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     ts->used = 1;
 194     ts->sigaltstack_used = (struct target_sigaltstack) {
 195         .ss_sp = 0,
 196         .ss_size = 0,
 197         .ss_flags = TARGET_SS_DISABLE,
 198     };
 199 }
 200
 201 CPUArchState *cpu_copy(CPUArchState *env)
 202 {
 203     CPUState *cpu = env_cpu(env);
 204     CPUState *new_cpu = cpu_create(cpu_type);
 205     CPUArchState *new_env = new_cpu->env_ptr;
 206     CPUBreakpoint *bp;
 207
 208     /* Reset non arch specific state */
 209     cpu_reset(new_cpu);
 210
 211     new_cpu->tcg_cflags = cpu->tcg_cflags;
 212     memcpy(new_env, env, sizeof(CPUArchState));
 213
 214     /* Clone all break/watchpoints.
 215        Note: Once we support ptrace with hw-debug register access, make sure
 216        BP_CPU break/watchpoints are handled correctly on clone. */
 217     QTAILQ_INIT(&new_cpu->breakpoints);
 218     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
 219         cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
 220     }
 221
 222     return new_env;
 223 }
 224
 225 static void handle_arg_help(const char *arg)
 226 {
 227     usage(EXIT_SUCCESS);
 228 }
 229
 230 static void handle_arg_log(const char *arg)
 231 {
 232     last_log_mask = qemu_str_to_log_mask(arg);
 233     if (!last_log_mask) {
 234         qemu_print_log_usage(stdout);
 235         exit(EXIT_FAILURE);
 236     }
 237 }
 238
 239 static void handle_arg_dfilter(const char *arg)
 240 {
 241     qemu_set_dfilter_ranges(arg, &error_fatal);
 242 }
 243
 244 static void handle_arg_log_filename(const char *arg)
 245 {
 246     qemu_set_log_filename(arg, &error_fatal);
 247 }
 248
 249 static void handle_arg_set_env(const char *arg)
 250 {
 251     char *r, *p, *token;
 252     r = p = strdup(arg);
 253     while ((token = strsep(&p, ",")) != NULL) {
 254         if (envlist_setenv(envlist, token) != 0) {
 255             usage(EXIT_FAILURE);
 256         }
 257     }
 258     free(r);
 259 }
 260
 261 static void handle_arg_unset_env(const char *arg)
 262 {
 263     char *r, *p, *token;
 264     r = p = strdup(arg);
 265     while ((token = strsep(&p, ",")) != NULL) {
 266         if (envlist_unsetenv(envlist, token) != 0) {
 267             usage(EXIT_FAILURE);
 268         }
 269     }
 270     free(r);
 271 }
 272
 273 static void handle_arg_argv0(const char *arg)
 274 {
 275     argv0 = strdup(arg);
 276 }
 277
 278 static void handle_arg_stack_size(const char *arg)
 279 {
 280     char *p;
 281     guest_stack_size = strtoul(arg, &p, 0);
 282     if (guest_stack_size == 0) {
 283         usage(EXIT_FAILURE);
 284     }
 285
 286     if (*p == 'M') {
 287         guest_stack_size *= MiB;
 288     } else if (*p == 'k' || *p == 'K') {
 289         guest_stack_size *= KiB;
 290     }
 291 }
 292
 293 static void handle_arg_ld_prefix(const char *arg)
 294 {
 295     interp_prefix = strdup(arg);
 296 }
 297
 298 static void handle_arg_pagesize(const char *arg)
 299 {
 300     qemu_host_page_size = atoi(arg);
 301     if (qemu_host_page_size == 0 ||
 302         (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 303         fprintf(stderr, "page size must be a power of two\n");
 304         exit(EXIT_FAILURE);
 305     }
 306 }
 307
 308 static void handle_arg_seed(const char *arg)
 309 {
 310     seed_optarg = arg;
 311 }
 312
 313 static void handle_arg_gdb(const char *arg)
 314 {
 315     gdbstub = g_strdup(arg);
 316 }
 317
 318 static void handle_arg_uname(const char *arg)
 319 {
 320     qemu_uname_release = strdup(arg);
 321 }
 322
 323 static void handle_arg_cpu(const char *arg)
 324 {
 325     cpu_model = strdup(arg);
 326     if (cpu_model == NULL || is_help_option(cpu_model)) {
 327         /* XXX: implement xxx_cpu_list for targets that still miss it */
 328 #if defined(cpu_list)
 329         cpu_list();
 330 #endif
 331         exit(EXIT_FAILURE);
 332     }
 333 }
 334
 335 static void handle_arg_guest_base(const char *arg)
 336 {
 337     guest_base = strtol(arg, NULL, 0);
 338     have_guest_base = true;
 339 }
 340
 341 static void handle_arg_reserved_va(const char *arg)
 342 {
 343     char *p;
 344     int shift = 0;
 345     reserved_va = strtoul(arg, &p, 0);
 346     switch (*p) {
 347     case 'k':
 348     case 'K':
 349         shift = 10;
 350         break;
 351     case 'M':
 352         shift = 20;
 353         break;
 354     case 'G':
 355         shift = 30;
 356         break;
 357     }
 358     if (shift) {
 359         unsigned long unshifted = reserved_va;
 360         p++;
 361         reserved_va <<= shift;
 362         if (reserved_va >> shift != unshifted) {
 363             fprintf(stderr, "Reserved virtual address too big\n");
 364             exit(EXIT_FAILURE);
 365         }
 366     }
 367     if (*p) {
 368         fprintf(stderr, "Unrecognised -R size suffix '%s'\n", p);
 369         exit(EXIT_FAILURE);
 370     }
 371 }
 372
 373 static void handle_arg_singlestep(const char *arg)
 374 {
 375     singlestep = 1;
 376 }
 377
 378 static void handle_arg_strace(const char *arg)
 379 {
 380     enable_strace = true;
 381 }
 382
 383 static void handle_arg_version(const char *arg)
 384 {
 385     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 386            "\n" QEMU_COPYRIGHT "\n");
 387     exit(EXIT_SUCCESS);
 388 }
 389
 390 static void handle_arg_trace(const char *arg)
 391 {
 392     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>[,<argname>=<argvalue>]"},
 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     bool preserve_argv0;
 635
 636     error_init(argv[0]);
 637     module_call_init(MODULE_INIT_TRACE);
 638     qemu_init_cpu_list();
 639     module_call_init(MODULE_INIT_QOM);
 640
 641     envlist = envlist_create();
 642
 643     /* add current environment into the list */
 644     for (wrk = environ; *wrk != NULL; wrk++) {
 645         (void) envlist_setenv(envlist, *wrk);
 646     }
 647
 648     /* Read the stack limit from the kernel.  If it's "unlimited",
 649        then we can do little else besides use the default.  */
 650     {
 651         struct rlimit lim;
 652         if (getrlimit(RLIMIT_STACK, &lim) == 0
 653             && lim.rlim_cur != RLIM_INFINITY
 654             && lim.rlim_cur == (target_long)lim.rlim_cur) {
 655             guest_stack_size = lim.rlim_cur;
 656         }
 657     }
 658
 659     cpu_model = NULL;
 660
 661     qemu_add_opts(&qemu_trace_opts);
 662     qemu_plugin_add_opts();
 663
 664     optind = parse_args(argc, argv);
 665
 666     log_mask = last_log_mask | (enable_strace ? LOG_STRACE : 0);
 667     if (log_mask) {
 668         qemu_log_needs_buffers();
 669         qemu_set_log(log_mask);
 670     }
 671
 672     if (!trace_init_backends()) {
 673         exit(1);
 674     }
 675     trace_init_file();
 676     qemu_plugin_load_list(&plugins, &error_fatal);
 677
 678     /* Zero out regs */
 679     memset(regs, 0, sizeof(struct target_pt_regs));
 680
 681     /* Zero out image_info */
 682     memset(info, 0, sizeof(struct image_info));
 683
 684     memset(&bprm, 0, sizeof (bprm));
 685
 686     /* Scan interp_prefix dir for replacement files. */
 687     init_paths(interp_prefix);
 688
 689     init_qemu_uname_release();
 690
 691     /*
 692      * Manage binfmt-misc open-binary flag
 693      */
 694     execfd = qemu_getauxval(AT_EXECFD);
 695     if (execfd == 0) {
 696         execfd = open(exec_path, O_RDONLY);
 697         if (execfd < 0) {
 698             printf("Error while loading %s: %s\n", exec_path, strerror(errno));
 699             _exit(EXIT_FAILURE);
 700         }
 701     }
 702
 703     /*
 704      * get binfmt_misc flags
 705      */
 706     preserve_argv0 = !!(qemu_getauxval(AT_FLAGS) & AT_FLAGS_PRESERVE_ARGV0);
 707
 708     /*
 709      * Manage binfmt-misc preserve-arg[0] flag
 710      *    argv[optind]     full path to the binary
 711      *    argv[optind + 1] original argv[0]
 712      */
 713     if (optind + 1 < argc && preserve_argv0) {
 714         optind++;
 715     }
 716
 717     if (cpu_model == NULL) {
 718         cpu_model = cpu_get_model(get_elf_eflags(execfd));
 719     }
 720     cpu_type = parse_cpu_option(cpu_model);
 721
 722     /* init tcg before creating CPUs and to get qemu_host_page_size */
 723     {
 724         AccelClass *ac = ACCEL_GET_CLASS(current_accel());
 725
 726         accel_init_interfaces(ac);
 727         ac->init_machine(NULL);
 728     }
 729     cpu = cpu_create(cpu_type);
 730     env = cpu->env_ptr;
 731     cpu_reset(cpu);
 732     thread_cpu = cpu;
 733
 734     /*
 735      * Reserving too much vm space via mmap can run into problems
 736      * with rlimits, oom due to page table creation, etc.  We will
 737      * still try it, if directed by the command-line option, but
 738      * not by default.
 739      */
 740     max_reserved_va = MAX_RESERVED_VA(cpu);
 741     if (reserved_va != 0) {
 742         if (max_reserved_va && reserved_va > max_reserved_va) {
 743             fprintf(stderr, "Reserved virtual address too big\n");
 744             exit(EXIT_FAILURE);
 745         }
 746     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 747         /*
 748          * reserved_va must be aligned with the host page size
 749          * as it is used with mmap()
 750          */
 751         reserved_va = max_reserved_va & qemu_host_page_mask;
 752     }
 753
 754     {
 755         Error *err = NULL;
 756         if (seed_optarg != NULL) {
 757             qemu_guest_random_seed_main(seed_optarg, &err);
 758         } else {
 759             qcrypto_init(&err);
 760         }
 761         if (err) {
 762             error_reportf_err(err, "cannot initialize crypto: ");
 763             exit(1);
 764         }
 765     }
 766
 767     target_environ = envlist_to_environ(envlist, NULL);
 768     envlist_free(envlist);
 769
 770     /*
 771      * Read in mmap_min_addr kernel parameter.  This value is used
 772      * When loading the ELF image to determine whether guest_base
 773      * is needed.  It is also used in mmap_find_vma.
 774      */
 775     {
 776         FILE *fp;
 777
 778         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
 779             unsigned long tmp;
 780             if (fscanf(fp, "%lu", &tmp) == 1 && tmp != 0) {
 781                 mmap_min_addr = tmp;
 782                 qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n",
 783                               mmap_min_addr);
 784             }
 785             fclose(fp);
 786         }
 787     }
 788
 789     /*
 790      * We prefer to not make NULL pointers accessible to QEMU.
 791      * If we're in a chroot with no /proc, fall back to 1 page.
 792      */
 793     if (mmap_min_addr == 0) {
 794         mmap_min_addr = qemu_host_page_size;
 795         qemu_log_mask(CPU_LOG_PAGE,
 796                       "host mmap_min_addr=0x%lx (fallback)\n",
 797                       mmap_min_addr);
 798     }
 799
 800     /*
 801      * Prepare copy of argv vector for target.
 802      */
 803     target_argc = argc - optind;
 804     target_argv = calloc(target_argc + 1, sizeof (char *));
 805     if (target_argv == NULL) {
 806         (void) fprintf(stderr, "Unable to allocate memory for target_argv\n");
 807         exit(EXIT_FAILURE);
 808     }
 809
 810     /*
 811      * If argv0 is specified (using '-0' switch) we replace
 812      * argv[0] pointer with the given one.
 813      */
 814     i = 0;
 815     if (argv0 != NULL) {
 816         target_argv[i++] = strdup(argv0);
 817     }
 818     for (; i < target_argc; i++) {
 819         target_argv[i] = strdup(argv[optind + i]);
 820     }
 821     target_argv[target_argc] = NULL;
 822
 823     ts = g_new0(TaskState, 1);
 824     init_task_state(ts);
 825     /* build Task State */
 826     ts->info = info;
 827     ts->bprm = &bprm;
 828     cpu->opaque = ts;
 829     task_settid(ts);
 830
 831     fd_trans_init();
 832
 833     ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
 834         info, &bprm);
 835     if (ret != 0) {
 836         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
 837         _exit(EXIT_FAILURE);
 838     }
 839
 840     for (wrk = target_environ; *wrk; wrk++) {
 841         g_free(*wrk);
 842     }
 843
 844     g_free(target_environ);
 845
 846     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 847         qemu_log("guest_base  %p\n", (void *)guest_base);
 848         log_page_dump("binary load");
 849
 850         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
 851         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
 852         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n", info->start_code);
 853         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n", info->start_data);
 854         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
 855         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n", info->start_stack);
 856         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 857         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 858         qemu_log("argv_start  0x" TARGET_ABI_FMT_lx "\n", info->arg_start);
 859         qemu_log("env_start   0x" TARGET_ABI_FMT_lx "\n",
 860                  info->arg_end + (abi_ulong)sizeof(abi_ulong));
 861         qemu_log("auxv_start  0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv);
 862     }
 863
 864     target_set_brk(info->brk);
 865     syscall_init();
 866     signal_init();
 867
 868     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 869        generating the prologue until now so that the prologue can take
 870        the real value of GUEST_BASE into account.  */
 871     tcg_prologue_init(tcg_ctx);
 872
 873     target_cpu_copy_regs(env, regs);
 874
 875     if (gdbstub) {
 876         if (gdbserver_start(gdbstub) < 0) {
 877             fprintf(stderr, "qemu: could not open gdbserver on %s\n",
 878                     gdbstub);
 879             exit(EXIT_FAILURE);
 880         }
 881         gdb_handlesig(cpu, 0);
 882     }
 883     cpu_loop(env);
 884     /* never exits */
 885     return 0;
 886 }