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 "qemu/plugin.h"
  39 #include "user/guest-base.h"
  40 #include "user/page-protection.h"
  41 #include "accel/accel-ops.h"
  42 #include "tcg/startup.h"
  43 #include "qemu/timer.h"
  44 #include "qemu/envlist.h"
  45 #include "qemu/cutils.h"
  46 #include "exec/log.h"
  47 #include "trace/control.h"
  48 #include "crypto/init.h"
  49 #include "qemu/guest-random.h"
  50 #include "gdbstub/user.h"
  51 #include "exec/page-vary.h"
  52
  53 #include "host-os.h"
  54 #include "target_arch_cpu.h"
  55
  56
  57 /*
  58  * TODO: Remove these and rely only on qemu_real_host_page_size().
  59  */
  60 uintptr_t qemu_host_page_size;
  61 intptr_t qemu_host_page_mask;
  62
  63 static bool opt_one_insn_per_tb;
  64 static unsigned long opt_tb_size;
  65 uintptr_t guest_base;
  66 bool have_guest_base;
  67 /*
  68  * When running 32-on-64 we should make sure we can fit all of the possible
  69  * guest address space into a contiguous chunk of virtual host memory.
  70  *
  71  * This way we will never overlap with our own libraries or binaries or stack
  72  * or anything else that QEMU maps.
  73  *
  74  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
  75  * of the address for the kernel.  Some cpus rely on this and user space
  76  * uses the high bit(s) for pointer tagging and the like.  For them, we
  77  * must preserve the expected address space.
  78  */
  79 #ifndef MAX_RESERVED_VA
  80 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
  81 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
  82       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
  83 #   define MAX_RESERVED_VA(CPU)  0xfffffffful
  84 #  else
  85 #   define MAX_RESERVED_VA(CPU)  ((1ul << TARGET_VIRT_ADDR_SPACE_BITS) - 1)
  86 #  endif
  87 # else
  88 #  define MAX_RESERVED_VA(CPU)  0
  89 # endif
  90 #endif
  91
  92 unsigned long reserved_va;
  93 unsigned long guest_addr_max;
  94
  95 const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
  96 const char *qemu_uname_release;
  97
  98 unsigned long target_maxtsiz = TARGET_MAXTSIZ;   /* max text size */
  99 unsigned long target_dfldsiz = TARGET_DFLDSIZ;   /* initial data size limit */
 100 unsigned long target_maxdsiz = TARGET_MAXDSIZ;   /* max data size */
 101 unsigned long target_dflssiz = TARGET_DFLSSIZ;   /* initial data size limit */
 102 unsigned long target_maxssiz = TARGET_MAXSSIZ;   /* max stack size */
 103 unsigned long target_sgrowsiz = TARGET_SGROWSIZ; /* amount to grow stack */
 104
 105 /* Helper routines for implementing atomic operations. */
 106
 107 void fork_start(void)
 108 {
 109     start_exclusive();
 110     mmap_fork_start();
 111     cpu_list_lock();
 112     qemu_plugin_user_prefork_lock();
 113     gdbserver_fork_start();
 114 }
 115
 116 void fork_end(pid_t pid)
 117 {
 118     bool child = pid == 0;
 119
 120     qemu_plugin_user_postfork(child);
 121     mmap_fork_end(child);
 122     if (child) {
 123         CPUState *cpu, *next_cpu;
 124         /*
 125          * Child processes created by fork() only have a single thread.
 126          * Discard information about the parent threads.
 127          */
 128         CPU_FOREACH_SAFE(cpu, next_cpu) {
 129             if (cpu != thread_cpu) {
 130                 QTAILQ_REMOVE_RCU(&cpus_queue, cpu, node);
 131             }
 132         }
 133         qemu_init_cpu_list();
 134         get_task_state(thread_cpu)->ts_tid = qemu_get_thread_id();
 135     } else {
 136         cpu_list_unlock();
 137     }
 138     gdbserver_fork_end(thread_cpu, pid);
 139     /*
 140      * qemu_init_cpu_list() reinitialized the child exclusive state, but we
 141      * also need to keep current_cpu consistent, so call end_exclusive() for
 142      * both child and parent.
 143      */
 144     end_exclusive();
 145 }
 146
 147 void cpu_loop(CPUArchState *env)
 148 {
 149     target_cpu_loop(env);
 150 }
 151
 152 static void usage(void)
 153 {
 154     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
 155            "\n" QEMU_COPYRIGHT "\n"
 156            "usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
 157            "BSD CPU emulator (compiled for %s emulation)\n"
 158            "\n"
 159            "Standard options:\n"
 160            "-h                print this help\n"
 161            "-g port           wait gdb connection to port\n"
 162            "-L path           set the elf interpreter prefix (default=%s)\n"
 163            "-s size           set the stack size in bytes (default=%ld)\n"
 164            "-cpu model        select CPU (-cpu help for list)\n"
 165            "-drop-ld-preload  drop LD_PRELOAD for target process\n"
 166            "-E var=value      sets/modifies targets environment variable(s)\n"
 167            "-U var            unsets targets environment variable(s)\n"
 168            "-B address        set guest_base address to address\n"
 169            "\n"
 170            "Debug options:\n"
 171            "-d item1[,...]    enable logging of specified items\n"
 172            "                  (use '-d help' for a list of log items)\n"
 173            "-D logfile        write logs to 'logfile' (default stderr)\n"
 174            "-one-insn-per-tb  run with one guest instruction per emulated TB\n"
 175            "-tb-size size     TCG translation block cache size\n"
 176            "-strace           log system calls\n"
 177            "-trace            [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
 178            "                  specify tracing options\n"
 179 #ifdef CONFIG_PLUGIN
 180            "-plugin           [file=]<file>[,<argname>=<argvalue>]\n"
 181 #endif
 182            "\n"
 183            "Environment variables:\n"
 184            "QEMU_STRACE       Print system calls and arguments similar to the\n"
 185            "                  'strace' program.  Enable by setting to any value.\n"
 186            "You can use -E and -U options to set/unset environment variables\n"
 187            "for target process.  It is possible to provide several variables\n"
 188            "by repeating the option.  For example:\n"
 189            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
 190            "Note that if you provide several changes to single variable\n"
 191            "last change will stay in effect.\n"
 192            "\n"
 193            QEMU_HELP_BOTTOM "\n"
 194            ,
 195            TARGET_NAME,
 196            interp_prefix,
 197            target_dflssiz);
 198     exit(1);
 199 }
 200
 201 __thread CPUState *thread_cpu;
 202
 203 void stop_all_tasks(void)
 204 {
 205     /*
 206      * We trust when using NPTL (pthreads) start_exclusive() handles thread
 207      * stopping correctly.
 208      */
 209     start_exclusive();
 210 }
 211
 212 bool qemu_cpu_is_self(CPUState *cpu)
 213 {
 214     return thread_cpu == cpu;
 215 }
 216
 217 void qemu_cpu_kick(CPUState *cpu)
 218 {
 219     cpu_exit(cpu);
 220 }
 221
 222 /* Assumes contents are already zeroed.  */
 223 static void init_task_state(TaskState *ts)
 224 {
 225     ts->sigaltstack_used = (struct target_sigaltstack) {
 226         .ss_sp = 0,
 227         .ss_size = 0,
 228         .ss_flags = TARGET_SS_DISABLE,
 229     };
 230 }
 231
 232 static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
 233
 234 void gemu_log(const char *fmt, ...)
 235 {
 236     va_list ap;
 237
 238     va_start(ap, fmt);
 239     vfprintf(stderr, fmt, ap);
 240     va_end(ap);
 241 }
 242
 243 static void
 244 adjust_ssize(void)
 245 {
 246     struct rlimit rl;
 247
 248     if (getrlimit(RLIMIT_STACK, &rl) != 0) {
 249         return;
 250     }
 251
 252     target_maxssiz = MIN(target_maxssiz, rl.rlim_max);
 253     target_dflssiz = MIN(MAX(target_dflssiz, rl.rlim_cur), target_maxssiz);
 254
 255     rl.rlim_max = target_maxssiz;
 256     rl.rlim_cur = target_dflssiz;
 257     setrlimit(RLIMIT_STACK, &rl);
 258 }
 259
 260 int main(int argc, char **argv)
 261 {
 262     const char *filename;
 263     const char *cpu_model;
 264     const char *cpu_type;
 265     const char *log_file = NULL;
 266     const char *log_mask = NULL;
 267     const char *seed_optarg = NULL;
 268     struct target_pt_regs regs1, *regs = &regs1;
 269     struct image_info info1, *info = &info1;
 270     struct bsd_binprm bprm;
 271     TaskState *ts;
 272     CPUArchState *env;
 273     CPUState *cpu;
 274     int optind, rv;
 275     const char *r;
 276     const char *gdbstub = NULL;
 277     char **target_environ, **wrk;
 278     envlist_t *envlist = NULL;
 279     char *argv0 = NULL;
 280     int host_page_size;
 281     unsigned long max_reserved_va;
 282
 283     adjust_ssize();
 284
 285     if (argc <= 1) {
 286         usage();
 287     }
 288
 289
 290     error_init(argv[0]);
 291     module_call_init(MODULE_INIT_TRACE);
 292     qemu_init_cpu_list();
 293     module_call_init(MODULE_INIT_QOM);
 294
 295     envlist = envlist_create();
 296
 297     /*
 298      * add current environment into the list
 299      * envlist_setenv adds to the front of the list; to preserve environ
 300      * order add from back to front
 301      */
 302     for (wrk = environ; *wrk != NULL; wrk++) {
 303         continue;
 304     }
 305     while (wrk != environ) {
 306         wrk--;
 307         (void) envlist_setenv(envlist, *wrk);
 308     }
 309
 310     qemu_host_page_size = getpagesize();
 311     qemu_host_page_size = MAX(qemu_host_page_size, TARGET_PAGE_SIZE);
 312
 313     cpu_model = NULL;
 314
 315     qemu_add_opts(&qemu_trace_opts);
 316     qemu_plugin_add_opts();
 317
 318     optind = 1;
 319     for (;;) {
 320         if (optind >= argc) {
 321             break;
 322         }
 323         r = argv[optind];
 324         if (r[0] != '-') {
 325             break;
 326         }
 327         optind++;
 328         r++;
 329         if (!strcmp(r, "-")) {
 330             break;
 331         } else if (!strcmp(r, "d")) {
 332             if (optind >= argc) {
 333                 break;
 334             }
 335             log_mask = argv[optind++];
 336         } else if (!strcmp(r, "D")) {
 337             if (optind >= argc) {
 338                 break;
 339             }
 340             log_file = argv[optind++];
 341         } else if (!strcmp(r, "E")) {
 342             r = argv[optind++];
 343             if (envlist_setenv(envlist, r) != 0) {
 344                 usage();
 345             }
 346         } else if (!strcmp(r, "ignore-environment")) {
 347             envlist_free(envlist);
 348             envlist = envlist_create();
 349         } else if (!strcmp(r, "U")) {
 350             r = argv[optind++];
 351             if (envlist_unsetenv(envlist, r) != 0) {
 352                 usage();
 353             }
 354         } else if (!strcmp(r, "s")) {
 355             r = argv[optind++];
 356             rv = qemu_strtoul(r, &r, 0, &target_dflssiz);
 357             if (rv < 0 || target_dflssiz <= 0) {
 358                 usage();
 359             }
 360             if (*r == 'M') {
 361                 target_dflssiz *= 1024 * 1024;
 362             } else if (*r == 'k' || *r == 'K') {
 363                 target_dflssiz *= 1024;
 364             }
 365             if (target_dflssiz > target_maxssiz) {
 366                 usage();
 367             }
 368         } else if (!strcmp(r, "L")) {
 369             interp_prefix = argv[optind++];
 370         } else if (!strcmp(r, "g")) {
 371             gdbstub = g_strdup(argv[optind++]);
 372         } else if (!strcmp(r, "r")) {
 373             qemu_uname_release = argv[optind++];
 374         } else if (!strcmp(r, "cpu")) {
 375             cpu_model = argv[optind++];
 376             if (is_help_option(cpu_model)) {
 377                 list_cpus();
 378                 exit(1);
 379             }
 380         } else if (!strcmp(r, "B")) {
 381             rv = qemu_strtoul(argv[optind++], NULL, 0, &guest_base);
 382             if (rv < 0) {
 383                 usage();
 384             }
 385             have_guest_base = true;
 386         } else if (!strcmp(r, "drop-ld-preload")) {
 387             (void) envlist_unsetenv(envlist, "LD_PRELOAD");
 388         } else if (!strcmp(r, "seed")) {
 389             seed_optarg = optarg;
 390         } else if (!strcmp(r, "one-insn-per-tb")) {
 391             opt_one_insn_per_tb = true;
 392         } else if (!strcmp(r, "tb-size")) {
 393             r = argv[optind++];
 394             if (qemu_strtoul(r, NULL, 0, &opt_tb_size)) {
 395                 usage();
 396             }
 397         } else if (!strcmp(r, "strace")) {
 398             do_strace = 1;
 399         } else if (!strcmp(r, "trace")) {
 400             trace_opt_parse(optarg);
 401 #ifdef CONFIG_PLUGIN
 402         } else if (!strcmp(r, "plugin")) {
 403             r = argv[optind++];
 404             qemu_plugin_opt_parse(r, &plugins);
 405 #endif
 406         } else if (!strcmp(r, "0")) {
 407             argv0 = argv[optind++];
 408         } else {
 409             usage();
 410         }
 411     }
 412
 413     qemu_host_page_mask = -qemu_host_page_size;
 414
 415     /* init debug */
 416     {
 417         int mask = 0;
 418         if (log_mask) {
 419             mask = qemu_str_to_log_mask(log_mask);
 420             if (!mask) {
 421                 qemu_print_log_usage(stdout);
 422                 exit(1);
 423             }
 424         }
 425         qemu_set_log_filename_flags(log_file, mask, &error_fatal);
 426     }
 427
 428     if (optind >= argc) {
 429         usage();
 430     }
 431     filename = argv[optind];
 432     if (argv0) {
 433         argv[optind] = argv0;
 434     }
 435
 436     if (!trace_init_backends()) {
 437         exit(1);
 438     }
 439     trace_init_file();
 440     qemu_plugin_load_list(&plugins, &error_fatal);
 441
 442     /* Zero out regs */
 443     memset(regs, 0, sizeof(struct target_pt_regs));
 444
 445     /* Zero bsd params */
 446     memset(&bprm, 0, sizeof(bprm));
 447
 448     /* Zero out image_info */
 449     memset(info, 0, sizeof(struct image_info));
 450
 451     /* Scan interp_prefix dir for replacement files. */
 452     init_paths(interp_prefix);
 453
 454     if (cpu_model == NULL) {
 455         cpu_model = TARGET_DEFAULT_CPU_MODEL;
 456     }
 457
 458     cpu_type = parse_cpu_option(cpu_model);
 459
 460     /* init tcg before creating CPUs and to get qemu_host_page_size */
 461     {
 462         AccelState *accel = current_accel();
 463         AccelClass *ac = ACCEL_GET_CLASS(accel);
 464
 465         accel_init_interfaces(ac);
 466         object_property_set_bool(OBJECT(accel), "one-insn-per-tb",
 467                                  opt_one_insn_per_tb, &error_abort);
 468         object_property_set_int(OBJECT(accel), "tb-size",
 469                                 opt_tb_size, &error_abort);
 470         ac->init_machine(accel, NULL);
 471     }
 472
 473     /*
 474      * Finalize page size before creating CPUs.
 475      * This will do nothing if !TARGET_PAGE_BITS_VARY.
 476      * The most efficient setting is to match the host.
 477      */
 478     host_page_size = qemu_real_host_page_size();
 479     set_preferred_target_page_bits(ctz32(host_page_size));
 480     finalize_target_page_bits();
 481
 482     cpu = cpu_create(cpu_type);
 483     env = cpu_env(cpu);
 484     cpu_reset(cpu);
 485     thread_cpu = cpu;
 486
 487     /*
 488      * Reserving too much vm space via mmap can run into problems with rlimits,
 489      * oom due to page table creation, etc.  We will still try it, if directed
 490      * by the command-line option, but not by default. Unless we're running a
 491      * target address space of 32 or fewer bits on a host with 64 bits.
 492      */
 493     max_reserved_va = MAX_RESERVED_VA(cpu);
 494     if (reserved_va != 0) {
 495         if ((reserved_va + 1) % host_page_size) {
 496             char *s = size_to_str(host_page_size);
 497             fprintf(stderr, "Reserved virtual address not aligned mod %s\n", s);
 498             g_free(s);
 499             exit(EXIT_FAILURE);
 500         }
 501         if (max_reserved_va && reserved_va > max_reserved_va) {
 502             fprintf(stderr, "Reserved virtual address too big\n");
 503             exit(EXIT_FAILURE);
 504         }
 505     } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
 506         /* MAX_RESERVED_VA + 1 is a large power of 2, so is aligned. */
 507         reserved_va = max_reserved_va;
 508     }
 509     if (reserved_va != 0) {
 510         guest_addr_max = reserved_va;
 511     } else if (MIN(TARGET_VIRT_ADDR_SPACE_BITS, TARGET_ABI_BITS) <= 32) {
 512         guest_addr_max = UINT32_MAX;
 513     } else {
 514         guest_addr_max = ~0ul;
 515     }
 516
 517     if (getenv("QEMU_STRACE")) {
 518         do_strace = 1;
 519     }
 520
 521     target_environ = envlist_to_environ(envlist, NULL);
 522     envlist_free(envlist);
 523
 524     {
 525         Error *err = NULL;
 526         if (seed_optarg != NULL) {
 527             qemu_guest_random_seed_main(seed_optarg, &err);
 528         } else {
 529             qcrypto_init(&err);
 530         }
 531         if (err) {
 532             error_reportf_err(err, "cannot initialize crypto: ");
 533             exit(1);
 534         }
 535     }
 536
 537     /*
 538      * Now that page sizes are configured we can do
 539      * proper page alignment for guest_base.
 540      */
 541     if (have_guest_base) {
 542         if (guest_base & ~qemu_host_page_mask) {
 543             error_report("Selected guest base not host page aligned");
 544             exit(1);
 545         }
 546     }
 547
 548     /*
 549      * If reserving host virtual address space, do so now.
 550      * Combined with '-B', ensure that the chosen range is free.
 551      */
 552     if (reserved_va) {
 553         void *p;
 554
 555         if (have_guest_base) {
 556             p = mmap((void *)guest_base, reserved_va + 1, PROT_NONE,
 557                      MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_EXCL, -1, 0);
 558         } else {
 559             p = mmap(NULL, reserved_va + 1, PROT_NONE,
 560                      MAP_ANON | MAP_PRIVATE, -1, 0);
 561         }
 562         if (p == MAP_FAILED) {
 563             const char *err = strerror(errno);
 564             char *sz = size_to_str(reserved_va + 1);
 565
 566             if (have_guest_base) {
 567                 error_report("Cannot allocate %s bytes at -B %p for guest "
 568                              "address space: %s", sz, (void *)guest_base, err);
 569             } else {
 570                 error_report("Cannot allocate %s bytes for guest "
 571                              "address space: %s", sz, err);
 572             }
 573             exit(1);
 574         }
 575         guest_base = (uintptr_t)p;
 576         have_guest_base = true;
 577
 578         /* Ensure that mmap_next_start is within range. */
 579         if (reserved_va <= mmap_next_start) {
 580             mmap_next_start = (reserved_va / 4 * 3)
 581                               & TARGET_PAGE_MASK & qemu_host_page_mask;
 582         }
 583     }
 584
 585     if (loader_exec(filename, argv + optind, target_environ, regs, info,
 586                     &bprm) != 0) {
 587         printf("Error loading %s\n", filename);
 588         _exit(1);
 589     }
 590
 591     for (wrk = target_environ; *wrk; wrk++) {
 592         g_free(*wrk);
 593     }
 594
 595     g_free(target_environ);
 596
 597     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
 598         FILE *f = qemu_log_trylock();
 599         if (f) {
 600             fprintf(f, "guest_base  %p\n", (void *)guest_base);
 601             fprintf(f, "page layout changed following binary load\n");
 602             page_dump(f);
 603
 604             fprintf(f, "end_code    0x" TARGET_ABI_FMT_lx "\n",
 605                     info->end_code);
 606             fprintf(f, "start_code  0x" TARGET_ABI_FMT_lx "\n",
 607                     info->start_code);
 608             fprintf(f, "start_data  0x" TARGET_ABI_FMT_lx "\n",
 609                     info->start_data);
 610             fprintf(f, "end_data    0x" TARGET_ABI_FMT_lx "\n",
 611                     info->end_data);
 612             fprintf(f, "start_stack 0x" TARGET_ABI_FMT_lx "\n",
 613                     info->start_stack);
 614             fprintf(f, "brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
 615             fprintf(f, "entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
 616
 617             qemu_log_unlock(f);
 618         }
 619     }
 620
 621     /* build Task State */
 622     ts = g_new0(TaskState, 1);
 623     init_task_state(ts);
 624     ts->info = info;
 625     ts->bprm = &bprm;
 626     ts->ts_tid = qemu_get_thread_id();
 627     cpu->opaque = ts;
 628
 629     target_set_brk(info->brk);
 630     syscall_init();
 631     signal_init();
 632
 633     /*
 634      * Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
 635      * generating the prologue until now so that the prologue can take
 636      * the real value of GUEST_BASE into account.
 637      */
 638     tcg_prologue_init();
 639
 640     target_cpu_init(env, regs);
 641
 642     if (gdbstub) {
 643         gdbserver_start(gdbstub, &error_fatal);
 644     }
 645     cpu_loop(env);
 646     /* never exits */
 647     return 0;
 648 }