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
fork_start(void)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
fork_end(pid_t pid)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
cpu_loop(CPUArchState * env)147 void cpu_loop(CPUArchState *env)
148 {
149 target_cpu_loop(env);
150 }
151
usage(void)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
stop_all_tasks(void)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
qemu_cpu_is_self(CPUState * cpu)212 bool qemu_cpu_is_self(CPUState *cpu)
213 {
214 return thread_cpu == cpu;
215 }
216
qemu_cpu_kick(CPUState * cpu)217 void qemu_cpu_kick(CPUState *cpu)
218 {
219 cpu_exit(cpu);
220 }
221
222 /* Assumes contents are already zeroed. */
init_task_state(TaskState * ts)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
gemu_log(const char * fmt,...)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
adjust_ssize(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
main(int argc,char ** argv)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 = ®s1;
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, "p")) {
371 unsigned size, want = qemu_real_host_page_size();
372
373 r = argv[optind++];
374 if (qemu_strtoui(r, NULL, 10, &size) || size != want) {
375 warn_report("Deprecated page size option cannot "
376 "change host page size (%u)", want);
377 }
378 } else if (!strcmp(r, "g")) {
379 gdbstub = g_strdup(argv[optind++]);
380 } else if (!strcmp(r, "r")) {
381 qemu_uname_release = argv[optind++];
382 } else if (!strcmp(r, "cpu")) {
383 cpu_model = argv[optind++];
384 if (is_help_option(cpu_model)) {
385 list_cpus();
386 exit(1);
387 }
388 } else if (!strcmp(r, "B")) {
389 rv = qemu_strtoul(argv[optind++], NULL, 0, &guest_base);
390 if (rv < 0) {
391 usage();
392 }
393 have_guest_base = true;
394 } else if (!strcmp(r, "drop-ld-preload")) {
395 (void) envlist_unsetenv(envlist, "LD_PRELOAD");
396 } else if (!strcmp(r, "seed")) {
397 seed_optarg = optarg;
398 } else if (!strcmp(r, "one-insn-per-tb")) {
399 opt_one_insn_per_tb = true;
400 } else if (!strcmp(r, "tb-size")) {
401 r = argv[optind++];
402 if (qemu_strtoul(r, NULL, 0, &opt_tb_size)) {
403 usage();
404 }
405 } else if (!strcmp(r, "strace")) {
406 do_strace = 1;
407 } else if (!strcmp(r, "trace")) {
408 trace_opt_parse(optarg);
409 #ifdef CONFIG_PLUGIN
410 } else if (!strcmp(r, "plugin")) {
411 r = argv[optind++];
412 qemu_plugin_opt_parse(r, &plugins);
413 #endif
414 } else if (!strcmp(r, "0")) {
415 argv0 = argv[optind++];
416 } else {
417 usage();
418 }
419 }
420
421 qemu_host_page_mask = -qemu_host_page_size;
422
423 /* init debug */
424 {
425 int mask = 0;
426 if (log_mask) {
427 mask = qemu_str_to_log_mask(log_mask);
428 if (!mask) {
429 qemu_print_log_usage(stdout);
430 exit(1);
431 }
432 }
433 qemu_set_log_filename_flags(log_file, mask, &error_fatal);
434 }
435
436 if (optind >= argc) {
437 usage();
438 }
439 filename = argv[optind];
440 if (argv0) {
441 argv[optind] = argv0;
442 }
443
444 if (!trace_init_backends()) {
445 exit(1);
446 }
447 trace_init_file();
448 qemu_plugin_load_list(&plugins, &error_fatal);
449
450 /* Zero out regs */
451 memset(regs, 0, sizeof(struct target_pt_regs));
452
453 /* Zero bsd params */
454 memset(&bprm, 0, sizeof(bprm));
455
456 /* Zero out image_info */
457 memset(info, 0, sizeof(struct image_info));
458
459 /* Scan interp_prefix dir for replacement files. */
460 init_paths(interp_prefix);
461
462 if (cpu_model == NULL) {
463 cpu_model = TARGET_DEFAULT_CPU_MODEL;
464 }
465
466 cpu_type = parse_cpu_option(cpu_model);
467
468 /* init tcg before creating CPUs and to get qemu_host_page_size */
469 {
470 AccelState *accel = current_accel();
471 AccelClass *ac = ACCEL_GET_CLASS(accel);
472
473 accel_init_interfaces(ac);
474 object_property_set_bool(OBJECT(accel), "one-insn-per-tb",
475 opt_one_insn_per_tb, &error_abort);
476 object_property_set_int(OBJECT(accel), "tb-size",
477 opt_tb_size, &error_abort);
478 ac->init_machine(accel, NULL);
479 }
480
481 /*
482 * Finalize page size before creating CPUs.
483 * This will do nothing if !TARGET_PAGE_BITS_VARY.
484 * The most efficient setting is to match the host.
485 */
486 host_page_size = qemu_real_host_page_size();
487 set_preferred_target_page_bits(ctz32(host_page_size));
488 finalize_target_page_bits();
489
490 cpu = cpu_create(cpu_type);
491 env = cpu_env(cpu);
492 cpu_reset(cpu);
493 thread_cpu = cpu;
494
495 /*
496 * Reserving too much vm space via mmap can run into problems with rlimits,
497 * oom due to page table creation, etc. We will still try it, if directed
498 * by the command-line option, but not by default. Unless we're running a
499 * target address space of 32 or fewer bits on a host with 64 bits.
500 */
501 max_reserved_va = MAX_RESERVED_VA(cpu);
502 if (reserved_va != 0) {
503 if ((reserved_va + 1) % host_page_size) {
504 char *s = size_to_str(host_page_size);
505 fprintf(stderr, "Reserved virtual address not aligned mod %s\n", s);
506 g_free(s);
507 exit(EXIT_FAILURE);
508 }
509 if (max_reserved_va && reserved_va > max_reserved_va) {
510 fprintf(stderr, "Reserved virtual address too big\n");
511 exit(EXIT_FAILURE);
512 }
513 } else if (HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32) {
514 /* MAX_RESERVED_VA + 1 is a large power of 2, so is aligned. */
515 reserved_va = max_reserved_va;
516 }
517 if (reserved_va != 0) {
518 guest_addr_max = reserved_va;
519 } else if (MIN(TARGET_VIRT_ADDR_SPACE_BITS, TARGET_ABI_BITS) <= 32) {
520 guest_addr_max = UINT32_MAX;
521 } else {
522 guest_addr_max = ~0ul;
523 }
524
525 if (getenv("QEMU_STRACE")) {
526 do_strace = 1;
527 }
528
529 target_environ = envlist_to_environ(envlist, NULL);
530 envlist_free(envlist);
531
532 {
533 Error *err = NULL;
534 if (seed_optarg != NULL) {
535 qemu_guest_random_seed_main(seed_optarg, &err);
536 } else {
537 qcrypto_init(&err);
538 }
539 if (err) {
540 error_reportf_err(err, "cannot initialize crypto: ");
541 exit(1);
542 }
543 }
544
545 /*
546 * Now that page sizes are configured we can do
547 * proper page alignment for guest_base.
548 */
549 if (have_guest_base) {
550 if (guest_base & ~qemu_host_page_mask) {
551 error_report("Selected guest base not host page aligned");
552 exit(1);
553 }
554 }
555
556 /*
557 * If reserving host virtual address space, do so now.
558 * Combined with '-B', ensure that the chosen range is free.
559 */
560 if (reserved_va) {
561 void *p;
562
563 if (have_guest_base) {
564 p = mmap((void *)guest_base, reserved_va + 1, PROT_NONE,
565 MAP_ANON | MAP_PRIVATE | MAP_FIXED | MAP_EXCL, -1, 0);
566 } else {
567 p = mmap(NULL, reserved_va + 1, PROT_NONE,
568 MAP_ANON | MAP_PRIVATE, -1, 0);
569 }
570 if (p == MAP_FAILED) {
571 const char *err = strerror(errno);
572 char *sz = size_to_str(reserved_va + 1);
573
574 if (have_guest_base) {
575 error_report("Cannot allocate %s bytes at -B %p for guest "
576 "address space: %s", sz, (void *)guest_base, err);
577 } else {
578 error_report("Cannot allocate %s bytes for guest "
579 "address space: %s", sz, err);
580 }
581 exit(1);
582 }
583 guest_base = (uintptr_t)p;
584 have_guest_base = true;
585
586 /* Ensure that mmap_next_start is within range. */
587 if (reserved_va <= mmap_next_start) {
588 mmap_next_start = (reserved_va / 4 * 3)
589 & TARGET_PAGE_MASK & qemu_host_page_mask;
590 }
591 }
592
593 if (loader_exec(filename, argv + optind, target_environ, regs, info,
594 &bprm) != 0) {
595 printf("Error loading %s\n", filename);
596 _exit(1);
597 }
598
599 for (wrk = target_environ; *wrk; wrk++) {
600 g_free(*wrk);
601 }
602
603 g_free(target_environ);
604
605 if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
606 FILE *f = qemu_log_trylock();
607 if (f) {
608 fprintf(f, "guest_base %p\n", (void *)guest_base);
609 fprintf(f, "page layout changed following binary load\n");
610 page_dump(f);
611
612 fprintf(f, "end_code 0x" TARGET_ABI_FMT_lx "\n",
613 info->end_code);
614 fprintf(f, "start_code 0x" TARGET_ABI_FMT_lx "\n",
615 info->start_code);
616 fprintf(f, "start_data 0x" TARGET_ABI_FMT_lx "\n",
617 info->start_data);
618 fprintf(f, "end_data 0x" TARGET_ABI_FMT_lx "\n",
619 info->end_data);
620 fprintf(f, "start_stack 0x" TARGET_ABI_FMT_lx "\n",
621 info->start_stack);
622 fprintf(f, "brk 0x" TARGET_ABI_FMT_lx "\n", info->brk);
623 fprintf(f, "entry 0x" TARGET_ABI_FMT_lx "\n", info->entry);
624
625 qemu_log_unlock(f);
626 }
627 }
628
629 /* build Task State */
630 ts = g_new0(TaskState, 1);
631 init_task_state(ts);
632 ts->info = info;
633 ts->bprm = &bprm;
634 ts->ts_tid = qemu_get_thread_id();
635 cpu->opaque = ts;
636
637 target_set_brk(info->brk);
638 syscall_init();
639 signal_init();
640
641 /*
642 * Now that we've loaded the binary, GUEST_BASE is fixed. Delay
643 * generating the prologue until now so that the prologue can take
644 * the real value of GUEST_BASE into account.
645 */
646 tcg_prologue_init();
647
648 target_cpu_init(env, regs);
649
650 if (gdbstub) {
651 gdbserver_start(gdbstub, &error_fatal);
652 }
653 cpu_loop(env);
654 /* never exits */
655 return 0;
656 }
657