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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/cpu.h>
7#include <linux/delay.h>
8#include <linux/init.h>
9#include <linux/mm.h>
10#include <linux/ctype.h>
11#include <linux/module.h>
12#include <linux/panic_notifier.h>
13#include <linux/seq_file.h>
14#include <linux/string.h>
15#include <linux/utsname.h>
16#include <linux/sched.h>
17#include <linux/sched/task.h>
18#include <linux/kmsg_dump.h>
19#include <linux/suspend.h>
20#include <linux/random.h>
21
22#include <asm/processor.h>
23#include <asm/cpufeature.h>
24#include <asm/sections.h>
25#include <asm/setup.h>
26#include <asm/text-patching.h>
27#include <as-layout.h>
28#include <arch.h>
29#include <init.h>
30#include <kern.h>
31#include <kern_util.h>
32#include <mem_user.h>
33#include <os.h>
34
35#include "um_arch.h"
36
37#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
38#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
39
40/* Changed in add_arg and setup_arch, which run before SMP is started */
41static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
42
43static void __init add_arg(char *arg)
44{
45 if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
46 os_warn("add_arg: Too many command line arguments!\n");
47 exit(1);
48 }
49 if (strlen(command_line) > 0)
50 strcat(command_line, " ");
51 strcat(command_line, arg);
52}
53
54/*
55 * These fields are initialized at boot time and not changed.
56 * XXX This structure is used only in the non-SMP case. Maybe this
57 * should be moved to smp.c.
58 */
59struct cpuinfo_um boot_cpu_data = {
60 .loops_per_jiffy = 0,
61 .ipi_pipe = { -1, -1 },
62 .cache_alignment = L1_CACHE_BYTES,
63 .x86_capability = { 0 }
64};
65
66EXPORT_SYMBOL(boot_cpu_data);
67
68
69/* Changed in setup_arch, which is called in early boot */
70static char host_info[(__NEW_UTS_LEN + 1) * 5];
71
72static int show_cpuinfo(struct seq_file *m, void *v)
73{
74 int i = 0;
75
76 seq_printf(m, "processor\t: %d\n", i);
77 seq_printf(m, "vendor_id\t: User Mode Linux\n");
78 seq_printf(m, "model name\t: UML\n");
79 seq_printf(m, "mode\t\t: skas\n");
80 seq_printf(m, "host\t\t: %s\n", host_info);
81 seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
82 seq_printf(m, "flags\t\t:");
83 for (i = 0; i < 32*NCAPINTS; i++)
84 if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
85 seq_printf(m, " %s", x86_cap_flags[i]);
86 seq_printf(m, "\n");
87 seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
88 seq_printf(m, "bogomips\t: %lu.%02lu\n",
89 loops_per_jiffy/(500000/HZ),
90 (loops_per_jiffy/(5000/HZ)) % 100);
91
92
93 return 0;
94}
95
96static void *c_start(struct seq_file *m, loff_t *pos)
97{
98 return *pos < nr_cpu_ids ? &boot_cpu_data + *pos : NULL;
99}
100
101static void *c_next(struct seq_file *m, void *v, loff_t *pos)
102{
103 ++*pos;
104 return c_start(m, pos);
105}
106
107static void c_stop(struct seq_file *m, void *v)
108{
109}
110
111const struct seq_operations cpuinfo_op = {
112 .start = c_start,
113 .next = c_next,
114 .stop = c_stop,
115 .show = show_cpuinfo,
116};
117
118/* Set in linux_main */
119unsigned long uml_physmem;
120EXPORT_SYMBOL(uml_physmem);
121
122unsigned long uml_reserved; /* Also modified in mem_init */
123unsigned long start_vm;
124unsigned long end_vm;
125
126/* Set in early boot */
127static int have_root __initdata;
128static int have_console __initdata;
129
130/* Set in uml_mem_setup and modified in linux_main */
131unsigned long long physmem_size = 64 * 1024 * 1024;
132EXPORT_SYMBOL(physmem_size);
133
134static const char *usage_string =
135"User Mode Linux v%s\n"
136" available at http://user-mode-linux.sourceforge.net/\n\n";
137
138static int __init uml_version_setup(char *line, int *add)
139{
140 /* Explicitly use printf() to show version in stdout */
141 printf("%s\n", init_utsname()->release);
142 exit(0);
143
144 return 0;
145}
146
147__uml_setup("--version", uml_version_setup,
148"--version\n"
149" Prints the version number of the kernel.\n\n"
150);
151
152static int __init uml_root_setup(char *line, int *add)
153{
154 have_root = 1;
155 return 0;
156}
157
158__uml_setup("root=", uml_root_setup,
159"root=<file containing the root fs>\n"
160" This is actually used by the generic kernel in exactly the same\n"
161" way as in any other kernel. If you configure a number of block\n"
162" devices and want to boot off something other than ubd0, you \n"
163" would use something like:\n"
164" root=/dev/ubd5\n\n"
165);
166
167static int __init uml_console_setup(char *line, int *add)
168{
169 have_console = 1;
170 return 0;
171}
172
173__uml_setup("console=", uml_console_setup,
174"console=<preferred console>\n"
175" Specify the preferred console output driver\n\n"
176);
177
178static int __init Usage(char *line, int *add)
179{
180 const char **p;
181
182 printf(usage_string, init_utsname()->release);
183 p = &__uml_help_start;
184 /* Explicitly use printf() to show help in stdout */
185 while (p < &__uml_help_end) {
186 printf("%s", *p);
187 p++;
188 }
189 exit(0);
190 return 0;
191}
192
193__uml_setup("--help", Usage,
194"--help\n"
195" Prints this message.\n\n"
196);
197
198static void __init uml_checksetup(char *line, int *add)
199{
200 struct uml_param *p;
201
202 p = &__uml_setup_start;
203 while (p < &__uml_setup_end) {
204 size_t n;
205
206 n = strlen(p->str);
207 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
208 return;
209 p++;
210 }
211}
212
213static void __init uml_postsetup(void)
214{
215 initcall_t *p;
216
217 p = &__uml_postsetup_start;
218 while (p < &__uml_postsetup_end) {
219 (*p)();
220 p++;
221 }
222 return;
223}
224
225static int panic_exit(struct notifier_block *self, unsigned long unused1,
226 void *unused2)
227{
228 kmsg_dump(KMSG_DUMP_PANIC);
229 bust_spinlocks(1);
230 bust_spinlocks(0);
231 uml_exitcode = 1;
232 os_dump_core();
233
234 return NOTIFY_DONE;
235}
236
237static struct notifier_block panic_exit_notifier = {
238 .notifier_call = panic_exit,
239 .priority = INT_MAX - 1, /* run as 2nd notifier, won't return */
240};
241
242void uml_finishsetup(void)
243{
244 cpu_tasks[0] = &init_task;
245
246 atomic_notifier_chain_register(&panic_notifier_list,
247 &panic_exit_notifier);
248
249 uml_postsetup();
250
251 new_thread_handler();
252}
253
254/* Set during early boot */
255unsigned long stub_start;
256unsigned long task_size;
257EXPORT_SYMBOL(task_size);
258
259unsigned long host_task_size;
260
261unsigned long brk_start;
262unsigned long end_iomem;
263EXPORT_SYMBOL(end_iomem);
264
265#define MIN_VMALLOC (32 * 1024 * 1024)
266
267static void parse_host_cpu_flags(char *line)
268{
269 int i;
270 for (i = 0; i < 32*NCAPINTS; i++) {
271 if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
272 set_cpu_cap(&boot_cpu_data, i);
273 }
274}
275static void parse_cache_line(char *line)
276{
277 long res;
278 char *to_parse = strstr(line, ":");
279 if (to_parse) {
280 to_parse++;
281 while (*to_parse != 0 && isspace(*to_parse)) {
282 to_parse++;
283 }
284 if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
285 boot_cpu_data.cache_alignment = res;
286 else
287 boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
288 }
289}
290
291static unsigned long get_top_address(char **envp)
292{
293 unsigned long top_addr = (unsigned long) &top_addr;
294 int i;
295
296 /* The earliest variable should be after the program name in ELF */
297 for (i = 0; envp[i]; i++) {
298 if ((unsigned long) envp[i] > top_addr)
299 top_addr = (unsigned long) envp[i];
300 }
301
302 top_addr &= ~(UM_KERN_PAGE_SIZE - 1);
303 top_addr += UM_KERN_PAGE_SIZE;
304
305 return top_addr;
306}
307
308int __init linux_main(int argc, char **argv, char **envp)
309{
310 unsigned long avail, diff;
311 unsigned long virtmem_size, max_physmem;
312 unsigned long stack;
313 unsigned int i;
314 int add;
315
316 for (i = 1; i < argc; i++) {
317 if ((i == 1) && (argv[i][0] == ' '))
318 continue;
319 add = 1;
320 uml_checksetup(argv[i], &add);
321 if (add)
322 add_arg(argv[i]);
323 }
324 if (have_root == 0)
325 add_arg(DEFAULT_COMMAND_LINE_ROOT);
326
327 if (have_console == 0)
328 add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
329
330 host_task_size = get_top_address(envp);
331 /* reserve a few pages for the stubs */
332 stub_start = host_task_size - STUB_DATA_PAGES * PAGE_SIZE;
333 /* another page for the code portion */
334 stub_start -= PAGE_SIZE;
335 host_task_size = stub_start;
336
337 /* Limit TASK_SIZE to what is addressable by the page table */
338 task_size = host_task_size;
339 if (task_size > (unsigned long long) PTRS_PER_PGD * PGDIR_SIZE)
340 task_size = PTRS_PER_PGD * PGDIR_SIZE;
341
342 /*
343 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
344 * out
345 */
346 task_size = task_size & PGDIR_MASK;
347
348 /* OS sanity checks that need to happen before the kernel runs */
349 os_early_checks();
350
351 get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
352
353 brk_start = (unsigned long) sbrk(0);
354
355 /*
356 * Increase physical memory size for exec-shield users
357 * so they actually get what they asked for. This should
358 * add zero for non-exec shield users
359 */
360
361 diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
362 if (diff > 1024 * 1024) {
363 os_info("Adding %ld bytes to physical memory to account for "
364 "exec-shield gap\n", diff);
365 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
366 }
367
368 uml_physmem = (unsigned long) __binary_start & PAGE_MASK;
369
370 /* Reserve up to 4M after the current brk */
371 uml_reserved = ROUND_4M(brk_start) + (1 << 22);
372
373 setup_machinename(init_utsname()->machine);
374
375 physmem_size = (physmem_size + PAGE_SIZE - 1) & PAGE_MASK;
376 iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
377
378 max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
379
380 if (physmem_size + iomem_size > max_physmem) {
381 physmem_size = max_physmem - iomem_size;
382 os_info("Physical memory size shrunk to %llu bytes\n",
383 physmem_size);
384 }
385
386 high_physmem = uml_physmem + physmem_size;
387 end_iomem = high_physmem + iomem_size;
388 high_memory = (void *) end_iomem;
389
390 start_vm = VMALLOC_START;
391
392 virtmem_size = physmem_size;
393 stack = (unsigned long) argv;
394 stack &= ~(1024 * 1024 - 1);
395 avail = stack - start_vm;
396 if (physmem_size > avail)
397 virtmem_size = avail;
398 end_vm = start_vm + virtmem_size;
399
400 if (virtmem_size < physmem_size)
401 os_info("Kernel virtual memory size shrunk to %lu bytes\n",
402 virtmem_size);
403
404 arch_task_struct_size = sizeof(struct task_struct) + host_fp_size;
405
406 os_flush_stdout();
407
408 return start_uml();
409}
410
411int __init __weak read_initrd(void)
412{
413 return 0;
414}
415
416void __init setup_arch(char **cmdline_p)
417{
418 u8 rng_seed[32];
419
420 stack_protections((unsigned long) init_task.stack);
421 setup_physmem(uml_physmem, uml_reserved, physmem_size);
422 mem_total_pages(physmem_size, iomem_size);
423 uml_dtb_init();
424 read_initrd();
425
426 paging_init();
427 strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
428 *cmdline_p = command_line;
429 setup_hostinfo(host_info, sizeof host_info);
430
431 if (os_getrandom(rng_seed, sizeof(rng_seed), 0) == sizeof(rng_seed)) {
432 add_bootloader_randomness(rng_seed, sizeof(rng_seed));
433 memzero_explicit(rng_seed, sizeof(rng_seed));
434 }
435}
436
437void __init arch_cpu_finalize_init(void)
438{
439 arch_check_bugs();
440 os_check_bugs();
441}
442
443void apply_seal_endbr(s32 *start, s32 *end, struct module *mod)
444{
445}
446
447void apply_retpolines(s32 *start, s32 *end, struct module *mod)
448{
449}
450
451void apply_returns(s32 *start, s32 *end, struct module *mod)
452{
453}
454
455void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
456 s32 *start_cfi, s32 *end_cfi, struct module *mod)
457{
458}
459
460void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
461 struct module *mod)
462{
463}
464
465void *text_poke(void *addr, const void *opcode, size_t len)
466{
467 /*
468 * In UML, the only reference to this function is in
469 * apply_relocate_add(), which shouldn't ever actually call this
470 * because UML doesn't have live patching.
471 */
472 WARN_ON(1);
473
474 return memcpy(addr, opcode, len);
475}
476
477void *text_poke_copy(void *addr, const void *opcode, size_t len)
478{
479 return text_poke(addr, opcode, len);
480}
481
482void text_poke_sync(void)
483{
484}
485
486void uml_pm_wake(void)
487{
488 pm_system_wakeup();
489}
490
491#ifdef CONFIG_PM_SLEEP
492static int um_suspend_valid(suspend_state_t state)
493{
494 return state == PM_SUSPEND_MEM;
495}
496
497static int um_suspend_prepare(void)
498{
499 um_irqs_suspend();
500 return 0;
501}
502
503static int um_suspend_enter(suspend_state_t state)
504{
505 if (WARN_ON(state != PM_SUSPEND_MEM))
506 return -EINVAL;
507
508 /*
509 * This is identical to the idle sleep, but we've just
510 * (during suspend) turned off all interrupt sources
511 * except for the ones we want, so now we can only wake
512 * up on something we actually want to wake up on. All
513 * timing has also been suspended.
514 */
515 um_idle_sleep();
516 return 0;
517}
518
519static void um_suspend_finish(void)
520{
521 um_irqs_resume();
522}
523
524const struct platform_suspend_ops um_suspend_ops = {
525 .valid = um_suspend_valid,
526 .prepare = um_suspend_prepare,
527 .enter = um_suspend_enter,
528 .finish = um_suspend_finish,
529};
530
531static int init_pm_wake_signal(void)
532{
533 /*
534 * In external time-travel mode we can't use signals to wake up
535 * since that would mess with the scheduling. We'll have to do
536 * some additional work to support wakeup on virtio devices or
537 * similar, perhaps implementing a fake RTC controller that can
538 * trigger wakeup (and request the appropriate scheduling from
539 * the external scheduler when going to suspend.)
540 */
541 if (time_travel_mode != TT_MODE_EXTERNAL)
542 register_pm_wake_signal();
543
544 suspend_set_ops(&um_suspend_ops);
545
546 return 0;
547}
548
549late_initcall(init_pm_wake_signal);
550#endif
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/cpu.h>
7#include <linux/delay.h>
8#include <linux/init.h>
9#include <linux/mm.h>
10#include <linux/ctype.h>
11#include <linux/module.h>
12#include <linux/panic_notifier.h>
13#include <linux/seq_file.h>
14#include <linux/string.h>
15#include <linux/utsname.h>
16#include <linux/sched.h>
17#include <linux/sched/task.h>
18#include <linux/kmsg_dump.h>
19#include <linux/suspend.h>
20#include <linux/random.h>
21
22#include <asm/processor.h>
23#include <asm/cpufeature.h>
24#include <asm/sections.h>
25#include <asm/setup.h>
26#include <as-layout.h>
27#include <arch.h>
28#include <init.h>
29#include <kern.h>
30#include <kern_util.h>
31#include <mem_user.h>
32#include <os.h>
33
34#include "um_arch.h"
35
36#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
37#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
38
39/* Changed in add_arg and setup_arch, which run before SMP is started */
40static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
41
42static void __init add_arg(char *arg)
43{
44 if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
45 os_warn("add_arg: Too many command line arguments!\n");
46 exit(1);
47 }
48 if (strlen(command_line) > 0)
49 strcat(command_line, " ");
50 strcat(command_line, arg);
51}
52
53/*
54 * These fields are initialized at boot time and not changed.
55 * XXX This structure is used only in the non-SMP case. Maybe this
56 * should be moved to smp.c.
57 */
58struct cpuinfo_um boot_cpu_data = {
59 .loops_per_jiffy = 0,
60 .ipi_pipe = { -1, -1 },
61 .cache_alignment = L1_CACHE_BYTES,
62 .x86_capability = { 0 }
63};
64
65EXPORT_SYMBOL(boot_cpu_data);
66
67union thread_union cpu0_irqstack
68 __section(".data..init_irqstack") =
69 { .thread_info = INIT_THREAD_INFO(init_task) };
70
71/* Changed in setup_arch, which is called in early boot */
72static char host_info[(__NEW_UTS_LEN + 1) * 5];
73
74static int show_cpuinfo(struct seq_file *m, void *v)
75{
76 int i = 0;
77
78 seq_printf(m, "processor\t: %d\n", i);
79 seq_printf(m, "vendor_id\t: User Mode Linux\n");
80 seq_printf(m, "model name\t: UML\n");
81 seq_printf(m, "mode\t\t: skas\n");
82 seq_printf(m, "host\t\t: %s\n", host_info);
83 seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no");
84 seq_printf(m, "flags\t\t:");
85 for (i = 0; i < 32*NCAPINTS; i++)
86 if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL))
87 seq_printf(m, " %s", x86_cap_flags[i]);
88 seq_printf(m, "\n");
89 seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment);
90 seq_printf(m, "bogomips\t: %lu.%02lu\n",
91 loops_per_jiffy/(500000/HZ),
92 (loops_per_jiffy/(5000/HZ)) % 100);
93
94
95 return 0;
96}
97
98static void *c_start(struct seq_file *m, loff_t *pos)
99{
100 return *pos < nr_cpu_ids ? &boot_cpu_data + *pos : NULL;
101}
102
103static void *c_next(struct seq_file *m, void *v, loff_t *pos)
104{
105 ++*pos;
106 return c_start(m, pos);
107}
108
109static void c_stop(struct seq_file *m, void *v)
110{
111}
112
113const struct seq_operations cpuinfo_op = {
114 .start = c_start,
115 .next = c_next,
116 .stop = c_stop,
117 .show = show_cpuinfo,
118};
119
120/* Set in linux_main */
121unsigned long uml_physmem;
122EXPORT_SYMBOL(uml_physmem);
123
124unsigned long uml_reserved; /* Also modified in mem_init */
125unsigned long start_vm;
126unsigned long end_vm;
127
128/* Set in uml_ncpus_setup */
129int ncpus = 1;
130
131/* Set in early boot */
132static int have_root __initdata;
133static int have_console __initdata;
134
135/* Set in uml_mem_setup and modified in linux_main */
136long long physmem_size = 64 * 1024 * 1024;
137EXPORT_SYMBOL(physmem_size);
138
139static const char *usage_string =
140"User Mode Linux v%s\n"
141" available at http://user-mode-linux.sourceforge.net/\n\n";
142
143static int __init uml_version_setup(char *line, int *add)
144{
145 /* Explicitly use printf() to show version in stdout */
146 printf("%s\n", init_utsname()->release);
147 exit(0);
148
149 return 0;
150}
151
152__uml_setup("--version", uml_version_setup,
153"--version\n"
154" Prints the version number of the kernel.\n\n"
155);
156
157static int __init uml_root_setup(char *line, int *add)
158{
159 have_root = 1;
160 return 0;
161}
162
163__uml_setup("root=", uml_root_setup,
164"root=<file containing the root fs>\n"
165" This is actually used by the generic kernel in exactly the same\n"
166" way as in any other kernel. If you configure a number of block\n"
167" devices and want to boot off something other than ubd0, you \n"
168" would use something like:\n"
169" root=/dev/ubd5\n\n"
170);
171
172static int __init no_skas_debug_setup(char *line, int *add)
173{
174 os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
175 os_warn("'gdb linux'\n");
176
177 return 0;
178}
179
180__uml_setup("debug", no_skas_debug_setup,
181"debug\n"
182" this flag is not needed to run gdb on UML in skas mode\n\n"
183);
184
185static int __init uml_console_setup(char *line, int *add)
186{
187 have_console = 1;
188 return 0;
189}
190
191__uml_setup("console=", uml_console_setup,
192"console=<preferred console>\n"
193" Specify the preferred console output driver\n\n"
194);
195
196static int __init Usage(char *line, int *add)
197{
198 const char **p;
199
200 printf(usage_string, init_utsname()->release);
201 p = &__uml_help_start;
202 /* Explicitly use printf() to show help in stdout */
203 while (p < &__uml_help_end) {
204 printf("%s", *p);
205 p++;
206 }
207 exit(0);
208 return 0;
209}
210
211__uml_setup("--help", Usage,
212"--help\n"
213" Prints this message.\n\n"
214);
215
216static void __init uml_checksetup(char *line, int *add)
217{
218 struct uml_param *p;
219
220 p = &__uml_setup_start;
221 while (p < &__uml_setup_end) {
222 size_t n;
223
224 n = strlen(p->str);
225 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
226 return;
227 p++;
228 }
229}
230
231static void __init uml_postsetup(void)
232{
233 initcall_t *p;
234
235 p = &__uml_postsetup_start;
236 while (p < &__uml_postsetup_end) {
237 (*p)();
238 p++;
239 }
240 return;
241}
242
243static int panic_exit(struct notifier_block *self, unsigned long unused1,
244 void *unused2)
245{
246 kmsg_dump(KMSG_DUMP_PANIC);
247 bust_spinlocks(1);
248 bust_spinlocks(0);
249 uml_exitcode = 1;
250 os_dump_core();
251
252 return NOTIFY_DONE;
253}
254
255static struct notifier_block panic_exit_notifier = {
256 .notifier_call = panic_exit,
257 .priority = INT_MAX - 1, /* run as 2nd notifier, won't return */
258};
259
260void uml_finishsetup(void)
261{
262 atomic_notifier_chain_register(&panic_notifier_list,
263 &panic_exit_notifier);
264
265 uml_postsetup();
266
267 new_thread_handler();
268}
269
270/* Set during early boot */
271unsigned long stub_start;
272unsigned long task_size;
273EXPORT_SYMBOL(task_size);
274
275unsigned long host_task_size;
276
277unsigned long brk_start;
278unsigned long end_iomem;
279EXPORT_SYMBOL(end_iomem);
280
281#define MIN_VMALLOC (32 * 1024 * 1024)
282
283static void parse_host_cpu_flags(char *line)
284{
285 int i;
286 for (i = 0; i < 32*NCAPINTS; i++) {
287 if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i]))
288 set_cpu_cap(&boot_cpu_data, i);
289 }
290}
291static void parse_cache_line(char *line)
292{
293 long res;
294 char *to_parse = strstr(line, ":");
295 if (to_parse) {
296 to_parse++;
297 while (*to_parse != 0 && isspace(*to_parse)) {
298 to_parse++;
299 }
300 if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res))
301 boot_cpu_data.cache_alignment = res;
302 else
303 boot_cpu_data.cache_alignment = L1_CACHE_BYTES;
304 }
305}
306
307int __init linux_main(int argc, char **argv)
308{
309 unsigned long avail, diff;
310 unsigned long virtmem_size, max_physmem;
311 unsigned long stack;
312 unsigned int i;
313 int add;
314
315 for (i = 1; i < argc; i++) {
316 if ((i == 1) && (argv[i][0] == ' '))
317 continue;
318 add = 1;
319 uml_checksetup(argv[i], &add);
320 if (add)
321 add_arg(argv[i]);
322 }
323 if (have_root == 0)
324 add_arg(DEFAULT_COMMAND_LINE_ROOT);
325
326 if (have_console == 0)
327 add_arg(DEFAULT_COMMAND_LINE_CONSOLE);
328
329 host_task_size = os_get_top_address();
330 /* reserve a few pages for the stubs (taking care of data alignment) */
331 /* align the data portion */
332 BUILD_BUG_ON(!is_power_of_2(STUB_DATA_PAGES));
333 stub_start = (host_task_size - 1) & ~(STUB_DATA_PAGES * PAGE_SIZE - 1);
334 /* another page for the code portion */
335 stub_start -= PAGE_SIZE;
336 host_task_size = stub_start;
337
338 /*
339 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
340 * out
341 */
342 task_size = host_task_size & PGDIR_MASK;
343
344 /* OS sanity checks that need to happen before the kernel runs */
345 os_early_checks();
346
347 get_host_cpu_features(parse_host_cpu_flags, parse_cache_line);
348
349 brk_start = (unsigned long) sbrk(0);
350
351 /*
352 * Increase physical memory size for exec-shield users
353 * so they actually get what they asked for. This should
354 * add zero for non-exec shield users
355 */
356
357 diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
358 if (diff > 1024 * 1024) {
359 os_info("Adding %ld bytes to physical memory to account for "
360 "exec-shield gap\n", diff);
361 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
362 }
363
364 uml_physmem = (unsigned long) __binary_start & PAGE_MASK;
365
366 /* Reserve up to 4M after the current brk */
367 uml_reserved = ROUND_4M(brk_start) + (1 << 22);
368
369 setup_machinename(init_utsname()->machine);
370
371 highmem = 0;
372 iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
373 max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
374
375 /*
376 * Zones have to begin on a 1 << MAX_PAGE_ORDER page boundary,
377 * so this makes sure that's true for highmem
378 */
379 max_physmem &= ~((1 << (PAGE_SHIFT + MAX_PAGE_ORDER)) - 1);
380 if (physmem_size + iomem_size > max_physmem) {
381 highmem = physmem_size + iomem_size - max_physmem;
382 physmem_size -= highmem;
383 }
384
385 high_physmem = uml_physmem + physmem_size;
386 end_iomem = high_physmem + iomem_size;
387 high_memory = (void *) end_iomem;
388
389 start_vm = VMALLOC_START;
390
391 virtmem_size = physmem_size;
392 stack = (unsigned long) argv;
393 stack &= ~(1024 * 1024 - 1);
394 avail = stack - start_vm;
395 if (physmem_size > avail)
396 virtmem_size = avail;
397 end_vm = start_vm + virtmem_size;
398
399 if (virtmem_size < physmem_size)
400 os_info("Kernel virtual memory size shrunk to %lu bytes\n",
401 virtmem_size);
402
403 os_flush_stdout();
404
405 return start_uml();
406}
407
408int __init __weak read_initrd(void)
409{
410 return 0;
411}
412
413void __init setup_arch(char **cmdline_p)
414{
415 u8 rng_seed[32];
416
417 stack_protections((unsigned long) &init_thread_info);
418 setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
419 mem_total_pages(physmem_size, iomem_size, highmem);
420 uml_dtb_init();
421 read_initrd();
422
423 paging_init();
424 strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
425 *cmdline_p = command_line;
426 setup_hostinfo(host_info, sizeof host_info);
427
428 if (os_getrandom(rng_seed, sizeof(rng_seed), 0) == sizeof(rng_seed)) {
429 add_bootloader_randomness(rng_seed, sizeof(rng_seed));
430 memzero_explicit(rng_seed, sizeof(rng_seed));
431 }
432}
433
434void __init arch_cpu_finalize_init(void)
435{
436 arch_check_bugs();
437 os_check_bugs();
438}
439
440void apply_seal_endbr(s32 *start, s32 *end)
441{
442}
443
444void apply_retpolines(s32 *start, s32 *end)
445{
446}
447
448void apply_returns(s32 *start, s32 *end)
449{
450}
451
452void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline,
453 s32 *start_cfi, s32 *end_cfi)
454{
455}
456
457void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
458{
459}
460
461void *text_poke(void *addr, const void *opcode, size_t len)
462{
463 /*
464 * In UML, the only reference to this function is in
465 * apply_relocate_add(), which shouldn't ever actually call this
466 * because UML doesn't have live patching.
467 */
468 WARN_ON(1);
469
470 return memcpy(addr, opcode, len);
471}
472
473void text_poke_sync(void)
474{
475}
476
477void uml_pm_wake(void)
478{
479 pm_system_wakeup();
480}
481
482#ifdef CONFIG_PM_SLEEP
483static int um_suspend_valid(suspend_state_t state)
484{
485 return state == PM_SUSPEND_MEM;
486}
487
488static int um_suspend_prepare(void)
489{
490 um_irqs_suspend();
491 return 0;
492}
493
494static int um_suspend_enter(suspend_state_t state)
495{
496 if (WARN_ON(state != PM_SUSPEND_MEM))
497 return -EINVAL;
498
499 /*
500 * This is identical to the idle sleep, but we've just
501 * (during suspend) turned off all interrupt sources
502 * except for the ones we want, so now we can only wake
503 * up on something we actually want to wake up on. All
504 * timing has also been suspended.
505 */
506 um_idle_sleep();
507 return 0;
508}
509
510static void um_suspend_finish(void)
511{
512 um_irqs_resume();
513}
514
515const struct platform_suspend_ops um_suspend_ops = {
516 .valid = um_suspend_valid,
517 .prepare = um_suspend_prepare,
518 .enter = um_suspend_enter,
519 .finish = um_suspend_finish,
520};
521
522static int init_pm_wake_signal(void)
523{
524 /*
525 * In external time-travel mode we can't use signals to wake up
526 * since that would mess with the scheduling. We'll have to do
527 * some additional work to support wakeup on virtio devices or
528 * similar, perhaps implementing a fake RTC controller that can
529 * trigger wakeup (and request the appropriate scheduling from
530 * the external scheduler when going to suspend.)
531 */
532 if (time_travel_mode != TT_MODE_EXTERNAL)
533 register_pm_wake_signal();
534
535 suspend_set_ops(&um_suspend_ops);
536
537 return 0;
538}
539
540late_initcall(init_pm_wake_signal);
541#endif