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 "qemu/path.h"
  34 #include "qemu/queue.h"
  35 #include "qemu/config-file.h"
  36 #include "qemu/cutils.h"
  37 #include "qemu/error-report.h"
  38 #include "qemu/help_option.h"
  39 #include "qemu/module.h"
  40 #include "qemu/plugin.h"
  41 #include "exec/exec-all.h"
  42 #include "tcg/tcg.h"
  43 #include "qemu/timer.h"
  44 #include "qemu/envlist.h"
  45 #include "qemu/guest-random.h"
  46 #include "elf.h"
  47 #include "trace/control.h"
  48 #include "target_elf.h"
  49 #include "cpu_loop-common.h"
  50 #include "crypto/init.h"
  51
  52 #ifndef AT_FLAGS_PRESERVE_ARGV0
  53 #define AT_FLAGS_PRESERVE_ARGV0_BIT 0
  54 #define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
  55 #endif
  56
  57 char *exec_path;
  58
  59 int singlestep;
  60 static const char *argv0;
  61 static const char *gdbstub;
  62 static envlist_t *envlist;
  63 static const char *cpu_model;
  64 static const char *cpu_type;
  65 static const char *seed_optarg;
  66 unsigned long mmap_min_addr;
  67 uintptr_t guest_base;
  68 bool have_guest_base;
  69
  70 /*
  71  * Used to implement backwards-compatibility for the `-strace`, and
  72  * QEMU_STRACE options. Without this, the QEMU_LOG can be overwritten by
  73  * -strace, or vice versa.
  74  */
  75 static bool enable_strace;
  76
  77 /*
  78  * The last log mask given by the user in an environment variable or argument.
  79  * Used to support command line arguments overriding environment variables.
  80  */
  81 static int last_log_mask;
  82
  83 /*
  84  * When running 32-on-64 we should make sure we can fit all of the possible
  85  * guest address space into a contiguous chunk of virtual host memory.
  86  *
  87  * This way we will never overlap with our own libraries or binaries or stack
  88  * or anything else that QEMU maps.
  89  *
  90  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  91  * of the address for the kernel.  Some cpus rely on this and user space
  92  * uses the high bit(s) for pointer tagging and the like.  For them, we
  93  * must preserve the expected address space.
  94  */
  95 #ifndef MAX_RESERVED_VA
  96 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
  97 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
  98       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
  99 /* There are a number of places where we assign reserved_va to a variable
 100    of type abi_ulong and expect it to fit.  Avoid the last page.  */
 101 #   define MAX_RESERVED_VA(CPU)  (0xfffffffful & TARGET_PAGE_MASK)
 102 #  else
 103 #   define MAX_RESERVED_VA(CPU)  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
 104 #  endif
 105 # else
 106 #  define MAX_RESERVED_VA(CPU)  0
 107 # endif
 108 #endif
 109
 110 unsigned long reserved_va;
 111
 112 static void usage(int exitcode);
 113
 114 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
 115 const char *qemu_uname_release;
 116
 117 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
 118    we allocate a bigger stack. Need a better solution, for example
 119    by remapping the process stack directly at the right place */
 120 unsigned long guest_stack_size = 8 * 1024 * 1024UL;
 121
 122 #if defined(TARGET_I386)
 123 int cpu_get_pic_interrupt(CPUX86State *env)
 124 {
 125     return -1;
 126 }
 127 #endif
 128
 129 /***********************************************************/
 130 /* Helper routines for implementing atomic operations.  */
 131
 132 /* Make sure everything is in a consistent state for calling fork().  */
 133 void fork_start(void)
 134 {
 135     start_exclusive();
 136     mmap_fork_start();
 137     cpu_list_lock();
 138 }
 139
 140 void fork_end(int child)
 141 {
 142     mmap_fork_end(child);
 143     if (child) {
 144         CPUState *cpu, *next_cpu;
 145         /* Child processes created by fork() only have a single thread.
 146            Discard information about the parent threads.  */
 147         CPU_FOREACH_SAFE(cpu, next_cpu) {
 148             if (cpu != thread_cpu) {
 149                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
 150             }
 151         }
 152         qemu_init_cpu_list();
 153         gdbserver_fork(thread_cpu);
 154         /* qemu_init_cpu_list() takes care of reinitializing the
 155          * exclusive state, so we don't need to end_exclusive() here.
 156          */
 157     } else {
 158         cpu_list_unlock();
 159         end_exclusive();
 160     }
 161 }
 162
 163 __thread CPUState *thread_cpu;
 164
 165 bool qemu_cpu_is_self(CPUState *cpu)
 166 {
 167     return thread_cpu == cpu;
 168 }
 169
 170 void qemu_cpu_kick(CPUState *cpu)
 171 {
 172     cpu_exit(cpu);
 173 }
 174
 175 void task_settid(TaskState *ts)
 176 {
 177     if (ts->ts_tid == 0) {
 178         ts->ts_tid = (pid_t)syscall(SYS_gettid);
 179     }
 180 }
 181
 182 void stop_all_tasks(void)
 183 {
 184     /*
 185      * We trust that when using NPTL, start_exclusive()
 186      * handles thread stopping correctly.
 187      */
 188     start_exclusive();
 189 }
 190
 191 /* Assumes contents are already zeroed.  */
 192 void init_task_state(TaskState *ts)
 193 {
 194     ts->used = 1;
 195     ts->sigaltstack_used = (struct target_sigaltstack) {
 196         .ss_sp = 0,
 197         .ss_size = 0,
 198         .ss_flags = TARGET_SS_DISABLE,
 199     };
 200 }
 201
 202 CPUArchState *cpu_copy(CPUArchState *env)
 203 {
 204     CPUState *cpu = env_cpu(env);
 205     CPUState *new_cpu = cpu_create(cpu_type);
 206     CPUArchState *new_env = new_cpu->env_ptr;
 207     CPUBreakpoint *bp;
 208
 209     /* Reset non arch specific state */
 210     cpu_reset(new_cpu);
 211
 212     new_cpu->tcg_cflags = cpu->tcg_cflags;
 213     memcpy(new_env, env, sizeof(CPUArchState));
 214
 215     /* Clone all break/watchpoints.
 216        Note: Once we support ptrace with hw-debug register access, make sure
 217        BP_CPU break/watchpoints are handled correctly on clone. */
 218     QTAILQ_INIT(&new_cpu->breakpoints);
 219     QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
 220         cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
 221     }
 222
 223     return new_env;
 224 }
 225
 226 static void handle_arg_help(const char *arg)
 227 {
 228     usage(EXIT_SUCCESS);
 229 }
 230
 231 static void handle_arg_log(const char *arg)
 232 {
 233     last_log_mask = qemu_str_to_log_mask(arg);
 234     if (!last_log_mask) {
 235         qemu_print_log_usage(stdout);
 236         exit(EXIT_FAILURE);
 237     }
 238 }
 239
 240 static void handle_arg_dfilter(const char *arg)
 241 {
 242     qemu_set_dfilter_ranges(arg, &error_fatal);
 243 }
 244
 245 static void handle_arg_log_filename(const char *arg)
 246 {
 247     qemu_set_log_filename(arg, &error_fatal);
 248 }
 249
 250 static void handle_arg_set_env(const char *arg)
 251 {
 252     char *r, *p, *token;
 253     r = p = strdup(arg);
 254     while ((token = strsep(&p, ",")) != NULL) {
 255         if (envlist_setenv(envlist, token) != 0) {
 256             usage(EXIT_FAILURE);
 257         }
 258     }
 259     free(r);
 260 }
 261
 262 static void handle_arg_unset_env(const char *arg)
 263 {
 264     char *r, *p, *token;
 265     r = p = strdup(arg);
 266     while ((token = strsep(&p, ",")) != NULL) {
 267         if (envlist_unsetenv(envlist, token) != 0) {
 268             usage(EXIT_FAILURE);
 269         }
 270     }
 271     free(r);
 272 }
 273
 274 static void handle_arg_argv0(const char *arg)
 275 {
 276     argv0 = strdup(arg);
 277 }
 278
 279 static void handle_arg_stack_size(const char *arg)
 280 {
 281     char *p;
 282     guest_stack_size = strtoul(arg, &p, 0);
 283     if (guest_stack_size == 0) {
 284         usage(EXIT_FAILURE);
 285     }
 286
 287     if (*p == 'M') {
 288         guest_stack_size *= MiB;
 289     } else if (*p == 'k' || *p == 'K') {
 290         guest_stack_size *= KiB;
 291     }
 292 }
 293
 294 static void handle_arg_ld_prefix(const char *arg)
 295 {
 296     interp_prefix = strdup(arg);
 297 }
 298
 299 static void handle_arg_pagesize(const char *arg)
 300 {
 301     qemu_host_page_size = atoi(arg);
 302     if (qemu_host_page_size == 0 ||
 303         (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 304         fprintf(stderr, "page size must be a power of two\n");
 305         exit(EXIT_FAILURE);
 306     }
 307 }
 308
 309 static void handle_arg_seed(const char *arg)
 310 {
 311     seed_optarg = arg;
 312 }
 313
 314 static void handle_arg_gdb(const char *arg)
 315 {
 316     gdbstub = g_strdup(arg);
 317 }
 318
 319 static void handle_arg_uname(const char *arg)
 320 {
 321     qemu_uname_release = strdup(arg);
 322 }
 323
 324 static void handle_arg_cpu(const char *arg)
 325 {
 326     cpu_model = strdup(arg);
 327     if (cpu_model == NULL || is_help_option(cpu_model)) {
 328         /* XXX: implement xxx_cpu_list for targets that still miss it */
 329 #if defined(cpu_list)
 330         cpu_list();
 331 #endif
 332         exit(EXIT_FAILURE);
 333     }
 334 }
 335
 336 static void handle_arg_guest_base(const char *arg)
 337 {
 338     guest_base = strtol(arg, NULL, 0);
 339     have_guest_base = true;
 340 }
 341
 342 static void handle_arg_reserved_va(const char *arg)
 343 {
 344     char *p;
 345     int shift = 0;
 346     reserved_va = strtoul(arg, &p, 0);
 347     switch (*p) {
 348     case 'k':
 349     case 'K':
 350         shift = 10;
 351         break;
 352     case 'M':
 353         shift = 20;
 354         break;
 355     case 'G':
 356         shift = 30;
 357         break;
 358     }
 359     if (shift) {
 360         unsigned long unshifted = reserved_va;
 361         p++;
 362         reserved_va <<= shift;
 363         if (reserved_va >> shift != unshifted) {
 364             fprintf(stderr, "Reserved virtual address too big\n");
 365             exit(EXIT_FAILURE);
 366         }
 367     }
 368     if (*p) {
 369         fprintf(stderr, "Unrecognised -R size suffix '%s'\n", p);
 370         exit(EXIT_FAILURE);
 371     }
 372 }
 373
 374 static void handle_arg_singlestep(const char *arg)
 375 {
 376     singlestep = 1;
 377 }
 378
 379 static void handle_arg_strace(const char *arg)
 380 {
 381     enable_strace = true;
 382 }
 383
 384 static void handle_arg_version(const char *arg)
 385 {
 386     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 387            "\n" QEMU_COPYRIGHT "\n");
 388     exit(EXIT_SUCCESS);
 389 }
 390
 391 static void handle_arg_trace(const char *arg)
 392 {
 393     trace_opt_parse(arg);
 394 }
 395
 396 #if defined(TARGET_XTENSA)
 397 static void handle_arg_abi_call0(const char *arg)
 398 {
 399     xtensa_set_abi_call0();
 400 }
 401 #endif
 402
 403 static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
 404
 405 #ifdef CONFIG_PLUGIN
 406 static void handle_arg_plugin(const char *arg)
 407 {
 408     qemu_plugin_opt_parse(arg, &plugins);
 409 }
 410 #endif
 411
 412 struct qemu_argument {
 413     const char *argv;
 414     const char *env;
 415     bool has_arg;
 416     void (*handle_opt)(const char *arg);
 417     const char *example;
 418     const char *help;
 419 };
 420
 421 static const struct qemu_argument arg_table[] = {
 422     {"h",          "",                 false, handle_arg_help,
 423      "",           "print this help"},
 424     {"help",       "",                 false, handle_arg_help,
 425      "",           ""},
 426     {"g",          "QEMU_GDB",         true,  handle_arg_gdb,
 427      "port",       "wait gdb connection to 'port'"},
 428     {"L",          "QEMU_LD_PREFIX",   true,  handle_arg_ld_prefix,
 429      "path",       "set the elf interpreter prefix to 'path'"},
 430     {"s",          "QEMU_STACK_SIZE",  true,  handle_arg_stack_size,
 431      "size",       "set the stack size to 'size' bytes"},
 432     {"cpu",        "QEMU_CPU",         true,  handle_arg_cpu,
 433      "model",      "select CPU (-cpu help for list)"},
 434     {"E",          "QEMU_SET_ENV",     true,  handle_arg_set_env,
 435      "var=value",  "sets targets environment variable (see below)"},
 436     {"U",          "QEMU_UNSET_ENV",   true,  handle_arg_unset_env,
 437      "var",        "unsets targets environment variable (see below)"},
 438     {"0",          "QEMU_ARGV0",       true,  handle_arg_argv0,
 439      "argv0",      "forces target process argv[0] to be 'argv0'"},
 440     {"r",          "QEMU_UNAME",       true,  handle_arg_uname,
 441      "uname",      "set qemu uname release string to 'uname'"},
 442     {"B",          "QEMU_GUEST_BASE",  true,  handle_arg_guest_base,
 443      "address",    "set guest_base address to 'address'"},
 444     {"R",          "QEMU_RESERVED_VA", true,  handle_arg_reserved_va,
 445      "size",       "reserve 'size' bytes for guest virtual address space"},
 446     {"d",          "QEMU_LOG",         true,  handle_arg_log,
 447      "item[,...]", "enable logging of specified items "
 448      "(use '-d help' for a list of items)"},
 449     {"dfilter",    "QEMU_DFILTER",     true,  handle_arg_dfilter,
 450      "range[,...]","filter logging based on address range"},
 451     {"D",          "QEMU_LOG_FILENAME", true, handle_arg_log_filename,
 452      "logfile",     "write logs to 'logfile' (default stderr)"},
 453     {"p",          "QEMU_PAGESIZE",    true,  handle_arg_pagesize,
 454      "pagesize",   "set the host page size to 'pagesize'"},
 455     {"singlestep", "QEMU_SINGLESTEP",  false, handle_arg_singlestep,
 456      "",           "run in singlestep mode"},
 457     {"strace",     "QEMU_STRACE",      false, handle_arg_strace,
 458      "",           "log system calls"},
 459     {"seed",       "QEMU_RAND_SEED",   true,  handle_arg_seed,
 460      "",           "Seed for pseudo-random number generator"},
 461     {"trace",      "QEMU_TRACE",       true,  handle_arg_trace,
 462      "",           "[[enable=]<pattern>][,events=<file>][,file=<file>]"},
 463 #ifdef CONFIG_PLUGIN
 464     {"plugin",     "QEMU_PLUGIN",      true,  handle_arg_plugin,
 465      "",           "[file=]<file>[,arg=<string>]"},
 466 #endif
 467     {"version",    "QEMU_VERSION",     false, handle_arg_version,
 468      "",           "display version information and exit"},
 469 #if defined(TARGET_XTENSA)
 470     {"xtensa-abi-call0", "QEMU_XTENSA_ABI_CALL0", false, handle_arg_abi_call0,
 471      "",           "assume CALL0 Xtensa ABI"},
 472 #endif
 473     {NULL, NULL, false, NULL, NULL, NULL}
 474 };
 475
 476 static void usage(int exitcode)
 477 {
 478     const struct qemu_argument *arginfo;
 479     int maxarglen;
 480     int maxenvlen;
 481
 482     printf("usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 483            "Linux CPU emulator (compiled for " TARGET_NAME " emulation)\n"
 484            "\n"
 485            "Options and associated environment variables:\n"
 486            "\n");
 487
 488     /* Calculate column widths. We must always have at least enough space
 489      * for the column header.
 490      */
 491     maxarglen = strlen("Argument");
 492     maxenvlen = strlen("Env-variable");
 493
 494     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 495         int arglen = strlen(arginfo->argv);
 496         if (arginfo->has_arg) {
 497             arglen += strlen(arginfo->example) + 1;
 498         }
 499         if (strlen(arginfo->env) > maxenvlen) {
 500             maxenvlen = strlen(arginfo->env);
 501         }
 502         if (arglen > maxarglen) {
 503             maxarglen = arglen;
 504         }
 505     }
 506
 507     printf("%-*s %-*s Description\n", maxarglen+1, "Argument",
 508             maxenvlen, "Env-variable");
 509
 510     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 511         if (arginfo->has_arg) {
 512             printf("-%s %-*s %-*s %s\n", arginfo->argv,
 513                    (int)(maxarglen - strlen(arginfo->argv) - 1),
 514                    arginfo->example, maxenvlen, arginfo->env, arginfo->help);
 515         } else {
 516             printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
 517                     maxenvlen, arginfo->env,
 518                     arginfo->help);
 519         }
 520     }
 521
 522     printf("\n"
 523            "Defaults:\n"
 524            "QEMU_LD_PREFIX  = %s\n"
 525            "QEMU_STACK_SIZE = %ld byte\n",
 526            interp_prefix,
 527            guest_stack_size);
 528
 529     printf("\n"
 530            "You can use -E and -U options or the QEMU_SET_ENV and\n"
 531            "QEMU_UNSET_ENV environment variables to set and unset\n"
 532            "environment variables for the target process.\n"
 533            "It is possible to provide several variables by separating them\n"
 534            "by commas in getsubopt(3) style. Additionally it is possible to\n"
 535            "provide the -E and -U options multiple times.\n"
 536            "The following lines are equivalent:\n"
 537            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 538            "    -E var1=val2,var2=val2 -U LD_PRELOAD,LD_DEBUG\n"
 539            "    QEMU_SET_ENV=var1=val2,var2=val2 QEMU_UNSET_ENV=LD_PRELOAD,LD_DEBUG\n"
 540            "Note that if you provide several changes to a single variable\n"
 541            "the last change will stay in effect.\n"
 542            "\n"
 543            QEMU_HELP_BOTTOM "\n");
 544
 545     exit(exitcode);
 546 }
 547
 548 static int parse_args(int argc, char **argv)
 549 {
 550     const char *r;
 551     int optind;
 552     const struct qemu_argument *arginfo;
 553
 554     for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 555         if (arginfo->env == NULL) {
 556             continue;
 557         }
 558
 559         r = getenv(arginfo->env);
 560         if (r != NULL) {
 561             arginfo->handle_opt(r);
 562         }
 563     }
 564
 565     optind = 1;
 566     for (;;) {
 567         if (optind >= argc) {
 568             break;
 569         }
 570         r = argv[optind];
 571         if (r[0] != '-') {
 572             break;
 573         }
 574         optind++;
 575         r++;
 576         if (!strcmp(r, "-")) {
 577             break;
 578         }
 579         /* Treat --foo the same as -foo.  */
 580         if (r[0] == '-') {
 581             r++;
 582         }
 583
 584         for (arginfo = arg_table; arginfo->handle_opt != NULL; arginfo++) {
 585             if (!strcmp(r, arginfo->argv)) {
 586                 if (arginfo->has_arg) {
 587                     if (optind >= argc) {
 588                         (void) fprintf(stderr,
 589                             "qemu: missing argument for option '%s'\n", r);
 590                         exit(EXIT_FAILURE);
 591                     }
 592                     arginfo->handle_opt(argv[optind]);
 593                     optind++;
 594                 } else {
 595                     arginfo->handle_opt(NULL);
 596                 }
 597                 break;
 598             }
 599         }
 600
 601         /* no option matched the current argv */
 602         if (arginfo->handle_opt == NULL) {
 603             (void) fprintf(stderr, "qemu: unknown option '%s'\n", r);
 604             exit(EXIT_FAILURE);
 605         }
 606     }
 607
 608     if (optind >= argc) {
 609         (void) fprintf(stderr, "qemu: no user program specified\n");
 610         exit(EXIT_FAILURE);
 611     }
 612
 613     exec_path = argv[optind];
 614
 615     return optind;
 616 }
 617
 618 int main(int argc, char **argv, char **envp)
 619 {
 620     struct target_pt_regs regs1, *regs = &regs1;
 621     struct image_info info1, *info = &info1;
 622     struct linux_binprm bprm;
 623     TaskState *ts;
 624     CPUArchState *env;
 625     CPUState *cpu;
 626     int optind;
 627     char **target_environ, **wrk;
 628     char **target_argv;
 629     int target_argc;
 630     int i;
 631     int ret;
 632     int execfd;
 633     int log_mask;
 634     unsigned long max_reserved_va;
 635     bool preserve_argv0;
 636
 637     error_init(argv[0]);
 638     module_call_init(MODULE_INIT_TRACE);
 639     qemu_init_cpu_list();
 640     module_call_init(MODULE_INIT_QOM);
 641
 642     envlist = envlist_create();
 643
 644     /* add current environment into the list */
 645     for (wrk = environ; *wrk != NULL; wrk++) {
 646         (void) envlist_setenv(envlist, *wrk);
 647     }
 648
 649     /* Read the stack limit from the kernel.  If it's "unlimited",
 650        then we can do little else besides use the default.  */
 651     {
 652         struct rlimit lim;
 653         if (getrlimit(RLIMIT_STACK, &lim) == 0
 654             && lim.rlim_cur != RLIM_INFINITY
 655             && lim.rlim_cur == (target_long)lim.rlim_cur) {
 656             guest_stack_size = lim.rlim_cur;
 657         }
 658     }
 659
 660     cpu_model = NULL;
 661
 662     qemu_add_opts(&qemu_trace_opts);
 663     qemu_plugin_add_opts();
 664
 665     optind = parse_args(argc, argv);
 666
 667     log_mask = last_log_mask | (enable_strace ? LOG_STRACE : 0);
 668     if (log_mask) {
 669         qemu_log_needs_buffers();
 670         qemu_set_log(log_mask);
 671     }
 672
 673     if (!trace_init_backends()) {
 674         exit(1);
 675     }
 676     trace_init_file();
 677     qemu_plugin_load_list(&plugins, &error_fatal);
 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     /*
 693      * Manage binfmt-misc open-binary flag
 694      */
 695     execfd = qemu_getauxval(AT_EXECFD);
 696     if (execfd == 0) {
 697         execfd = open(exec_path, O_RDONLY);
 698         if (execfd < 0) {
 699             printf("Error while loading %s: %s\n", exec_path, strerror(errno));
 700             _exit(EXIT_FAILURE);
 701         }
 702     }
 703
 704     /*
 705      * get binfmt_misc flags
 706      */
 707     preserve_argv0 = !!(qemu_getauxval(AT_FLAGS) & AT_FLAGS_PRESERVE_ARGV0);
 708
 709     /*
 710      * Manage binfmt-misc preserve-arg[0] flag
 711      *    argv[optind]     full path to the binary
 712      *    argv[optind + 1] original argv[0]
 713      */
 714     if (optind + 1 < argc && preserve_argv0) {
 715         optind++;
 716     }
 717
 718     if (cpu_model == NULL) {
 719         cpu_model = cpu_get_model(get_elf_eflags(execfd));
 720     }
 721     cpu_type = parse_cpu_option(cpu_model);
 722
 723     /* init tcg before creating CPUs and to get qemu_host_page_size */
 724     {
 725         AccelClass *ac = ACCEL_GET_CLASS(current_accel());
 726
 727         accel_init_interfaces(ac);
 728         ac->init_machine(NULL);
 729     }
 730     cpu = cpu_create(cpu_type);
 731     env = cpu->env_ptr;
 732     cpu_reset(cpu);
 733     thread_cpu = cpu;
 734
 735     /*
 736      * Reserving too much vm space via mmap can run into problems
 737      * with rlimits, oom due to page table creation, etc.  We will
 738      * still try it, if directed by the command-line option, but
 739      * not by default.
 740      */
 741     max_reserved_va = MAX_RESERVED_VA(cpu);
 742     if (reserved_va != 0) {
 743         if (max_reserved_va && reserved_va > max_reserved_va) {
 744             fprintf(stderr, "Reserved virtual address too big\n");
 745             exit(EXIT_FAILURE);
 746         }
 747     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 748         /*
 749          * reserved_va must be aligned with the host page size
 750          * as it is used with mmap()
 751          */
 752         reserved_va = max_reserved_va & qemu_host_page_mask;
 753     }
 754
 755     {
 756         Error *err = NULL;
 757         if (seed_optarg != NULL) {
 758             qemu_guest_random_seed_main(seed_optarg, &err);
 759         } else {
 760             qcrypto_init(&err);
 761         }
 762         if (err) {
 763             error_reportf_err(err, "cannot initialize crypto: ");
 764             exit(1);
 765         }
 766     }
 767
 768     target_environ = envlist_to_environ(envlist, NULL);
 769     envlist_free(envlist);
 770
 771     /*
 772      * Read in mmap_min_addr kernel parameter.  This value is used
 773      * When loading the ELF image to determine whether guest_base
 774      * is needed.  It is also used in mmap_find_vma.
 775      */
 776     {
 777         FILE *fp;
 778
 779         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
 780             unsigned long tmp;
 781             if (fscanf(fp, "%lu", &tmp) == 1 && tmp != 0) {
 782                 mmap_min_addr = tmp;
 783                 qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n",
 784                               mmap_min_addr);
 785             }
 786             fclose(fp);
 787         }
 788     }
 789
 790     /*
 791      * We prefer to not make NULL pointers accessible to QEMU.
 792      * If we're in a chroot with no /proc, fall back to 1 page.
 793      */
 794     if (mmap_min_addr == 0) {
 795         mmap_min_addr = qemu_host_page_size;
 796         qemu_log_mask(CPU_LOG_PAGE,
 797                       "host mmap_min_addr=0x%lx (fallback)\n",
 798                       mmap_min_addr);
 799     }
 800
 801     /*
 802      * Prepare copy of argv vector for target.
 803      */
 804     target_argc = argc - optind;
 805     target_argv = calloc(target_argc + 1, sizeof (char *));
 806     if (target_argv == NULL) {
 807         (void) fprintf(stderr, "Unable to allocate memory for target_argv\n");
 808         exit(EXIT_FAILURE);
 809     }
 810
 811     /*
 812      * If argv0 is specified (using '-0' switch) we replace
 813      * argv[0] pointer with the given one.
 814      */
 815     i = 0;
 816     if (argv0 != NULL) {
 817         target_argv[i++] = strdup(argv0);
 818     }
 819     for (; i < target_argc; i++) {
 820         target_argv[i] = strdup(argv[optind + i]);
 821     }
 822     target_argv[target_argc] = NULL;
 823
 824     ts = g_new0(TaskState, 1);
 825     init_task_state(ts);
 826     /* build Task State */
 827     ts->info = info;
 828     ts->bprm = &bprm;
 829     cpu->opaque = ts;
 830     task_settid(ts);
 831
 832     ret = loader_exec(execfd, exec_path, target_argv, target_environ, regs,
 833         info, &bprm);
 834     if (ret != 0) {
 835         printf("Error while loading %s: %s\n", exec_path, strerror(-ret));
 836         _exit(EXIT_FAILURE);
 837     }
 838
 839     for (wrk = target_environ; *wrk; wrk++) {
 840         g_free(*wrk);
 841     }
 842
 843     g_free(target_environ);
 844
 845     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 846         qemu_log("guest_base  %p\n", (void *)guest_base);
 847         log_page_dump("binary load");
 848
 849         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
 850         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
 851         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n", info->start_code);
 852         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n", info->start_data);
 853         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
 854         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n", info->start_stack);
 855         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 856         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 857         qemu_log("argv_start  0x" TARGET_ABI_FMT_lx "\n", info->arg_start);
 858         qemu_log("env_start   0x" TARGET_ABI_FMT_lx "\n",
 859                  info->arg_end + (abi_ulong)sizeof(abi_ulong));
 860         qemu_log("auxv_start  0x" TARGET_ABI_FMT_lx "\n", info->saved_auxv);
 861     }
 862
 863     target_set_brk(info->brk);
 864     syscall_init();
 865     signal_init();
 866
 867     /* Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 868        generating the prologue until now so that the prologue can take
 869        the real value of GUEST_BASE into account.  */
 870     tcg_prologue_init(tcg_ctx);
 871     tcg_region_init();
 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 }