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 "tcg/startup.h"
42 #include "qemu/timer.h"
43 #include "qemu/envlist.h"
44 #include "qemu/cutils.h"
45 #include "exec/log.h"
46 #include "trace/control.h"
47 #include "crypto/init.h"
48 #include "qemu/guest-random.h"
49 #include "gdbstub/user.h"
50 #include "exec/page-vary.h"
51
52 #include "host-os.h"
53 #include "target_arch_cpu.h"
54
55
56 /*
57 * TODO: Remove these and rely only on qemu_real_host_page_size().
58 */
59 uintptr_t qemu_host_page_size;
60 intptr_t qemu_host_page_mask;
61
62 static bool opt_one_insn_per_tb;
63 static unsigned long opt_tb_size;
64 uintptr_t guest_base;
65 bool have_guest_base;
66 /*
67 * When running 32-on-64 we should make sure we can fit all of the possible
68 * guest address space into a contiguous chunk of virtual host memory.
69 *
70 * This way we will never overlap with our own libraries or binaries or stack
71 * or anything else that QEMU maps.
72 *
73 * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
74 * of the address for the kernel. Some cpus rely on this and user space
75 * uses the high bit(s) for pointer tagging and the like. For them, we
76 * must preserve the expected address space.
77 */
78 #ifndef MAX_RESERVED_VA
79 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
80 # if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
81 (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
82 # define MAX_RESERVED_VA(CPU) 0xfffffffful
83 # else
84 # define MAX_RESERVED_VA(CPU) ((1ul << TARGET_VIRT_ADDR_SPACE_BITS) - 1)
85 # endif
86 # else
87 # define MAX_RESERVED_VA(CPU) 0
88 # endif
89 #endif
90
91 unsigned long reserved_va;
92 unsigned long guest_addr_max;
93
94 const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
95 const char *qemu_uname_release;
96
97 unsigned long target_maxtsiz = TARGET_MAXTSIZ; /* max text size */
98 unsigned long target_dfldsiz = TARGET_DFLDSIZ; /* initial data size limit */
99 unsigned long target_maxdsiz = TARGET_MAXDSIZ; /* max data size */
100 unsigned long target_dflssiz = TARGET_DFLSSIZ; /* initial data size limit */
101 unsigned long target_maxssiz = TARGET_MAXSSIZ; /* max stack size */
102 unsigned long target_sgrowsiz = TARGET_SGROWSIZ; /* amount to grow stack */
103
104 /* Helper routines for implementing atomic operations. */
105
fork_start(void)106 void fork_start(void)
107 {
108 start_exclusive();
109 mmap_fork_start();
110 cpu_list_lock();
111 qemu_plugin_user_prefork_lock();
112 gdbserver_fork_start();
113 }
114
fork_end(pid_t pid)115 void fork_end(pid_t pid)
116 {
117 bool child = pid == 0;
118
119 qemu_plugin_user_postfork(child);
120 mmap_fork_end(child);
121 if (child) {
122 CPUState *cpu, *next_cpu;
123 /*
124 * Child processes created by fork() only have a single thread.
125 * Discard information about the parent threads.
126 */
127 CPU_FOREACH_SAFE(cpu, next_cpu) {
128 if (cpu != thread_cpu) {
129 QTAILQ_REMOVE_RCU(&cpus_queue, cpu, node);
130 }
131 }
132 qemu_init_cpu_list();
133 get_task_state(thread_cpu)->ts_tid = qemu_get_thread_id();
134 } else {
135 cpu_list_unlock();
136 }
137 gdbserver_fork_end(thread_cpu, pid);
138 /*
139 * qemu_init_cpu_list() reinitialized the child exclusive state, but we
140 * also need to keep current_cpu consistent, so call end_exclusive() for
141 * both child and parent.
142 */
143 end_exclusive();
144 }
145
cpu_loop(CPUArchState * env)146 void cpu_loop(CPUArchState *env)
147 {
148 target_cpu_loop(env);
149 }
150
usage(void)151 static void usage(void)
152 {
153 printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
154 "\n" QEMU_COPYRIGHT "\n"
155 "usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
156 "BSD CPU emulator (compiled for %s emulation)\n"
157 "\n"
158 "Standard options:\n"
159 "-h print this help\n"
160 "-g port wait gdb connection to port\n"
161 "-L path set the elf interpreter prefix (default=%s)\n"
162 "-s size set the stack size in bytes (default=%ld)\n"
163 "-cpu model select CPU (-cpu help for list)\n"
164 "-drop-ld-preload drop LD_PRELOAD for target process\n"
165 "-E var=value sets/modifies targets environment variable(s)\n"
166 "-U var unsets targets environment variable(s)\n"
167 "-B address set guest_base address to address\n"
168 "\n"
169 "Debug options:\n"
170 "-d item1[,...] enable logging of specified items\n"
171 " (use '-d help' for a list of log items)\n"
172 "-D logfile write logs to 'logfile' (default stderr)\n"
173 "-one-insn-per-tb run with one guest instruction per emulated TB\n"
174 "-tb-size size TCG translation block cache size\n"
175 "-strace log system calls\n"
176 "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
177 " specify tracing options\n"
178 #ifdef CONFIG_PLUGIN
179 "-plugin [file=]<file>[,<argname>=<argvalue>]\n"
180 #endif
181 "\n"
182 "Environment variables:\n"
183 "QEMU_STRACE Print system calls and arguments similar to the\n"
184 " 'strace' program. Enable by setting to any value.\n"
185 "You can use -E and -U options to set/unset environment variables\n"
186 "for target process. It is possible to provide several variables\n"
187 "by repeating the option. For example:\n"
188 " -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
189 "Note that if you provide several changes to single variable\n"
190 "last change will stay in effect.\n"
191 "\n"
192 QEMU_HELP_BOTTOM "\n"
193 ,
194 TARGET_NAME,
195 interp_prefix,
196 target_dflssiz);
197 exit(1);
198 }
199
200 __thread CPUState *thread_cpu;
201
stop_all_tasks(void)202 void stop_all_tasks(void)
203 {
204 /*
205 * We trust when using NPTL (pthreads) start_exclusive() handles thread
206 * stopping correctly.
207 */
208 start_exclusive();
209 }
210
qemu_cpu_is_self(CPUState * cpu)211 bool qemu_cpu_is_self(CPUState *cpu)
212 {
213 return thread_cpu == cpu;
214 }
215
qemu_cpu_kick(CPUState * cpu)216 void qemu_cpu_kick(CPUState *cpu)
217 {
218 cpu_exit(cpu);
219 }
220
221 /* Assumes contents are already zeroed. */
init_task_state(TaskState * ts)222 static void init_task_state(TaskState *ts)
223 {
224 ts->sigaltstack_used = (struct target_sigaltstack) {
225 .ss_sp = 0,
226 .ss_size = 0,
227 .ss_flags = TARGET_SS_DISABLE,
228 };
229 }
230
231 static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
232
gemu_log(const char * fmt,...)233 void gemu_log(const char *fmt, ...)
234 {
235 va_list ap;
236
237 va_start(ap, fmt);
238 vfprintf(stderr, fmt, ap);
239 va_end(ap);
240 }
241
242 static void
adjust_ssize(void)243 adjust_ssize(void)
244 {
245 struct rlimit rl;
246
247 if (getrlimit(RLIMIT_STACK, &rl) != 0) {
248 return;
249 }
250
251 target_maxssiz = MIN(target_maxssiz, rl.rlim_max);
252 target_dflssiz = MIN(MAX(target_dflssiz, rl.rlim_cur), target_maxssiz);
253
254 rl.rlim_max = target_maxssiz;
255 rl.rlim_cur = target_dflssiz;
256 setrlimit(RLIMIT_STACK, &rl);
257 }
258
main(int argc,char ** argv)259 int main(int argc, char **argv)
260 {
261 const char *filename;
262 const char *cpu_model;
263 const char *cpu_type;
264 const char *log_file = NULL;
265 const char *log_mask = NULL;
266 const char *seed_optarg = NULL;
267 struct target_pt_regs regs1, *regs = ®s1;
268 struct image_info info1, *info = &info1;
269 struct bsd_binprm bprm;
270 TaskState *ts;
271 CPUArchState *env;
272 CPUState *cpu;
273 int optind, rv;
274 const char *r;
275 const char *gdbstub = NULL;
276 char **target_environ, **wrk;
277 envlist_t *envlist = NULL;
278 char *argv0 = NULL;
279 int host_page_size;
280 unsigned long max_reserved_va;
281
282 adjust_ssize();
283
284 if (argc <= 1) {
285 usage();
286 }
287
288
289 error_init(argv[0]);
290 module_call_init(MODULE_INIT_TRACE);
291 qemu_init_cpu_list();
292 module_call_init(MODULE_INIT_QOM);
293
294 envlist = envlist_create();
295
296 /*
297 * add current environment into the list
298 * envlist_setenv adds to the front of the list; to preserve environ
299 * order add from back to front
300 */
301 for (wrk = environ; *wrk != NULL; wrk++) {
302 continue;
303 }
304 while (wrk != environ) {
305 wrk--;
306 (void) envlist_setenv(envlist, *wrk);
307 }
308
309 qemu_host_page_size = getpagesize();
310 qemu_host_page_size = MAX(qemu_host_page_size, TARGET_PAGE_SIZE);
311
312 cpu_model = NULL;
313
314 qemu_add_opts(&qemu_trace_opts);
315 qemu_plugin_add_opts();
316
317 optind = 1;
318 for (;;) {
319 if (optind >= argc) {
320 break;
321 }
322 r = argv[optind];
323 if (r[0] != '-') {
324 break;
325 }
326 optind++;
327 r++;
328 if (!strcmp(r, "-")) {
329 break;
330 } else if (!strcmp(r, "d")) {
331 if (optind >= argc) {
332 break;
333 }
334 log_mask = argv[optind++];
335 } else if (!strcmp(r, "D")) {
336 if (optind >= argc) {
337 break;
338 }
339 log_file = argv[optind++];
340 } else if (!strcmp(r, "E")) {
341 r = argv[optind++];
342 if (envlist_setenv(envlist, r) != 0) {
343 usage();
344 }
345 } else if (!strcmp(r, "ignore-environment")) {
346 envlist_free(envlist);
347 envlist = envlist_create();
348 } else if (!strcmp(r, "U")) {
349 r = argv[optind++];
350 if (envlist_unsetenv(envlist, r) != 0) {
351 usage();
352 }
353 } else if (!strcmp(r, "s")) {
354 r = argv[optind++];
355 rv = qemu_strtoul(r, &r, 0, &target_dflssiz);
356 if (rv < 0 || target_dflssiz <= 0) {
357 usage();
358 }
359 if (*r == 'M') {
360 target_dflssiz *= 1024 * 1024;
361 } else if (*r == 'k' || *r == 'K') {
362 target_dflssiz *= 1024;
363 }
364 if (target_dflssiz > target_maxssiz) {
365 usage();
366 }
367 } else if (!strcmp(r, "L")) {
368 interp_prefix = argv[optind++];
369 } else if (!strcmp(r, "p")) {
370 unsigned size, want = qemu_real_host_page_size();
371
372 r = argv[optind++];
373 if (qemu_strtoui(r, NULL, 10, &size) || size != want) {
374 warn_report("Deprecated page size option cannot "
375 "change host page size (%u)", want);
376 }
377 } else if (!strcmp(r, "g")) {
378 gdbstub = g_strdup(argv[optind++]);
379 } else if (!strcmp(r, "r")) {
380 qemu_uname_release = argv[optind++];
381 } else if (!strcmp(r, "cpu")) {
382 cpu_model = argv[optind++];
383 if (is_help_option(cpu_model)) {
384 list_cpus();
385 exit(1);
386 }
387 } else if (!strcmp(r, "B")) {
388 rv = qemu_strtoul(argv[optind++], NULL, 0, &guest_base);
389 if (rv < 0) {
390 usage();
391 }
392 have_guest_base = true;
393 } else if (!strcmp(r, "drop-ld-preload")) {
394 (void) envlist_unsetenv(envlist, "LD_PRELOAD");
395 } else if (!strcmp(r, "seed")) {
396 seed_optarg = optarg;
397 } else if (!strcmp(r, "one-insn-per-tb")) {
398 opt_one_insn_per_tb = true;
399 } else if (!strcmp(r, "tb-size")) {
400 r = argv[optind++];
401 if (qemu_strtoul(r, NULL, 0, &opt_tb_size)) {
402 usage();
403 }
404 } else if (!strcmp(r, "strace")) {
405 do_strace = 1;
406 } else if (!strcmp(r, "trace")) {
407 trace_opt_parse(optarg);
408 #ifdef CONFIG_PLUGIN
409 } else if (!strcmp(r, "plugin")) {
410 r = argv[optind++];
411 qemu_plugin_opt_parse(r, &plugins);
412 #endif
413 } else if (!strcmp(r, "0")) {
414 argv0 = argv[optind++];
415 } else {
416 usage();
417 }
418 }
419
420 qemu_host_page_mask = -qemu_host_page_size;
421
422 /* init debug */
423 {
424 int mask = 0;
425 if (log_mask) {
426 mask = qemu_str_to_log_mask(log_mask);
427 if (!mask) {
428 qemu_print_log_usage(stdout);
429 exit(1);
430 }
431 }
432 qemu_set_log_filename_flags(log_file, mask, &error_fatal);
433 }
434
435 if (optind >= argc) {
436 usage();
437 }
438 filename = argv[optind];
439 if (argv0) {
440 argv[optind] = argv0;
441 }
442
443 if (!trace_init_backends()) {
444 exit(1);
445 }
446 trace_init_file();
447 qemu_plugin_load_list(&plugins, &error_fatal);
448
449 /* Zero out regs */
450 memset(regs, 0, sizeof(struct target_pt_regs));
451
452 /* Zero bsd params */
453 memset(&bprm, 0, sizeof(bprm));
454
455 /* Zero out image_info */
456 memset(info, 0, sizeof(struct image_info));
457
458 /* Scan interp_prefix dir for replacement files. */
459 init_paths(interp_prefix);
460
461 if (cpu_model == NULL) {
462 cpu_model = TARGET_DEFAULT_CPU_MODEL;
463 }
464
465 cpu_type = parse_cpu_option(cpu_model);
466
467 /* init tcg before creating CPUs and to get qemu_host_page_size */
468 {
469 AccelState *accel = current_accel();
470 AccelClass *ac = ACCEL_GET_CLASS(accel);
471
472 accel_init_interfaces(ac);
473 object_property_set_bool(OBJECT(accel), "one-insn-per-tb",
474 opt_one_insn_per_tb, &error_abort);
475 object_property_set_int(OBJECT(accel), "tb-size",
476 opt_tb_size, &error_abort);
477 ac->init_machine(NULL);
478 }
479
480 /*
481 * Finalize page size before creating CPUs.
482 * This will do nothing if !TARGET_PAGE_BITS_VARY.
483 * The most efficient setting is to match the host.
484 */
485 host_page_size = qemu_real_host_page_size();
486 set_preferred_target_page_bits(ctz32(host_page_size));
487 finalize_target_page_bits();
488
489 cpu = cpu_create(cpu_type);
490 env = cpu_env(cpu);
491 cpu_reset(cpu);
492 thread_cpu = cpu;
493
494 /*
495 * Reserving too much vm space via mmap can run into problems with rlimits,
496 * oom due to page table creation, etc. We will still try it, if directed
497 * by the command-line option, but not by default. Unless we're running a
498 * target address space of 32 or fewer bits on a host with 64 bits.
499 */
500 max_reserved_va = MAX_RESERVED_VA(cpu);
501 if (reserved_va != 0) {
502 if ((reserved_va + 1) % host_page_size) {
503 char *s = size_to_str(host_page_size);
504 fprintf(stderr, "Reserved virtual address not aligned mod %s\n", s);
505 g_free(s);
506 exit(EXIT_FAILURE);
507 }
508 if (max_reserved_va && reserved_va > max_reserved_va) {
509 fprintf(stderr, "Reserved virtual address too big\n");
510 exit(EXIT_FAILURE);
511 }
512 } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
513 /* MAX_RESERVED_VA + 1 is a large power of 2, so is aligned. */
514 reserved_va = max_reserved_va;
515 }
516 if (reserved_va != 0) {
517 guest_addr_max = reserved_va;
518 } else if (MIN(TARGET_VIRT_ADDR_SPACE_BITS, TARGET_ABI_BITS) <= 32) {
519 guest_addr_max = UINT32_MAX;
520 } else {
521 guest_addr_max = ~0ul;
522 }
523
524 if (getenv("QEMU_STRACE")) {
525 do_strace = 1;
526 }
527
528 target_environ = envlist_to_environ(envlist, NULL);
529 envlist_free(envlist);
530
531 {
532 Error *err = NULL;
533 if (seed_optarg != NULL) {
534 qemu_guest_random_seed_main(seed_optarg, &err);
535 } else {
536 qcrypto_init(&err);
537 }
538 if (err) {
539 error_reportf_err(err, "cannot initialize crypto: ");
540 exit(1);
541 }
542 }
543
544 /*
545 * Now that page sizes are configured we can do
546 * proper page alignment for guest_base.
547 */
548 if (have_guest_base) {
549 if (guest_base & ~qemu_host_page_mask) {
550 error_report("Selected guest base not host page aligned");
551 exit(1);
552 }
553 }
554
555 /*
556 * If reserving host virtual address space, do so now.
557 * Combined with '-B', ensure that the chosen range is free.
558 */
559 if (reserved_va) {
560 void *p;
561
562 if (have_guest_base) {
563 p = mmap((void *)guest_base, reserved_va + 1, PROT_NONE,
564 MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_EXCL, -1, 0);
565 } else {
566 p = mmap(NULL, reserved_va + 1, PROT_NONE,
567 MAP_ANON | MAP_PRIVATE, -1, 0);
568 }
569 if (p == MAP_FAILED) {
570 const char *err = strerror(errno);
571 char *sz = size_to_str(reserved_va + 1);
572
573 if (have_guest_base) {
574 error_report("Cannot allocate %s bytes at -B %p for guest "
575 "address space: %s", sz, (void *)guest_base, err);
576 } else {
577 error_report("Cannot allocate %s bytes for guest "
578 "address space: %s", sz, err);
579 }
580 exit(1);
581 }
582 guest_base = (uintptr_t)p;
583 have_guest_base = true;
584
585 /* Ensure that mmap_next_start is within range. */
586 if (reserved_va <= mmap_next_start) {
587 mmap_next_start = (reserved_va / 4 * 3)
588 & TARGET_PAGE_MASK & qemu_host_page_mask;
589 }
590 }
591
592 if (loader_exec(filename, argv + optind, target_environ, regs, info,
593 &bprm) != 0) {
594 printf("Error loading %s\n", filename);
595 _exit(1);
596 }
597
598 for (wrk = target_environ; *wrk; wrk++) {
599 g_free(*wrk);
600 }
601
602 g_free(target_environ);
603
604 if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
605 FILE *f = qemu_log_trylock();
606 if (f) {
607 fprintf(f, "guest_base %p\n", (void *)guest_base);
608 fprintf(f, "page layout changed following binary load\n");
609 page_dump(f);
610
611 fprintf(f, "end_code 0x" TARGET_ABI_FMT_lx "\n",
612 info->end_code);
613 fprintf(f, "start_code 0x" TARGET_ABI_FMT_lx "\n",
614 info->start_code);
615 fprintf(f, "start_data 0x" TARGET_ABI_FMT_lx "\n",
616 info->start_data);
617 fprintf(f, "end_data 0x" TARGET_ABI_FMT_lx "\n",
618 info->end_data);
619 fprintf(f, "start_stack 0x" TARGET_ABI_FMT_lx "\n",
620 info->start_stack);
621 fprintf(f, "brk 0x" TARGET_ABI_FMT_lx "\n", info->brk);
622 fprintf(f, "entry 0x" TARGET_ABI_FMT_lx "\n", info->entry);
623
624 qemu_log_unlock(f);
625 }
626 }
627
628 /* build Task State */
629 ts = g_new0(TaskState, 1);
630 init_task_state(ts);
631 ts->info = info;
632 ts->bprm = &bprm;
633 ts->ts_tid = qemu_get_thread_id();
634 cpu->opaque = ts;
635
636 target_set_brk(info->brk);
637 syscall_init();
638 signal_init();
639
640 /*
641 * Now that we've loaded the binary, GUEST_BASE is fixed. Delay
642 * generating the prologue until now so that the prologue can take
643 * the real value of GUEST_BASE into account.
644 */
645 tcg_prologue_init();
646
647 target_cpu_init(env, regs);
648
649 if (gdbstub) {
650 gdbserver_start(gdbstub, &error_fatal);
651 }
652 cpu_loop(env);
653 /* never exits */
654 return 0;
655 }
656