linux-user/main.c

   1 /*
   2  *  qemu user main
   3  *
   4  *  Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu-common.h"
  22 #include "qemu/units.h"
  23 #include "sysemu/tcg.h"
  24 #include "qemu-version.h"
  25 #include <sys/syscall.h>
  26 #include <sys/resource.h>
  27
  28 #include "qapi/error.h"
  29 #include "qemu.h"
  30 #include "qemu/path.h"
  31 #include "qemu/queue.h"
  32 #include "qemu/config-file.h"
  33 #include "qemu/cutils.h"
  34 #include "qemu/error-report.h"
  35 #include "qemu/help_option.h"
  36 #include "qemu/module.h"
  37 #include "cpu.h"
  38 #include "exec/exec-all.h"
  39 #include "tcg.h"
  40 #include "qemu/timer.h"
  41 #include "qemu/envlist.h"
  42 #include "qemu/guest-random.h"
  43 #include "elf.h"
  44 #include "trace/control.h"
  45 #include "target_elf.h"
  46 #include "cpu_loop-common.h"
  47 #include "crypto/init.h"
  48
  49 char *exec_path;
  50
  51 int singlestep;
  52 static const char *argv0;
  53 static int gdbstub_port;
  54 static envlist_t *envlist;
  55 static const char *cpu_model;
  56 static const char *cpu_type;
  57 static const char *seed_optarg;
  58 unsigned long mmap_min_addr;
  59 unsigned long guest_base;
  60 int have_guest_base;
  61
  62 /*
  63  * When running 32-on-64 we should make sure we can fit all of the possible
  64  * guest address space into a contiguous chunk of virtual host memory.
  65  *
  66  * This way we will never overlap with our own libraries or binaries or stack
  67  * or anything else that QEMU maps.
  68  *
  69  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  70  * of the address for the kernel.  Some cpus rely on this and user space
  71  * uses the high bit(s) for pointer tagging and the like.  For them, we
  72  * must preserve the expected address space.
  73  */
  74 #ifndef MAX_RESERVED_VA
  75 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
  76 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
  77       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
  78 /* There are a number of places where we assign reserved_va to a variable
  79    of type abi_ulong and expect it to fit.  Avoid the last page.  */
  80 #   define MAX_RESERVED_VA(CPU)  (0xfffffffful & TARGET_PAGE_MASK)
  81 #  else
  82 #   define MAX_RESERVED_VA(CPU)  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
  83 #  endif
  84 # else
  85 #  define MAX_RESERVED_VA(CPU)  0
  86 # endif
  87 #endif
  88
  89 unsigned long reserved_va;
  90
  91 static void usage(int exitcode);
  92
  93 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
  94 const char *qemu_uname_release;
  95
  96 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
  97    we allocate a bigger stack. Need a better solution, for example
  98    by remapping the process stack directly at the right place */
  99 unsigned long guest_stack_size = 8 * 1024 * 1024UL;
 100
 101 void gemu_log(const char *fmt, ...)
 102 {
 103     va_list ap;
 104
 105     va_start(ap, fmt);
 106     vfprintf(stderr, fmt, ap);
 107     va_end(ap);
 108 }
 109
 110 #if defined(TARGET_I386)
 111 int cpu_get_pic_interrupt(CPUX86State *env)
 112 {
 113     return -1;
 114 }
 115 #endif
 116
 117 /***********************************************************/
 118 /* Helper routines for implementing atomic operations.  */
 119
 120 /* Make sure everything is in a consistent state for calling fork().  */
 121 void fork_start(void)
 122 {
 123     start_exclusive();
 124     mmap_fork_start();
 125     cpu_list_lock();
 126 }
 127
 128 void fork_end(int child)
 129 {
 130     mmap_fork_end(child);
 131     if (child) {
 132         CPUState *cpu, *next_cpu;
 133         /* Child processes created by fork() only have a single thread.
 134            Discard information about the parent threads.  */
 135         CPU_FOREACH_SAFE(cpu, next_cpu) {
 136             if (cpu != thread_cpu) {
 137                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
 138             }
 139         }
 140         qemu_init_cpu_list();
 141         gdbserver_fork(thread_cpu);
 142         /* qemu_init_cpu_list() takes care of reinitializing the
 143          * exclusive state, so we don't need to end_exclusive() here.
 144          */
 145     } else {
 146         cpu_list_unlock();
 147         end_exclusive();
 148     }
 149 }
 150
 151 __thread CPUState *thread_cpu;
 152
 153 bool qemu_cpu_is_self(CPUState *cpu)
 154 {
 155     return thread_cpu == cpu;
 156 }
 157
 158 void qemu_cpu_kick(CPUState *cpu)
 159 {
 160     cpu_exit(cpu);
 161 }
 162
 163 void task_settid(TaskState *ts)
 164 {
 165     if (ts->ts_tid == 0) {
 166         ts->ts_tid = (pid_t)syscall(SYS_gettid);
 167     }
 168 }
 169
 170 void stop_all_tasks(void)
 171 {
 172     /*
 173      * We trust that when using NPTL, start_exclusive()
 174      * handles thread stopping correctly.
 175      */
 176     start_exclusive();
 177 }
 178
 179 /* Assumes contents are already zeroed.  */
 180 void init_task_state(TaskState *ts)
 181 {
 182     ts->used = 1;
 183     ts->sigaltstack_used = (struct target_sigaltstack) {
 184         .ss_sp = 0,
 185         .ss_size = 0,
 186         .ss_flags = TARGET_SS_DISABLE,
 187     };
 188 }
 189
 190 CPUArchState *cpu_copy(CPUArchState *env)
 191 {
 192     CPUState *cpu = env_cpu(env);
 193     CPUState *new_cpu = cpu_create(cpu_type);
 194     CPUArchState *new_env = new_cpu->env_ptr;
 195     CPUBreakpoint *bp;
 196     CPUWatchpoint *wp;
 197
 198     /* Reset non arch specific state */
 199     cpu_reset(new_cpu);
 200
 201     memcpy(new_env, env, sizeof(CPUArchState));
 202
 203     /* Clone all break/watchpoints.
 204        Note: Once we support ptrace with hw-debug register access, make sure
 205        BP_CPU break/watchpoints are handled correctly on clone. */
 206     QTAILQ_INIT(&new_cpu->breakpoints);
 207     QTAILQ_INIT(&new_cpu->watchpoints);
 208     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
 209         cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
 210     }
 211     QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
 212         cpu_watchpoint_insert(new_cpu, wp->vaddr, wp->len, wp->flags, NULL);
 213     }
 214
 215     return new_env;
 216 }
 217
 218 static void handle_arg_help(const char *arg)
 219 {
 220     usage(EXIT_SUCCESS);
 221 }
 222
 223 static void handle_arg_log(const char *arg)
 224 {
 225     int mask;
 226
 227     mask = qemu_str_to_log_mask(arg);
 228     if (!mask) {
 229         qemu_print_log_usage(stdout);
 230         exit(EXIT_FAILURE);
 231     }
 232     qemu_log_needs_buffers();
 233     qemu_set_log(mask);
 234 }
 235
 236 static void handle_arg_dfilter(const char *arg)
 237 {
 238     qemu_set_dfilter_ranges(arg, &error_fatal);
 239 }
 240
 241 static void handle_arg_log_filename(const char *arg)
 242 {
 243     qemu_set_log_filename(arg, &error_fatal);
 244 }
 245
 246 static void handle_arg_set_env(const char *arg)
 247 {
 248     char *r, *p, *token;
 249     r = p = strdup(arg);
 250     while ((token = strsep(&p, ",")) != NULL) {
 251         if (envlist_setenv(envlist, token) != 0) {
 252             usage(EXIT_FAILURE);
 253         }
 254     }
 255     free(r);
 256 }
 257
 258 static void handle_arg_unset_env(const char *arg)
 259 {
 260     char *r, *p, *token;
 261     r = p = strdup(arg);
 262     while ((token = strsep(&p, ",")) != NULL) {
 263         if (envlist_unsetenv(envlist, token) != 0) {
 264             usage(EXIT_FAILURE);
 265         }
 266     }
 267     free(r);
 268 }
 269
 270 static void handle_arg_argv0(const char *arg)
 271 {
 272     argv0 = strdup(arg);
 273 }
 274
 275 static void handle_arg_stack_size(const char *arg)
 276 {
 277     char *p;
 278     guest_stack_size = strtoul(arg, &p, 0);
 279     if (guest_stack_size == 0) {
 280         usage(EXIT_FAILURE);
 281     }
 282
 283     if (*p == 'M') {
 284         guest_stack_size *= MiB;
 285     } else if (*p == 'k' || *p == 'K') {
 286         guest_stack_size *= KiB;
 287     }
 288 }
 289
 290 static void handle_arg_ld_prefix(const char *arg)
 291 {
 292     interp_prefix = strdup(arg);
 293 }
 294
 295 static void handle_arg_pagesize(const char *arg)
 296 {
 297     qemu_host_page_size = atoi(arg);
 298     if (qemu_host_page_size == 0 ||
 299         (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 300         fprintf(stderr, "page size must be a power of two\n");
 301         exit(EXIT_FAILURE);
 302     }
 303 }
 304
 305 static void handle_arg_seed(const char *arg)
 306 {
 307     seed_optarg = arg;
 308 }
 309
 310 static void handle_arg_gdb(const char *arg)
 311 {
 312     gdbstub_port = atoi(arg);
 313 }
 314
 315 static void handle_arg_uname(const char *arg)
 316 {
 317     qemu_uname_release = strdup(arg);
 318 }
 319
 320 static void handle_arg_cpu(const char *arg)
 321 {
 322     cpu_model = strdup(arg);
 323     if (cpu_model == NULL || is_help_option(cpu_model)) {
 324         /* XXX: implement xxx_cpu_list for targets that still miss it */
 325 #if defined(cpu_list)
 326         cpu_list();
 327 #endif
 328         exit(EXIT_FAILURE);
 329     }
 330 }
 331
 332 static void handle_arg_guest_base(const char *arg)
 333 {
 334     guest_base = strtol(arg, NULL, 0);
 335     have_guest_base = 1;
 336 }
 337
 338 static void handle_arg_reserved_va(const char *arg)
 339 {
 340     char *p;
 341     int shift = 0;
 342     reserved_va = strtoul(arg, &p, 0);
 343     switch (*p) {
 344     case 'k':
 345     case 'K':
 346         shift = 10;
 347         break;
 348     case 'M':
 349         shift = 20;
 350         break;
 351     case 'G':
 352         shift = 30;
 353         break;
 354     }
 355     if (shift) {
 356         unsigned long unshifted = reserved_va;
 357         p++;
 358         reserved_va <<= shift;
 359         if (reserved_va >> shift != unshifted) {
 360             fprintf(stderr, "Reserved virtual address too big\n");
 361             exit(EXIT_FAILURE);
 362         }
 363     }
 364     if (*p) {
 365         fprintf(stderr, "Unrecognised -R size suffix '%s'\n", p);
 366         exit(EXIT_FAILURE);
 367     }
 368 }
 369
 370 static void handle_arg_singlestep(const char *arg)
 371 {
 372     singlestep = 1;
 373 }
 374
 375 static void handle_arg_strace(const char *arg)
 376 {
 377     do_strace = 1;
 378 }
 379
 380 static void handle_arg_version(const char *arg)
 381 {
 382     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 383            "\n" QEMU_COPYRIGHT "\n");
 384     exit(EXIT_SUCCESS);
 385 }
 386
 387 static char *trace_file;
 388 static void handle_arg_trace(const char *arg)
 389 {
 390     g_free(trace_file);
 391     trace_file = trace_opt_parse(arg);
 392 }
 393
 394 #if defined(TARGET_XTENSA)
 395 static void handle_arg_abi_call0(const char *arg)
 396 {
 397     xtensa_set_abi_call0();
 398 }
 399 #endif
 400
 401 struct qemu_argument {
 402     const char *argv;
 403     const char *env;
 404     bool has_arg;
 405     void (*handle_opt)(const char *arg);
 406     const char *example;
 407     const char *help;
 408 };
 409
 410 static const struct qemu_argument arg_table[] = {
 411     {"h",          "",                 false, handle_arg_help,
 412      "",           "print this help"},
 413     {"help",       "",                 false, handle_arg_help,
 414      "",           ""},
 415     {"g",          "QEMU_GDB",         true,  handle_arg_gdb,
 416      "port",       "wait gdb connection to 'port'"},
 417     {"L",          "QEMU_LD_PREFIX",   true,  handle_arg_ld_prefix,
 418      "path",       "set the elf interpreter prefix to 'path'"},
 419     {"s",          "QEMU_STACK_SIZE",  true,  handle_arg_stack_size,
 420      "size",       "set the stack size to 'size' bytes"},
 421     {"cpu",        "QEMU_CPU",         true,  handle_arg_cpu,
 422      "model",      "select CPU (-cpu help for list)"},
 423     {"E",          "QEMU_SET_ENV",     true,  handle_arg_set_env,
 424      "var=value",  "sets targets environment variable (see below)"},
 425     {"U",          "QEMU_UNSET_ENV",   true,  handle_arg_unset_env,
 426      "var",        "unsets targets environment variable (see below)"},
 427     {"0",          "QEMU_ARGV0",       true,  handle_arg_argv0,
 428      "argv0",      "forces target process argv[0] to be 'argv0'"},
 429     {"r",          "QEMU_UNAME",       true,  handle_arg_uname,
 430      "uname",      "set qemu uname release string to 'uname'"},
 431     {"B",          "QEMU_GUEST_BASE",  true,  handle_arg_guest_base,
 432      "address",    "set guest_base address to 'address'"},
 433     {"R",          "QEMU_RESERVED_VA", true,  handle_arg_reserved_va,
 434      "size",       "reserve 'size' bytes for guest virtual address space"},
 435     {"d",          "QEMU_LOG",         true,  handle_arg_log,
 436      "item[,...]", "enable logging of specified items "
 437      "(use '-d help' for a list of items)"},
 438     {"dfilter",    "QEMU_DFILTER",     true,  handle_arg_dfilter,
 439      "range[,...]","filter logging based on address range"},
 440     {"D",          "QEMU_LOG_FILENAME", true, handle_arg_log_filename,
 441      "logfile",     "write logs to 'logfile' (default stderr)"},
 442     {"p",          "QEMU_PAGESIZE",    true,  handle_arg_pagesize,
 443      "pagesize",   "set the host page size to 'pagesize'"},
 444     {"singlestep", "QEMU_SINGLESTEP",  false, handle_arg_singlestep,
 445      "",           "run in singlestep mode"},
 446     {"strace",     "QEMU_STRACE",      false, handle_arg_strace,
 447      "",           "log system calls"},
 448     {"seed",       "QEMU_RAND_SEED",   true,  handle_arg_seed,
 449      "",           "Seed for pseudo-random number generator"},
 450     {"trace",      "QEMU_TRACE",       true,  handle_arg_trace,
 451      "",           "[[enable=]<pattern>][,events=<file>][,file=<file>]"},
 452     {"version",    "QEMU_VERSION",     false, handle_arg_version,
 453      "",           "display version information and exit"},
 454 #if defined(TARGET_XTENSA)
 455     {"xtensa-abi-call0", "QEMU_XTENSA_ABI_CALL0", false, handle_arg_abi_call0,
 456      "",           "assume CALL0 Xtensa ABI"},
 457 #endif
 458     {NULL, NULL, false, NULL, NULL, NULL}
 459 };
 460
 461 static void usage(int exitcode)
 462 {
 463     const struct qemu_argument *arginfo;
 464     int maxarglen;
 465     int maxenvlen;
 466
 467     printf("usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 468            "Linux CPU emulator (compiled for " TARGET_NAME " emulation)\n"
 469            "\n"
 470            "Options and associated environment variables:\n"
 471            "\n");
 472
 473     /* Calculate column widths. We must always have at least enough space
 474      * for the column header.
 475      */
 476     maxarglen = strlen("Argument");
 477     maxenvlen = strlen("Env-variable");
 478
 479     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 480         int arglen = strlen(arginfo->argv);
 481         if (arginfo->has_arg) {
 482             arglen += strlen(arginfo->example) + 1;
 483         }
 484         if (strlen(arginfo->env) > maxenvlen) {
 485             maxenvlen = strlen(arginfo->env);
 486         }
 487         if (arglen > maxarglen) {
 488             maxarglen = arglen;
 489         }
 490     }
 491
 492     printf("%-*s %-*s Description\n", maxarglen+1, "Argument",
 493             maxenvlen, "Env-variable");
 494
 495     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 496         if (arginfo->has_arg) {
 497             printf("-%s %-*s %-*s %s\n", arginfo->argv,
 498                    (int)(maxarglen - strlen(arginfo->argv) - 1),
 499                    arginfo->example, maxenvlen, arginfo->env, arginfo->help);
 500         } else {
 501             printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
 502                     maxenvlen, arginfo->env,
 503                     arginfo->help);
 504         }
 505     }
 506
 507     printf("\n"
 508            "Defaults:\n"
 509            "QEMU_LD_PREFIX  = %s\n"
 510            "QEMU_STACK_SIZE = %ld byte\n",
 511            interp_prefix,
 512            guest_stack_size);
 513
 514     printf("\n"
 515            "You can use -E and -U options or the QEMU_SET_ENV and\n"
 516            "QEMU_UNSET_ENV environment variables to set and unset\n"
 517            "environment variables for the target process.\n"
 518            "It is possible to provide several variables by separating them\n"
 519            "by commas in getsubopt(3) style. Additionally it is possible to\n"
 520            "provide the -E and -U options multiple times.\n"
 521            "The following lines are equivalent:\n"
 522            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 523            "    -E var1=val2,var2=val2 -U LD_PRELOAD,LD_DEBUG\n"
 524            "    QEMU_SET_ENV=var1=val2,var2=val2 QEMU_UNSET_ENV=LD_PRELOAD,LD_DEBUG\n"
 525            "Note that if you provide several changes to a single variable\n"
 526            "the last change will stay in effect.\n"
 527            "\n"
 528            QEMU_HELP_BOTTOM "\n");
 529
 530     exit(exitcode);
 531 }
 532
 533 static int parse_args(int argc, char **argv)
 534 {
 535     const char *r;
 536     int optind;
 537     const struct qemu_argument *arginfo;
 538
 539     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 540         if (arginfo->env == NULL) {
 541             continue;
 542         }
 543
 544         r = getenv(arginfo->env);
 545         if (r != NULL) {
 546             arginfo->handle_opt(r);
 547         }
 548     }
 549
 550     optind = 1;
 551     for (;;) {
 552         if (optind >= argc) {
 553             break;
 554         }
 555         r = argv[optind];
 556         if (r[0] != '-') {
 557             break;
 558         }
 559         optind++;
 560         r++;
 561         if (!strcmp(r, "-")) {
 562             break;
 563         }
 564         /* Treat --foo the same as -foo.  */
 565         if (r[0] == '-') {
 566             r++;
 567         }
 568
 569         for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 570             if (!strcmp(r, arginfo->argv)) {
 571                 if (arginfo->has_arg) {
 572                     if (optind >= argc) {
 573                         (void) fprintf(stderr,
 574                             "qemu: missing argument for option '%s'\n", r);
 575                         exit(EXIT_FAILURE);
 576                     }
 577                     arginfo->handle_opt(argv[optind]);
 578                     optind++;
 579                 } else {
 580                     arginfo->handle_opt(NULL);
 581                 }
 582                 break;
 583             }
 584         }
 585
 586         /* no option matched the current argv */
 587         if (arginfo->handle_opt == NULL) {
 588             (void) fprintf(stderr, "qemu: unknown option '%s'\n", r);
 589             exit(EXIT_FAILURE);
 590         }
 591     }
 592
 593     if (optind >= argc) {
 594         (void) fprintf(stderr, "qemu: no user program specified\n");
 595         exit(EXIT_FAILURE);
 596     }
 597
 598     exec_path = argv[optind];
 599
 600     return optind;
 601 }
 602
 603 int main(int argc, char **argv, char **envp)
 604 {
 605     struct target_pt_regs regs1, *regs = &regs1;
 606     struct image_info info1, *info = &info1;
 607     struct linux_binprm bprm;
 608     TaskState *ts;
 609     CPUArchState *env;
 610     CPUState *cpu;
 611     int optind;
 612     char **target_environ, **wrk;
 613     char **target_argv;
 614     int target_argc;
 615     int i;
 616     int ret;
 617     int execfd;
 618     unsigned long max_reserved_va;
 619
 620     error_init(argv[0]);
 621     module_call_init(MODULE_INIT_TRACE);
 622     qemu_init_cpu_list();
 623     module_call_init(MODULE_INIT_QOM);
 624
 625     envlist = envlist_create();
 626
 627     /* add current environment into the list */
 628     for (wrk = environ; *wrk != NULL; wrk++) {
 629         (void) envlist_setenv(envlist, *wrk);
 630     }
 631
 632     /* Read the stack limit from the kernel.  If it's "unlimited",
 633        then we can do little else besides use the default.  */
 634     {
 635         struct rlimit lim;
 636         if (getrlimit(RLIMIT_STACK, &lim) == 0
 637             && lim.rlim_cur != RLIM_INFINITY
 638             && lim.rlim_cur == (target_long)lim.rlim_cur) {
 639             guest_stack_size = lim.rlim_cur;
 640         }
 641     }
 642
 643     cpu_model = NULL;
 644
 645     qemu_add_opts(&qemu_trace_opts);
 646
 647     optind = parse_args(argc, argv);
 648
 649     if (!trace_init_backends()) {
 650         exit(1);
 651     }
 652     trace_init_file(trace_file);
 653
 654     /* Zero out regs */
 655     memset(regs, 0, sizeof(struct target_pt_regs));
 656
 657     /* Zero out image_info */
 658     memset(info, 0, sizeof(struct image_info));
 659
 660     memset(&bprm, 0, sizeof (bprm));
 661
 662     /* Scan interp_prefix dir for replacement files. */
 663     init_paths(interp_prefix);
 664
 665     init_qemu_uname_release();
 666
 667     execfd = qemu_getauxval(AT_EXECFD);
 668     if (execfd == 0) {
 669         execfd = open(exec_path, O_RDONLY);
 670         if (execfd < 0) {
 671             printf("Error while loading %s: %s\n", exec_path, strerror(errno));
 672             _exit(EXIT_FAILURE);
 673         }
 674     }
 675
 676     if (cpu_model == NULL) {
 677         cpu_model = cpu_get_model(get_elf_eflags(execfd));
 678     }
 679     cpu_type = parse_cpu_option(cpu_model);
 680
 681     /* init tcg before creating CPUs and to get qemu_host_page_size */
 682     tcg_exec_init(0);
 683
 684     cpu = cpu_create(cpu_type);
 685     env = cpu->env_ptr;
 686     cpu_reset(cpu);
 687     thread_cpu = cpu;
 688
 689     /*
 690      * Reserving too much vm space via mmap can run into problems
 691      * with rlimits, oom due to page table creation, etc.  We will
 692      * still try it, if directed by the command-line option, but
 693      * not by default.
 694      */
 695     max_reserved_va = MAX_RESERVED_VA(cpu);
 696     if (reserved_va != 0) {
 697         if (max_reserved_va && reserved_va > max_reserved_va) {
 698             fprintf(stderr, "Reserved virtual address too big\n");
 699             exit(EXIT_FAILURE);
 700         }
 701     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 702         /*
 703          * reserved_va must be aligned with the host page size
 704          * as it is used with mmap()
 705          */
 706         reserved_va = max_reserved_va & qemu_host_page_mask;
 707     }
 708
 709     {
 710         Error *err = NULL;
 711         if (seed_optarg != NULL) {
 712             qemu_guest_random_seed_main(seed_optarg, &err);
 713         } else {
 714             qcrypto_init(&err);
 715         }
 716         if (err) {
 717             error_reportf_err(err, "cannot initialize crypto: ");
 718             exit(1);
 719         }
 720     }
 721
 722     target_environ = envlist_to_environ(envlist, NULL);
 723     envlist_free(envlist);
 724
 725     /*
 726      * Now that page sizes are configured in tcg_exec_init() we can do
 727      * proper page alignment for guest_base.
 728      */
 729     guest_base = HOST_PAGE_ALIGN(guest_base);
 730
 731     if (reserved_va || have_guest_base) {
 732         guest_base = init_guest_space(guest_base, reserved_va, 0,
 733                                       have_guest_base);
 734         if (guest_base == (unsigned long)-1) {
 735             fprintf(stderr, "Unable to reserve 0x%lx bytes of virtual address "
 736                     "space for use as guest address space (check your virtual "
 737                     "memory ulimit setting or reserve less using -R option)\n",
 738                     reserved_va);
 739             exit(EXIT_FAILURE);
 740         }
 741
 742         if (reserved_va) {
 743             mmap_next_start = reserved_va;
 744         }
 745     }
 746
 747     /*
 748      * Read in mmap_min_addr kernel parameter.  This value is used
 749      * When loading the ELF image to determine whether guest_base
 750      * is needed.  It is also used in mmap_find_vma.
 751      */
 752     {
 753         FILE *fp;
 754
 755         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
 756             unsigned long tmp;
 757             if (fscanf(fp, "%lu", &tmp) == 1) {
 758                 mmap_min_addr = tmp;
 759                 qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n", mmap_min_addr);
 760             }
 761             fclose(fp);
 762         }
 763     }
 764
 765     /*
 766      * Prepare copy of argv vector for target.
 767      */
 768     target_argc = argc - optind;
 769     target_argv = calloc(target_argc + 1, sizeof (char *));
 770     if (target_argv == NULL) {
 771         (void) fprintf(stderr, "Unable to allocate memory for target_argv\n");
 772         exit(EXIT_FAILURE);
 773     }
 774
 775     /*
 776      * If argv0 is specified (using '-0' switch) we replace
 777      * argv[0] pointer with the given one.
 778      */
 779     i = 0;
 780     if (argv0 != NULL) {
 781         target_argv[i++] = strdup(argv0);
 782     }
 783     for (; i < target_argc; i++) {
 784         target_argv[i] = strdup(argv[optind + i]);
 785     }
 786     target_argv[target_argc] = NULL;
 787
 788     ts = g_new0(TaskState, 1);
 789     init_task_state(ts);
 790     /* build Task State */
 791     ts->info = info;
 792     ts->bprm = &bprm;
 793     cpu->opaque = ts;
 794     task_settid(ts);
 795
 796     ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
 797         info, &bprm);
 798     if (ret != 0) {
 799         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
 800         _exit(EXIT_FAILURE);
 801     }
 802
 803     for (wrk = target_environ; *wrk; wrk++) {
 804         g_free(*wrk);
 805     }
 806
 807     g_free(target_environ);
 808
 809     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 810         qemu_log("guest_base  0x%lx\n", guest_base);
 811         log_page_dump();
 812
 813         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
 814         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
 815         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n", info->start_code);
 816         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n", info->start_data);
 817         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
 818         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n", info->start_stack);
 819         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 820         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 821         qemu_log("argv_start  0x" TARGET_ABI_FMT_lx "\n", info->arg_start);
 822         qemu_log("env_start   0x" TARGET_ABI_FMT_lx "\n",
 823                  info->arg_end + (abi_ulong)sizeof(abi_ulong));
 824         qemu_log("auxv_start  0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv);
 825     }
 826
 827     target_set_brk(info->brk);
 828     syscall_init();
 829     signal_init();
 830
 831     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 832        generating the prologue until now so that the prologue can take
 833        the real value of GUEST_BASE into account.  */
 834     tcg_prologue_init(tcg_ctx);
 835     tcg_region_init();
 836
 837     target_cpu_copy_regs(env, regs);
 838
 839     if (gdbstub_port) {
 840         if (gdbserver_start(gdbstub_port) < 0) {
 841             fprintf(stderr, "qemu: could not open gdbserver on port %d\n",
 842                     gdbstub_port);
 843             exit(EXIT_FAILURE);
 844         }
 845         gdb_handlesig(cpu, 0);
 846     }
 847     cpu_loop(env);
 848     /* never exits */
 849     return 0;
 850 }