - strlen(argv1_begin));
#endif
}

static char *usage_string = 
"User Mode Linux v%s\n"
"	available at http://user-mode-linux.sourceforge.net/\n\n";

static int __init uml_version_setup(char *line, int *add)
{
	printf("%s\n", system_utsname.release);
	exit(0);

	return 0;
}

__uml_setup("--version", uml_version_setup,
"--version\n"
"    Prints the version number of the kernel.\n\n"
);

static int __init uml_root_setup(char *line, int *add)
{
	have_root = 1;
	return 0;
}

__uml_setup("root=", uml_root_setup,
"root=<file containing the root fs>\n"
"    This is actually used by the generic kernel in exactly the same\n"
"    way as in any other kernel. If you configure a number of block\n"
"    devices and want to boot off something other than ubd0, you \n"
"    would use something like:\n"
"        root=/dev/ubd5\n\n"
);

#ifdef CONFIG_SMP
static int __init uml_ncpus_setup(char *line, int *add)
{
       if (!sscanf(line, "%d", &ncpus)) {
               printf("Couldn't parse [%s]\n", line);
               return -1;
       }

       return 0;
}

__uml_setup("ncpus=", uml_ncpus_setup,
"ncpus=<# of desired CPUs>\n"
"    This tells an SMP kernel how many virtual processors to start.\n\n" 
);
#endif

static int force_tt = 0;

#if defined(CONFIG_MODE_TT) && defined(CONFIG_MODE_SKAS)
#define DEFAULT_TT 0

static int __init mode_tt_setup(char *line, int *add)
{
	force_tt = 1;
	return(0);
}

#else
#ifdef CONFIG_MODE_SKAS

#define DEFAULT_TT 0

static int __init mode_tt_setup(char *line, int *add)
{
	printf("CONFIG_MODE_TT disabled - 'mode=tt' ignored\n");
	return(0);
}

#else
#ifdef CONFIG_MODE_TT

#define DEFAULT_TT 1

static int __init mode_tt_setup(char *line, int *add)
{
	printf("CONFIG_MODE_SKAS disabled - 'mode=tt' redundant\n");
	return(0);
}

#else

#error Either CONFIG_MODE_TT or CONFIG_MODE_SKAS must be enabled

#endif
#endif
#endif

__uml_setup("mode=tt", mode_tt_setup,
"mode=tt\n"
"    When both CONFIG_MODE_TT and CONFIG_MODE_SKAS are enabled, this option\n"
"    forces UML to run in tt (tracing thread) mode.  It is not the default\n"
"    because it's slower and less secure than skas mode.\n\n"
);

int mode_tt = DEFAULT_TT;

static int __init Usage(char *line, int *add)
{
 	const char **p;

	printf(usage_string, system_utsname.release);
 	p = &__uml_help_start;
 	while (p < &__uml_help_end) {
 		printf("%s", *p);
 		p++;
 	}
	exit(0);

	return 0;
}

__uml_setup("--help", Usage,
"--help\n"
"    Prints this message.\n\n"
);

static int __init uml_checksetup(char *line, int *add)
{
	struct uml_param *p;

	p = &__uml_setup_start;
	while(p < &__uml_setup_end) {
		int n;

		n = strlen(p->str);
		if(!strncmp(line, p->str, n)){
			if (p->setup_func(line + n, add)) return 1;
		}
		p++;
	}
	return 0;
}

static void __init uml_postsetup(void)
{
	initcall_t *p;

	p = &__uml_postsetup_start;
	while(p < &__uml_postsetup_end){
		(*p)();
		p++;
	}
	return;
}

/* Set during early boot */
unsigned long brk_start;
unsigned long end_iomem;
EXPORT_SYMBOL(end_iomem);

#define MIN_VMALLOC (32 * 1024 * 1024)

int linux_main(int argc, char **argv)
{
	unsigned long avail, diff;
	unsigned long virtmem_size, max_physmem;
	unsigned int i, add;
	char * mode;

	for (i = 1; i < argc; i++){
		if((i == 1) && (argv[i][0] == ' ')) continue;
		add = 1;
		uml_checksetup(argv[i], &add);
		if (add)
			add_arg(argv[i]);
	}
	if(have_root == 0)
		add_arg(DEFAULT_COMMAND_LINE);

	os_early_checks();
	if (force_tt)
		clear_can_do_skas();
	mode_tt = force_tt ? 1 : !can_do_skas();
#ifndef CONFIG_MODE_TT
	if (mode_tt) {
		/*Since CONFIG_MODE_TT is #undef'ed, force_tt cannot be 1. So,
		 * can_do_skas() returned 0, and the message is correct. */
		printf("Support for TT mode is disabled, and no SKAS support is present on the host.\n");
		exit(1);
	}
#endif

#ifndef CONFIG_MODE_SKAS
	mode = "TT";
#else
	/* Show to the user the result of selection */
	if (mode_tt)
		mode = "TT";
	else if (proc_mm && ptrace_faultinfo)
		mode = "SKAS3";
	else
		mode = "SKAS0";
#endif

	printf("UML running in %s mode\n", mode);

	uml_start = CHOOSE_MODE_PROC(set_task_sizes_tt, set_task_sizes_skas, 0,
				     &host_task_size, &task_size);

	/*
 	 * Setting up handlers to 'sig_info' struct
 	 */
	os_fill_handlinfo(handlinfo_kern);

	brk_start = (unsigned long) sbrk(0);
	CHOOSE_MODE_PROC(before_mem_tt, before_mem_skas, brk_start);
	/* Increase physical memory size for exec-shield users
	so they actually get what they asked for. This should
	add zero for non-exec shield users */

	diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
	if(diff > 1024 * 1024){
		printf("Adding %ld bytes to physical memory to account for "
		       "exec-shield gap\n", diff);
		physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
	}

	uml_physmem = uml_start;

	/* Reserve up to 4M after the current brk */
	uml_reserved = ROUND_4M(brk_start) + (1 << 22);

	setup_machinename(system_utsname.machine);

#ifdef CONFIG_CMDLINE_ON_HOST
	argv1_begin = argv[1];
	argv1_end = &argv[1][strlen(argv[1])];
#endif
  
	highmem = 0;
	iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
	max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;

	/* Zones have to begin on a 1 << MAX_ORDER page boundary,
	 * so this makes sure that's true for highmem
	 */
	max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
	if(physmem_size + iomem_size > max_physmem){
		highmem = physmem_size + iomem_size - max_physmem;
		physmem_size -= highmem;
#ifndef CONFIG_HIGHMEM
		highmem = 0;
		printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
		       "to %lu bytes\n", physmem_size);
#endif
	}

	high_physmem = uml_physmem + physmem_size;
	end_iomem = high_physmem + iomem_size;
	high_memory = (void *) end_iomem;

	start_vm = VMALLOC_START;

	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
	if(init_maps(physmem_size, iomem_size, highmem)){
		printf("Failed to allocate mem_map for %lu bytes of physical "
		       "memory and %lu bytes of highmem\n", physmem_size,
		       highmem);
		exit(1);
	}

	virtmem_size = physmem_size;
	avail = get_kmem_end() - start_vm;
	if(physmem_size > avail) virtmem_size = avail;
	end_vm = start_vm + virtmem_size;

	if(virtmem_size < physmem_size)
		printf("Kernel virtual memory size shrunk to %lu bytes\n",
		       virtmem_size);

  	uml_postsetup();

	task_protections((unsigned long) &init_thread_info);
	os_flush_stdout();

	return(CHOOSE_MODE(start_uml_tt(), start_uml_skas()));
}

extern int uml_exitcode;

static int panic_exit(struct notifier_block *self, unsigned long unused1,
		      void *unused2)
{
	bust_spinlocks(1);
	show_regs(&(current->thread.regs));
	bust_spinlocks(0);
	uml_exitcode = 1;
	machine_halt();
	return(0);
}

static struct notifier_block panic_exit_notifier = {
	.notifier_call 		= panic_exit,
	.next 			= NULL,
	.priority 		= 0
};

void __init setup_arch(char **cmdline_p)
{
	notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
	paging_init();
        strlcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = command_line;
	setup_hostinfo();
}

void __init check_bugs(void)
{
	arch_check_bugs();
	check_sigio();
	check_devanon();
}

void apply_alternatives(void *start, void *end)
{
}
OpenPOWER on IntegriCloud