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 "qemu/plugin.h"
  38 #include "cpu.h"
  39 #include "exec/exec-all.h"
  40 #include "tcg.h"
  41 #include "qemu/timer.h"
  42 #include "qemu/envlist.h"
  43 #include "qemu/guest-random.h"
  44 #include "elf.h"
  45 #include "trace/control.h"
  46 #include "target_elf.h"
  47 #include "cpu_loop-common.h"
  48 #include "crypto/init.h"
  49
  50 char *exec_path;
  51
  52 int singlestep;
  53 static const char *argv0;
  54 static int gdbstub_port;
  55 static envlist_t *envlist;
  56 static const char *cpu_model;
  57 static const char *cpu_type;
  58 static const char *seed_optarg;
  59 unsigned long mmap_min_addr;
  60 unsigned long guest_base;
  61 int have_guest_base;
  62
  63 /*
  64  * When running 32-on-64 we should make sure we can fit all of the possible
  65  * guest address space into a contiguous chunk of virtual host memory.
  66  *
  67  * This way we will never overlap with our own libraries or binaries or stack
  68  * or anything else that QEMU maps.
  69  *
  70  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  71  * of the address for the kernel.  Some cpus rely on this and user space
  72  * uses the high bit(s) for pointer tagging and the like.  For them, we
  73  * must preserve the expected address space.
  74  */
  75 #ifndef MAX_RESERVED_VA
  76 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
  77 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
  78       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
  79 /* There are a number of places where we assign reserved_va to a variable
  80    of type abi_ulong and expect it to fit.  Avoid the last page.  */
  81 #   define MAX_RESERVED_VA(CPU)  (0xfffffffful & TARGET_PAGE_MASK)
  82 #  else
  83 #   define MAX_RESERVED_VA(CPU)  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
  84 #  endif
  85 # else
  86 #  define MAX_RESERVED_VA(CPU)  0
  87 # endif
  88 #endif
  89
  90 unsigned long reserved_va;
  91
  92 static void usage(int exitcode);
  93
  94 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
  95 const char *qemu_uname_release;
  96
  97 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
  98    we allocate a bigger stack. Need a better solution, for example
  99    by remapping the process stack directly at the right place */
 100 unsigned long guest_stack_size = 8 * 1024 * 1024UL;
 101
 102 void gemu_log(const char *fmt, ...)
 103 {
 104     va_list ap;
 105
 106     va_start(ap, fmt);
 107     vfprintf(stderr, fmt, ap);
 108     va_end(ap);
 109 }
 110
 111 #if defined(TARGET_I386)
 112 int cpu_get_pic_interrupt(CPUX86State *env)
 113 {
 114     return -1;
 115 }
 116 #endif
 117
 118 /***********************************************************/
 119 /* Helper routines for implementing atomic operations.  */
 120
 121 /* Make sure everything is in a consistent state for calling fork().  */
 122 void fork_start(void)
 123 {
 124     start_exclusive();
 125     mmap_fork_start();
 126     cpu_list_lock();
 127 }
 128
 129 void fork_end(int child)
 130 {
 131     mmap_fork_end(child);
 132     if (child) {
 133         CPUState *cpu, *next_cpu;
 134         /* Child processes created by fork() only have a single thread.
 135            Discard information about the parent threads.  */
 136         CPU_FOREACH_SAFE(cpu, next_cpu) {
 137             if (cpu != thread_cpu) {
 138                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
 139             }
 140         }
 141         qemu_init_cpu_list();
 142         gdbserver_fork(thread_cpu);
 143         /* qemu_init_cpu_list() takes care of reinitializing the
 144          * exclusive state, so we don't need to end_exclusive() here.
 145          */
 146     } else {
 147         cpu_list_unlock();
 148         end_exclusive();
 149     }
 150 }
 151
 152 __thread CPUState *thread_cpu;
 153
 154 bool qemu_cpu_is_self(CPUState *cpu)
 155 {
 156     return thread_cpu == cpu;
 157 }
 158
 159 void qemu_cpu_kick(CPUState *cpu)
 160 {
 161     cpu_exit(cpu);
 162 }
 163
 164 void task_settid(TaskState *ts)
 165 {
 166     if (ts->ts_tid == 0) {
 167         ts->ts_tid = (pid_t)syscall(SYS_gettid);
 168     }
 169 }
 170
 171 void stop_all_tasks(void)
 172 {
 173     /*
 174      * We trust that when using NPTL, start_exclusive()
 175      * handles thread stopping correctly.
 176      */
 177     start_exclusive();
 178 }
 179
 180 /* Assumes contents are already zeroed.  */
 181 void init_task_state(TaskState *ts)
 182 {
 183     ts->used = 1;
 184     ts->sigaltstack_used = (struct target_sigaltstack) {
 185         .ss_sp = 0,
 186         .ss_size = 0,
 187         .ss_flags = TARGET_SS_DISABLE,
 188     };
 189 }
 190
 191 CPUArchState *cpu_copy(CPUArchState *env)
 192 {
 193     CPUState *cpu = env_cpu(env);
 194     CPUState *new_cpu = cpu_create(cpu_type);
 195     CPUArchState *new_env = new_cpu->env_ptr;
 196     CPUBreakpoint *bp;
 197     CPUWatchpoint *wp;
 198
 199     /* Reset non arch specific state */
 200     cpu_reset(new_cpu);
 201
 202     memcpy(new_env, env, sizeof(CPUArchState));
 203
 204     /* Clone all break/watchpoints.
 205        Note: Once we support ptrace with hw-debug register access, make sure
 206        BP_CPU break/watchpoints are handled correctly on clone. */
 207     QTAILQ_INIT(&new_cpu->breakpoints);
 208     QTAILQ_INIT(&new_cpu->watchpoints);
 209     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
 210         cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
 211     }
 212     QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
 213         cpu_watchpoint_insert(new_cpu, wp->vaddr, wp->len, wp->flags, NULL);
 214     }
 215
 216     return new_env;
 217 }
 218
 219 static void handle_arg_help(const char *arg)
 220 {
 221     usage(EXIT_SUCCESS);
 222 }
 223
 224 static void handle_arg_log(const char *arg)
 225 {
 226     int mask;
 227
 228     mask = qemu_str_to_log_mask(arg);
 229     if (!mask) {
 230         qemu_print_log_usage(stdout);
 231         exit(EXIT_FAILURE);
 232     }
 233     qemu_log_needs_buffers();
 234     qemu_set_log(mask);
 235 }
 236
 237 static void handle_arg_dfilter(const char *arg)
 238 {
 239     qemu_set_dfilter_ranges(arg, &error_fatal);
 240 }
 241
 242 static void handle_arg_log_filename(const char *arg)
 243 {
 244     qemu_set_log_filename(arg, &error_fatal);
 245 }
 246
 247 static void handle_arg_set_env(const char *arg)
 248 {
 249     char *r, *p, *token;
 250     r = p = strdup(arg);
 251     while ((token = strsep(&p, ",")) != NULL) {
 252         if (envlist_setenv(envlist, token) != 0) {
 253             usage(EXIT_FAILURE);
 254         }
 255     }
 256     free(r);
 257 }
 258
 259 static void handle_arg_unset_env(const char *arg)
 260 {
 261     char *r, *p, *token;
 262     r = p = strdup(arg);
 263     while ((token = strsep(&p, ",")) != NULL) {
 264         if (envlist_unsetenv(envlist, token) != 0) {
 265             usage(EXIT_FAILURE);
 266         }
 267     }
 268     free(r);
 269 }
 270
 271 static void handle_arg_argv0(const char *arg)
 272 {
 273     argv0 = strdup(arg);
 274 }
 275
 276 static void handle_arg_stack_size(const char *arg)
 277 {
 278     char *p;
 279     guest_stack_size = strtoul(arg, &p, 0);
 280     if (guest_stack_size == 0) {
 281         usage(EXIT_FAILURE);
 282     }
 283
 284     if (*p == 'M') {
 285         guest_stack_size *= MiB;
 286     } else if (*p == 'k' || *p == 'K') {
 287         guest_stack_size *= KiB;
 288     }
 289 }
 290
 291 static void handle_arg_ld_prefix(const char *arg)
 292 {
 293     interp_prefix = strdup(arg);
 294 }
 295
 296 static void handle_arg_pagesize(const char *arg)
 297 {
 298     qemu_host_page_size = atoi(arg);
 299     if (qemu_host_page_size == 0 ||
 300         (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 301         fprintf(stderr, "page size must be a power of two\n");
 302         exit(EXIT_FAILURE);
 303     }
 304 }
 305
 306 static void handle_arg_seed(const char *arg)
 307 {
 308     seed_optarg = arg;
 309 }
 310
 311 static void handle_arg_gdb(const char *arg)
 312 {
 313     gdbstub_port = atoi(arg);
 314 }
 315
 316 static void handle_arg_uname(const char *arg)
 317 {
 318     qemu_uname_release = strdup(arg);
 319 }
 320
 321 static void handle_arg_cpu(const char *arg)
 322 {
 323     cpu_model = strdup(arg);
 324     if (cpu_model == NULL || is_help_option(cpu_model)) {
 325         /* XXX: implement xxx_cpu_list for targets that still miss it */
 326 #if defined(cpu_list)
 327         cpu_list();
 328 #endif
 329         exit(EXIT_FAILURE);
 330     }
 331 }
 332
 333 static void handle_arg_guest_base(const char *arg)
 334 {
 335     guest_base = strtol(arg, NULL, 0);
 336     have_guest_base = 1;
 337 }
 338
 339 static void handle_arg_reserved_va(const char *arg)
 340 {
 341     char *p;
 342     int shift = 0;
 343     reserved_va = strtoul(arg, &p, 0);
 344     switch (*p) {
 345     case 'k':
 346     case 'K':
 347         shift = 10;
 348         break;
 349     case 'M':
 350         shift = 20;
 351         break;
 352     case 'G':
 353         shift = 30;
 354         break;
 355     }
 356     if (shift) {
 357         unsigned long unshifted = reserved_va;
 358         p++;
 359         reserved_va <<= shift;
 360         if (reserved_va >> shift != unshifted) {
 361             fprintf(stderr, "Reserved virtual address too big\n");
 362             exit(EXIT_FAILURE);
 363         }
 364     }
 365     if (*p) {
 366         fprintf(stderr, "Unrecognised -R size suffix '%s'\n", p);
 367         exit(EXIT_FAILURE);
 368     }
 369 }
 370
 371 static void handle_arg_singlestep(const char *arg)
 372 {
 373     singlestep = 1;
 374 }
 375
 376 static void handle_arg_strace(const char *arg)
 377 {
 378     do_strace = 1;
 379 }
 380
 381 static void handle_arg_version(const char *arg)
 382 {
 383     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 384            "\n" QEMU_COPYRIGHT "\n");
 385     exit(EXIT_SUCCESS);
 386 }
 387
 388 static char *trace_file;
 389 static void handle_arg_trace(const char *arg)
 390 {
 391     g_free(trace_file);
 392     trace_file = trace_opt_parse(arg);
 393 }
 394
 395 #if defined(TARGET_XTENSA)
 396 static void handle_arg_abi_call0(const char *arg)
 397 {
 398     xtensa_set_abi_call0();
 399 }
 400 #endif
 401
 402 static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
 403
 404 #ifdef CONFIG_PLUGIN
 405 static void handle_arg_plugin(const char *arg)
 406 {
 407     qemu_plugin_opt_parse(arg, &plugins);
 408 }
 409 #endif
 410
 411 struct qemu_argument {
 412     const char *argv;
 413     const char *env;
 414     bool has_arg;
 415     void (*handle_opt)(const char *arg);
 416     const char *example;
 417     const char *help;
 418 };
 419
 420 static const struct qemu_argument arg_table[] = {
 421     {"h",          "",                 false, handle_arg_help,
 422      "",           "print this help"},
 423     {"help",       "",                 false, handle_arg_help,
 424      "",           ""},
 425     {"g",          "QEMU_GDB",         true,  handle_arg_gdb,
 426      "port",       "wait gdb connection to 'port'"},
 427     {"L",          "QEMU_LD_PREFIX",   true,  handle_arg_ld_prefix,
 428      "path",       "set the elf interpreter prefix to 'path'"},
 429     {"s",          "QEMU_STACK_SIZE",  true,  handle_arg_stack_size,
 430      "size",       "set the stack size to 'size' bytes"},
 431     {"cpu",        "QEMU_CPU",         true,  handle_arg_cpu,
 432      "model",      "select CPU (-cpu help for list)"},
 433     {"E",          "QEMU_SET_ENV",     true,  handle_arg_set_env,
 434      "var=value",  "sets targets environment variable (see below)"},
 435     {"U",          "QEMU_UNSET_ENV",   true,  handle_arg_unset_env,
 436      "var",        "unsets targets environment variable (see below)"},
 437     {"0",          "QEMU_ARGV0",       true,  handle_arg_argv0,
 438      "argv0",      "forces target process argv[0] to be 'argv0'"},
 439     {"r",          "QEMU_UNAME",       true,  handle_arg_uname,
 440      "uname",      "set qemu uname release string to 'uname'"},
 441     {"B",          "QEMU_GUEST_BASE",  true,  handle_arg_guest_base,
 442      "address",    "set guest_base address to 'address'"},
 443     {"R",          "QEMU_RESERVED_VA", true,  handle_arg_reserved_va,
 444      "size",       "reserve 'size' bytes for guest virtual address space"},
 445     {"d",          "QEMU_LOG",         true,  handle_arg_log,
 446      "item[,...]", "enable logging of specified items "
 447      "(use '-d help' for a list of items)"},
 448     {"dfilter",    "QEMU_DFILTER",     true,  handle_arg_dfilter,
 449      "range[,...]","filter logging based on address range"},
 450     {"D",          "QEMU_LOG_FILENAME", true, handle_arg_log_filename,
 451      "logfile",     "write logs to 'logfile' (default stderr)"},
 452     {"p",          "QEMU_PAGESIZE",    true,  handle_arg_pagesize,
 453      "pagesize",   "set the host page size to 'pagesize'"},
 454     {"singlestep", "QEMU_SINGLESTEP",  false, handle_arg_singlestep,
 455      "",           "run in singlestep mode"},
 456     {"strace",     "QEMU_STRACE",      false, handle_arg_strace,
 457      "",           "log system calls"},
 458     {"seed",       "QEMU_RAND_SEED",   true,  handle_arg_seed,
 459      "",           "Seed for pseudo-random number generator"},
 460     {"trace",      "QEMU_TRACE",       true,  handle_arg_trace,
 461      "",           "[[enable=]<pattern>][,events=<file>][,file=<file>]"},
 462 #ifdef CONFIG_PLUGIN
 463     {"plugin",     "QEMU_PLUGIN",      true,  handle_arg_plugin,
 464      "",           "[file=]<file>[,arg=<string>]"},
 465 #endif
 466     {"version",    "QEMU_VERSION",     false, handle_arg_version,
 467      "",           "display version information and exit"},
 468 #if defined(TARGET_XTENSA)
 469     {"xtensa-abi-call0", "QEMU_XTENSA_ABI_CALL0", false, handle_arg_abi_call0,
 470      "",           "assume CALL0 Xtensa ABI"},
 471 #endif
 472     {NULL, NULL, false, NULL, NULL, NULL}
 473 };
 474
 475 static void usage(int exitcode)
 476 {
 477     const struct qemu_argument *arginfo;
 478     int maxarglen;
 479     int maxenvlen;
 480
 481     printf("usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 482            "Linux CPU emulator (compiled for " TARGET_NAME " emulation)\n"
 483            "\n"
 484            "Options and associated environment variables:\n"
 485            "\n");
 486
 487     /* Calculate column widths. We must always have at least enough space
 488      * for the column header.
 489      */
 490     maxarglen = strlen("Argument");
 491     maxenvlen = strlen("Env-variable");
 492
 493     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 494         int arglen = strlen(arginfo->argv);
 495         if (arginfo->has_arg) {
 496             arglen += strlen(arginfo->example) + 1;
 497         }
 498         if (strlen(arginfo->env) > maxenvlen) {
 499             maxenvlen = strlen(arginfo->env);
 500         }
 501         if (arglen > maxarglen) {
 502             maxarglen = arglen;
 503         }
 504     }
 505
 506     printf("%-*s %-*s Description\n", maxarglen+1, "Argument",
 507             maxenvlen, "Env-variable");
 508
 509     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 510         if (arginfo->has_arg) {
 511             printf("-%s %-*s %-*s %s\n", arginfo->argv,
 512                    (int)(maxarglen - strlen(arginfo->argv) - 1),
 513                    arginfo->example, maxenvlen, arginfo->env, arginfo->help);
 514         } else {
 515             printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
 516                     maxenvlen, arginfo->env,
 517                     arginfo->help);
 518         }
 519     }
 520
 521     printf("\n"
 522            "Defaults:\n"
 523            "QEMU_LD_PREFIX  = %s\n"
 524            "QEMU_STACK_SIZE = %ld byte\n",
 525            interp_prefix,
 526            guest_stack_size);
 527
 528     printf("\n"
 529            "You can use -E and -U options or the QEMU_SET_ENV and\n"
 530            "QEMU_UNSET_ENV environment variables to set and unset\n"
 531            "environment variables for the target process.\n"
 532            "It is possible to provide several variables by separating them\n"
 533            "by commas in getsubopt(3) style. Additionally it is possible to\n"
 534            "provide the -E and -U options multiple times.\n"
 535            "The following lines are equivalent:\n"
 536            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 537            "    -E var1=val2,var2=val2 -U LD_PRELOAD,LD_DEBUG\n"
 538            "    QEMU_SET_ENV=var1=val2,var2=val2 QEMU_UNSET_ENV=LD_PRELOAD,LD_DEBUG\n"
 539            "Note that if you provide several changes to a single variable\n"
 540            "the last change will stay in effect.\n"
 541            "\n"
 542            QEMU_HELP_BOTTOM "\n");
 543
 544     exit(exitcode);
 545 }
 546
 547 static int parse_args(int argc, char **argv)
 548 {
 549     const char *r;
 550     int optind;
 551     const struct qemu_argument *arginfo;
 552
 553     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 554         if (arginfo->env == NULL) {
 555             continue;
 556         }
 557
 558         r = getenv(arginfo->env);
 559         if (r != NULL) {
 560             arginfo->handle_opt(r);
 561         }
 562     }
 563
 564     optind = 1;
 565     for (;;) {
 566         if (optind >= argc) {
 567             break;
 568         }
 569         r = argv[optind];
 570         if (r[0] != '-') {
 571             break;
 572         }
 573         optind++;
 574         r++;
 575         if (!strcmp(r, "-")) {
 576             break;
 577         }
 578         /* Treat --foo the same as -foo.  */
 579         if (r[0] == '-') {
 580             r++;
 581         }
 582
 583         for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 584             if (!strcmp(r, arginfo->argv)) {
 585                 if (arginfo->has_arg) {
 586                     if (optind >= argc) {
 587                         (void) fprintf(stderr,
 588                             "qemu: missing argument for option '%s'\n", r);
 589                         exit(EXIT_FAILURE);
 590                     }
 591                     arginfo->handle_opt(argv[optind]);
 592                     optind++;
 593                 } else {
 594                     arginfo->handle_opt(NULL);
 595                 }
 596                 break;
 597             }
 598         }
 599
 600         /* no option matched the current argv */
 601         if (arginfo->handle_opt == NULL) {
 602             (void) fprintf(stderr, "qemu: unknown option '%s'\n", r);
 603             exit(EXIT_FAILURE);
 604         }
 605     }
 606
 607     if (optind >= argc) {
 608         (void) fprintf(stderr, "qemu: no user program specified\n");
 609         exit(EXIT_FAILURE);
 610     }
 611
 612     exec_path = argv[optind];
 613
 614     return optind;
 615 }
 616
 617 int main(int argc, char **argv, char **envp)
 618 {
 619     struct target_pt_regs regs1, *regs = &regs1;
 620     struct image_info info1, *info = &info1;
 621     struct linux_binprm bprm;
 622     TaskState *ts;
 623     CPUArchState *env;
 624     CPUState *cpu;
 625     int optind;
 626     char **target_environ, **wrk;
 627     char **target_argv;
 628     int target_argc;
 629     int i;
 630     int ret;
 631     int execfd;
 632     unsigned long max_reserved_va;
 633
 634     error_init(argv[0]);
 635     module_call_init(MODULE_INIT_TRACE);
 636     qemu_init_cpu_list();
 637     module_call_init(MODULE_INIT_QOM);
 638
 639     envlist = envlist_create();
 640
 641     /* add current environment into the list */
 642     for (wrk = environ; *wrk != NULL; wrk++) {
 643         (void) envlist_setenv(envlist, *wrk);
 644     }
 645
 646     /* Read the stack limit from the kernel.  If it's "unlimited",
 647        then we can do little else besides use the default.  */
 648     {
 649         struct rlimit lim;
 650         if (getrlimit(RLIMIT_STACK, &lim) == 0
 651             && lim.rlim_cur != RLIM_INFINITY
 652             && lim.rlim_cur == (target_long)lim.rlim_cur) {
 653             guest_stack_size = lim.rlim_cur;
 654         }
 655     }
 656
 657     cpu_model = NULL;
 658
 659     qemu_add_opts(&qemu_trace_opts);
 660     qemu_plugin_add_opts();
 661
 662     optind = parse_args(argc, argv);
 663
 664     if (!trace_init_backends()) {
 665         exit(1);
 666     }
 667     trace_init_file(trace_file);
 668     if (qemu_plugin_load_list(&plugins)) {
 669         exit(1);
 670     }
 671
 672     /* Zero out regs */
 673     memset(regs, 0, sizeof(struct target_pt_regs));
 674
 675     /* Zero out image_info */
 676     memset(info, 0, sizeof(struct image_info));
 677
 678     memset(&bprm, 0, sizeof (bprm));
 679
 680     /* Scan interp_prefix dir for replacement files. */
 681     init_paths(interp_prefix);
 682
 683     init_qemu_uname_release();
 684
 685     execfd = qemu_getauxval(AT_EXECFD);
 686     if (execfd == 0) {
 687         execfd = open(exec_path, O_RDONLY);
 688         if (execfd < 0) {
 689             printf("Error while loading %s: %s\n", exec_path, strerror(errno));
 690             _exit(EXIT_FAILURE);
 691         }
 692     }
 693
 694     if (cpu_model == NULL) {
 695         cpu_model = cpu_get_model(get_elf_eflags(execfd));
 696     }
 697     cpu_type = parse_cpu_option(cpu_model);
 698
 699     /* init tcg before creating CPUs and to get qemu_host_page_size */
 700     tcg_exec_init(0);
 701
 702     cpu = cpu_create(cpu_type);
 703     env = cpu->env_ptr;
 704     cpu_reset(cpu);
 705     thread_cpu = cpu;
 706
 707     /*
 708      * Reserving too much vm space via mmap can run into problems
 709      * with rlimits, oom due to page table creation, etc.  We will
 710      * still try it, if directed by the command-line option, but
 711      * not by default.
 712      */
 713     max_reserved_va = MAX_RESERVED_VA(cpu);
 714     if (reserved_va != 0) {
 715         if (max_reserved_va && reserved_va > max_reserved_va) {
 716             fprintf(stderr, "Reserved virtual address too big\n");
 717             exit(EXIT_FAILURE);
 718         }
 719     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 720         /*
 721          * reserved_va must be aligned with the host page size
 722          * as it is used with mmap()
 723          */
 724         reserved_va = max_reserved_va & qemu_host_page_mask;
 725     }
 726
 727     {
 728         Error *err = NULL;
 729         if (seed_optarg != NULL) {
 730             qemu_guest_random_seed_main(seed_optarg, &err);
 731         } else {
 732             qcrypto_init(&err);
 733         }
 734         if (err) {
 735             error_reportf_err(err, "cannot initialize crypto: ");
 736             exit(1);
 737         }
 738     }
 739
 740     target_environ = envlist_to_environ(envlist, NULL);
 741     envlist_free(envlist);
 742
 743     /*
 744      * Now that page sizes are configured in tcg_exec_init() we can do
 745      * proper page alignment for guest_base.
 746      */
 747     guest_base = HOST_PAGE_ALIGN(guest_base);
 748
 749     if (reserved_va || have_guest_base) {
 750         guest_base = init_guest_space(guest_base, reserved_va, 0,
 751                                       have_guest_base);
 752         if (guest_base == (unsigned long)-1) {
 753             fprintf(stderr, "Unable to reserve 0x%lx bytes of virtual address "
 754                     "space for use as guest address space (check your virtual "
 755                     "memory ulimit setting or reserve less using -R option)\n",
 756                     reserved_va);
 757             exit(EXIT_FAILURE);
 758         }
 759
 760         if (reserved_va) {
 761             mmap_next_start = reserved_va;
 762         }
 763     }
 764
 765     /*
 766      * Read in mmap_min_addr kernel parameter.  This value is used
 767      * When loading the ELF image to determine whether guest_base
 768      * is needed.  It is also used in mmap_find_vma.
 769      */
 770     {
 771         FILE *fp;
 772
 773         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
 774             unsigned long tmp;
 775             if (fscanf(fp, "%lu", &tmp) == 1) {
 776                 mmap_min_addr = tmp;
 777                 qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n", mmap_min_addr);
 778             }
 779             fclose(fp);
 780         }
 781     }
 782
 783     /*
 784      * Prepare copy of argv vector for target.
 785      */
 786     target_argc = argc - optind;
 787     target_argv = calloc(target_argc + 1, sizeof (char *));
 788     if (target_argv == NULL) {
 789         (void) fprintf(stderr, "Unable to allocate memory for target_argv\n");
 790         exit(EXIT_FAILURE);
 791     }
 792
 793     /*
 794      * If argv0 is specified (using '-0' switch) we replace
 795      * argv[0] pointer with the given one.
 796      */
 797     i = 0;
 798     if (argv0 != NULL) {
 799         target_argv[i++] = strdup(argv0);
 800     }
 801     for (; i < target_argc; i++) {
 802         target_argv[i] = strdup(argv[optind + i]);
 803     }
 804     target_argv[target_argc] = NULL;
 805
 806     ts = g_new0(TaskState, 1);
 807     init_task_state(ts);
 808     /* build Task State */
 809     ts->info = info;
 810     ts->bprm = &bprm;
 811     cpu->opaque = ts;
 812     task_settid(ts);
 813
 814     ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
 815         info, &bprm);
 816     if (ret != 0) {
 817         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
 818         _exit(EXIT_FAILURE);
 819     }
 820
 821     for (wrk = target_environ; *wrk; wrk++) {
 822         g_free(*wrk);
 823     }
 824
 825     g_free(target_environ);
 826
 827     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 828         qemu_log("guest_base  0x%lx\n", guest_base);
 829         log_page_dump();
 830
 831         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
 832         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
 833         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n", info->start_code);
 834         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n", info->start_data);
 835         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
 836         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n", info->start_stack);
 837         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 838         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 839         qemu_log("argv_start  0x" TARGET_ABI_FMT_lx "\n", info->arg_start);
 840         qemu_log("env_start   0x" TARGET_ABI_FMT_lx "\n",
 841                  info->arg_end + (abi_ulong)sizeof(abi_ulong));
 842         qemu_log("auxv_start  0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv);
 843     }
 844
 845     target_set_brk(info->brk);
 846     syscall_init();
 847     signal_init();
 848
 849     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 850        generating the prologue until now so that the prologue can take
 851        the real value of GUEST_BASE into account.  */
 852     tcg_prologue_init(tcg_ctx);
 853     tcg_region_init();
 854
 855     target_cpu_copy_regs(env, regs);
 856
 857     if (gdbstub_port) {
 858         if (gdbserver_start(gdbstub_port) < 0) {
 859             fprintf(stderr, "qemu: could not open gdbserver on port %d\n",
 860                     gdbstub_port);
 861             exit(EXIT_FAILURE);
 862         }
 863         gdb_handlesig(cpu, 0);
 864     }
 865     cpu_loop(env);
 866     /* never exits */
 867     return 0;
 868 }