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 "qemu/accel.h"
  24 #include "sysemu/tcg.h"
  25 #include "qemu-version.h"
  26 #include <sys/syscall.h>
  27 #include <sys/resource.h>
  28 #include <sys/shm.h>
  29 #include <linux/binfmts.h>
  30
  31 #include "qapi/error.h"
  32 #include "qemu.h"
  33 #include "user-internals.h"
  34 #include "qemu/path.h"
  35 #include "qemu/queue.h"
  36 #include "qemu/config-file.h"
  37 #include "qemu/cutils.h"
  38 #include "qemu/error-report.h"
  39 #include "qemu/help_option.h"
  40 #include "qemu/module.h"
  41 #include "qemu/plugin.h"
  42 #include "exec/exec-all.h"
  43 #include "exec/gdbstub.h"
  44 #include "tcg/tcg.h"
  45 #include "qemu/timer.h"
  46 #include "qemu/envlist.h"
  47 #include "qemu/guest-random.h"
  48 #include "elf.h"
  49 #include "trace/control.h"
  50 #include "target_elf.h"
  51 #include "cpu_loop-common.h"
  52 #include "crypto/init.h"
  53 #include "fd-trans.h"
  54 #include "signal-common.h"
  55 #include "loader.h"
  56 #include "user-mmap.h"
  57
  58 #ifndef AT_FLAGS_PRESERVE_ARGV0
  59 #define AT_FLAGS_PRESERVE_ARGV0_BIT 0
  60 #define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
  61 #endif
  62
  63 char *exec_path;
  64
  65 int singlestep;
  66 static const char *argv0;
  67 static const char *gdbstub;
  68 static envlist_t *envlist;
  69 static const char *cpu_model;
  70 static const char *cpu_type;
  71 static const char *seed_optarg;
  72 unsigned long mmap_min_addr;
  73 uintptr_t guest_base;
  74 bool have_guest_base;
  75
  76 /*
  77  * Used to implement backwards-compatibility for the `-strace`, and
  78  * QEMU_STRACE options. Without this, the QEMU_LOG can be overwritten by
  79  * -strace, or vice versa.
  80  */
  81 static bool enable_strace;
  82
  83 /*
  84  * The last log mask given by the user in an environment variable or argument.
  85  * Used to support command line arguments overriding environment variables.
  86  */
  87 static int last_log_mask;
  88
  89 /*
  90  * When running 32-on-64 we should make sure we can fit all of the possible
  91  * guest address space into a contiguous chunk of virtual host memory.
  92  *
  93  * This way we will never overlap with our own libraries or binaries or stack
  94  * or anything else that QEMU maps.
  95  *
  96  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  97  * of the address for the kernel.  Some cpus rely on this and user space
  98  * uses the high bit(s) for pointer tagging and the like.  For them, we
  99  * must preserve the expected address space.
 100  */
 101 #ifndef MAX_RESERVED_VA
 102 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
 103 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
 104       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
 105 /* There are a number of places where we assign reserved_va to a variable
 106    of type abi_ulong and expect it to fit.  Avoid the last page.  */
 107 #   define MAX_RESERVED_VA(CPU)  (0xfffffffful & TARGET_PAGE_MASK)
 108 #  else
 109 #   define MAX_RESERVED_VA(CPU)  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
 110 #  endif
 111 # else
 112 #  define MAX_RESERVED_VA(CPU)  0
 113 # endif
 114 #endif
 115
 116 unsigned long reserved_va;
 117
 118 static void usage(int exitcode);
 119
 120 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
 121 const char *qemu_uname_release;
 122
 123 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
 124    we allocate a bigger stack. Need a better solution, for example
 125    by remapping the process stack directly at the right place */
 126 unsigned long guest_stack_size = 8 * 1024 * 1024UL;
 127
 128 /***********************************************************/
 129 /* Helper routines for implementing atomic operations.  */
 130
 131 /* Make sure everything is in a consistent state for calling fork().  */
 132 void fork_start(void)
 133 {
 134     start_exclusive();
 135     mmap_fork_start();
 136     cpu_list_lock();
 137 }
 138
 139 void fork_end(int child)
 140 {
 141     mmap_fork_end(child);
 142     if (child) {
 143         CPUState *cpu, *next_cpu;
 144         /* Child processes created by fork() only have a single thread.
 145            Discard information about the parent threads.  */
 146         CPU_FOREACH_SAFE(cpu, next_cpu) {
 147             if (cpu != thread_cpu) {
 148                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
 149             }
 150         }
 151         qemu_init_cpu_list();
 152         gdbserver_fork(thread_cpu);
 153         /* qemu_init_cpu_list() takes care of reinitializing the
 154          * exclusive state, so we don't need to end_exclusive() here.
 155          */
 156     } else {
 157         cpu_list_unlock();
 158         end_exclusive();
 159     }
 160 }
 161
 162 __thread CPUState *thread_cpu;
 163
 164 bool qemu_cpu_is_self(CPUState *cpu)
 165 {
 166     return thread_cpu == cpu;
 167 }
 168
 169 void qemu_cpu_kick(CPUState *cpu)
 170 {
 171     cpu_exit(cpu);
 172 }
 173
 174 void task_settid(TaskState *ts)
 175 {
 176     if (ts->ts_tid == 0) {
 177         ts->ts_tid = (pid_t)syscall(SYS_gettid);
 178     }
 179 }
 180
 181 void stop_all_tasks(void)
 182 {
 183     /*
 184      * We trust that when using NPTL, start_exclusive()
 185      * handles thread stopping correctly.
 186      */
 187     start_exclusive();
 188 }
 189
 190 /* Assumes contents are already zeroed.  */
 191 void init_task_state(TaskState *ts)
 192 {
 193     long ticks_per_sec;
 194     struct timespec bt;
 195
 196     ts->used = 1;
 197     ts->sigaltstack_used = (struct target_sigaltstack) {
 198         .ss_sp = 0,
 199         .ss_size = 0,
 200         .ss_flags = TARGET_SS_DISABLE,
 201     };
 202
 203     /* Capture task start time relative to system boot */
 204
 205     ticks_per_sec = sysconf(_SC_CLK_TCK);
 206
 207     if ((ticks_per_sec > 0) && !clock_gettime(CLOCK_BOOTTIME, &bt)) {
 208         /* start_boottime is expressed in clock ticks */
 209         ts->start_boottime = bt.tv_sec * (uint64_t) ticks_per_sec;
 210         ts->start_boottime += bt.tv_nsec * (uint64_t) ticks_per_sec /
 211                               NANOSECONDS_PER_SECOND;
 212     }
 213 }
 214
 215 CPUArchState *cpu_copy(CPUArchState *env)
 216 {
 217     CPUState *cpu = env_cpu(env);
 218     CPUState *new_cpu = cpu_create(cpu_type);
 219     CPUArchState *new_env = new_cpu->env_ptr;
 220     CPUBreakpoint *bp;
 221
 222     /* Reset non arch specific state */
 223     cpu_reset(new_cpu);
 224
 225     new_cpu->tcg_cflags = cpu->tcg_cflags;
 226     memcpy(new_env, env, sizeof(CPUArchState));
 227
 228     /* Clone all break/watchpoints.
 229        Note: Once we support ptrace with hw-debug register access, make sure
 230        BP_CPU break/watchpoints are handled correctly on clone. */
 231     QTAILQ_INIT(&new_cpu->breakpoints);
 232     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
 233         cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
 234     }
 235
 236     return new_env;
 237 }
 238
 239 static void handle_arg_help(const char *arg)
 240 {
 241     usage(EXIT_SUCCESS);
 242 }
 243
 244 static void handle_arg_log(const char *arg)
 245 {
 246     last_log_mask = qemu_str_to_log_mask(arg);
 247     if (!last_log_mask) {
 248         qemu_print_log_usage(stdout);
 249         exit(EXIT_FAILURE);
 250     }
 251 }
 252
 253 static void handle_arg_dfilter(const char *arg)
 254 {
 255     qemu_set_dfilter_ranges(arg, &error_fatal);
 256 }
 257
 258 static void handle_arg_log_filename(const char *arg)
 259 {
 260     qemu_set_log_filename(arg, &error_fatal);
 261 }
 262
 263 static void handle_arg_set_env(const char *arg)
 264 {
 265     char *r, *p, *token;
 266     r = p = strdup(arg);
 267     while ((token = strsep(&p, ",")) != NULL) {
 268         if (envlist_setenv(envlist, token) != 0) {
 269             usage(EXIT_FAILURE);
 270         }
 271     }
 272     free(r);
 273 }
 274
 275 static void handle_arg_unset_env(const char *arg)
 276 {
 277     char *r, *p, *token;
 278     r = p = strdup(arg);
 279     while ((token = strsep(&p, ",")) != NULL) {
 280         if (envlist_unsetenv(envlist, token) != 0) {
 281             usage(EXIT_FAILURE);
 282         }
 283     }
 284     free(r);
 285 }
 286
 287 static void handle_arg_argv0(const char *arg)
 288 {
 289     argv0 = strdup(arg);
 290 }
 291
 292 static void handle_arg_stack_size(const char *arg)
 293 {
 294     char *p;
 295     guest_stack_size = strtoul(arg, &p, 0);
 296     if (guest_stack_size == 0) {
 297         usage(EXIT_FAILURE);
 298     }
 299
 300     if (*p == 'M') {
 301         guest_stack_size *= MiB;
 302     } else if (*p == 'k' || *p == 'K') {
 303         guest_stack_size *= KiB;
 304     }
 305 }
 306
 307 static void handle_arg_ld_prefix(const char *arg)
 308 {
 309     interp_prefix = strdup(arg);
 310 }
 311
 312 static void handle_arg_pagesize(const char *arg)
 313 {
 314     qemu_host_page_size = atoi(arg);
 315     if (qemu_host_page_size == 0 ||
 316         (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 317         fprintf(stderr, "page size must be a power of two\n");
 318         exit(EXIT_FAILURE);
 319     }
 320 }
 321
 322 static void handle_arg_seed(const char *arg)
 323 {
 324     seed_optarg = arg;
 325 }
 326
 327 static void handle_arg_gdb(const char *arg)
 328 {
 329     gdbstub = g_strdup(arg);
 330 }
 331
 332 static void handle_arg_uname(const char *arg)
 333 {
 334     qemu_uname_release = strdup(arg);
 335 }
 336
 337 static void handle_arg_cpu(const char *arg)
 338 {
 339     cpu_model = strdup(arg);
 340     if (cpu_model == NULL || is_help_option(cpu_model)) {
 341         /* XXX: implement xxx_cpu_list for targets that still miss it */
 342 #if defined(cpu_list)
 343         cpu_list();
 344 #endif
 345         exit(EXIT_FAILURE);
 346     }
 347 }
 348
 349 static void handle_arg_guest_base(const char *arg)
 350 {
 351     guest_base = strtol(arg, NULL, 0);
 352     have_guest_base = true;
 353 }
 354
 355 static void handle_arg_reserved_va(const char *arg)
 356 {
 357     char *p;
 358     int shift = 0;
 359     reserved_va = strtoul(arg, &p, 0);
 360     switch (*p) {
 361     case 'k':
 362     case 'K':
 363         shift = 10;
 364         break;
 365     case 'M':
 366         shift = 20;
 367         break;
 368     case 'G':
 369         shift = 30;
 370         break;
 371     }
 372     if (shift) {
 373         unsigned long unshifted = reserved_va;
 374         p++;
 375         reserved_va <<= shift;
 376         if (reserved_va >> shift != unshifted) {
 377             fprintf(stderr, "Reserved virtual address too big\n");
 378             exit(EXIT_FAILURE);
 379         }
 380     }
 381     if (*p) {
 382         fprintf(stderr, "Unrecognised -R size suffix '%s'\n", p);
 383         exit(EXIT_FAILURE);
 384     }
 385 }
 386
 387 static void handle_arg_singlestep(const char *arg)
 388 {
 389     singlestep = 1;
 390 }
 391
 392 static void handle_arg_strace(const char *arg)
 393 {
 394     enable_strace = true;
 395 }
 396
 397 static void handle_arg_version(const char *arg)
 398 {
 399     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 400            "\n" QEMU_COPYRIGHT "\n");
 401     exit(EXIT_SUCCESS);
 402 }
 403
 404 static void handle_arg_trace(const char *arg)
 405 {
 406     trace_opt_parse(arg);
 407 }
 408
 409 #if defined(TARGET_XTENSA)
 410 static void handle_arg_abi_call0(const char *arg)
 411 {
 412     xtensa_set_abi_call0();
 413 }
 414 #endif
 415
 416 static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
 417
 418 #ifdef CONFIG_PLUGIN
 419 static void handle_arg_plugin(const char *arg)
 420 {
 421     qemu_plugin_opt_parse(arg, &plugins);
 422 }
 423 #endif
 424
 425 struct qemu_argument {
 426     const char *argv;
 427     const char *env;
 428     bool has_arg;
 429     void (*handle_opt)(const char *arg);
 430     const char *example;
 431     const char *help;
 432 };
 433
 434 static const struct qemu_argument arg_table[] = {
 435     {"h",          "",                 false, handle_arg_help,
 436      "",           "print this help"},
 437     {"help",       "",                 false, handle_arg_help,
 438      "",           ""},
 439     {"g",          "QEMU_GDB",         true,  handle_arg_gdb,
 440      "port",       "wait gdb connection to 'port'"},
 441     {"L",          "QEMU_LD_PREFIX",   true,  handle_arg_ld_prefix,
 442      "path",       "set the elf interpreter prefix to 'path'"},
 443     {"s",          "QEMU_STACK_SIZE",  true,  handle_arg_stack_size,
 444      "size",       "set the stack size to 'size' bytes"},
 445     {"cpu",        "QEMU_CPU",         true,  handle_arg_cpu,
 446      "model",      "select CPU (-cpu help for list)"},
 447     {"E",          "QEMU_SET_ENV",     true,  handle_arg_set_env,
 448      "var=value",  "sets targets environment variable (see below)"},
 449     {"U",          "QEMU_UNSET_ENV",   true,  handle_arg_unset_env,
 450      "var",        "unsets targets environment variable (see below)"},
 451     {"0",          "QEMU_ARGV0",       true,  handle_arg_argv0,
 452      "argv0",      "forces target process argv[0] to be 'argv0'"},
 453     {"r",          "QEMU_UNAME",       true,  handle_arg_uname,
 454      "uname",      "set qemu uname release string to 'uname'"},
 455     {"B",          "QEMU_GUEST_BASE",  true,  handle_arg_guest_base,
 456      "address",    "set guest_base address to 'address'"},
 457     {"R",          "QEMU_RESERVED_VA", true,  handle_arg_reserved_va,
 458      "size",       "reserve 'size' bytes for guest virtual address space"},
 459     {"d",          "QEMU_LOG",         true,  handle_arg_log,
 460      "item[,...]", "enable logging of specified items "
 461      "(use '-d help' for a list of items)"},
 462     {"dfilter",    "QEMU_DFILTER",     true,  handle_arg_dfilter,
 463      "range[,...]","filter logging based on address range"},
 464     {"D",          "QEMU_LOG_FILENAME", true, handle_arg_log_filename,
 465      "logfile",     "write logs to 'logfile' (default stderr)"},
 466     {"p",          "QEMU_PAGESIZE",    true,  handle_arg_pagesize,
 467      "pagesize",   "set the host page size to 'pagesize'"},
 468     {"singlestep", "QEMU_SINGLESTEP",  false, handle_arg_singlestep,
 469      "",           "run in singlestep mode"},
 470     {"strace",     "QEMU_STRACE",      false, handle_arg_strace,
 471      "",           "log system calls"},
 472     {"seed",       "QEMU_RAND_SEED",   true,  handle_arg_seed,
 473      "",           "Seed for pseudo-random number generator"},
 474     {"trace",      "QEMU_TRACE",       true,  handle_arg_trace,
 475      "",           "[[enable=]<pattern>][,events=<file>][,file=<file>]"},
 476 #ifdef CONFIG_PLUGIN
 477     {"plugin",     "QEMU_PLUGIN",      true,  handle_arg_plugin,
 478      "",           "[file=]<file>[,<argname>=<argvalue>]"},
 479 #endif
 480     {"version",    "QEMU_VERSION",     false, handle_arg_version,
 481      "",           "display version information and exit"},
 482 #if defined(TARGET_XTENSA)
 483     {"xtensa-abi-call0", "QEMU_XTENSA_ABI_CALL0", false, handle_arg_abi_call0,
 484      "",           "assume CALL0 Xtensa ABI"},
 485 #endif
 486     {NULL, NULL, false, NULL, NULL, NULL}
 487 };
 488
 489 static void usage(int exitcode)
 490 {
 491     const struct qemu_argument *arginfo;
 492     int maxarglen;
 493     int maxenvlen;
 494
 495     printf("usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 496            "Linux CPU emulator (compiled for " TARGET_NAME " emulation)\n"
 497            "\n"
 498            "Options and associated environment variables:\n"
 499            "\n");
 500
 501     /* Calculate column widths. We must always have at least enough space
 502      * for the column header.
 503      */
 504     maxarglen = strlen("Argument");
 505     maxenvlen = strlen("Env-variable");
 506
 507     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 508         int arglen = strlen(arginfo->argv);
 509         if (arginfo->has_arg) {
 510             arglen += strlen(arginfo->example) + 1;
 511         }
 512         if (strlen(arginfo->env) > maxenvlen) {
 513             maxenvlen = strlen(arginfo->env);
 514         }
 515         if (arglen > maxarglen) {
 516             maxarglen = arglen;
 517         }
 518     }
 519
 520     printf("%-*s %-*s Description\n", maxarglen+1, "Argument",
 521             maxenvlen, "Env-variable");
 522
 523     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 524         if (arginfo->has_arg) {
 525             printf("-%s %-*s %-*s %s\n", arginfo->argv,
 526                    (int)(maxarglen - strlen(arginfo->argv) - 1),
 527                    arginfo->example, maxenvlen, arginfo->env, arginfo->help);
 528         } else {
 529             printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
 530                     maxenvlen, arginfo->env,
 531                     arginfo->help);
 532         }
 533     }
 534
 535     printf("\n"
 536            "Defaults:\n"
 537            "QEMU_LD_PREFIX  = %s\n"
 538            "QEMU_STACK_SIZE = %ld byte\n",
 539            interp_prefix,
 540            guest_stack_size);
 541
 542     printf("\n"
 543            "You can use -E and -U options or the QEMU_SET_ENV and\n"
 544            "QEMU_UNSET_ENV environment variables to set and unset\n"
 545            "environment variables for the target process.\n"
 546            "It is possible to provide several variables by separating them\n"
 547            "by commas in getsubopt(3) style. Additionally it is possible to\n"
 548            "provide the -E and -U options multiple times.\n"
 549            "The following lines are equivalent:\n"
 550            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 551            "    -E var1=val2,var2=val2 -U LD_PRELOAD,LD_DEBUG\n"
 552            "    QEMU_SET_ENV=var1=val2,var2=val2 QEMU_UNSET_ENV=LD_PRELOAD,LD_DEBUG\n"
 553            "Note that if you provide several changes to a single variable\n"
 554            "the last change will stay in effect.\n"
 555            "\n"
 556            QEMU_HELP_BOTTOM "\n");
 557
 558     exit(exitcode);
 559 }
 560
 561 static int parse_args(int argc, char **argv)
 562 {
 563     const char *r;
 564     int optind;
 565     const struct qemu_argument *arginfo;
 566
 567     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 568         if (arginfo->env == NULL) {
 569             continue;
 570         }
 571
 572         r = getenv(arginfo->env);
 573         if (r != NULL) {
 574             arginfo->handle_opt(r);
 575         }
 576     }
 577
 578     optind = 1;
 579     for (;;) {
 580         if (optind >= argc) {
 581             break;
 582         }
 583         r = argv[optind];
 584         if (r[0] != '-') {
 585             break;
 586         }
 587         optind++;
 588         r++;
 589         if (!strcmp(r, "-")) {
 590             break;
 591         }
 592         /* Treat --foo the same as -foo.  */
 593         if (r[0] == '-') {
 594             r++;
 595         }
 596
 597         for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 598             if (!strcmp(r, arginfo->argv)) {
 599                 if (arginfo->has_arg) {
 600                     if (optind >= argc) {
 601                         (void) fprintf(stderr,
 602                             "qemu: missing argument for option '%s'\n", r);
 603                         exit(EXIT_FAILURE);
 604                     }
 605                     arginfo->handle_opt(argv[optind]);
 606                     optind++;
 607                 } else {
 608                     arginfo->handle_opt(NULL);
 609                 }
 610                 break;
 611             }
 612         }
 613
 614         /* no option matched the current argv */
 615         if (arginfo->handle_opt == NULL) {
 616             (void) fprintf(stderr, "qemu: unknown option '%s'\n", r);
 617             exit(EXIT_FAILURE);
 618         }
 619     }
 620
 621     if (optind >= argc) {
 622         (void) fprintf(stderr, "qemu: no user program specified\n");
 623         exit(EXIT_FAILURE);
 624     }
 625
 626     exec_path = argv[optind];
 627
 628     return optind;
 629 }
 630
 631 int main(int argc, char **argv, char **envp)
 632 {
 633     struct target_pt_regs regs1, *regs = &regs1;
 634     struct image_info info1, *info = &info1;
 635     struct linux_binprm bprm;
 636     TaskState *ts;
 637     CPUArchState *env;
 638     CPUState *cpu;
 639     int optind;
 640     char **target_environ, **wrk;
 641     char **target_argv;
 642     int target_argc;
 643     int i;
 644     int ret;
 645     int execfd;
 646     int log_mask;
 647     unsigned long max_reserved_va;
 648     bool preserve_argv0;
 649
 650     error_init(argv[0]);
 651     module_call_init(MODULE_INIT_TRACE);
 652     qemu_init_cpu_list();
 653     module_call_init(MODULE_INIT_QOM);
 654
 655     envlist = envlist_create();
 656
 657     /* add current environment into the list */
 658     for (wrk = environ; *wrk != NULL; wrk++) {
 659         (void) envlist_setenv(envlist, *wrk);
 660     }
 661
 662     /* Read the stack limit from the kernel.  If it's "unlimited",
 663        then we can do little else besides use the default.  */
 664     {
 665         struct rlimit lim;
 666         if (getrlimit(RLIMIT_STACK, &lim) == 0
 667             && lim.rlim_cur != RLIM_INFINITY
 668             && lim.rlim_cur == (target_long)lim.rlim_cur) {
 669             guest_stack_size = lim.rlim_cur;
 670         }
 671     }
 672
 673     cpu_model = NULL;
 674
 675     qemu_add_opts(&qemu_trace_opts);
 676     qemu_plugin_add_opts();
 677
 678     optind = parse_args(argc, argv);
 679
 680     log_mask = last_log_mask | (enable_strace ? LOG_STRACE : 0);
 681     if (log_mask) {
 682         qemu_log_needs_buffers();
 683         qemu_set_log(log_mask);
 684     }
 685
 686     if (!trace_init_backends()) {
 687         exit(1);
 688     }
 689     trace_init_file();
 690     qemu_plugin_load_list(&plugins, &error_fatal);
 691
 692     /* Zero out regs */
 693     memset(regs, 0, sizeof(struct target_pt_regs));
 694
 695     /* Zero out image_info */
 696     memset(info, 0, sizeof(struct image_info));
 697
 698     memset(&bprm, 0, sizeof (bprm));
 699
 700     /* Scan interp_prefix dir for replacement files. */
 701     init_paths(interp_prefix);
 702
 703     init_qemu_uname_release();
 704
 705     /*
 706      * Manage binfmt-misc open-binary flag
 707      */
 708     execfd = qemu_getauxval(AT_EXECFD);
 709     if (execfd == 0) {
 710         execfd = open(exec_path, O_RDONLY);
 711         if (execfd < 0) {
 712             printf("Error while loading %s: %s\n", exec_path, strerror(errno));
 713             _exit(EXIT_FAILURE);
 714         }
 715     }
 716
 717     /*
 718      * get binfmt_misc flags
 719      */
 720     preserve_argv0 = !!(qemu_getauxval(AT_FLAGS) & AT_FLAGS_PRESERVE_ARGV0);
 721
 722     /*
 723      * Manage binfmt-misc preserve-arg[0] flag
 724      *    argv[optind]     full path to the binary
 725      *    argv[optind + 1] original argv[0]
 726      */
 727     if (optind + 1 < argc && preserve_argv0) {
 728         optind++;
 729     }
 730
 731     if (cpu_model == NULL) {
 732         cpu_model = cpu_get_model(get_elf_eflags(execfd));
 733     }
 734     cpu_type = parse_cpu_option(cpu_model);
 735
 736     /* init tcg before creating CPUs and to get qemu_host_page_size */
 737     {
 738         AccelClass *ac = ACCEL_GET_CLASS(current_accel());
 739
 740         accel_init_interfaces(ac);
 741         ac->init_machine(NULL);
 742     }
 743     cpu = cpu_create(cpu_type);
 744     env = cpu->env_ptr;
 745     cpu_reset(cpu);
 746     thread_cpu = cpu;
 747
 748     /*
 749      * Reserving too much vm space via mmap can run into problems
 750      * with rlimits, oom due to page table creation, etc.  We will
 751      * still try it, if directed by the command-line option, but
 752      * not by default.
 753      */
 754     max_reserved_va = MAX_RESERVED_VA(cpu);
 755     if (reserved_va != 0) {
 756         if (max_reserved_va && reserved_va > max_reserved_va) {
 757             fprintf(stderr, "Reserved virtual address too big\n");
 758             exit(EXIT_FAILURE);
 759         }
 760     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 761         /*
 762          * reserved_va must be aligned with the host page size
 763          * as it is used with mmap()
 764          */
 765         reserved_va = max_reserved_va & qemu_host_page_mask;
 766     }
 767
 768     {
 769         Error *err = NULL;
 770         if (seed_optarg != NULL) {
 771             qemu_guest_random_seed_main(seed_optarg, &err);
 772         } else {
 773             qcrypto_init(&err);
 774         }
 775         if (err) {
 776             error_reportf_err(err, "cannot initialize crypto: ");
 777             exit(1);
 778         }
 779     }
 780
 781     target_environ = envlist_to_environ(envlist, NULL);
 782     envlist_free(envlist);
 783
 784     /*
 785      * Read in mmap_min_addr kernel parameter.  This value is used
 786      * When loading the ELF image to determine whether guest_base
 787      * is needed.  It is also used in mmap_find_vma.
 788      */
 789     {
 790         FILE *fp;
 791
 792         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
 793             unsigned long tmp;
 794             if (fscanf(fp, "%lu", &tmp) == 1 && tmp != 0) {
 795                 mmap_min_addr = tmp;
 796                 qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n",
 797                               mmap_min_addr);
 798             }
 799             fclose(fp);
 800         }
 801     }
 802
 803     /*
 804      * We prefer to not make NULL pointers accessible to QEMU.
 805      * If we're in a chroot with no /proc, fall back to 1 page.
 806      */
 807     if (mmap_min_addr == 0) {
 808         mmap_min_addr = qemu_host_page_size;
 809         qemu_log_mask(CPU_LOG_PAGE,
 810                       "host mmap_min_addr=0x%lx (fallback)\n",
 811                       mmap_min_addr);
 812     }
 813
 814     /*
 815      * Prepare copy of argv vector for target.
 816      */
 817     target_argc = argc - optind;
 818     target_argv = calloc(target_argc + 1, sizeof (char *));
 819     if (target_argv == NULL) {
 820         (void) fprintf(stderr, "Unable to allocate memory for target_argv\n");
 821         exit(EXIT_FAILURE);
 822     }
 823
 824     /*
 825      * If argv0 is specified (using '-0' switch) we replace
 826      * argv[0] pointer with the given one.
 827      */
 828     i = 0;
 829     if (argv0 != NULL) {
 830         target_argv[i++] = strdup(argv0);
 831     }
 832     for (; i < target_argc; i++) {
 833         target_argv[i] = strdup(argv[optind + i]);
 834     }
 835     target_argv[target_argc] = NULL;
 836
 837     ts = g_new0(TaskState, 1);
 838     init_task_state(ts);
 839     /* build Task State */
 840     ts->info = info;
 841     ts->bprm = &bprm;
 842     cpu->opaque = ts;
 843     task_settid(ts);
 844
 845     fd_trans_init();
 846
 847     ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
 848         info, &bprm);
 849     if (ret != 0) {
 850         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
 851         _exit(EXIT_FAILURE);
 852     }
 853
 854     for (wrk = target_environ; *wrk; wrk++) {
 855         g_free(*wrk);
 856     }
 857
 858     g_free(target_environ);
 859
 860     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 861         qemu_log("guest_base  %p\n", (void *)guest_base);
 862         log_page_dump("binary load");
 863
 864         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
 865         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
 866         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n", info->start_code);
 867         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n", info->start_data);
 868         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
 869         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n", info->start_stack);
 870         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 871         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 872         qemu_log("argv_start  0x" TARGET_ABI_FMT_lx "\n", info->arg_start);
 873         qemu_log("env_start   0x" TARGET_ABI_FMT_lx "\n",
 874                  info->arg_end + (abi_ulong)sizeof(abi_ulong));
 875         qemu_log("auxv_start  0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv);
 876     }
 877
 878     target_set_brk(info->brk);
 879     syscall_init();
 880     signal_init();
 881
 882     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 883        generating the prologue until now so that the prologue can take
 884        the real value of GUEST_BASE into account.  */
 885     tcg_prologue_init(tcg_ctx);
 886
 887     target_cpu_copy_regs(env, regs);
 888
 889     if (gdbstub) {
 890         if (gdbserver_start(gdbstub) < 0) {
 891             fprintf(stderr, "qemu: could not open gdbserver on %s\n",
 892                     gdbstub);
 893             exit(EXIT_FAILURE);
 894         }
 895         gdb_handlesig(cpu, 0);
 896     }
 897     cpu_loop(env);
 898     /* never exits */
 899     return 0;
 900 }