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/startup.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 static bool opt_one_insn_per_tb;
  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 #   define MAX_RESERVED_VA  0xfffffffful
  72 #  else
  73 #   define MAX_RESERVED_VA  ((1ul << TARGET_VIRT_ADDR_SPACE_BITS) - 1)
  74 #  endif
  75 # else
  76 #  define MAX_RESERVED_VA  0
  77 # endif
  78 #endif
  79
  80 /*
  81  * That said, reserving *too* much vm space via mmap can run into problems
  82  * with rlimits, oom due to page table creation, etc.  We will still try it,
  83  * if directed by the command-line option, but not by default.
  84  */
  85 #if HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32
  86 unsigned long reserved_va = MAX_RESERVED_VA;
  87 #else
  88 unsigned long reserved_va;
  89 #endif
  90
  91 const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
  92 const char *qemu_uname_release;
  93 char qemu_proc_pathname[PATH_MAX];  /* full path to exeutable */
  94
  95 unsigned long target_maxtsiz = TARGET_MAXTSIZ;   /* max text size */
  96 unsigned long target_dfldsiz = TARGET_DFLDSIZ;   /* initial data size limit */
  97 unsigned long target_maxdsiz = TARGET_MAXDSIZ;   /* max data size */
  98 unsigned long target_dflssiz = TARGET_DFLSSIZ;   /* initial data size limit */
  99 unsigned long target_maxssiz = TARGET_MAXSSIZ;   /* max stack size */
 100 unsigned long target_sgrowsiz = TARGET_SGROWSIZ; /* amount to grow stack */
 101
 102 /* Helper routines for implementing atomic operations. */
 103
 104 void fork_start(void)
 105 {
 106     start_exclusive();
 107     cpu_list_lock();
 108     mmap_fork_start();
 109 }
 110
 111 void fork_end(int child)
 112 {
 113     if (child) {
 114         CPUState *cpu, *next_cpu;
 115         /*
 116          * Child processes created by fork() only have a single thread.  Discard
 117          * information about the parent threads.
 118          */
 119         CPU_FOREACH_SAFE(cpu, next_cpu) {
 120             if (cpu != thread_cpu) {
 121                 QTAILQ_REMOVE_RCU(&cpus_queue, cpu, node);
 122             }
 123         }
 124         mmap_fork_end(child);
 125         /*
 126          * qemu_init_cpu_list() takes care of reinitializing the exclusive
 127          * state, so we don't need to end_exclusive() here.
 128          */
 129         qemu_init_cpu_list();
 130         gdbserver_fork(thread_cpu);
 131     } else {
 132         mmap_fork_end(child);
 133         cpu_list_unlock();
 134         end_exclusive();
 135     }
 136 }
 137
 138 void cpu_loop(CPUArchState *env)
 139 {
 140     target_cpu_loop(env);
 141 }
 142
 143 static void usage(void)
 144 {
 145     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 146            "\n" QEMU_COPYRIGHT "\n"
 147            "usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 148            "BSD CPU emulator (compiled for %s emulation)\n"
 149            "\n"
 150            "Standard options:\n"
 151            "-h                print this help\n"
 152            "-g port           wait gdb connection to port\n"
 153            "-L path           set the elf interpreter prefix (default=%s)\n"
 154            "-s size           set the stack size in bytes (default=%ld)\n"
 155            "-cpu model        select CPU (-cpu help for list)\n"
 156            "-drop-ld-preload  drop LD_PRELOAD for target process\n"
 157            "-E var=value      sets/modifies targets environment variable(s)\n"
 158            "-U var            unsets targets environment variable(s)\n"
 159            "-B address        set guest_base address to address\n"
 160            "\n"
 161            "Debug options:\n"
 162            "-d item1[,...]    enable logging of specified items\n"
 163            "                  (use '-d help' for a list of log items)\n"
 164            "-D logfile        write logs to 'logfile' (default stderr)\n"
 165            "-one-insn-per-tb  run with one guest instruction per emulated TB\n"
 166            "-singlestep       deprecated synonym for -one-insn-per-tb\n"
 167            "-strace           log system calls\n"
 168            "-trace            [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 169            "                  specify tracing options\n"
 170            "\n"
 171            "Environment variables:\n"
 172            "QEMU_STRACE       Print system calls and arguments similar to the\n"
 173            "                  'strace' program.  Enable by setting to any value.\n"
 174            "You can use -E and -U options to set/unset environment variables\n"
 175            "for target process.  It is possible to provide several variables\n"
 176            "by repeating the option.  For example:\n"
 177            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 178            "Note that if you provide several changes to single variable\n"
 179            "last change will stay in effect.\n"
 180            "\n"
 181            QEMU_HELP_BOTTOM "\n"
 182            ,
 183            TARGET_NAME,
 184            interp_prefix,
 185            target_dflssiz);
 186     exit(1);
 187 }
 188
 189 __thread CPUState *thread_cpu;
 190
 191 void stop_all_tasks(void)
 192 {
 193     /*
 194      * We trust when using NPTL (pthreads) start_exclusive() handles thread
 195      * stopping correctly.
 196      */
 197     start_exclusive();
 198 }
 199
 200 bool qemu_cpu_is_self(CPUState *cpu)
 201 {
 202     return thread_cpu == cpu;
 203 }
 204
 205 void qemu_cpu_kick(CPUState *cpu)
 206 {
 207     cpu_exit(cpu);
 208 }
 209
 210 /* Assumes contents are already zeroed.  */
 211 static void init_task_state(TaskState *ts)
 212 {
 213     ts->sigaltstack_used = (struct target_sigaltstack) {
 214         .ss_sp = 0,
 215         .ss_size = 0,
 216         .ss_flags = TARGET_SS_DISABLE,
 217     };
 218 }
 219
 220 void gemu_log(const char *fmt, ...)
 221 {
 222     va_list ap;
 223
 224     va_start(ap, fmt);
 225     vfprintf(stderr, fmt, ap);
 226     va_end(ap);
 227 }
 228
 229 static void
 230 adjust_ssize(void)
 231 {
 232     struct rlimit rl;
 233
 234     if (getrlimit(RLIMIT_STACK, &rl) != 0) {
 235         return;
 236     }
 237
 238     target_maxssiz = MIN(target_maxssiz, rl.rlim_max);
 239     target_dflssiz = MIN(MAX(target_dflssiz, rl.rlim_cur), target_maxssiz);
 240
 241     rl.rlim_max = target_maxssiz;
 242     rl.rlim_cur = target_dflssiz;
 243     setrlimit(RLIMIT_STACK, &rl);
 244 }
 245
 246 static void save_proc_pathname(char *argv0)
 247 {
 248     int mib[4];
 249     size_t len;
 250
 251     mib[0] = CTL_KERN;
 252     mib[1] = KERN_PROC;
 253     mib[2] = KERN_PROC_PATHNAME;
 254     mib[3] = -1;
 255
 256     len = sizeof(qemu_proc_pathname);
 257     if (sysctl(mib, 4, qemu_proc_pathname, &len, NULL, 0)) {
 258         perror("sysctl");
 259     }
 260 }
 261
 262 int main(int argc, char **argv)
 263 {
 264     const char *filename;
 265     const char *cpu_model;
 266     const char *cpu_type;
 267     const char *log_file = NULL;
 268     const char *log_mask = NULL;
 269     const char *seed_optarg = NULL;
 270     struct target_pt_regs regs1, *regs = &regs1;
 271     struct image_info info1, *info = &info1;
 272     struct bsd_binprm bprm;
 273     TaskState *ts;
 274     CPUArchState *env;
 275     CPUState *cpu;
 276     int optind, rv;
 277     const char *r;
 278     const char *gdbstub = NULL;
 279     char **target_environ, **wrk;
 280     envlist_t *envlist = NULL;
 281     char *argv0 = NULL;
 282
 283     adjust_ssize();
 284
 285     if (argc <= 1) {
 286         usage();
 287     }
 288
 289     save_proc_pathname(argv[0]);
 290
 291     error_init(argv[0]);
 292     module_call_init(MODULE_INIT_TRACE);
 293     qemu_init_cpu_list();
 294     module_call_init(MODULE_INIT_QOM);
 295
 296     envlist = envlist_create();
 297
 298     /*
 299      * add current environment into the list
 300      * envlist_setenv adds to the front of the list; to preserve environ
 301      * order add from back to front
 302      */
 303     for (wrk = environ; *wrk != NULL; wrk++) {
 304         continue;
 305     }
 306     while (wrk != environ) {
 307         wrk--;
 308         (void) envlist_setenv(envlist, *wrk);
 309     }
 310
 311     cpu_model = NULL;
 312
 313     qemu_add_opts(&qemu_trace_opts);
 314
 315     optind = 1;
 316     for (;;) {
 317         if (optind >= argc) {
 318             break;
 319         }
 320         r = argv[optind];
 321         if (r[0] != '-') {
 322             break;
 323         }
 324         optind++;
 325         r++;
 326         if (!strcmp(r, "-")) {
 327             break;
 328         } else if (!strcmp(r, "d")) {
 329             if (optind >= argc) {
 330                 break;
 331             }
 332             log_mask = argv[optind++];
 333         } else if (!strcmp(r, "D")) {
 334             if (optind >= argc) {
 335                 break;
 336             }
 337             log_file = argv[optind++];
 338         } else if (!strcmp(r, "E")) {
 339             r = argv[optind++];
 340             if (envlist_setenv(envlist, r) != 0) {
 341                 usage();
 342             }
 343         } else if (!strcmp(r, "ignore-environment")) {
 344             envlist_free(envlist);
 345             envlist = envlist_create();
 346         } else if (!strcmp(r, "U")) {
 347             r = argv[optind++];
 348             if (envlist_unsetenv(envlist, r) != 0) {
 349                 usage();
 350             }
 351         } else if (!strcmp(r, "s")) {
 352             r = argv[optind++];
 353             rv = qemu_strtoul(r, &r, 0, &target_dflssiz);
 354             if (rv < 0 || target_dflssiz <= 0) {
 355                 usage();
 356             }
 357             if (*r == 'M') {
 358                 target_dflssiz *= 1024 * 1024;
 359             } else if (*r == 'k' || *r == 'K') {
 360                 target_dflssiz *= 1024;
 361             }
 362             if (target_dflssiz > target_maxssiz) {
 363                 usage();
 364             }
 365         } else if (!strcmp(r, "L")) {
 366             interp_prefix = argv[optind++];
 367         } else if (!strcmp(r, "p")) {
 368             qemu_host_page_size = atoi(argv[optind++]);
 369             if (qemu_host_page_size == 0 ||
 370                 (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
 371                 fprintf(stderr, "page size must be a power of two\n");
 372                 exit(1);
 373             }
 374         } else if (!strcmp(r, "g")) {
 375             gdbstub = g_strdup(argv[optind++]);
 376         } else if (!strcmp(r, "r")) {
 377             qemu_uname_release = argv[optind++];
 378         } else if (!strcmp(r, "cpu")) {
 379             cpu_model = argv[optind++];
 380             if (is_help_option(cpu_model)) {
 381                 list_cpus();
 382                 exit(1);
 383             }
 384         } else if (!strcmp(r, "B")) {
 385             rv = qemu_strtoul(argv[optind++], NULL, 0, &guest_base);
 386             if (rv < 0) {
 387                 usage();
 388             }
 389             have_guest_base = true;
 390         } else if (!strcmp(r, "drop-ld-preload")) {
 391             (void) envlist_unsetenv(envlist, "LD_PRELOAD");
 392         } else if (!strcmp(r, "seed")) {
 393             seed_optarg = optarg;
 394         } else if (!strcmp(r, "singlestep") || !strcmp(r, "one-insn-per-tb")) {
 395             opt_one_insn_per_tb = true;
 396         } else if (!strcmp(r, "strace")) {
 397             do_strace = 1;
 398         } else if (!strcmp(r, "trace")) {
 399             trace_opt_parse(optarg);
 400         } else if (!strcmp(r, "0")) {
 401             argv0 = argv[optind++];
 402         } else {
 403             usage();
 404         }
 405     }
 406
 407     /* init debug */
 408     {
 409         int mask = 0;
 410         if (log_mask) {
 411             mask = qemu_str_to_log_mask(log_mask);
 412             if (!mask) {
 413                 qemu_print_log_usage(stdout);
 414                 exit(1);
 415             }
 416         }
 417         qemu_set_log_filename_flags(log_file, mask, &error_fatal);
 418     }
 419
 420     if (optind >= argc) {
 421         usage();
 422     }
 423     filename = argv[optind];
 424     if (argv0) {
 425         argv[optind] = argv0;
 426     }
 427
 428     if (!trace_init_backends()) {
 429         exit(1);
 430     }
 431     trace_init_file();
 432
 433     /* Zero out regs */
 434     memset(regs, 0, sizeof(struct target_pt_regs));
 435
 436     /* Zero bsd params */
 437     memset(&bprm, 0, sizeof(bprm));
 438
 439     /* Zero out image_info */
 440     memset(info, 0, sizeof(struct image_info));
 441
 442     /* Scan interp_prefix dir for replacement files. */
 443     init_paths(interp_prefix);
 444
 445     if (cpu_model == NULL) {
 446         cpu_model = TARGET_DEFAULT_CPU_MODEL;
 447     }
 448
 449     cpu_type = parse_cpu_option(cpu_model);
 450
 451     /* init tcg before creating CPUs and to get qemu_host_page_size */
 452     {
 453         AccelState *accel = current_accel();
 454         AccelClass *ac = ACCEL_GET_CLASS(accel);
 455
 456         accel_init_interfaces(ac);
 457         object_property_set_bool(OBJECT(accel), "one-insn-per-tb",
 458                                  opt_one_insn_per_tb, &error_abort);
 459         ac->init_machine(NULL);
 460     }
 461     cpu = cpu_create(cpu_type);
 462     env = cpu_env(cpu);
 463     cpu_reset(cpu);
 464     thread_cpu = cpu;
 465
 466     if (getenv("QEMU_STRACE")) {
 467         do_strace = 1;
 468     }
 469
 470     target_environ = envlist_to_environ(envlist, NULL);
 471     envlist_free(envlist);
 472
 473     {
 474         Error *err = NULL;
 475         if (seed_optarg != NULL) {
 476             qemu_guest_random_seed_main(seed_optarg, &err);
 477         } else {
 478             qcrypto_init(&err);
 479         }
 480         if (err) {
 481             error_reportf_err(err, "cannot initialize crypto: ");
 482             exit(1);
 483         }
 484     }
 485
 486     /*
 487      * Now that page sizes are configured we can do
 488      * proper page alignment for guest_base.
 489      */
 490     if (have_guest_base) {
 491         if (guest_base & ~qemu_host_page_mask) {
 492             error_report("Selected guest base not host page aligned");
 493             exit(1);
 494         }
 495     }
 496
 497     /*
 498      * If reserving host virtual address space, do so now.
 499      * Combined with '-B', ensure that the chosen range is free.
 500      */
 501     if (reserved_va) {
 502         void *p;
 503
 504         if (have_guest_base) {
 505             p = mmap((void *)guest_base, reserved_va + 1, PROT_NONE,
 506                      MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_EXCL, -1, 0);
 507         } else {
 508             p = mmap(NULL, reserved_va + 1, PROT_NONE,
 509                      MAP_ANON | MAP_PRIVATE, -1, 0);
 510         }
 511         if (p == MAP_FAILED) {
 512             const char *err = strerror(errno);
 513             char *sz = size_to_str(reserved_va + 1);
 514
 515             if (have_guest_base) {
 516                 error_report("Cannot allocate %s bytes at -B %p for guest "
 517                              "address space: %s", sz, (void *)guest_base, err);
 518             } else {
 519                 error_report("Cannot allocate %s bytes for guest "
 520                              "address space: %s", sz, err);
 521             }
 522             exit(1);
 523         }
 524         guest_base = (uintptr_t)p;
 525         have_guest_base = true;
 526
 527         /* Ensure that mmap_next_start is within range. */
 528         if (reserved_va <= mmap_next_start) {
 529             mmap_next_start = (reserved_va / 4 * 3)
 530                               & TARGET_PAGE_MASK & qemu_host_page_mask;
 531         }
 532     }
 533
 534     if (loader_exec(filename, argv + optind, target_environ, regs, info,
 535                     &bprm) != 0) {
 536         printf("Error loading %s\n", filename);
 537         _exit(1);
 538     }
 539
 540     for (wrk = target_environ; *wrk; wrk++) {
 541         g_free(*wrk);
 542     }
 543
 544     g_free(target_environ);
 545
 546     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 547         FILE *f = qemu_log_trylock();
 548         if (f) {
 549             fprintf(f, "guest_base  %p\n", (void *)guest_base);
 550             fprintf(f, "page layout changed following binary load\n");
 551             page_dump(f);
 552
 553             fprintf(f, "end_code    0x" TARGET_ABI_FMT_lx "\n",
 554                     info->end_code);
 555             fprintf(f, "start_code  0x" TARGET_ABI_FMT_lx "\n",
 556                     info->start_code);
 557             fprintf(f, "start_data  0x" TARGET_ABI_FMT_lx "\n",
 558                     info->start_data);
 559             fprintf(f, "end_data    0x" TARGET_ABI_FMT_lx "\n",
 560                     info->end_data);
 561             fprintf(f, "start_stack 0x" TARGET_ABI_FMT_lx "\n",
 562                     info->start_stack);
 563             fprintf(f, "brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 564             fprintf(f, "entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 565
 566             qemu_log_unlock(f);
 567         }
 568     }
 569
 570     /* build Task State */
 571     ts = g_new0(TaskState, 1);
 572     init_task_state(ts);
 573     ts->info = info;
 574     ts->bprm = &bprm;
 575     cpu->opaque = ts;
 576
 577     target_set_brk(info->brk);
 578     syscall_init();
 579     signal_init();
 580
 581     /*
 582      * Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 583      * generating the prologue until now so that the prologue can take
 584      * the real value of GUEST_BASE into account.
 585      */
 586     tcg_prologue_init();
 587
 588     target_cpu_init(env, regs);
 589
 590     if (gdbstub) {
 591         gdbserver_start(gdbstub);
 592         gdb_handlesig(cpu, 0);
 593     }
 594     cpu_loop(env);
 595     /* never exits */
 596     return 0;
 597 }