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