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/config.h"
   7 #include "linux/kernel.h"
   8 #include "linux/sched.h"
   9 #include "linux/notifier.h"
  10 #include "linux/mm.h"
  11 #include "linux/types.h"
  12 #include "linux/tty.h"
  13 #include "linux/init.h"
  14 #include "linux/bootmem.h"
  15 #include "linux/spinlock.h"
  16 #include "linux/utsname.h"
  17 #include "linux/sysrq.h"
  18 #include "linux/seq_file.h"
  19 #include "linux/delay.h"
  20 #include "linux/module.h"
  21 #include "asm/page.h"
  22 #include "asm/pgtable.h"
  23 #include "asm/ptrace.h"
  24 #include "asm/elf.h"
  25 #include "asm/user.h"
  26 #include "asm/setup.h"
  27 #include "ubd_user.h"
  28 #include "asm/current.h"
  29 #include "asm/setup.h"
  30 #include "user_util.h"
  31 #include "kern_util.h"
  32 #include "kern.h"
  33 #include "mem_user.h"
  34 #include "mem.h"
  35 #include "umid.h"
  36 #include "initrd.h"
  37 #include "init.h"
  38 #include "os.h"
  39 #include "choose-mode.h"
  40 #include "mode_kern.h"
  41 #include "mode.h"
  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 command_line[COMMAND_LINE_SIZE] = { 0 };
  47
  48 static void 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 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_MODE_TT
 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 physmem_size = 32 * 1024 * 1024;
 139
 140 void set_cmdline(char *cmd)
 141 {
 142 #ifdef CONFIG_MODE_TT
 143         char *umid, *ptr;
 144
 145         if(CHOOSE_MODE(honeypot, 0)) return;
 146
 147         umid = get_umid(1);
 148         if(umid != NULL){
 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", system_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 #ifdef CONFIG_SMP
 195 static int __init uml_ncpus_setup(char *line, int *add)
 196 {
 197        if (!sscanf(line, "%d", &ncpus)) {
 198                printf("Couldn't parse [%s]\n", line);
 199                return -1;
 200        }
 201
 202        return 0;
 203 }
 204
 205 __uml_setup("ncpus=", uml_ncpus_setup,
 206 "ncpus=<# of desired CPUs>\n"
 207 "    This tells an SMP kernel how many virtual processors to start.\n\n"
 208 );
 209 #endif
 210
 211 static int force_tt = 0;
 212
 213 #if defined(CONFIG_MODE_TT) && defined(CONFIG_MODE_SKAS)
 214 #define DEFAULT_TT 0
 215
 216 static int __init mode_tt_setup(char *line, int *add)
 217 {
 218         force_tt = 1;
 219         return(0);
 220 }
 221
 222 #else
 223 #ifdef CONFIG_MODE_SKAS
 224
 225 #define DEFAULT_TT 0
 226
 227 static int __init mode_tt_setup(char *line, int *add)
 228 {
 229         printf("CONFIG_MODE_TT disabled - 'mode=tt' ignored\n");
 230         return(0);
 231 }
 232
 233 #else
 234 #ifdef CONFIG_MODE_TT
 235
 236 #define DEFAULT_TT 1
 237
 238 static int __init mode_tt_setup(char *line, int *add)
 239 {
 240         printf("CONFIG_MODE_SKAS disabled - 'mode=tt' redundant\n");
 241         return(0);
 242 }
 243
 244 #else
 245
 246 #error Either CONFIG_MODE_TT or CONFIG_MODE_SKAS must be enabled
 247
 248 #endif
 249 #endif
 250 #endif
 251
 252 __uml_setup("mode=tt", mode_tt_setup,
 253 "mode=tt\n"
 254 "    When both CONFIG_MODE_TT and CONFIG_MODE_SKAS are enabled, this option\n"
 255 "    forces UML to run in tt (tracing thread) mode.  It is not the default\n"
 256 "    because it's slower and less secure than skas mode.\n\n"
 257 );
 258
 259 int mode_tt = DEFAULT_TT;
 260
 261 static int __init Usage(char *line, int *add)
 262 {
 263         const char **p;
 264
 265         printf(usage_string, system_utsname.release);
 266         p = &__uml_help_start;
 267         while (p < &__uml_help_end) {
 268                 printf("%s", *p);
 269                 p++;
 270         }
 271         exit(0);
 272
 273         return 0;
 274 }
 275
 276 __uml_setup("--help", Usage,
 277 "--help\n"
 278 "    Prints this message.\n\n"
 279 );
 280
 281 static int __init uml_checksetup(char *line, int *add)
 282 {
 283         struct uml_param *p;
 284
 285         p = &__uml_setup_start;
 286         while(p < &__uml_setup_end) {
 287                 int n;
 288
 289                 n = strlen(p->str);
 290                 if(!strncmp(line, p->str, n)){
 291                         if (p->setup_func(line + n, add)) return 1;
 292                 }
 293                 p++;
 294         }
 295         return 0;
 296 }
 297
 298 static void __init uml_postsetup(void)
 299 {
 300         initcall_t *p;
 301
 302         p = &__uml_postsetup_start;
 303         while(p < &__uml_postsetup_end){
 304                 (*p)();
 305                 p++;
 306         }
 307         return;
 308 }
 309
 310 /* Set during early boot */
 311 unsigned long brk_start;
 312 unsigned long end_iomem;
 313 EXPORT_SYMBOL(end_iomem);
 314
 315 #define MIN_VMALLOC (32 * 1024 * 1024)
 316
 317 int linux_main(int argc, char **argv)
 318 {
 319         unsigned long avail, diff;
 320         unsigned long virtmem_size, max_physmem;
 321         unsigned int i, add;
 322
 323         for (i = 1; i < argc; i++){
 324                 if((i == 1) && (argv[i][0] == ' ')) continue;
 325                 add = 1;
 326                 uml_checksetup(argv[i], &add);
 327                 if (add)
 328                         add_arg(argv[i]);
 329         }
 330         if(have_root == 0)
 331                 add_arg(DEFAULT_COMMAND_LINE);
 332
 333         mode_tt = force_tt ? 1 : !can_do_skas();
 334 #ifndef CONFIG_MODE_TT
 335         if (mode_tt) {
 336                 /*Since CONFIG_MODE_TT is #undef'ed, force_tt cannot be 1. So,
 337                  * can_do_skas() returned 0, and the message is correct. */
 338                 printf("Support for TT mode is disabled, and no SKAS support is present on the host.\n");
 339                 exit(1);
 340         }
 341 #endif
 342         uml_start = CHOOSE_MODE_PROC(set_task_sizes_tt, set_task_sizes_skas, 0,
 343                                      &host_task_size, &task_size);
 344
 345         /* Need to check this early because mmapping happens before the
 346          * kernel is running.
 347          */
 348         check_tmpexec();
 349
 350         brk_start = (unsigned long) sbrk(0);
 351         CHOOSE_MODE_PROC(before_mem_tt, before_mem_skas, brk_start);
 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         diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 357         if(diff > 1024 * 1024){
 358                 printf("Adding %ld bytes to physical memory to account for "
 359                        "exec-shield gap\n", diff);
 360                 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 361         }
 362
 363         uml_physmem = uml_start;
 364
 365         /* Reserve up to 4M after the current brk */
 366         uml_reserved = ROUND_4M(brk_start) + (1 << 22);
 367
 368         setup_machinename(system_utsname.machine);
 369
 370 #ifdef CONFIG_MODE_TT
 371         argv1_begin = argv[1];
 372         argv1_end = &argv[1][strlen(argv[1])];
 373 #endif
 374
 375         highmem = 0;
 376         iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
 377         max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
 378
 379         /* Zones have to begin on a 1 << MAX_ORDER page boundary,
 380          * so this makes sure that's true for highmem
 381          */
 382         max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
 383         if(physmem_size + iomem_size > max_physmem){
 384                 highmem = physmem_size + iomem_size - max_physmem;
 385                 physmem_size -= highmem;
 386 #ifndef CONFIG_HIGHMEM
 387                 highmem = 0;
 388                 printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
 389                        "to %ld bytes\n", physmem_size);
 390 #endif
 391         }
 392
 393         high_physmem = uml_physmem + physmem_size;
 394         end_iomem = high_physmem + iomem_size;
 395         high_memory = (void *) end_iomem;
 396
 397         start_vm = VMALLOC_START;
 398
 399         setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
 400         if(init_maps(physmem_size, iomem_size, highmem)){
 401                 printf("Failed to allocate mem_map for %ld bytes of physical "
 402                        "memory and %ld bytes of highmem\n", physmem_size,
 403                        highmem);
 404                 exit(1);
 405         }
 406
 407         virtmem_size = physmem_size;
 408         avail = get_kmem_end() - start_vm;
 409         if(physmem_size > avail) virtmem_size = avail;
 410         end_vm = start_vm + virtmem_size;
 411
 412         if(virtmem_size < physmem_size)
 413                 printf("Kernel virtual memory size shrunk to %ld bytes\n",
 414                        virtmem_size);
 415
 416         uml_postsetup();
 417
 418         task_protections((unsigned long) &init_thread_info);
 419         os_flush_stdout();
 420
 421         return(CHOOSE_MODE(start_uml_tt(), start_uml_skas()));
 422 }
 423
 424 extern int uml_exitcode;
 425
 426 static int panic_exit(struct notifier_block *self, unsigned long unused1,
 427                       void *unused2)
 428 {
 429         bust_spinlocks(1);
 430         show_regs(&(current->thread.regs));
 431         bust_spinlocks(0);
 432         uml_exitcode = 1;
 433         machine_halt();
 434         return(0);
 435 }
 436
 437 static struct notifier_block panic_exit_notifier = {
 438         .notifier_call          = panic_exit,
 439         .next                   = NULL,
 440         .priority               = 0
 441 };
 442
 443 void __init setup_arch(char **cmdline_p)
 444 {
 445         notifier_chain_register(&panic_notifier_list, &panic_exit_notifier);
 446         paging_init();
 447         strlcpy(saved_command_line, command_line, COMMAND_LINE_SIZE);
 448         *cmdline_p = command_line;
 449         setup_hostinfo();
 450 }
 451
 452 void __init check_bugs(void)
 453 {
 454         arch_check_bugs();
 455         check_ptrace();
 456         check_sigio();
 457         check_devanon();
 458 }
 459
 460 void apply_alternatives(void *start, void *end)
 461 {
 462 }