bsd-user/main.c

   1 /*
   2  *  qemu bsd user main
   3  *
   4  *  Copyright (c) 2003-2008 Fabrice Bellard
   5  *  Copyright (c) 2013-14 Stacey Son
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include <sys/resource.h>
  23 #include <sys/sysctl.h>
  24
  25 #include "qemu/help-texts.h"
  26 #include "qemu/units.h"
  27 #include "qemu/accel.h"
  28 #include "qemu-version.h"
  29 #include <machine/trap.h>
  30
  31 #include "qapi/error.h"
  32 #include "qemu.h"
  33 #include "qemu/config-file.h"
  34 #include "qemu/error-report.h"
  35 #include "qemu/path.h"
  36 #include "qemu/help_option.h"
  37 #include "qemu/module.h"
  38 #include "exec/exec-all.h"
  39 #include "tcg/tcg.h"
  40 #include "qemu/timer.h"
  41 #include "qemu/envlist.h"
  42 #include "qemu/cutils.h"
  43 #include "exec/log.h"
  44 #include "trace/control.h"
  45 #include "crypto/init.h"
  46 #include "qemu/guest-random.h"
  47 #include "gdbstub/user.h"
  48
  49 #include "host-os.h"
  50 #include "target_arch_cpu.h"
  51
  52 int singlestep;
  53 uintptr_t guest_base;
  54 bool have_guest_base;
  55 /*
  56  * When running 32-on-64 we should make sure we can fit all of the possible
  57  * guest address space into a contiguous chunk of virtual host memory.
  58  *
  59  * This way we will never overlap with our own libraries or binaries or stack
  60  * or anything else that QEMU maps.
  61  *
  62  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  63  * of the address for the kernel.  Some cpus rely on this and user space
  64  * uses the high bit(s) for pointer tagging and the like.  For them, we
  65  * must preserve the expected address space.
  66  */
  67 #ifndef MAX_RESERVED_VA
  68 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
  69 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
  70       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
  71 /*
  72  * There are a number of places where we assign reserved_va to a variable
  73  * of type abi_ulong and expect it to fit.  Avoid the last page.
  74  */
  75 #   define MAX_RESERVED_VA  (0xfffffffful & TARGET_PAGE_MASK)
  76 #  else
  77 #   define MAX_RESERVED_VA  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
  78 #  endif
  79 # else
  80 #  define MAX_RESERVED_VA  0
  81 # endif
  82 #endif
  83
  84 /*
  85  * That said, reserving *too* much vm space via mmap can run into problems
  86  * with rlimits, oom due to page table creation, etc.  We will still try it,
  87  * if directed by the command-line option, but not by default.
  88  */
  89 #if HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32
  90 unsigned long reserved_va = MAX_RESERVED_VA;
  91 #else
  92 unsigned long reserved_va;
  93 #endif
  94
  95 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
  96 const char *qemu_uname_release;
  97 char qemu_proc_pathname[PATH_MAX];  /* full path to exeutable */
  98
  99 unsigned long target_maxtsiz = TARGET_MAXTSIZ;   /* max text size */
 100 unsigned long target_dfldsiz = TARGET_DFLDSIZ;   /* initial data size limit */
 101 unsigned long target_maxdsiz = TARGET_MAXDSIZ;   /* max data size */
 102 unsigned long target_dflssiz = TARGET_DFLSSIZ;   /* initial data size limit */
 103 unsigned long target_maxssiz = TARGET_MAXSSIZ;   /* max stack size */
 104 unsigned long target_sgrowsiz = TARGET_SGROWSIZ; /* amount to grow stack */
 105
 106 /* Helper routines for implementing atomic operations. */
 107
 108 void fork_start(void)
 109 {
 110     start_exclusive();
 111     cpu_list_lock();
 112     mmap_fork_start();
 113 }
 114
 115 void fork_end(int child)
 116 {
 117     if (child) {
 118         CPUState *cpu, *next_cpu;
 119         /*
 120          * Child processes created by fork() only have a single thread.  Discard
 121          * information about the parent threads.
 122          */
 123         CPU_FOREACH_SAFE(cpu, next_cpu) {
 124             if (cpu != thread_cpu) {
 125                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
 126             }
 127         }
 128         mmap_fork_end(child);
 129         /*
 130          * qemu_init_cpu_list() takes care of reinitializing the exclusive
 131          * state, so we don't need to end_exclusive() here.
 132          */
 133         qemu_init_cpu_list();
 134         gdbserver_fork(thread_cpu);
 135     } else {
 136         mmap_fork_end(child);
 137         cpu_list_unlock();
 138         end_exclusive();
 139     }
 140 }
 141
 142 void cpu_loop(CPUArchState *env)
 143 {
 144     target_cpu_loop(env);
 145 }
 146
 147 static void usage(void)
 148 {
 149     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 150            "\n" QEMU_COPYRIGHT "\n"
 151            "usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 152            "BSD CPU emulator (compiled for %s emulation)\n"
 153            "\n"
 154            "Standard options:\n"
 155            "-h                print this help\n"
 156            "-g port           wait gdb connection to port\n"
 157            "-L path           set the elf interpreter prefix (default=%s)\n"
 158            "-s size           set the stack size in bytes (default=%ld)\n"
 159            "-cpu model        select CPU (-cpu help for list)\n"
 160            "-drop-ld-preload  drop LD_PRELOAD for target process\n"
 161            "-E var=value      sets/modifies targets environment variable(s)\n"
 162            "-U var            unsets targets environment variable(s)\n"
 163            "-B address        set guest_base address to address\n"
 164            "\n"
 165            "Debug options:\n"
 166            "-d item1[,...]    enable logging of specified items\n"
 167            "                  (use '-d help' for a list of log items)\n"
 168            "-D logfile        write logs to 'logfile' (default stderr)\n"
 169            "-singlestep       always run in singlestep mode\n"
 170            "-strace           log system calls\n"
 171            "-trace            [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 172            "                  specify tracing options\n"
 173            "\n"
 174            "Environment variables:\n"
 175            "QEMU_STRACE       Print system calls and arguments similar to the\n"
 176            "                  'strace' program.  Enable by setting to any value.\n"
 177            "You can use -E and -U options to set/unset environment variables\n"
 178            "for target process.  It is possible to provide several variables\n"
 179            "by repeating the option.  For example:\n"
 180            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 181            "Note that if you provide several changes to single variable\n"
 182            "last change will stay in effect.\n"
 183            "\n"
 184            QEMU_HELP_BOTTOM "\n"
 185            ,
 186            TARGET_NAME,
 187            interp_prefix,
 188            target_dflssiz);
 189     exit(1);
 190 }
 191
 192 __thread CPUState *thread_cpu;
 193
 194 void stop_all_tasks(void)
 195 {
 196     /*
 197      * We trust when using NPTL (pthreads) start_exclusive() handles thread
 198      * stopping correctly.
 199      */
 200     start_exclusive();
 201 }
 202
 203 bool qemu_cpu_is_self(CPUState *cpu)
 204 {
 205     return thread_cpu == cpu;
 206 }
 207
 208 void qemu_cpu_kick(CPUState *cpu)
 209 {
 210     cpu_exit(cpu);
 211 }
 212
 213 /* Assumes contents are already zeroed.  */
 214 static void init_task_state(TaskState *ts)
 215 {
 216     ts->sigaltstack_used = (struct target_sigaltstack) {
 217         .ss_sp = 0,
 218         .ss_size = 0,
 219         .ss_flags = TARGET_SS_DISABLE,
 220     };
 221 }
 222
 223 void gemu_log(const char *fmt, ...)
 224 {
 225     va_list ap;
 226
 227     va_start(ap, fmt);
 228     vfprintf(stderr, fmt, ap);
 229     va_end(ap);
 230 }
 231
 232 static void
 233 adjust_ssize(void)
 234 {
 235     struct rlimit rl;
 236
 237     if (getrlimit(RLIMIT_STACK, &rl) != 0) {
 238         return;
 239     }
 240
 241     target_maxssiz = MIN(target_maxssiz, rl.rlim_max);
 242     target_dflssiz = MIN(MAX(target_dflssiz, rl.rlim_cur), target_maxssiz);
 243
 244     rl.rlim_max = target_maxssiz;
 245     rl.rlim_cur = target_dflssiz;
 246     setrlimit(RLIMIT_STACK, &rl);
 247 }
 248
 249 static void save_proc_pathname(char *argv0)
 250 {
 251     int mib[4];
 252     size_t len;
 253
 254     mib[0] = CTL_KERN;
 255     mib[1] = KERN_PROC;
 256     mib[2] = KERN_PROC_PATHNAME;
 257     mib[3] = -1;
 258
 259     len = sizeof(qemu_proc_pathname);
 260     if (sysctl(mib, 4, qemu_proc_pathname, &len, NULL, 0)) {
 261         perror("sysctl");
 262     }
 263 }
 264
 265 int main(int argc, char **argv)
 266 {
 267     const char *filename;
 268     const char *cpu_model;
 269     const char *cpu_type;
 270     const char *log_file = NULL;
 271     const char *log_mask = NULL;
 272     const char *seed_optarg = NULL;
 273     struct target_pt_regs regs1, *regs = &regs1;
 274     struct image_info info1, *info = &info1;
 275     struct bsd_binprm bprm;
 276     TaskState *ts;
 277     CPUArchState *env;
 278     CPUState *cpu;
 279     int optind, rv;
 280     const char *r;
 281     const char *gdbstub = NULL;
 282     char **target_environ, **wrk;
 283     envlist_t *envlist = NULL;
 284     char *argv0 = NULL;
 285
 286     adjust_ssize();
 287
 288     if (argc <= 1) {
 289         usage();
 290     }
 291
 292     save_proc_pathname(argv[0]);
 293
 294     error_init(argv[0]);
 295     module_call_init(MODULE_INIT_TRACE);
 296     qemu_init_cpu_list();
 297     module_call_init(MODULE_INIT_QOM);
 298
 299     envlist = envlist_create();
 300
 301     /* add current environment into the list */
 302     for (wrk = environ; *wrk != NULL; wrk++) {
 303         (void) envlist_setenv(envlist, *wrk);
 304     }
 305
 306     cpu_model = NULL;
 307
 308     qemu_add_opts(&qemu_trace_opts);
 309
 310     optind = 1;
 311     for (;;) {
 312         if (optind >= argc) {
 313             break;
 314         }
 315         r = argv[optind];
 316         if (r[0] != '-') {
 317             break;
 318         }
 319         optind++;
 320         r++;
 321         if (!strcmp(r, "-")) {
 322             break;
 323         } else if (!strcmp(r, "d")) {
 324             if (optind >= argc) {
 325                 break;
 326             }
 327             log_mask = argv[optind++];
 328         } else if (!strcmp(r, "D")) {
 329             if (optind >= argc) {
 330                 break;
 331             }
 332             log_file = argv[optind++];
 333         } else if (!strcmp(r, "E")) {
 334             r = argv[optind++];
 335             if (envlist_setenv(envlist, r) != 0) {
 336                 usage();
 337             }
 338         } else if (!strcmp(r, "ignore-environment")) {
 339             envlist_free(envlist);
 340             envlist = envlist_create();
 341         } else if (!strcmp(r, "U")) {
 342             r = argv[optind++];
 343             if (envlist_unsetenv(envlist, r) != 0) {
 344                 usage();
 345             }
 346         } else if (!strcmp(r, "s")) {
 347             r = argv[optind++];
 348             rv = qemu_strtoul(r, &r, 0, &target_dflssiz);
 349             if (rv < 0 || target_dflssiz <= 0) {
 350                 usage();
 351             }
 352             if (*r == 'M') {
 353                 target_dflssiz *= 1024 * 1024;
 354             } else if (*r == 'k' || *r == 'K') {
 355                 target_dflssiz *= 1024;
 356             }
 357             if (target_dflssiz > target_maxssiz) {
 358                 usage();
 359             }
 360         } else if (!strcmp(r, "L")) {
 361             interp_prefix = argv[optind++];
 362         } else if (!strcmp(r, "p")) {
 363             qemu_host_page_size = atoi(argv[optind++]);
 364             if (qemu_host_page_size == 0 ||
 365                 (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 366                 fprintf(stderr, "page size must be a power of two\n");
 367                 exit(1);
 368             }
 369         } else if (!strcmp(r, "g")) {
 370             gdbstub = g_strdup(argv[optind++]);
 371         } else if (!strcmp(r, "r")) {
 372             qemu_uname_release = argv[optind++];
 373         } else if (!strcmp(r, "cpu")) {
 374             cpu_model = argv[optind++];
 375             if (is_help_option(cpu_model)) {
 376                 /* XXX: implement xxx_cpu_list for targets that still miss it */
 377 #if defined(cpu_list)
 378                 cpu_list();
 379 #endif
 380                 exit(1);
 381             }
 382         } else if (!strcmp(r, "B")) {
 383             rv = qemu_strtoul(argv[optind++], NULL, 0, &guest_base);
 384             if (rv < 0) {
 385                 usage();
 386             }
 387             have_guest_base = true;
 388         } else if (!strcmp(r, "drop-ld-preload")) {
 389             (void) envlist_unsetenv(envlist, "LD_PRELOAD");
 390         } else if (!strcmp(r, "seed")) {
 391             seed_optarg = optarg;
 392         } else if (!strcmp(r, "singlestep")) {
 393             singlestep = 1;
 394         } else if (!strcmp(r, "strace")) {
 395             do_strace = 1;
 396         } else if (!strcmp(r, "trace")) {
 397             trace_opt_parse(optarg);
 398         } else if (!strcmp(r, "0")) {
 399             argv0 = argv[optind++];
 400         } else {
 401             usage();
 402         }
 403     }
 404
 405     /* init debug */
 406     {
 407         int mask = 0;
 408         if (log_mask) {
 409             mask = qemu_str_to_log_mask(log_mask);
 410             if (!mask) {
 411                 qemu_print_log_usage(stdout);
 412                 exit(1);
 413             }
 414         }
 415         qemu_set_log_filename_flags(log_file, mask, &error_fatal);
 416     }
 417
 418     if (optind >= argc) {
 419         usage();
 420     }
 421     filename = argv[optind];
 422     if (argv0) {
 423         argv[optind] = argv0;
 424     }
 425
 426     if (!trace_init_backends()) {
 427         exit(1);
 428     }
 429     trace_init_file();
 430
 431     /* Zero out regs */
 432     memset(regs, 0, sizeof(struct target_pt_regs));
 433
 434     /* Zero bsd params */
 435     memset(&bprm, 0, sizeof(bprm));
 436
 437     /* Zero out image_info */
 438     memset(info, 0, sizeof(struct image_info));
 439
 440     /* Scan interp_prefix dir for replacement files. */
 441     init_paths(interp_prefix);
 442
 443     if (cpu_model == NULL) {
 444         cpu_model = TARGET_DEFAULT_CPU_MODEL;
 445     }
 446
 447     cpu_type = parse_cpu_option(cpu_model);
 448
 449     /* init tcg before creating CPUs and to get qemu_host_page_size */
 450     {
 451         AccelClass *ac = ACCEL_GET_CLASS(current_accel());
 452
 453         accel_init_interfaces(ac);
 454         ac->init_machine(NULL);
 455     }
 456     cpu = cpu_create(cpu_type);
 457     env = cpu->env_ptr;
 458     cpu_reset(cpu);
 459     thread_cpu = cpu;
 460
 461     if (getenv("QEMU_STRACE")) {
 462         do_strace = 1;
 463     }
 464
 465     target_environ = envlist_to_environ(envlist, NULL);
 466     envlist_free(envlist);
 467
 468     if (reserved_va) {
 469             mmap_next_start = reserved_va;
 470     }
 471
 472     {
 473         Error *err = NULL;
 474         if (seed_optarg != NULL) {
 475             qemu_guest_random_seed_main(seed_optarg, &err);
 476         } else {
 477             qcrypto_init(&err);
 478         }
 479         if (err) {
 480             error_reportf_err(err, "cannot initialize crypto: ");
 481             exit(1);
 482         }
 483     }
 484
 485     /*
 486      * Now that page sizes are configured we can do
 487      * proper page alignment for guest_base.
 488      */
 489     guest_base = HOST_PAGE_ALIGN(guest_base);
 490
 491     if (loader_exec(filename, argv + optind, target_environ, regs, info,
 492                     &bprm) != 0) {
 493         printf("Error loading %s\n", filename);
 494         _exit(1);
 495     }
 496
 497     for (wrk = target_environ; *wrk; wrk++) {
 498         g_free(*wrk);
 499     }
 500
 501     g_free(target_environ);
 502
 503     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 504         FILE *f = qemu_log_trylock();
 505         if (f) {
 506             fprintf(f, "guest_base  %p\n", (void *)guest_base);
 507             fprintf(f, "page layout changed following binary load\n");
 508             page_dump(f);
 509
 510             fprintf(f, "start_brk   0x" TARGET_ABI_FMT_lx "\n",
 511                     info->start_brk);
 512             fprintf(f, "end_code    0x" TARGET_ABI_FMT_lx "\n",
 513                     info->end_code);
 514             fprintf(f, "start_code  0x" TARGET_ABI_FMT_lx "\n",
 515                     info->start_code);
 516             fprintf(f, "start_data  0x" TARGET_ABI_FMT_lx "\n",
 517                     info->start_data);
 518             fprintf(f, "end_data    0x" TARGET_ABI_FMT_lx "\n",
 519                     info->end_data);
 520             fprintf(f, "start_stack 0x" TARGET_ABI_FMT_lx "\n",
 521                     info->start_stack);
 522             fprintf(f, "brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 523             fprintf(f, "entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 524
 525             qemu_log_unlock(f);
 526         }
 527     }
 528
 529     /* build Task State */
 530     ts = g_new0(TaskState, 1);
 531     init_task_state(ts);
 532     ts->info = info;
 533     ts->bprm = &bprm;
 534     cpu->opaque = ts;
 535
 536     target_set_brk(info->brk);
 537     syscall_init();
 538     signal_init();
 539
 540     /*
 541      * Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 542      * generating the prologue until now so that the prologue can take
 543      * the real value of GUEST_BASE into account.
 544      */
 545     tcg_prologue_init(tcg_ctx);
 546
 547     target_cpu_init(env, regs);
 548
 549     if (gdbstub) {
 550         gdbserver_start(gdbstub);
 551         gdb_handlesig(cpu, 0);
 552     }
 553     cpu_loop(env);
 554     /* never exits */
 555     return 0;
 556 }