xref: /openbmc/qemu/bsd-user/main.c (revision d201cf7a)
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 <sys/types.h>
22 #include <sys/time.h>
23 #include <sys/resource.h>
24 #include <sys/sysctl.h>
25 
26 #include "qemu/osdep.h"
27 #include "qemu-common.h"
28 #include "qemu/units.h"
29 #include "qemu/accel.h"
30 #include "sysemu/tcg.h"
31 #include "qemu-version.h"
32 #include <machine/trap.h>
33 
34 #include "qapi/error.h"
35 #include "qemu.h"
36 #include "qemu/config-file.h"
37 #include "qemu/error-report.h"
38 #include "qemu/path.h"
39 #include "qemu/help_option.h"
40 #include "qemu/module.h"
41 #include "exec/exec-all.h"
42 #include "tcg/tcg.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 
51 #include "host-os.h"
52 #include "target_arch_cpu.h"
53 
54 int singlestep;
55 uintptr_t guest_base;
56 bool have_guest_base;
57 /*
58  * When running 32-on-64 we should make sure we can fit all of the possible
59  * guest address space into a contiguous chunk of virtual host memory.
60  *
61  * This way we will never overlap with our own libraries or binaries or stack
62  * or anything else that QEMU maps.
63  *
64  * Many cpus reserve the high bit (or more than one for some 64-bit cpus)
65  * of the address for the kernel.  Some cpus rely on this and user space
66  * uses the high bit(s) for pointer tagging and the like.  For them, we
67  * must preserve the expected address space.
68  */
69 #ifndef MAX_RESERVED_VA
70 # if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS
71 #  if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \
72       (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32))
73 /*
74  * There are a number of places where we assign reserved_va to a variable
75  * of type abi_ulong and expect it to fit.  Avoid the last page.
76  */
77 #   define MAX_RESERVED_VA  (0xfffffffful & TARGET_PAGE_MASK)
78 #  else
79 #   define MAX_RESERVED_VA  (1ul << TARGET_VIRT_ADDR_SPACE_BITS)
80 #  endif
81 # else
82 #  define MAX_RESERVED_VA  0
83 # endif
84 #endif
85 
86 /*
87  * That said, reserving *too* much vm space via mmap can run into problems
88  * with rlimits, oom due to page table creation, etc.  We will still try it,
89  * if directed by the command-line option, but not by default.
90  */
91 #if HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32
92 unsigned long reserved_va = MAX_RESERVED_VA;
93 #else
94 unsigned long reserved_va;
95 #endif
96 
97 static const char *interp_prefix = CONFIG_QEMU_INTERP_PREFIX;
98 const char *qemu_uname_release;
99 enum BSDType bsd_type;
100 char qemu_proc_pathname[PATH_MAX];  /* full path to exeutable */
101 
102 unsigned long target_maxtsiz = TARGET_MAXTSIZ;   /* max text size */
103 unsigned long target_dfldsiz = TARGET_DFLDSIZ;   /* initial data size limit */
104 unsigned long target_maxdsiz = TARGET_MAXDSIZ;   /* max data size */
105 unsigned long target_dflssiz = TARGET_DFLSSIZ;   /* initial data size limit */
106 unsigned long target_maxssiz = TARGET_MAXSSIZ;   /* max stack size */
107 unsigned long target_sgrowsiz = TARGET_SGROWSIZ; /* amount to grow stack */
108 
109 /* Helper routines for implementing atomic operations. */
110 
111 void fork_start(void)
112 {
113     start_exclusive();
114     cpu_list_lock();
115     mmap_fork_start();
116 }
117 
118 void fork_end(int child)
119 {
120     if (child) {
121         CPUState *cpu, *next_cpu;
122         /*
123          * Child processes created by fork() only have a single thread.  Discard
124          * information about the parent threads.
125          */
126         CPU_FOREACH_SAFE(cpu, next_cpu) {
127             if (cpu != thread_cpu) {
128                 QTAILQ_REMOVE_RCU(&cpus, cpu, node);
129             }
130         }
131         mmap_fork_end(child);
132         /*
133          * qemu_init_cpu_list() takes care of reinitializing the exclusive
134          * state, so we don't need to end_exclusive() here.
135          */
136         qemu_init_cpu_list();
137         gdbserver_fork(thread_cpu);
138     } else {
139         mmap_fork_end(child);
140         cpu_list_unlock();
141         end_exclusive();
142     }
143 }
144 
145 void cpu_loop(CPUArchState *env)
146 {
147     target_cpu_loop(env);
148 }
149 
150 static void usage(void)
151 {
152     printf("qemu-" TARGET_NAME " version " QEMU_FULL_VERSION
153            "\n" QEMU_COPYRIGHT "\n"
154            "usage: qemu-" TARGET_NAME " [options] program [arguments...]\n"
155            "BSD CPU emulator (compiled for %s emulation)\n"
156            "\n"
157            "Standard options:\n"
158            "-h                print this help\n"
159            "-g port           wait gdb connection to port\n"
160            "-L path           set the elf interpreter prefix (default=%s)\n"
161            "-s size           set the stack size in bytes (default=%ld)\n"
162            "-cpu model        select CPU (-cpu help for list)\n"
163            "-drop-ld-preload  drop LD_PRELOAD for target process\n"
164            "-E var=value      sets/modifies targets environment variable(s)\n"
165            "-U var            unsets targets environment variable(s)\n"
166            "-B address        set guest_base address to address\n"
167            "-bsd type         select emulated BSD type FreeBSD/NetBSD/OpenBSD (default)\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            "-singlestep       always run in singlestep mode\n"
174            "-strace           log system calls\n"
175            "-trace            [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
176            "                  specify tracing options\n"
177            "\n"
178            "Environment variables:\n"
179            "QEMU_STRACE       Print system calls and arguments similar to the\n"
180            "                  'strace' program.  Enable by setting to any value.\n"
181            "You can use -E and -U options to set/unset environment variables\n"
182            "for target process.  It is possible to provide several variables\n"
183            "by repeating the option.  For example:\n"
184            "    -E var1=val2 -E var2=val2 -U LD_PRELOAD -U LD_DEBUG\n"
185            "Note that if you provide several changes to single variable\n"
186            "last change will stay in effect.\n"
187            "\n"
188            QEMU_HELP_BOTTOM "\n"
189            ,
190            TARGET_NAME,
191            interp_prefix,
192            target_dflssiz);
193     exit(1);
194 }
195 
196 __thread CPUState *thread_cpu;
197 
198 void stop_all_tasks(void)
199 {
200     /*
201      * We trust when using NPTL (pthreads) start_exclusive() handles thread
202      * stopping correctly.
203      */
204     start_exclusive();
205 }
206 
207 bool qemu_cpu_is_self(CPUState *cpu)
208 {
209     return thread_cpu == cpu;
210 }
211 
212 void qemu_cpu_kick(CPUState *cpu)
213 {
214     cpu_exit(cpu);
215 }
216 
217 /* Assumes contents are already zeroed.  */
218 static void init_task_state(TaskState *ts)
219 {
220     ts->sigaltstack_used = (struct target_sigaltstack) {
221         .ss_sp = 0,
222         .ss_size = 0,
223         .ss_flags = TARGET_SS_DISABLE,
224     };
225 }
226 
227 void gemu_log(const char *fmt, ...)
228 {
229     va_list ap;
230 
231     va_start(ap, fmt);
232     vfprintf(stderr, fmt, ap);
233     va_end(ap);
234 }
235 
236 static void
237 adjust_ssize(void)
238 {
239     struct rlimit rl;
240 
241     if (getrlimit(RLIMIT_STACK, &rl) != 0) {
242         return;
243     }
244 
245     target_maxssiz = MIN(target_maxssiz, rl.rlim_max);
246     target_dflssiz = MIN(MAX(target_dflssiz, rl.rlim_cur), target_maxssiz);
247 
248     rl.rlim_max = target_maxssiz;
249     rl.rlim_cur = target_dflssiz;
250     setrlimit(RLIMIT_STACK, &rl);
251 }
252 
253 static void save_proc_pathname(char *argv0)
254 {
255     int mib[4];
256     size_t len;
257 
258     mib[0] = CTL_KERN;
259     mib[1] = KERN_PROC;
260     mib[2] = KERN_PROC_PATHNAME;
261     mib[3] = -1;
262 
263     len = sizeof(qemu_proc_pathname);
264     if (sysctl(mib, 4, qemu_proc_pathname, &len, NULL, 0)) {
265         perror("sysctl");
266     }
267 }
268 
269 int main(int argc, char **argv)
270 {
271     const char *filename;
272     const char *cpu_model;
273     const char *cpu_type;
274     const char *log_file = NULL;
275     const char *log_mask = NULL;
276     const char *seed_optarg = NULL;
277     struct target_pt_regs regs1, *regs = &regs1;
278     struct image_info info1, *info = &info1;
279     struct bsd_binprm bprm;
280     TaskState *ts;
281     CPUArchState *env;
282     CPUState *cpu;
283     int optind, rv;
284     const char *r;
285     const char *gdbstub = NULL;
286     char **target_environ, **wrk;
287     envlist_t *envlist = NULL;
288     bsd_type = HOST_DEFAULT_BSD_TYPE;
289     char *argv0 = NULL;
290 
291     adjust_ssize();
292 
293     if (argc <= 1) {
294         usage();
295     }
296 
297     save_proc_pathname(argv[0]);
298 
299     error_init(argv[0]);
300     module_call_init(MODULE_INIT_TRACE);
301     qemu_init_cpu_list();
302     module_call_init(MODULE_INIT_QOM);
303 
304     envlist = envlist_create();
305 
306     /* add current environment into the list */
307     for (wrk = environ; *wrk != NULL; wrk++) {
308         (void) envlist_setenv(envlist, *wrk);
309     }
310 
311     cpu_model = NULL;
312 
313     qemu_add_opts(&qemu_trace_opts);
314 
315     optind = 1;
316     for (;;) {
317         if (optind >= argc) {
318             break;
319         }
320         r = argv[optind];
321         if (r[0] != '-') {
322             break;
323         }
324         optind++;
325         r++;
326         if (!strcmp(r, "-")) {
327             break;
328         } else if (!strcmp(r, "d")) {
329             if (optind >= argc) {
330                 break;
331             }
332             log_mask = argv[optind++];
333         } else if (!strcmp(r, "D")) {
334             if (optind >= argc) {
335                 break;
336             }
337             log_file = argv[optind++];
338         } else if (!strcmp(r, "E")) {
339             r = argv[optind++];
340             if (envlist_setenv(envlist, r) != 0) {
341                 usage();
342             }
343         } else if (!strcmp(r, "ignore-environment")) {
344             envlist_free(envlist);
345             envlist = envlist_create();
346         } else if (!strcmp(r, "U")) {
347             r = argv[optind++];
348             if (envlist_unsetenv(envlist, r) != 0) {
349                 usage();
350             }
351         } else if (!strcmp(r, "s")) {
352             r = argv[optind++];
353             rv = qemu_strtoul(r, &r, 0, &target_dflssiz);
354             if (rv < 0 || target_dflssiz <= 0) {
355                 usage();
356             }
357             if (*r == 'M') {
358                 target_dflssiz *= 1024 * 1024;
359             } else if (*r == 'k' || *r == 'K') {
360                 target_dflssiz *= 1024;
361             }
362             if (target_dflssiz > target_maxssiz) {
363                 usage();
364             }
365         } else if (!strcmp(r, "L")) {
366             interp_prefix = argv[optind++];
367         } else if (!strcmp(r, "p")) {
368             qemu_host_page_size = atoi(argv[optind++]);
369             if (qemu_host_page_size == 0 ||
370                 (qemu_host_page_size & (qemu_host_page_size - 1)) != 0) {
371                 fprintf(stderr, "page size must be a power of two\n");
372                 exit(1);
373             }
374         } else if (!strcmp(r, "g")) {
375             gdbstub = g_strdup(argv[optind++]);
376         } else if (!strcmp(r, "r")) {
377             qemu_uname_release = argv[optind++];
378         } else if (!strcmp(r, "cpu")) {
379             cpu_model = argv[optind++];
380             if (is_help_option(cpu_model)) {
381                 /* XXX: implement xxx_cpu_list for targets that still miss it */
382 #if defined(cpu_list)
383                 cpu_list();
384 #endif
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, "bsd")) {
396             if (!strcasecmp(argv[optind], "freebsd")) {
397                 bsd_type = target_freebsd;
398             } else if (!strcasecmp(argv[optind], "netbsd")) {
399                 bsd_type = target_netbsd;
400             } else if (!strcasecmp(argv[optind], "openbsd")) {
401                 bsd_type = target_openbsd;
402             } else {
403                 usage();
404             }
405             optind++;
406         } else if (!strcmp(r, "seed")) {
407             seed_optarg = optarg;
408         } else if (!strcmp(r, "singlestep")) {
409             singlestep = 1;
410         } else if (!strcmp(r, "strace")) {
411             do_strace = 1;
412         } else if (!strcmp(r, "trace")) {
413             trace_opt_parse(optarg);
414         } else if (!strcmp(r, "0")) {
415             argv0 = argv[optind++];
416         } else {
417             usage();
418         }
419     }
420 
421     /* init debug */
422     qemu_log_needs_buffers();
423     qemu_set_log_filename(log_file, &error_fatal);
424     if (log_mask) {
425         int mask;
426 
427         mask = qemu_str_to_log_mask(log_mask);
428         if (!mask) {
429             qemu_print_log_usage(stdout);
430             exit(1);
431         }
432         qemu_set_log(mask);
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 
448     /* Zero out regs */
449     memset(regs, 0, sizeof(struct target_pt_regs));
450 
451     /* Zero bsd params */
452     memset(&bprm, 0, sizeof(bprm));
453 
454     /* Zero out image_info */
455     memset(info, 0, sizeof(struct image_info));
456 
457     /* Scan interp_prefix dir for replacement files. */
458     init_paths(interp_prefix);
459 
460     if (cpu_model == NULL) {
461         cpu_model = TARGET_DEFAULT_CPU_MODEL;
462     }
463 
464     cpu_type = parse_cpu_option(cpu_model);
465 
466     /* init tcg before creating CPUs and to get qemu_host_page_size */
467     {
468         AccelClass *ac = ACCEL_GET_CLASS(current_accel());
469 
470         accel_init_interfaces(ac);
471         ac->init_machine(NULL);
472     }
473     cpu = cpu_create(cpu_type);
474     env = cpu->env_ptr;
475     cpu_reset(cpu);
476     thread_cpu = cpu;
477 
478     if (getenv("QEMU_STRACE")) {
479         do_strace = 1;
480     }
481 
482     target_environ = envlist_to_environ(envlist, NULL);
483     envlist_free(envlist);
484 
485     if (reserved_va) {
486             mmap_next_start = reserved_va;
487     }
488 
489     {
490         Error *err = NULL;
491         if (seed_optarg != NULL) {
492             qemu_guest_random_seed_main(seed_optarg, &err);
493         } else {
494             qcrypto_init(&err);
495         }
496         if (err) {
497             error_reportf_err(err, "cannot initialize crypto: ");
498             exit(1);
499         }
500     }
501 
502     /*
503      * Now that page sizes are configured we can do
504      * proper page alignment for guest_base.
505      */
506     guest_base = HOST_PAGE_ALIGN(guest_base);
507 
508     if (loader_exec(filename, argv + optind, target_environ, regs, info,
509                     &bprm) != 0) {
510         printf("Error loading %s\n", filename);
511         _exit(1);
512     }
513 
514     for (wrk = target_environ; *wrk; wrk++) {
515         g_free(*wrk);
516     }
517 
518     g_free(target_environ);
519 
520     if (qemu_loglevel_mask(CPU_LOG_PAGE)) {
521         qemu_log("guest_base  %p\n", (void *)guest_base);
522         log_page_dump("binary load");
523 
524         qemu_log("start_brk   0x" TARGET_ABI_FMT_lx "\n", info->start_brk);
525         qemu_log("end_code    0x" TARGET_ABI_FMT_lx "\n", info->end_code);
526         qemu_log("start_code  0x" TARGET_ABI_FMT_lx "\n",
527                  info->start_code);
528         qemu_log("start_data  0x" TARGET_ABI_FMT_lx "\n",
529                  info->start_data);
530         qemu_log("end_data    0x" TARGET_ABI_FMT_lx "\n", info->end_data);
531         qemu_log("start_stack 0x" TARGET_ABI_FMT_lx "\n",
532                  info->start_stack);
533         qemu_log("brk         0x" TARGET_ABI_FMT_lx "\n", info->brk);
534         qemu_log("entry       0x" TARGET_ABI_FMT_lx "\n", info->entry);
535     }
536 
537     /* build Task State */
538     ts = g_new0(TaskState, 1);
539     init_task_state(ts);
540     ts->info = info;
541     ts->bprm = &bprm;
542     cpu->opaque = ts;
543 
544     target_set_brk(info->brk);
545     syscall_init();
546     signal_init();
547 
548     /*
549      * Now that we've loaded the binary, GUEST_BASE is fixed.  Delay
550      * generating the prologue until now so that the prologue can take
551      * the real value of GUEST_BASE into account.
552      */
553     tcg_prologue_init(tcg_ctx);
554 
555     target_cpu_init(env, regs);
556 
557     if (gdbstub) {
558         gdbserver_start(gdbstub);
559         gdb_handlesig(cpu, 0);
560     }
561     cpu_loop(env);
562     /* never exits */
563     return 0;
564 }
565