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