Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 : */
5 :
6 : #include <linux/delay.h>
7 : #include <linux/init.h>
8 : #include <linux/mm.h>
9 : #include <linux/ctype.h>
10 : #include <linux/module.h>
11 : #include <linux/panic_notifier.h>
12 : #include <linux/seq_file.h>
13 : #include <linux/string.h>
14 : #include <linux/utsname.h>
15 : #include <linux/sched.h>
16 : #include <linux/sched/task.h>
17 : #include <linux/kmsg_dump.h>
18 : #include <linux/suspend.h>
19 : #include <linux/random.h>
20 :
21 : #include <asm/processor.h>
22 : #include <asm/cpufeature.h>
23 : #include <asm/sections.h>
24 : #include <asm/setup.h>
25 : #include <as-layout.h>
26 : #include <arch.h>
27 : #include <init.h>
28 : #include <kern.h>
29 : #include <kern_util.h>
30 : #include <mem_user.h>
31 : #include <os.h>
32 :
33 : #include "um_arch.h"
34 :
35 : #define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
36 : #define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
37 :
38 : /* Changed in add_arg and setup_arch, which run before SMP is started */
39 : static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
40 :
41 25 : static void __init add_arg(char *arg)
42 : {
43 25 : if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
44 0 : os_warn("add_arg: Too many command line arguments!\n");
45 0 : exit(1);
46 : }
47 25 : if (strlen(command_line) > 0)
48 20 : strcat(command_line, " ");
49 25 : strcat(command_line, arg);
50 25 : }
51 :
52 : /*
53 : * These fields are initialized at boot time and not changed.
54 : * XXX This structure is used only in the non-SMP case. Maybe this
55 : * should be moved to smp.c.
56 : */
57 : struct cpuinfo_um boot_cpu_data = {
58 : .loops_per_jiffy = 0,
59 : .ipi_pipe = { -1, -1 },
60 : .cache_alignment = L1_CACHE_BYTES,
61 : .x86_capability = { 0 }
62 : };
63 :
64 : EXPORT_SYMBOL(boot_cpu_data);
65 :
66 : union thread_union cpu0_irqstack
67 : __section(".data..init_irqstack") =
68 : { .thread_info = INIT_THREAD_INFO(init_task) };
69 :
70 : /* Changed in setup_arch, which is called in early boot */
71 : static char host_info[(__NEW_UTS_LEN + 1) * 5];
72 :
73 0 : static int show_cpuinfo(struct seq_file *m, void *v)
74 : {
75 0 : int i = 0;
76 :
77 0 : seq_printf(m, "processor\t: %d\n", i);
78 0 : seq_printf(m, "vendor_id\t: User Mode Linux\n");
79 0 : seq_printf(m, "model name\t: UML\n");
80 0 : seq_printf(m, "mode\t\t: skas\n");
81 0 : seq_printf(m, "host\t\t: %s\n", host_info);
82 0 : seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
83 0 : seq_printf(m, "flags\t\t:");
84 0 : for (i = 0; i < 32*NCAPINTS; i++)
85 0 : if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
86 0 : seq_printf(m, " %s", x86_cap_flags[i]);
87 0 : seq_printf(m, "\n");
88 0 : seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
89 0 : seq_printf(m, "bogomips\t: %lu.%02lu\n",
90 : loops_per_jiffy/(500000/HZ),
91 0 : (loops_per_jiffy/(5000/HZ)) % 100);
92 :
93 :
94 0 : return 0;
95 : }
96 :
97 0 : static void *c_start(struct seq_file *m, loff_t *pos)
98 : {
99 0 : return *pos < nr_cpu_ids ? &boot_cpu_data + *pos : NULL;
100 : }
101 :
102 0 : static void *c_next(struct seq_file *m, void *v, loff_t *pos)
103 : {
104 0 : ++*pos;
105 0 : return c_start(m, pos);
106 : }
107 :
108 0 : static void c_stop(struct seq_file *m, void *v)
109 : {
110 0 : }
111 :
112 : const struct seq_operations cpuinfo_op = {
113 : .start = c_start,
114 : .next = c_next,
115 : .stop = c_stop,
116 : .show = show_cpuinfo,
117 : };
118 :
119 : /* Set in linux_main */
120 : unsigned long uml_physmem;
121 : EXPORT_SYMBOL(uml_physmem);
122 :
123 : unsigned long uml_reserved; /* Also modified in mem_init */
124 : unsigned long start_vm;
125 : unsigned long end_vm;
126 :
127 : /* Set in uml_ncpus_setup */
128 : int ncpus = 1;
129 :
130 : /* Set in early boot */
131 : static int have_root __initdata;
132 : static int have_console __initdata;
133 :
134 : /* Set in uml_mem_setup and modified in linux_main */
135 : long long physmem_size = 64 * 1024 * 1024;
136 : EXPORT_SYMBOL(physmem_size);
137 :
138 : static const char *usage_string =
139 : "User Mode Linux v%s\n"
140 : " available at http://user-mode-linux.sourceforge.net/\n\n";
141 :
142 0 : static int __init uml_version_setup(char *line, int *add)
143 : {
144 : /* Explicitly use printf() to show version in stdout */
145 0 : printf("%s\n", init_utsname()->release);
146 0 : exit(0);
147 :
148 0 : return 0;
149 : }
150 :
151 : __uml_setup("--version", uml_version_setup,
152 : "--version\n"
153 : " Prints the version number of the kernel.\n\n"
154 : );
155 :
156 0 : static int __init uml_root_setup(char *line, int *add)
157 : {
158 0 : have_root = 1;
159 0 : return 0;
160 : }
161 :
162 : __uml_setup("root=", uml_root_setup,
163 : "root=<file containing the root fs>\n"
164 : " This is actually used by the generic kernel in exactly the same\n"
165 : " way as in any other kernel. If you configure a number of block\n"
166 : " devices and want to boot off something other than ubd0, you \n"
167 : " would use something like:\n"
168 : " root=/dev/ubd5\n\n"
169 : );
170 :
171 0 : static int __init no_skas_debug_setup(char *line, int *add)
172 : {
173 0 : os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
174 0 : os_warn("'gdb linux'\n");
175 :
176 0 : return 0;
177 : }
178 :
179 : __uml_setup("debug", no_skas_debug_setup,
180 : "debug\n"
181 : " this flag is not needed to run gdb on UML in skas mode\n\n"
182 : );
183 :
184 5 : static int __init uml_console_setup(char *line, int *add)
185 : {
186 5 : have_console = 1;
187 5 : return 0;
188 : }
189 :
190 : __uml_setup("console=", uml_console_setup,
191 : "console=<preferred console>\n"
192 : " Specify the preferred console output driver\n\n"
193 : );
194 :
195 0 : static int __init Usage(char *line, int *add)
196 : {
197 : const char **p;
198 :
199 0 : printf(usage_string, init_utsname()->release);
200 0 : p = &__uml_help_start;
201 : /* Explicitly use printf() to show help in stdout */
202 0 : while (p < &__uml_help_end) {
203 0 : printf("%s", *p);
204 0 : p++;
205 : }
206 0 : exit(0);
207 0 : return 0;
208 : }
209 :
210 : __uml_setup("--help", Usage,
211 : "--help\n"
212 : " Prints this message.\n\n"
213 : );
214 :
215 20 : static void __init uml_checksetup(char *line, int *add)
216 : {
217 : struct uml_param *p;
218 :
219 20 : p = &__uml_setup_start;
220 300 : while (p < &__uml_setup_end) {
221 : size_t n;
222 :
223 260 : n = strlen(p->str);
224 260 : if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
225 : return;
226 260 : p++;
227 : }
228 : }
229 :
230 1 : static void __init uml_postsetup(void)
231 : {
232 : initcall_t *p;
233 :
234 1 : p = &__uml_postsetup_start;
235 3 : while (p < &__uml_postsetup_end) {
236 1 : (*p)();
237 1 : p++;
238 : }
239 1 : return;
240 : }
241 :
242 0 : static int panic_exit(struct notifier_block *self, unsigned long unused1,
243 : void *unused2)
244 : {
245 0 : kmsg_dump(KMSG_DUMP_PANIC);
246 0 : bust_spinlocks(1);
247 0 : bust_spinlocks(0);
248 0 : uml_exitcode = 1;
249 0 : os_dump_core();
250 :
251 : return NOTIFY_DONE;
252 : }
253 :
254 : static struct notifier_block panic_exit_notifier = {
255 : .notifier_call = panic_exit,
256 : .priority = INT_MAX - 1, /* run as 2nd notifier, won't return */
257 : };
258 :
259 1 : void uml_finishsetup(void)
260 : {
261 1 : atomic_notifier_chain_register(&panic_notifier_list,
262 : &panic_exit_notifier);
263 :
264 1 : uml_postsetup();
265 :
266 1 : new_thread_handler();
267 0 : }
268 :
269 : /* Set during early boot */
270 : unsigned long stub_start;
271 : unsigned long task_size;
272 : EXPORT_SYMBOL(task_size);
273 :
274 : unsigned long host_task_size;
275 :
276 : unsigned long brk_start;
277 : unsigned long end_iomem;
278 : EXPORT_SYMBOL(end_iomem);
279 :
280 : #define MIN_VMALLOC (32 * 1024 * 1024)
281 :
282 2 : static void parse_host_cpu_flags(char *line)
283 : {
284 : int i;
285 1346 : for (i = 0; i < 32*NCAPINTS; i++) {
286 1344 : if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
287 135 : set_cpu_cap(&boot_cpu_data, i);
288 : }
289 2 : }
290 0 : static void parse_cache_line(char *line)
291 : {
292 : long res;
293 0 : char *to_parse = strstr(line, ":");
294 0 : if (to_parse) {
295 0 : to_parse++;
296 0 : while (*to_parse != 0 && isspace(*to_parse)) {
297 0 : to_parse++;
298 : }
299 0 : if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
300 0 : boot_cpu_data.cache_alignment = res;
301 : else
302 0 : boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
303 : }
304 0 : }
305 :
306 5 : int __init linux_main(int argc, char **argv)
307 : {
308 : unsigned long avail, diff;
309 : unsigned long virtmem_size, max_physmem;
310 : unsigned long stack;
311 : unsigned int i;
312 : int add;
313 :
314 25 : for (i = 1; i < argc; i++) {
315 20 : if ((i == 1) && (argv[i][0] == ' '))
316 0 : continue;
317 20 : add = 1;
318 20 : uml_checksetup(argv[i], &add);
319 20 : if (add)
320 20 : add_arg(argv[i]);
321 : }
322 5 : if (have_root == 0)
323 5 : add_arg(DEFAULT_COMMAND_LINE_ROOT);
324 :
325 5 : if (have_console == 0)
326 0 : add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
327 :
328 5 : host_task_size = os_get_top_address();
329 : /* reserve a few pages for the stubs (taking care of data alignment) */
330 : /* align the data portion */
331 5 : BUILD_BUG_ON(!is_power_of_2(STUB_DATA_PAGES));
332 5 : stub_start = (host_task_size - 1) & ~(STUB_DATA_PAGES * PAGE_SIZE - 1);
333 : /* another page for the code portion */
334 5 : stub_start -= PAGE_SIZE;
335 5 : host_task_size = stub_start;
336 :
337 : /*
338 : * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
339 : * out
340 : */
341 5 : task_size = host_task_size & PGDIR_MASK;
342 :
343 : /* OS sanity checks that need to happen before the kernel runs */
344 5 : os_early_checks();
345 :
346 1 : get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
347 :
348 1 : brk_start = (unsigned long) sbrk(0);
349 :
350 : /*
351 : * Increase physical memory size for exec-shield users
352 : * so they actually get what they asked for. This should
353 : * add zero for non-exec shield users
354 : */
355 :
356 1 : diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
357 1 : if (diff > 1024 * 1024) {
358 1 : os_info("Adding %ld bytes to physical memory to account for "
359 : "exec-shield gap\n", diff);
360 1 : physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
361 : }
362 :
363 1 : uml_physmem = (unsigned long) __binary_start & PAGE_MASK;
364 :
365 : /* Reserve up to 4M after the current brk */
366 1 : uml_reserved = ROUND_4M(brk_start) + (1 << 22);
367 :
368 1 : setup_machinename(init_utsname()->machine);
369 :
370 1 : highmem = 0;
371 1 : iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
372 1 : max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
373 :
374 : /*
375 : * Zones have to begin on a 1 << MAX_ORDER page boundary,
376 : * so this makes sure that's true for highmem
377 : */
378 1 : max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
379 1 : if (physmem_size + iomem_size > max_physmem) {
380 0 : highmem = physmem_size + iomem_size - max_physmem;
381 0 : physmem_size -= highmem;
382 : }
383 :
384 1 : high_physmem = uml_physmem + physmem_size;
385 1 : end_iomem = high_physmem + iomem_size;
386 1 : high_memory = (void *) end_iomem;
387 :
388 1 : start_vm = VMALLOC_START;
389 :
390 1 : virtmem_size = physmem_size;
391 1 : stack = (unsigned long) argv;
392 1 : stack &= ~(1024 * 1024 - 1);
393 1 : avail = stack - start_vm;
394 1 : if (physmem_size > avail)
395 0 : virtmem_size = avail;
396 1 : end_vm = start_vm + virtmem_size;
397 :
398 1 : if (virtmem_size < physmem_size)
399 0 : os_info("Kernel virtual memory size shrunk to %lu bytes\n",
400 : virtmem_size);
401 :
402 1 : os_flush_stdout();
403 :
404 1 : return start_uml();
405 : }
406 :
407 1 : int __init __weak read_initrd(void)
408 : {
409 1 : return 0;
410 : }
411 :
412 1 : void __init setup_arch(char **cmdline_p)
413 : {
414 : u8 rng_seed[32];
415 :
416 1 : stack_protections((unsigned long) &init_thread_info);
417 1 : setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
418 1 : mem_total_pages(physmem_size, iomem_size, highmem);
419 : uml_dtb_init();
420 1 : read_initrd();
421 :
422 1 : paging_init();
423 1 : strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
424 1 : *cmdline_p = command_line;
425 1 : setup_hostinfo(host_info, sizeof host_info);
426 :
427 1 : if (os_getrandom(rng_seed, sizeof(rng_seed), 0) == sizeof(rng_seed)) {
428 1 : add_bootloader_randomness(rng_seed, sizeof(rng_seed));
429 : memzero_explicit(rng_seed, sizeof(rng_seed));
430 : }
431 1 : }
432 :
433 1 : void __init check_bugs(void)
434 : {
435 1 : arch_check_bugs();
436 1 : os_check_bugs();
437 1 : }
438 :
439 0 : void apply_ibt_endbr(s32 *start, s32 *end)
440 : {
441 0 : }
442 :
443 0 : void apply_retpolines(s32 *start, s32 *end)
444 : {
445 0 : }
446 :
447 0 : void apply_returns(s32 *start, s32 *end)
448 : {
449 0 : }
450 :
451 0 : void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
452 : s32 *start_cfi, s32 *end_cfi)
453 : {
454 0 : }
455 :
456 0 : void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
457 : {
458 0 : }
459 :
460 0 : void *text_poke(void *addr, const void *opcode, size_t len)
461 : {
462 : /*
463 : * In UML, the only reference to this function is in
464 : * apply_relocate_add(), which shouldn't ever actually call this
465 : * because UML doesn't have live patching.
466 : */
467 0 : WARN_ON(1);
468 :
469 0 : return memcpy(addr, opcode, len);
470 : }
471 :
472 0 : void text_poke_sync(void)
473 : {
474 0 : }
475 :
476 0 : void uml_pm_wake(void)
477 : {
478 0 : pm_system_wakeup();
479 0 : }
480 :
481 : #ifdef CONFIG_PM_SLEEP
482 2 : static int um_suspend_valid(suspend_state_t state)
483 : {
484 2 : return state == PM_SUSPEND_MEM;
485 : }
486 :
487 0 : static int um_suspend_prepare(void)
488 : {
489 0 : um_irqs_suspend();
490 0 : return 0;
491 : }
492 :
493 0 : static int um_suspend_enter(suspend_state_t state)
494 : {
495 0 : if (WARN_ON(state != PM_SUSPEND_MEM))
496 : return -EINVAL;
497 :
498 : /*
499 : * This is identical to the idle sleep, but we've just
500 : * (during suspend) turned off all interrupt sources
501 : * except for the ones we want, so now we can only wake
502 : * up on something we actually want to wake up on. All
503 : * timing has also been suspended.
504 : */
505 0 : um_idle_sleep();
506 0 : return 0;
507 : }
508 :
509 0 : static void um_suspend_finish(void)
510 : {
511 0 : um_irqs_resume();
512 0 : }
513 :
514 : const struct platform_suspend_ops um_suspend_ops = {
515 : .valid = um_suspend_valid,
516 : .prepare = um_suspend_prepare,
517 : .enter = um_suspend_enter,
518 : .finish = um_suspend_finish,
519 : };
520 :
521 1 : static int init_pm_wake_signal(void)
522 : {
523 : /*
524 : * In external time-travel mode we can't use signals to wake up
525 : * since that would mess with the scheduling. We'll have to do
526 : * some additional work to support wakeup on virtio devices or
527 : * similar, perhaps implementing a fake RTC controller that can
528 : * trigger wakeup (and request the appropriate scheduling from
529 : * the external scheduler when going to suspend.)
530 : */
531 : if (time_travel_mode != TT_MODE_EXTERNAL)
532 1 : register_pm_wake_signal();
533 :
534 1 : suspend_set_ops(&um_suspend_ops);
535 :
536 1 : return 0;
537 : }
538 :
539 : late_initcall(init_pm_wake_signal);
540 : #endif
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