arch/um/kernel/um_arch.c

   1 /*
   2  * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/kernel.h"
   7 #include "linux/sched.h"
   8 #include "linux/notifier.h"
   9 #include "linux/mm.h"
  10 #include "linux/types.h"
  11 #include "linux/tty.h"
  12 #include "linux/init.h"
  13 #include "linux/bootmem.h"
  14 #include "linux/spinlock.h"
  15 #include "linux/utsname.h"
  16 #include "linux/sysrq.h"
  17 #include "linux/seq_file.h"
  18 #include "linux/delay.h"
  19 #include "linux/module.h"
  20 #include "asm/page.h"
  21 #include "asm/pgtable.h"
  22 #include "asm/ptrace.h"
  23 #include "asm/elf.h"
  24 #include "asm/user.h"
  25 #include "asm/setup.h"
  26 #include "ubd_user.h"
  27 #include "asm/current.h"
  28 #include "user_util.h"
  29 #include "kern_util.h"
  30 #include "kern.h"
  31 #include "mem_user.h"
  32 #include "mem.h"
  33 #include "initrd.h"
  34 #include "init.h"
  35 #include "os.h"
  36 #include "choose-mode.h"
  37 #include "mode_kern.h"
  38 #include "mode.h"
  39 #ifdef UML_CONFIG_MODE_SKAS
  40 #include "skas.h"
  41 #endif
  42
  43 #define DEFAULT_COMMAND_LINE "root=98:0"
  44
  45 /* Changed in linux_main and setup_arch, which run before SMP is started */
  46 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
  47
  48 static void __init add_arg(char *arg)
  49 {
  50         if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
  51                 printf("add_arg: Too many command line arguments!\n");
  52                 exit(1);
  53         }
  54         if(strlen(command_line) > 0)
  55                 strcat(command_line, " ");
  56         strcat(command_line, arg);
  57 }
  58
  59 struct cpuinfo_um boot_cpu_data = {
  60         .loops_per_jiffy        = 0,
  61         .ipi_pipe               = { -1, -1 }
  62 };
  63
  64 unsigned long thread_saved_pc(struct task_struct *task)
  65 {
  66         return(os_process_pc(CHOOSE_MODE_PROC(thread_pid_tt, thread_pid_skas,
  67                                               task)));
  68 }
  69
  70 static int show_cpuinfo(struct seq_file *m, void *v)
  71 {
  72         int index = 0;
  73
  74 #ifdef CONFIG_SMP
  75         index = (struct cpuinfo_um *) v - cpu_data;
  76         if (!cpu_online(index))
  77                 return 0;
  78 #endif
  79
  80         seq_printf(m, "processor\t: %d\n", index);
  81         seq_printf(m, "vendor_id\t: User Mode Linux\n");
  82         seq_printf(m, "model name\t: UML\n");
  83         seq_printf(m, "mode\t\t: %s\n", CHOOSE_MODE("tt", "skas"));
  84         seq_printf(m, "host\t\t: %s\n", host_info);
  85         seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
  86                    loops_per_jiffy/(500000/HZ),
  87                    (loops_per_jiffy/(5000/HZ)) % 100);
  88
  89         return(0);
  90 }
  91
  92 static void *c_start(struct seq_file *m, loff_t *pos)
  93 {
  94         return *pos < NR_CPUS ? cpu_data + *pos : NULL;
  95 }
  96
  97 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  98 {
  99         ++*pos;
 100         return c_start(m, pos);
 101 }
 102
 103 static void c_stop(struct seq_file *m, void *v)
 104 {
 105 }
 106
 107 const struct seq_operations cpuinfo_op = {
 108         .start  = c_start,
 109         .next   = c_next,
 110         .stop   = c_stop,
 111         .show   = show_cpuinfo,
 112 };
 113
 114 /* Set in linux_main */
 115 unsigned long host_task_size;
 116 unsigned long task_size;
 117
 118 unsigned long uml_start;
 119
 120 /* Set in early boot */
 121 unsigned long uml_physmem;
 122 unsigned long uml_reserved;
 123 unsigned long start_vm;
 124 unsigned long end_vm;
 125 int ncpus = 1;
 126
 127 #ifdef CONFIG_CMDLINE_ON_HOST
 128 /* Pointer set in linux_main, the array itself is private to each thread,
 129  * and changed at address space creation time so this poses no concurrency
 130  * problems.
 131  */
 132 static char *argv1_begin = NULL;
 133 static char *argv1_end = NULL;
 134 #endif
 135
 136 /* Set in early boot */
 137 static int have_root __initdata = 0;
 138 long long physmem_size = 32 * 1024 * 1024;
 139
 140 void set_cmdline(char *cmd)
 141 {
 142 #ifdef CONFIG_CMDLINE_ON_HOST
 143         char *umid, *ptr;
 144
 145         if(CHOOSE_MODE(honeypot, 0)) return;
 146
 147         umid = get_umid();
 148         if(*umid != '\0'){
 149                 snprintf(argv1_begin,
 150                          (argv1_end - argv1_begin) * sizeof(*ptr),
 151                          "(%s) ", umid);
 152                 ptr = &argv1_begin[strlen(argv1_begin)];
 153         }
 154         else ptr = argv1_begin;
 155
 156         snprintf(ptr, (argv1_end - ptr) * sizeof(*ptr), "[%s]", cmd);
 157         memset(argv1_begin + strlen(argv1_begin), '\0',
 158                argv1_end - argv1_begin - strlen(argv1_begin));
 159 #endif
 160 }
 161
 162 static char *usage_string =
 163 "User Mode Linux v%s\n"
 164 "       available at http://user-mode-linux.sourceforge.net/\n\n";
 165
 166 static int __init uml_version_setup(char *line, int *add)
 167 {
 168         printf("%s\n", init_utsname()->release);
 169         exit(0);
 170
 171         return 0;
 172 }
 173
 174 __uml_setup("--version", uml_version_setup,
 175 "--version\n"
 176 "    Prints the version number of the kernel.\n\n"
 177 );
 178
 179 static int __init uml_root_setup(char *line, int *add)
 180 {
 181         have_root = 1;
 182         return 0;
 183 }
 184
 185 __uml_setup("root=", uml_root_setup,
 186 "root=<file containing the root fs>\n"
 187 "    This is actually used by the generic kernel in exactly the same\n"
 188 "    way as in any other kernel. If you configure a number of block\n"
 189 "    devices and want to boot off something other than ubd0, you \n"
 190 "    would use something like:\n"
 191 "        root=/dev/ubd5\n\n"
 192 );
 193
 194 #ifndef CONFIG_MODE_TT
 195
 196 static int __init no_skas_debug_setup(char *line, int *add)
 197 {
 198         printf("'debug' is not necessary to gdb UML in skas mode - run \n");
 199         printf("'gdb linux' and disable CONFIG_CMDLINE_ON_HOST if gdb \n");
 200         printf("doesn't work as expected\n");
 201
 202         return 0;
 203 }
 204
 205 __uml_setup("debug", no_skas_debug_setup,
 206 "debug\n"
 207 "    this flag is not needed to run gdb on UML in skas mode\n\n"
 208 );
 209
 210 #endif
 211
 212 #ifdef CONFIG_SMP
 213 static int __init uml_ncpus_setup(char *line, int *add)
 214 {
 215        if (!sscanf(line, "%d", &ncpus)) {
 216                printf("Couldn't parse [%s]\n", line);
 217                return -1;
 218        }
 219
 220        return 0;
 221 }
 222
 223 __uml_setup("ncpus=", uml_ncpus_setup,
 224 "ncpus=<# of desired CPUs>\n"
 225 "    This tells an SMP kernel how many virtual processors to start.\n\n"
 226 );
 227 #endif
 228
 229 static int force_tt = 0;
 230
 231 #if defined(CONFIG_MODE_TT) && defined(CONFIG_MODE_SKAS)
 232 #define DEFAULT_TT 0
 233
 234 static int __init mode_tt_setup(char *line, int *add)
 235 {
 236         force_tt = 1;
 237         return(0);
 238 }
 239
 240 #else
 241 #ifdef CONFIG_MODE_SKAS
 242
 243 #define DEFAULT_TT 0
 244
 245 static int __init mode_tt_setup(char *line, int *add)
 246 {
 247         printf("CONFIG_MODE_TT disabled - 'mode=tt' ignored\n");
 248         return(0);
 249 }
 250
 251 #else
 252 #ifdef CONFIG_MODE_TT
 253
 254 #define DEFAULT_TT 1
 255
 256 static int __init mode_tt_setup(char *line, int *add)
 257 {
 258         printf("CONFIG_MODE_SKAS disabled - 'mode=tt' redundant\n");
 259         return(0);
 260 }
 261
 262 #endif
 263 #endif
 264 #endif
 265
 266 __uml_setup("mode=tt", mode_tt_setup,
 267 "mode=tt\n"
 268 "    When both CONFIG_MODE_TT and CONFIG_MODE_SKAS are enabled, this option\n"
 269 "    forces UML to run in tt (tracing thread) mode.  It is not the default\n"
 270 "    because it's slower and less secure than skas mode.\n\n"
 271 );
 272
 273 int mode_tt = DEFAULT_TT;
 274
 275 static int __init Usage(char *line, int *add)
 276 {
 277         const char **p;
 278
 279         printf(usage_string, init_utsname()->release);
 280         p = &__uml_help_start;
 281         while (p < &__uml_help_end) {
 282                 printf("%s", *p);
 283                 p++;
 284         }
 285         exit(0);
 286
 287         return 0;
 288 }
 289
 290 __uml_setup("--help", Usage,
 291 "--help\n"
 292 "    Prints this message.\n\n"
 293 );
 294
 295 static int __init uml_checksetup(char *line, int *add)
 296 {
 297         struct uml_param *p;
 298
 299         p = &__uml_setup_start;
 300         while(p < &__uml_setup_end) {
 301                 int n;
 302
 303                 n = strlen(p->str);
 304                 if(!strncmp(line, p->str, n)){
 305                         if (p->setup_func(line + n, add)) return 1;
 306                 }
 307                 p++;
 308         }
 309         return 0;
 310 }
 311
 312 static void __init uml_postsetup(void)
 313 {
 314         initcall_t *p;
 315
 316         p = &__uml_postsetup_start;
 317         while(p < &__uml_postsetup_end){
 318                 (*p)();
 319                 p++;
 320         }
 321         return;
 322 }
 323
 324 /* Set during early boot */
 325 unsigned long brk_start;
 326 unsigned long end_iomem;
 327 EXPORT_SYMBOL(end_iomem);
 328
 329 #define MIN_VMALLOC (32 * 1024 * 1024)
 330
 331 extern char __binary_start;
 332
 333 int __init linux_main(int argc, char **argv)
 334 {
 335         unsigned long avail, diff;
 336         unsigned long virtmem_size, max_physmem;
 337         unsigned int i, add;
 338         char * mode;
 339
 340         for (i = 1; i < argc; i++){
 341                 if((i == 1) && (argv[i][0] == ' ')) continue;
 342                 add = 1;
 343                 uml_checksetup(argv[i], &add);
 344                 if (add)
 345                         add_arg(argv[i]);
 346         }
 347         if(have_root == 0)
 348                 add_arg(DEFAULT_COMMAND_LINE);
 349
 350         os_early_checks();
 351         if (force_tt)
 352                 clear_can_do_skas();
 353         mode_tt = force_tt ? 1 : !can_do_skas();
 354 #ifndef CONFIG_MODE_TT
 355         if (mode_tt) {
 356                 /*Since CONFIG_MODE_TT is #undef'ed, force_tt cannot be 1. So,
 357                  * can_do_skas() returned 0, and the message is correct. */
 358                 printf("Support for TT mode is disabled, and no SKAS support is present on the host.\n");
 359                 exit(1);
 360         }
 361 #endif
 362
 363 #ifndef CONFIG_MODE_SKAS
 364         mode = "TT";
 365 #else
 366         /* Show to the user the result of selection */
 367         if (mode_tt)
 368                 mode = "TT";
 369         else if (proc_mm && ptrace_faultinfo)
 370                 mode = "SKAS3";
 371         else
 372                 mode = "SKAS0";
 373 #endif
 374
 375         printf("UML running in %s mode\n", mode);
 376
 377         uml_start = (unsigned long) &__binary_start;
 378         host_task_size = CHOOSE_MODE_PROC(set_task_sizes_tt,
 379                                           set_task_sizes_skas, &task_size);
 380
 381         /*
 382          * Setting up handlers to 'sig_info' struct
 383          */
 384         os_fill_handlinfo(handlinfo_kern);
 385
 386         brk_start = (unsigned long) sbrk(0);
 387         CHOOSE_MODE_PROC(before_mem_tt, before_mem_skas, brk_start);
 388         /* Increase physical memory size for exec-shield users
 389         so they actually get what they asked for. This should
 390         add zero for non-exec shield users */
 391
 392         diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 393         if(diff > 1024 * 1024){
 394                 printf("Adding %ld bytes to physical memory to account for "
 395                        "exec-shield gap\n", diff);
 396                 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 397         }
 398
 399         uml_physmem = uml_start & PAGE_MASK;
 400
 401         /* Reserve up to 4M after the current brk */
 402         uml_reserved = ROUND_4M(brk_start) + (1 << 22);
 403
 404         setup_machinename(init_utsname()->machine);
 405
 406 #ifdef CONFIG_CMDLINE_ON_HOST
 407         argv1_begin = argv[1];
 408         argv1_end = &argv[1][strlen(argv[1])];
 409 #endif
 410
 411         highmem = 0;
 412         iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
 413         max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
 414
 415         /* Zones have to begin on a 1 << MAX_ORDER page boundary,
 416          * so this makes sure that's true for highmem
 417          */
 418         max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
 419         if(physmem_size + iomem_size > max_physmem){
 420                 highmem = physmem_size + iomem_size - max_physmem;
 421                 physmem_size -= highmem;
 422 #ifndef CONFIG_HIGHMEM
 423                 highmem = 0;
 424                 printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
 425                        "to %Lu bytes\n", physmem_size);
 426 #endif
 427         }
 428
 429         high_physmem = uml_physmem + physmem_size;
 430         end_iomem = high_physmem + iomem_size;
 431         high_memory = (void *) end_iomem;
 432
 433         start_vm = VMALLOC_START;
 434
 435         setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
 436         if(init_maps(physmem_size, iomem_size, highmem)){
 437                 printf("Failed to allocate mem_map for %Lu bytes of physical "
 438                        "memory and %Lu bytes of highmem\n", physmem_size,
 439                        highmem);
 440                 exit(1);
 441         }
 442
 443         virtmem_size = physmem_size;
 444         avail = get_kmem_end() - start_vm;
 445         if(physmem_size > avail) virtmem_size = avail;
 446         end_vm = start_vm + virtmem_size;
 447
 448         if(virtmem_size < physmem_size)
 449                 printf("Kernel virtual memory size shrunk to %lu bytes\n",
 450                        virtmem_size);
 451
 452         uml_postsetup();
 453
 454         task_protections((unsigned long) &init_thread_info);
 455         os_flush_stdout();
 456
 457         return(CHOOSE_MODE(start_uml_tt(), start_uml_skas()));
 458 }
 459
 460 extern int uml_exitcode;
 461
 462 static int panic_exit(struct notifier_block *self, unsigned long unused1,
 463                       void *unused2)
 464 {
 465         bust_spinlocks(1);
 466         show_regs(&(current->thread.regs));
 467         bust_spinlocks(0);
 468         uml_exitcode = 1;
 469         machine_halt();
 470         return(0);
 471 }
 472
 473 static struct notifier_block panic_exit_notifier = {
 474         .notifier_call          = panic_exit,
 475         .next                   = NULL,
 476         .priority               = 0
 477 };
 478
 479 void __init setup_arch(char **cmdline_p)
 480 {
 481         atomic_notifier_chain_register(&panic_notifier_list,
 482                         &panic_exit_notifier);
 483         paging_init();
 484         strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 485         *cmdline_p = command_line;
 486         setup_hostinfo();
 487 }
 488
 489 void __init check_bugs(void)
 490 {
 491         arch_check_bugs();
 492         os_check_bugs();
 493 }
 494
 495 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 496 {
 497 }
 498
 499 #ifdef CONFIG_SMP
 500 void alternatives_smp_module_add(struct module *mod, char *name,
 501                                  void *locks, void *locks_end,
 502                                  void *text,  void *text_end)
 503 {
 504 }
 505
 506 void alternatives_smp_module_del(struct module *mod)
 507 {
 508 }
 509 #endif