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/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  * Used to implement backwards-compatibility for the `-strace`, and
  65  * QEMU_STRACE options. Without this, the QEMU_LOG can be overwritten by
  66  * -strace, or vice versa.
  67  */
  68 static bool enable_strace;
  69
  70 /*
  71  * The last log mask given by the user in an environment variable or argument.
  72  * Used to support command line arguments overriding environment variables.
  73  */
  74 static int last_log_mask;
  75
  76 /*
  77  * When running 32-on-64 we should make sure we can fit all of the possible
  78  * guest address space into a contiguous chunk of virtual host memory.
  79  *
  80  * This way we will never overlap with our own libraries or binaries or stack
  81  * or anything else that QEMU maps.
  82  *
  83  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  84  * of the address for the kernel.  Some cpus rely on this and user space
  85  * uses the high bit(s) for pointer tagging and the like.  For them, we
  86  * must preserve the expected address space.
  87  */
  88 #ifndef MAX_RESERVED_VA
  89 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
  90 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
  91       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
  92 /* There are a number of places where we assign reserved_va to a variable
  93    of type abi_ulong and expect it to fit.  Avoid the last page.  */
  94 #   define MAX_RESERVED_VA(CPU)  (0xfffffffful & TARGET_PAGE_MASK)
  95 #  else
  96 #   define MAX_RESERVED_VA(CPU)  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
  97 #  endif
  98 # else
  99 #  define MAX_RESERVED_VA(CPU)  0
 100 # endif
 101 #endif
 102
 103 unsigned long reserved_va;
 104
 105 static void usage(int exitcode);
 106
 107 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
 108 const char *qemu_uname_release;
 109
 110 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
 111    we allocate a bigger stack. Need a better solution, for example
 112    by remapping the process stack directly at the right place */
 113 unsigned long guest_stack_size = 8 * 1024 * 1024UL;
 114
 115 #if defined(TARGET_I386)
 116 int cpu_get_pic_interrupt(CPUX86State *env)
 117 {
 118     return -1;
 119 }
 120 #endif
 121
 122 /***********************************************************/
 123 /* Helper routines for implementing atomic operations.  */
 124
 125 /* Make sure everything is in a consistent state for calling fork().  */
 126 void fork_start(void)
 127 {
 128     start_exclusive();
 129     mmap_fork_start();
 130     cpu_list_lock();
 131 }
 132
 133 void fork_end(int child)
 134 {
 135     mmap_fork_end(child);
 136     if (child) {
 137         CPUState *cpu, *next_cpu;
 138         /* Child processes created by fork() only have a single thread.
 139            Discard information about the parent threads.  */
 140         CPU_FOREACH_SAFE(cpu, next_cpu) {
 141             if (cpu != thread_cpu) {
 142                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
 143             }
 144         }
 145         qemu_init_cpu_list();
 146         gdbserver_fork(thread_cpu);
 147         /* qemu_init_cpu_list() takes care of reinitializing the
 148          * exclusive state, so we don't need to end_exclusive() here.
 149          */
 150     } else {
 151         cpu_list_unlock();
 152         end_exclusive();
 153     }
 154 }
 155
 156 __thread CPUState *thread_cpu;
 157
 158 bool qemu_cpu_is_self(CPUState *cpu)
 159 {
 160     return thread_cpu == cpu;
 161 }
 162
 163 void qemu_cpu_kick(CPUState *cpu)
 164 {
 165     cpu_exit(cpu);
 166 }
 167
 168 void task_settid(TaskState *ts)
 169 {
 170     if (ts->ts_tid == 0) {
 171         ts->ts_tid = (pid_t)syscall(SYS_gettid);
 172     }
 173 }
 174
 175 void stop_all_tasks(void)
 176 {
 177     /*
 178      * We trust that when using NPTL, start_exclusive()
 179      * handles thread stopping correctly.
 180      */
 181     start_exclusive();
 182 }
 183
 184 /* Assumes contents are already zeroed.  */
 185 void init_task_state(TaskState *ts)
 186 {
 187     ts->used = 1;
 188     ts->sigaltstack_used = (struct target_sigaltstack) {
 189         .ss_sp = 0,
 190         .ss_size = 0,
 191         .ss_flags = TARGET_SS_DISABLE,
 192     };
 193 }
 194
 195 CPUArchState *cpu_copy(CPUArchState *env)
 196 {
 197     CPUState *cpu = env_cpu(env);
 198     CPUState *new_cpu = cpu_create(cpu_type);
 199     CPUArchState *new_env = new_cpu->env_ptr;
 200     CPUBreakpoint *bp;
 201     CPUWatchpoint *wp;
 202
 203     /* Reset non arch specific state */
 204     cpu_reset(new_cpu);
 205
 206     memcpy(new_env, env, sizeof(CPUArchState));
 207
 208     /* Clone all break/watchpoints.
 209        Note: Once we support ptrace with hw-debug register access, make sure
 210        BP_CPU break/watchpoints are handled correctly on clone. */
 211     QTAILQ_INIT(&new_cpu->breakpoints);
 212     QTAILQ_INIT(&new_cpu->watchpoints);
 213     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
 214         cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
 215     }
 216     QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
 217         cpu_watchpoint_insert(new_cpu, wp->vaddr, wp->len, wp->flags, NULL);
 218     }
 219
 220     return new_env;
 221 }
 222
 223 static void handle_arg_help(const char *arg)
 224 {
 225     usage(EXIT_SUCCESS);
 226 }
 227
 228 static void handle_arg_log(const char *arg)
 229 {
 230     last_log_mask = qemu_str_to_log_mask(arg);
 231     if (!last_log_mask) {
 232         qemu_print_log_usage(stdout);
 233         exit(EXIT_FAILURE);
 234     }
 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     enable_strace = true;
 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     int log_mask;
 633     unsigned long max_reserved_va;
 634
 635     error_init(argv[0]);
 636     module_call_init(MODULE_INIT_TRACE);
 637     qemu_init_cpu_list();
 638     module_call_init(MODULE_INIT_QOM);
 639
 640     envlist = envlist_create();
 641
 642     /* add current environment into the list */
 643     for (wrk = environ; *wrk != NULL; wrk++) {
 644         (void) envlist_setenv(envlist, *wrk);
 645     }
 646
 647     /* Read the stack limit from the kernel.  If it's "unlimited",
 648        then we can do little else besides use the default.  */
 649     {
 650         struct rlimit lim;
 651         if (getrlimit(RLIMIT_STACK, &lim) == 0
 652             && lim.rlim_cur != RLIM_INFINITY
 653             && lim.rlim_cur == (target_long)lim.rlim_cur) {
 654             guest_stack_size = lim.rlim_cur;
 655         }
 656     }
 657
 658     cpu_model = NULL;
 659
 660     qemu_add_opts(&qemu_trace_opts);
 661     qemu_plugin_add_opts();
 662
 663     optind = parse_args(argc, argv);
 664
 665     log_mask = last_log_mask | (enable_strace ? LOG_STRACE : 0);
 666     if (log_mask) {
 667         qemu_log_needs_buffers();
 668         qemu_set_log(log_mask);
 669     }
 670
 671     if (!trace_init_backends()) {
 672         exit(1);
 673     }
 674     trace_init_file(trace_file);
 675     if (qemu_plugin_load_list(&plugins)) {
 676         exit(1);
 677     }
 678
 679     /* Zero out regs */
 680     memset(regs, 0, sizeof(struct target_pt_regs));
 681
 682     /* Zero out image_info */
 683     memset(info, 0, sizeof(struct image_info));
 684
 685     memset(&bprm, 0, sizeof (bprm));
 686
 687     /* Scan interp_prefix dir for replacement files. */
 688     init_paths(interp_prefix);
 689
 690     init_qemu_uname_release();
 691
 692     execfd = qemu_getauxval(AT_EXECFD);
 693     if (execfd == 0) {
 694         execfd = open(exec_path, O_RDONLY);
 695         if (execfd < 0) {
 696             printf("Error while loading %s: %s\n", exec_path, strerror(errno));
 697             _exit(EXIT_FAILURE);
 698         }
 699     }
 700
 701     if (cpu_model == NULL) {
 702         cpu_model = cpu_get_model(get_elf_eflags(execfd));
 703     }
 704     cpu_type = parse_cpu_option(cpu_model);
 705
 706     /* init tcg before creating CPUs and to get qemu_host_page_size */
 707     tcg_exec_init(0);
 708
 709     cpu = cpu_create(cpu_type);
 710     env = cpu->env_ptr;
 711     cpu_reset(cpu);
 712     thread_cpu = cpu;
 713
 714     /*
 715      * Reserving too much vm space via mmap can run into problems
 716      * with rlimits, oom due to page table creation, etc.  We will
 717      * still try it, if directed by the command-line option, but
 718      * not by default.
 719      */
 720     max_reserved_va = MAX_RESERVED_VA(cpu);
 721     if (reserved_va != 0) {
 722         if (max_reserved_va && reserved_va > max_reserved_va) {
 723             fprintf(stderr, "Reserved virtual address too big\n");
 724             exit(EXIT_FAILURE);
 725         }
 726     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 727         /*
 728          * reserved_va must be aligned with the host page size
 729          * as it is used with mmap()
 730          */
 731         reserved_va = max_reserved_va & qemu_host_page_mask;
 732     }
 733
 734     {
 735         Error *err = NULL;
 736         if (seed_optarg != NULL) {
 737             qemu_guest_random_seed_main(seed_optarg, &err);
 738         } else {
 739             qcrypto_init(&err);
 740         }
 741         if (err) {
 742             error_reportf_err(err, "cannot initialize crypto: ");
 743             exit(1);
 744         }
 745     }
 746
 747     target_environ = envlist_to_environ(envlist, NULL);
 748     envlist_free(envlist);
 749
 750     /*
 751      * Now that page sizes are configured in tcg_exec_init() we can do
 752      * proper page alignment for guest_base.
 753      */
 754     guest_base = HOST_PAGE_ALIGN(guest_base);
 755
 756     if (reserved_va || have_guest_base) {
 757         guest_base = init_guest_space(guest_base, reserved_va, 0,
 758                                       have_guest_base);
 759         if (guest_base == (unsigned long)-1) {
 760             fprintf(stderr, "Unable to reserve 0x%lx bytes of virtual address "
 761                     "space for use as guest address space (check your virtual "
 762                     "memory ulimit setting or reserve less using -R option)\n",
 763                     reserved_va);
 764             exit(EXIT_FAILURE);
 765         }
 766
 767         if (reserved_va) {
 768             mmap_next_start = reserved_va;
 769         }
 770     }
 771
 772     /*
 773      * Read in mmap_min_addr kernel parameter.  This value is used
 774      * When loading the ELF image to determine whether guest_base
 775      * is needed.  It is also used in mmap_find_vma.
 776      */
 777     {
 778         FILE *fp;
 779
 780         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
 781             unsigned long tmp;
 782             if (fscanf(fp, "%lu", &tmp) == 1) {
 783                 mmap_min_addr = tmp;
 784                 qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n", mmap_min_addr);
 785             }
 786             fclose(fp);
 787         }
 788     }
 789
 790     /*
 791      * Prepare copy of argv vector for target.
 792      */
 793     target_argc = argc - optind;
 794     target_argv = calloc(target_argc + 1, sizeof (char *));
 795     if (target_argv == NULL) {
 796         (void) fprintf(stderr, "Unable to allocate memory for target_argv\n");
 797         exit(EXIT_FAILURE);
 798     }
 799
 800     /*
 801      * If argv0 is specified (using '-0' switch) we replace
 802      * argv[0] pointer with the given one.
 803      */
 804     i = 0;
 805     if (argv0 != NULL) {
 806         target_argv[i++] = strdup(argv0);
 807     }
 808     for (; i < target_argc; i++) {
 809         target_argv[i] = strdup(argv[optind + i]);
 810     }
 811     target_argv[target_argc] = NULL;
 812
 813     ts = g_new0(TaskState, 1);
 814     init_task_state(ts);
 815     /* build Task State */
 816     ts->info = info;
 817     ts->bprm = &bprm;
 818     cpu->opaque = ts;
 819     task_settid(ts);
 820
 821     ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
 822         info, &bprm);
 823     if (ret != 0) {
 824         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
 825         _exit(EXIT_FAILURE);
 826     }
 827
 828     for (wrk = target_environ; *wrk; wrk++) {
 829         g_free(*wrk);
 830     }
 831
 832     g_free(target_environ);
 833
 834     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 835         qemu_log("guest_base  0x%lx\n", guest_base);
 836         log_page_dump("binary load");
 837
 838         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
 839         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
 840         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n", info->start_code);
 841         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n", info->start_data);
 842         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
 843         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n", info->start_stack);
 844         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 845         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 846         qemu_log("argv_start  0x" TARGET_ABI_FMT_lx "\n", info->arg_start);
 847         qemu_log("env_start   0x" TARGET_ABI_FMT_lx "\n",
 848                  info->arg_end + (abi_ulong)sizeof(abi_ulong));
 849         qemu_log("auxv_start  0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv);
 850     }
 851
 852     target_set_brk(info->brk);
 853     syscall_init();
 854     signal_init();
 855
 856     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 857        generating the prologue until now so that the prologue can take
 858        the real value of GUEST_BASE into account.  */
 859     tcg_prologue_init(tcg_ctx);
 860     tcg_region_init();
 861
 862     target_cpu_copy_regs(env, regs);
 863
 864     if (gdbstub_port) {
 865         if (gdbserver_start(gdbstub_port) < 0) {
 866             fprintf(stderr, "qemu: could not open gdbserver on port %d\n",
 867                     gdbstub_port);
 868             exit(EXIT_FAILURE);
 869         }
 870         gdb_handlesig(cpu, 0);
 871     }
 872     cpu_loop(env);
 873     /* never exits */
 874     return 0;
 875 }