1 /*
2 * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
3 * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
4 * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
5 * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
6 * Copyright (c) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
7 * Linux for s390 port by D.J. Barrow
8 * <barrow_dj@mail.yahoo.com,djbarrow@de.ibm.com>
9 * Copyright (c) 1999-2018 The strace developers.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include "defs.h"
36 #include "mmap_notify.h"
37 #include "native_defs.h"
38 #include "ptrace.h"
39 #include "nsig.h"
40 #include "number_set.h"
41 #include "delay.h"
42 #include "retval.h"
43 #include <limits.h>
44
45 /* for struct iovec */
46 #include <sys/uio.h>
47
48 /* for __X32_SYSCALL_BIT */
49 #include <asm/unistd.h>
50
51 #include "regs.h"
52
53 #if defined(SPARC64)
54 # undef PTRACE_GETREGS
55 # define PTRACE_GETREGS PTRACE_GETREGS64
56 # undef PTRACE_SETREGS
57 # define PTRACE_SETREGS PTRACE_SETREGS64
58 #endif
59
60 #include "syscall.h"
61 #include "xstring.h"
62
63 /* Define these shorthand notations to simplify the syscallent files. */
64 #include "sysent_shorthand_defs.h"
65
66 #define SEN(syscall_name) SEN_ ## syscall_name, SYS_FUNC_NAME(sys_ ## syscall_name)
67
68 const struct_sysent sysent0[] = {
69 #include "syscallent.h"
70 };
71
72 #if SUPPORTED_PERSONALITIES > 1
73 # include PERSONALITY1_INCLUDE_FUNCS
74 static const struct_sysent sysent1[] = {
75 # include "syscallent1.h"
76 };
77 #endif
78
79 #if SUPPORTED_PERSONALITIES > 2
80 # include PERSONALITY2_INCLUDE_FUNCS
81 static const struct_sysent sysent2[] = {
82 # include "syscallent2.h"
83 };
84 #endif
85
86 /* Now undef them since short defines cause wicked namespace pollution. */
87 #include "sysent_shorthand_undefs.h"
88
89 const char *const errnoent[] = {
90 #include "errnoent.h"
91 };
92 const char *const signalent[] = {
93 #include "signalent.h"
94
95 };
96 /*
97 * `ioctlent[012].h' files are automatically generated by the auxiliary
98 * program `ioctlsort', such that the list is sorted by the `code' field.
99 * This has the side-effect of resolving the _IO.. macros into
100 * plain integers, eliminating the need to include here everything
101 * in "/usr/include".
102 */
103
104 const struct_ioctlent ioctlent0[] = {
105 #include "ioctlent0.h"
106 };
107
108 #if SUPPORTED_PERSONALITIES > 1
109 static const struct_ioctlent ioctlent1[] = {
110 # include "ioctlent1.h"
111 };
112 # include PERSONALITY0_INCLUDE_PRINTERS_DECLS
113 static const struct_printers printers0 = {
114 # include PERSONALITY0_INCLUDE_PRINTERS_DEFS
115 };
116 # include PERSONALITY1_INCLUDE_PRINTERS_DECLS
117 static const struct_printers printers1 = {
118 # include PERSONALITY1_INCLUDE_PRINTERS_DEFS
119 };
120 #endif
121
122 #if SUPPORTED_PERSONALITIES > 2
123 static const struct_ioctlent ioctlent2[] = {
124 # include "ioctlent2.h"
125 };
126 # include PERSONALITY2_INCLUDE_PRINTERS_DECLS
127 static const struct_printers printers2 = {
128 # include PERSONALITY2_INCLUDE_PRINTERS_DEFS
129 };
130 #endif
131
132 enum {
133 nsyscalls0 = ARRAY_SIZE(sysent0)
134 #if SUPPORTED_PERSONALITIES > 1
135 , nsyscalls1 = ARRAY_SIZE(sysent1)
136 # if SUPPORTED_PERSONALITIES > 2
137 , nsyscalls2 = ARRAY_SIZE(sysent2)
138 # endif
139 #endif
140 };
141
142 enum {
143 nioctlents0 = ARRAY_SIZE(ioctlent0)
144 #if SUPPORTED_PERSONALITIES > 1
145 , nioctlents1 = ARRAY_SIZE(ioctlent1)
146 # if SUPPORTED_PERSONALITIES > 2
147 , nioctlents2 = ARRAY_SIZE(ioctlent2)
148 # endif
149 #endif
150 };
151
152 #if SUPPORTED_PERSONALITIES > 1
153 const struct_sysent *sysent = sysent0;
154 const struct_ioctlent *ioctlent = ioctlent0;
155 const struct_printers *printers = &printers0;
156 #endif
157
158 const unsigned int nerrnos = ARRAY_SIZE(errnoent);
159 const unsigned int nsignals = ARRAY_SIZE(signalent);
160 unsigned nsyscalls = nsyscalls0;
161 unsigned nioctlents = nioctlents0;
162
163 const unsigned int nsyscall_vec[SUPPORTED_PERSONALITIES] = {
164 nsyscalls0,
165 #if SUPPORTED_PERSONALITIES > 1
166 nsyscalls1,
167 #endif
168 #if SUPPORTED_PERSONALITIES > 2
169 nsyscalls2,
170 #endif
171 };
172 const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
173 sysent0,
174 #if SUPPORTED_PERSONALITIES > 1
175 sysent1,
176 #endif
177 #if SUPPORTED_PERSONALITIES > 2
178 sysent2,
179 #endif
180 };
181
182 const char *const personality_names[] =
183 # if defined X86_64
184 {"64 bit", "32 bit", "x32"}
185 # elif defined X32
186 {"x32", "32 bit"}
187 # elif SUPPORTED_PERSONALITIES == 2
188 {"64 bit", "32 bit"}
189 # else
190 {STRINGIFY_VAL(__WORDSIZE) " bit"}
191 # endif
192 ;
193
194 const char *const personality_designators[] =
195 # if defined X86_64
196 { "64", "32", "x32" }
197 # elif defined X32
198 { "x32", "32" }
199 # elif SUPPORTED_PERSONALITIES == 2
200 { "64", "32" }
201 # else
202 { STRINGIFY_VAL(__WORDSIZE) }
203 # endif
204 ;
205
206 #if SUPPORTED_PERSONALITIES > 1
207
208 unsigned current_personality;
209
210 # ifndef current_wordsize
211 unsigned current_wordsize = PERSONALITY0_WORDSIZE;
212 static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
213 PERSONALITY0_WORDSIZE,
214 PERSONALITY1_WORDSIZE,
215 # if SUPPORTED_PERSONALITIES > 2
216 PERSONALITY2_WORDSIZE,
217 # endif
218 };
219 # endif
220
221 # ifndef current_klongsize
222 unsigned current_klongsize = PERSONALITY0_KLONGSIZE;
223 static const int personality_klongsize[SUPPORTED_PERSONALITIES] = {
224 PERSONALITY0_KLONGSIZE,
225 PERSONALITY1_KLONGSIZE,
226 # if SUPPORTED_PERSONALITIES > 2
227 PERSONALITY2_KLONGSIZE,
228 # endif
229 };
230 # endif
231
232 void
set_personality(unsigned int personality)233 set_personality(unsigned int personality)
234 {
235 if (personality == current_personality)
236 return;
237
238 if (personality >= SUPPORTED_PERSONALITIES)
239 error_msg_and_die("Requested switch to unsupported personality "
240 "%u", personality);
241
242 nsyscalls = nsyscall_vec[personality];
243 sysent = sysent_vec[personality];
244
245 switch (personality) {
246 case 0:
247 ioctlent = ioctlent0;
248 nioctlents = nioctlents0;
249 printers = &printers0;
250 break;
251
252 case 1:
253 ioctlent = ioctlent1;
254 nioctlents = nioctlents1;
255 printers = &printers1;
256 break;
257
258 # if SUPPORTED_PERSONALITIES > 2
259 case 2:
260 ioctlent = ioctlent2;
261 nioctlents = nioctlents2;
262 printers = &printers2;
263 break;
264 # endif
265 }
266
267 current_personality = personality;
268 # ifndef current_wordsize
269 current_wordsize = personality_wordsize[personality];
270 # endif
271 # ifndef current_klongsize
272 current_klongsize = personality_klongsize[personality];
273 # endif
274 }
275
276 static void
update_personality(struct tcb * tcp,unsigned int personality)277 update_personality(struct tcb *tcp, unsigned int personality)
278 {
279 static bool need_mpers_warning[] =
280 { false, !HAVE_PERSONALITY_1_MPERS, !HAVE_PERSONALITY_2_MPERS };
281
282 set_personality(personality);
283
284 if (personality == tcp->currpers)
285 return;
286 tcp->currpers = personality;
287
288 if (!qflag) {
289 error_msg("[ Process PID=%d runs in %s mode. ]",
290 tcp->pid, personality_names[personality]);
291 }
292
293 if (need_mpers_warning[personality]) {
294 error_msg("WARNING: Proper structure decoding for this "
295 "personality is not supported, please consider "
296 "building strace with mpers support enabled.");
297 need_mpers_warning[personality] = false;
298 }
299 }
300 #endif
301
302 #ifdef SYS_socket_subcall
303 static void
decode_socket_subcall(struct tcb * tcp)304 decode_socket_subcall(struct tcb *tcp)
305 {
306 const int call = tcp->u_arg[0];
307
308 if (call < 1 || call >= SYS_socket_nsubcalls)
309 return;
310
311 const kernel_ulong_t scno = SYS_socket_subcall + call;
312 const unsigned int nargs = sysent[scno].nargs;
313 uint64_t buf[nargs];
314
315 if (umoven(tcp, tcp->u_arg[1], nargs * current_wordsize, buf) < 0)
316 return;
317
318 tcp->scno = scno;
319 tcp->qual_flg = qual_flags(scno);
320 tcp->s_ent = &sysent[scno];
321
322 unsigned int i;
323 for (i = 0; i < nargs; ++i)
324 tcp->u_arg[i] = (sizeof(uint32_t) == current_wordsize)
325 ? ((uint32_t *) (void *) buf)[i] : buf[i];
326 }
327 #endif /* SYS_socket_subcall */
328
329 #ifdef SYS_ipc_subcall
330 static void
decode_ipc_subcall(struct tcb * tcp)331 decode_ipc_subcall(struct tcb *tcp)
332 {
333 unsigned int call = tcp->u_arg[0];
334 const unsigned int version = call >> 16;
335
336 if (version) {
337 # if defined S390 || defined S390X
338 return;
339 # else
340 # ifdef SPARC64
341 if (current_wordsize == 8)
342 return;
343 # endif
344 set_tcb_priv_ulong(tcp, version);
345 call &= 0xffff;
346 # endif
347 }
348
349 switch (call) {
350 case 1: case 2: case 3: case 4:
351 case 11: case 12: case 13: case 14:
352 case 21: case 22: case 23: case 24:
353 break;
354 default:
355 return;
356 }
357
358 tcp->scno = SYS_ipc_subcall + call;
359 tcp->qual_flg = qual_flags(tcp->scno);
360 tcp->s_ent = &sysent[tcp->scno];
361
362 const unsigned int n = tcp->s_ent->nargs;
363 unsigned int i;
364 for (i = 0; i < n; i++)
365 tcp->u_arg[i] = tcp->u_arg[i + 1];
366 }
367 #endif /* SYS_ipc_subcall */
368
369 #ifdef SYS_syscall_subcall
370 static void
decode_syscall_subcall(struct tcb * tcp)371 decode_syscall_subcall(struct tcb *tcp)
372 {
373 if (!scno_is_valid(tcp->u_arg[0]))
374 return;
375 tcp->scno = tcp->u_arg[0];
376 tcp->qual_flg = qual_flags(tcp->scno);
377 tcp->s_ent = &sysent[tcp->scno];
378 memmove(&tcp->u_arg[0], &tcp->u_arg[1],
379 sizeof(tcp->u_arg) - sizeof(tcp->u_arg[0]));
380 # ifdef LINUX_MIPSO32
381 /*
382 * Fetching the last arg of 7-arg syscalls (fadvise64_64
383 * and sync_file_range) requires additional code,
384 * see linux/mips/get_syscall_args.c
385 */
386 if (tcp->s_ent->nargs == MAX_ARGS) {
387 if (umoven(tcp,
388 mips_REG_SP + MAX_ARGS * sizeof(tcp->u_arg[0]),
389 sizeof(tcp->u_arg[0]),
390 &tcp->u_arg[MAX_ARGS - 1]) < 0)
391 tcp->u_arg[MAX_ARGS - 1] = 0;
392 }
393 # endif /* LINUX_MIPSO32 */
394 }
395 #endif /* SYS_syscall_subcall */
396
397 static void
dumpio(struct tcb * tcp)398 dumpio(struct tcb *tcp)
399 {
400 int fd = tcp->u_arg[0];
401 if (fd < 0)
402 return;
403
404 if (is_number_in_set(fd, write_set)) {
405 switch (tcp->s_ent->sen) {
406 case SEN_write:
407 case SEN_pwrite:
408 case SEN_send:
409 case SEN_sendto:
410 case SEN_mq_timedsend:
411 dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
412 break;
413 case SEN_writev:
414 case SEN_pwritev:
415 case SEN_pwritev2:
416 case SEN_vmsplice:
417 dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1], -1);
418 break;
419 case SEN_sendmsg:
420 dumpiov_in_msghdr(tcp, tcp->u_arg[1], -1);
421 break;
422 case SEN_sendmmsg:
423 dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
424 break;
425 }
426 }
427
428 if (syserror(tcp))
429 return;
430
431 if (is_number_in_set(fd, read_set)) {
432 switch (tcp->s_ent->sen) {
433 case SEN_read:
434 case SEN_pread:
435 case SEN_recv:
436 case SEN_recvfrom:
437 case SEN_mq_timedreceive:
438 dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
439 return;
440 case SEN_readv:
441 case SEN_preadv:
442 case SEN_preadv2:
443 dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1],
444 tcp->u_rval);
445 return;
446 case SEN_recvmsg:
447 dumpiov_in_msghdr(tcp, tcp->u_arg[1], tcp->u_rval);
448 return;
449 case SEN_recvmmsg:
450 dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
451 return;
452 }
453 }
454 }
455
456 const char *
err_name(unsigned long err)457 err_name(unsigned long err)
458 {
459 if ((err < nerrnos) && errnoent[err])
460 return errnoent[err];
461
462 return NULL;
463 }
464
465 static void
print_err_ret(kernel_ulong_t ret,unsigned long u_error)466 print_err_ret(kernel_ulong_t ret, unsigned long u_error)
467 {
468 const char *u_error_str = err_name(u_error);
469
470 if (u_error_str)
471 tprintf("= %" PRI_kld " %s (%s)",
472 ret, u_error_str, strerror(u_error));
473 else
474 tprintf("= %" PRI_kld " (errno %lu)", ret, u_error);
475 }
476
477 static long get_regs(struct tcb *);
478 static int get_syscall_args(struct tcb *);
479 static int get_syscall_result(struct tcb *);
480 static int arch_get_scno(struct tcb *tcp);
481 static int arch_set_scno(struct tcb *, kernel_ulong_t);
482 static void get_error(struct tcb *, const bool);
483 static int arch_set_error(struct tcb *);
484 static int arch_set_success(struct tcb *);
485
486 struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
487
488 static struct inject_opts *
tcb_inject_opts(struct tcb * tcp)489 tcb_inject_opts(struct tcb *tcp)
490 {
491 return (scno_in_range(tcp->scno) && tcp->inject_vec[current_personality])
492 ? &tcp->inject_vec[current_personality][tcp->scno] : NULL;
493 }
494
495
496 static long
tamper_with_syscall_entering(struct tcb * tcp,unsigned int * signo)497 tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo)
498 {
499 if (!tcp->inject_vec[current_personality]) {
500 tcp->inject_vec[current_personality] =
501 xcalloc(nsyscalls, sizeof(**inject_vec));
502 memcpy(tcp->inject_vec[current_personality],
503 inject_vec[current_personality],
504 nsyscalls * sizeof(**inject_vec));
505 }
506
507 struct inject_opts *opts = tcb_inject_opts(tcp);
508
509 if (!opts || opts->first == 0)
510 return 0;
511
512 --opts->first;
513
514 if (opts->first != 0)
515 return 0;
516
517 opts->first = opts->step;
518
519 if (!recovering(tcp)) {
520 if (opts->data.flags & INJECT_F_SIGNAL)
521 *signo = opts->data.signo;
522 if (opts->data.flags & (INJECT_F_ERROR | INJECT_F_RETVAL)) {
523 kernel_long_t scno =
524 (opts->data.flags & INJECT_F_SYSCALL)
525 ? (kernel_long_t) shuffle_scno(opts->data.scno)
526 : -1;
527
528 if (!arch_set_scno(tcp, scno)) {
529 tcp->flags |= TCB_TAMPERED;
530 if (scno != -1)
531 tcp->flags |= TCB_TAMPERED_NO_FAIL;
532 }
533 }
534 if (opts->data.flags & INJECT_F_DELAY_ENTER)
535 delay_tcb(tcp, opts->data.delay_idx, true);
536 if (opts->data.flags & INJECT_F_DELAY_EXIT)
537 tcp->flags |= TCB_INJECT_DELAY_EXIT;
538 }
539
540 return 0;
541 }
542
543 static long
tamper_with_syscall_exiting(struct tcb * tcp)544 tamper_with_syscall_exiting(struct tcb *tcp)
545 {
546 struct inject_opts *opts = tcb_inject_opts(tcp);
547 if (!opts)
548 return 0;
549
550 if (inject_delay_exit(tcp))
551 delay_tcb(tcp, opts->data.delay_idx, false);
552
553 if (!syscall_tampered(tcp))
554 return 0;
555
556 if (!syserror(tcp) ^ !!syscall_tampered_nofail(tcp)) {
557 error_msg("Failed to tamper with process %d: unexpectedly got"
558 " %serror (return value %#" PRI_klx ", error %lu)",
559 tcp->pid, syscall_tampered_nofail(tcp) ? "" : "no ",
560 tcp->u_rval, tcp->u_error);
561
562 return 1;
563 }
564
565 bool update_tcb = false;
566
567 if (opts->data.flags & INJECT_F_RETVAL) {
568 kernel_long_t inject_rval =
569 retval_get(opts->data.rval_idx);
570 kernel_long_t u_rval = tcp->u_rval;
571
572 tcp->u_rval = inject_rval;
573 if (arch_set_success(tcp)) {
574 tcp->u_rval = u_rval;
575 } else {
576 update_tcb = true;
577 tcp->u_error = 0;
578 }
579 } else {
580 unsigned long new_error = retval_get(opts->data.rval_idx);
581
582 if (new_error != tcp->u_error && new_error <= MAX_ERRNO_VALUE) {
583 unsigned long u_error = tcp->u_error;
584
585 tcp->u_error = new_error;
586 if (arch_set_error(tcp)) {
587 tcp->u_error = u_error;
588 } else {
589 update_tcb = true;
590 }
591 }
592 }
593
594 if (update_tcb) {
595 tcp->u_error = 0;
596 get_error(tcp, !(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS));
597 }
598
599 return 0;
600 }
601
602 /*
603 * Returns:
604 * 0: "ignore this ptrace stop", bail out silently.
605 * 1: ok, decoded; call
606 * syscall_entering_finish(tcp, syscall_entering_trace(tcp, ...)).
607 * other: error; call syscall_entering_finish(tcp, res), where res is the value
608 * returned.
609 */
610 int
syscall_entering_decode(struct tcb * tcp)611 syscall_entering_decode(struct tcb *tcp)
612 {
613 int res = get_scno(tcp);
614 if (res == 0)
615 return res;
616 int scno_good = res;
617 if (res != 1 || (res = get_syscall_args(tcp)) != 1) {
618 printleader(tcp);
619 tprintf("%s(", scno_good == 1 ? tcp->s_ent->sys_name : "????");
620 /*
621 * " <unavailable>" will be added later by the code which
622 * detects ptrace errors.
623 */
624 return res;
625 }
626
627 #if defined SYS_ipc_subcall \
628 || defined SYS_socket_subcall \
629 || defined SYS_syscall_subcall
630 for (;;) {
631 switch (tcp->s_ent->sen) {
632 # ifdef SYS_ipc_subcall
633 case SEN_ipc:
634 decode_ipc_subcall(tcp);
635 break;
636 # endif
637 # ifdef SYS_socket_subcall
638 case SEN_socketcall:
639 decode_socket_subcall(tcp);
640 break;
641 # endif
642 # ifdef SYS_syscall_subcall
643 case SEN_syscall:
644 decode_syscall_subcall(tcp);
645 if (tcp->s_ent->sen != SEN_syscall)
646 continue;
647 break;
648 # endif
649 }
650 break;
651 }
652 #endif
653
654 return 1;
655 }
656
657 int
syscall_entering_trace(struct tcb * tcp,unsigned int * sig)658 syscall_entering_trace(struct tcb *tcp, unsigned int *sig)
659 {
660 /* Restrain from fault injection while the trace executes strace code. */
661 if (hide_log(tcp)) {
662 tcp->qual_flg &= ~QUAL_INJECT;
663 }
664
665 switch (tcp->s_ent->sen) {
666 case SEN_execve:
667 case SEN_execveat:
668 #if defined SPARC || defined SPARC64
669 case SEN_execv:
670 #endif
671 tcp->flags &= ~TCB_HIDE_LOG;
672 break;
673 }
674
675 if (!traced(tcp) || (tracing_paths && !pathtrace_match(tcp))) {
676 tcp->flags |= TCB_FILTERED;
677 return 0;
678 }
679
680 tcp->flags &= ~TCB_FILTERED;
681
682 if (hide_log(tcp)) {
683 return 0;
684 }
685
686 if (inject(tcp))
687 tamper_with_syscall_entering(tcp, sig);
688
689 if (cflag == CFLAG_ONLY_STATS) {
690 return 0;
691 }
692
693 #ifdef ENABLE_STACKTRACE
694 if (stack_trace_enabled) {
695 if (tcp->s_ent->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)
696 unwind_tcb_capture(tcp);
697 }
698 #endif
699
700 printleader(tcp);
701 tprintf("%s(", tcp->s_ent->sys_name);
702 int res = raw(tcp) ? printargs(tcp) : tcp->s_ent->sys_func(tcp);
703 fflush(tcp->outf);
704 return res;
705 }
706
707 void
syscall_entering_finish(struct tcb * tcp,int res)708 syscall_entering_finish(struct tcb *tcp, int res)
709 {
710 tcp->flags |= TCB_INSYSCALL;
711 tcp->sys_func_rval = res;
712 /* Measure the entrance time as late as possible to avoid errors. */
713 if ((Tflag || cflag) && !filtered(tcp))
714 clock_gettime(CLOCK_MONOTONIC, &tcp->etime);
715 }
716
717 /* Returns:
718 * 0: "bail out".
719 * 1: ok.
720 * -1: error in one of ptrace ops.
721 *
722 * If not 0, call syscall_exiting_trace(tcp, res), where res is the return
723 * value. Anyway, call syscall_exiting_finish(tcp) then.
724 */
725 int
syscall_exiting_decode(struct tcb * tcp,struct timespec * pts)726 syscall_exiting_decode(struct tcb *tcp, struct timespec *pts)
727 {
728 /* Measure the exit time as early as possible to avoid errors. */
729 if ((Tflag || cflag) && !(filtered(tcp) || hide_log(tcp)))
730 clock_gettime(CLOCK_MONOTONIC, pts);
731
732 if (tcp->s_ent->sys_flags & MEMORY_MAPPING_CHANGE)
733 mmap_notify_report(tcp);
734
735 if (filtered(tcp) || hide_log(tcp))
736 return 0;
737
738 #if SUPPORTED_PERSONALITIES > 1
739 update_personality(tcp, tcp->currpers);
740 #endif
741
742 return get_syscall_result(tcp);
743 }
744
745 int
syscall_exiting_trace(struct tcb * tcp,struct timespec * ts,int res)746 syscall_exiting_trace(struct tcb *tcp, struct timespec *ts, int res)
747 {
748 if (syscall_tampered(tcp) || inject_delay_exit(tcp))
749 tamper_with_syscall_exiting(tcp);
750
751 if (cflag) {
752 count_syscall(tcp, ts);
753 if (cflag == CFLAG_ONLY_STATS) {
754 return 0;
755 }
756 }
757
758 /* If not in -ff mode, and printing_tcp != tcp,
759 * then the log currently does not end with output
760 * of _our syscall entry_, but with something else.
761 * We need to say which syscall's return is this.
762 *
763 * Forced reprinting via TCB_REPRINT is used only by
764 * "strace -ff -oLOG test/threaded_execve" corner case.
765 * It's the only case when -ff mode needs reprinting.
766 */
767 if ((followfork < 2 && printing_tcp != tcp) || (tcp->flags & TCB_REPRINT)) {
768 tcp->flags &= ~TCB_REPRINT;
769 printleader(tcp);
770 tprintf("<... %s resumed> ", tcp->s_ent->sys_name);
771 }
772 printing_tcp = tcp;
773
774 tcp->s_prev_ent = NULL;
775 if (res != 1) {
776 /* There was error in one of prior ptrace ops */
777 tprints(") ");
778 tabto();
779 tprints("= ? <unavailable>\n");
780 line_ended();
781 return res;
782 }
783 tcp->s_prev_ent = tcp->s_ent;
784
785 int sys_res = 0;
786 if (raw(tcp)) {
787 /* sys_res = printargs(tcp); - but it's nop on sysexit */
788 } else {
789 /* FIXME: not_failing_only (IOW, option -z) is broken:
790 * failure of syscall is known only after syscall return.
791 * Thus we end up with something like this on, say, ENOENT:
792 * open("does_not_exist", O_RDONLY <unfinished ...>
793 * {next syscall decode}
794 * whereas the intended result is that open(...) line
795 * is not shown at all.
796 */
797 if (not_failing_only && tcp->u_error)
798 return 0; /* ignore failed syscalls */
799 if (tcp->sys_func_rval & RVAL_DECODED)
800 sys_res = tcp->sys_func_rval;
801 else
802 sys_res = tcp->s_ent->sys_func(tcp);
803 }
804
805 tprints(") ");
806 tabto();
807
808 if (raw(tcp)) {
809 if (tcp->u_error)
810 print_err_ret(tcp->u_rval, tcp->u_error);
811 else
812 tprintf("= %#" PRI_klx, tcp->u_rval);
813
814 if (syscall_tampered(tcp))
815 tprints(" (INJECTED)");
816 } else if (!(sys_res & RVAL_NONE) && tcp->u_error) {
817 switch (tcp->u_error) {
818 /* Blocked signals do not interrupt any syscalls.
819 * In this case syscalls don't return ERESTARTfoo codes.
820 *
821 * Deadly signals set to SIG_DFL interrupt syscalls
822 * and kill the process regardless of which of the codes below
823 * is returned by the interrupted syscall.
824 * In some cases, kernel forces a kernel-generated deadly
825 * signal to be unblocked and set to SIG_DFL (and thus cause
826 * death) if it is blocked or SIG_IGNed: for example, SIGSEGV
827 * or SIGILL. (The alternative is to leave process spinning
828 * forever on the faulty instruction - not useful).
829 *
830 * SIG_IGNed signals and non-deadly signals set to SIG_DFL
831 * (for example, SIGCHLD, SIGWINCH) interrupt syscalls,
832 * but kernel will always restart them.
833 */
834 case ERESTARTSYS:
835 /* Most common type of signal-interrupted syscall exit code.
836 * The system call will be restarted with the same arguments
837 * if SA_RESTART is set; otherwise, it will fail with EINTR.
838 */
839 tprints("= ? ERESTARTSYS (To be restarted if SA_RESTART is set)");
840 break;
841 case ERESTARTNOINTR:
842 /* Rare. For example, fork() returns this if interrupted.
843 * SA_RESTART is ignored (assumed set): the restart is unconditional.
844 */
845 tprints("= ? ERESTARTNOINTR (To be restarted)");
846 break;
847 case ERESTARTNOHAND:
848 /* pause(), rt_sigsuspend() etc use this code.
849 * SA_RESTART is ignored (assumed not set):
850 * syscall won't restart (will return EINTR instead)
851 * even after signal with SA_RESTART set. However,
852 * after SIG_IGN or SIG_DFL signal it will restart
853 * (thus the name "restart only if has no handler").
854 */
855 tprints("= ? ERESTARTNOHAND (To be restarted if no handler)");
856 break;
857 case ERESTART_RESTARTBLOCK:
858 /* Syscalls like nanosleep(), poll() which can't be
859 * restarted with their original arguments use this
860 * code. Kernel will execute restart_syscall() instead,
861 * which changes arguments before restarting syscall.
862 * SA_RESTART is ignored (assumed not set) similarly
863 * to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
864 * since restart data is saved in "restart block"
865 * in task struct, and if signal handler uses a syscall
866 * which in turn saves another such restart block,
867 * old data is lost and restart becomes impossible)
868 */
869 tprints("= ? ERESTART_RESTARTBLOCK (Interrupted by signal)");
870 break;
871 default:
872 print_err_ret(tcp->u_rval, tcp->u_error);
873 break;
874 }
875 if (syscall_tampered(tcp))
876 tprints(" (INJECTED)");
877 if ((sys_res & RVAL_STR) && tcp->auxstr)
878 tprintf(" (%s)", tcp->auxstr);
879 } else {
880 if (sys_res & RVAL_NONE)
881 tprints("= ?");
882 else {
883 switch (sys_res & RVAL_MASK) {
884 case RVAL_HEX:
885 #if ANY_WORDSIZE_LESS_THAN_KERNEL_LONG
886 if (current_klongsize < sizeof(tcp->u_rval)) {
887 tprintf("= %#x",
888 (unsigned int) tcp->u_rval);
889 } else
890 #endif
891 {
892 tprintf("= %#" PRI_klx, tcp->u_rval);
893 }
894 break;
895 case RVAL_OCTAL:
896 tprints("= ");
897 print_numeric_long_umask(tcp->u_rval);
898 break;
899 case RVAL_UDECIMAL:
900 #if ANY_WORDSIZE_LESS_THAN_KERNEL_LONG
901 if (current_klongsize < sizeof(tcp->u_rval)) {
902 tprintf("= %u",
903 (unsigned int) tcp->u_rval);
904 } else
905 #endif
906 {
907 tprintf("= %" PRI_klu, tcp->u_rval);
908 }
909 break;
910 case RVAL_FD:
911 if (show_fd_path) {
912 tprints("= ");
913 printfd(tcp, tcp->u_rval);
914 } else
915 tprintf("= %" PRI_kld, tcp->u_rval);
916 break;
917 default:
918 error_msg("invalid rval format");
919 break;
920 }
921 }
922 if ((sys_res & RVAL_STR) && tcp->auxstr)
923 tprintf(" (%s)", tcp->auxstr);
924 if (syscall_tampered(tcp))
925 tprints(" (INJECTED)");
926 }
927 if (Tflag) {
928 ts_sub(ts, ts, &tcp->etime);
929 tprintf(" <%ld.%06ld>",
930 (long) ts->tv_sec, (long) ts->tv_nsec / 1000);
931 }
932 tprints("\n");
933 dumpio(tcp);
934 line_ended();
935
936 #ifdef ENABLE_STACKTRACE
937 if (stack_trace_enabled)
938 unwind_tcb_print(tcp);
939 #endif
940 return 0;
941 }
942
943 void
syscall_exiting_finish(struct tcb * tcp)944 syscall_exiting_finish(struct tcb *tcp)
945 {
946 tcp->flags &= ~(TCB_INSYSCALL | TCB_TAMPERED | TCB_INJECT_DELAY_EXIT);
947 tcp->sys_func_rval = 0;
948 free_tcb_priv_data(tcp);
949 }
950
951 bool
is_erestart(struct tcb * tcp)952 is_erestart(struct tcb *tcp)
953 {
954 switch (tcp->u_error) {
955 case ERESTARTSYS:
956 case ERESTARTNOINTR:
957 case ERESTARTNOHAND:
958 case ERESTART_RESTARTBLOCK:
959 return true;
960 default:
961 return false;
962 }
963 }
964
965 static unsigned long saved_u_error;
966
967 void
temporarily_clear_syserror(struct tcb * tcp)968 temporarily_clear_syserror(struct tcb *tcp)
969 {
970 saved_u_error = tcp->u_error;
971 tcp->u_error = 0;
972 }
973
974 void
restore_cleared_syserror(struct tcb * tcp)975 restore_cleared_syserror(struct tcb *tcp)
976 {
977 tcp->u_error = saved_u_error;
978 }
979
980 #define XLAT_MACROS_ONLY
981 # include "xlat/nt_descriptor_types.h"
982 #undef XLAT_MACROS_ONLY
983
984 #include "arch_regs.c"
985
986 #if HAVE_ARCH_GETRVAL2
987 # include "arch_getrval2.c"
988 #endif
989
990 void
print_pc(struct tcb * tcp)991 print_pc(struct tcb *tcp)
992 {
993 #if defined ARCH_PC_REG
994 # define ARCH_GET_PC 0
995 #elif defined ARCH_PC_PEEK_ADDR
996 kernel_ulong_t pc;
997 # define ARCH_PC_REG pc
998 # define ARCH_GET_PC upeek(tcp, ARCH_PC_PEEK_ADDR, &pc)
999 #else
1000 # error Neither ARCH_PC_REG nor ARCH_PC_PEEK_ADDR is defined
1001 #endif
1002 if (get_regs(tcp) < 0 || ARCH_GET_PC)
1003 tprints(current_wordsize == 4 ? "[????????] "
1004 : "[????????????????] ");
1005 else
1006 tprintf(current_wordsize == 4
1007 ? "[%08" PRI_klx "] " : "[%016" PRI_klx "] ",
1008 (kernel_ulong_t) ARCH_PC_REG);
1009 }
1010
1011 #include "getregs_old.h"
1012
1013 #undef ptrace_getregset_or_getregs
1014 #undef ptrace_setregset_or_setregs
1015 #ifdef ARCH_REGS_FOR_GETREGSET
1016
1017 # define ptrace_getregset_or_getregs ptrace_getregset
1018 static long
ptrace_getregset(pid_t pid)1019 ptrace_getregset(pid_t pid)
1020 {
1021 # ifdef ARCH_IOVEC_FOR_GETREGSET
1022 /* variable iovec */
1023 ARCH_IOVEC_FOR_GETREGSET.iov_len = sizeof(ARCH_REGS_FOR_GETREGSET);
1024 return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS,
1025 &ARCH_IOVEC_FOR_GETREGSET);
1026 # else
1027 /* constant iovec */
1028 static struct iovec io = {
1029 .iov_base = &ARCH_REGS_FOR_GETREGSET,
1030 .iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
1031 };
1032 return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &io);
1033
1034 # endif
1035 }
1036
1037 # ifndef HAVE_GETREGS_OLD
1038 # define ptrace_setregset_or_setregs ptrace_setregset
1039 static int
ptrace_setregset(pid_t pid)1040 ptrace_setregset(pid_t pid)
1041 {
1042 # ifdef ARCH_IOVEC_FOR_GETREGSET
1043 /* variable iovec */
1044 return ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS,
1045 &ARCH_IOVEC_FOR_GETREGSET);
1046 # else
1047 /* constant iovec */
1048 static struct iovec io = {
1049 .iov_base = &ARCH_REGS_FOR_GETREGSET,
1050 .iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
1051 };
1052 return ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &io);
1053 # endif
1054 }
1055 # endif /* !HAVE_GETREGS_OLD */
1056
1057 #elif defined ARCH_REGS_FOR_GETREGS
1058
1059 # define ptrace_getregset_or_getregs ptrace_getregs
1060 static long
ptrace_getregs(pid_t pid)1061 ptrace_getregs(pid_t pid)
1062 {
1063 # if defined SPARC || defined SPARC64
1064 /* SPARC systems have the meaning of data and addr reversed */
1065 return ptrace(PTRACE_GETREGS, pid, (void *) &ARCH_REGS_FOR_GETREGS, 0);
1066 # else
1067 return ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
1068 # endif
1069 }
1070
1071 # ifndef HAVE_GETREGS_OLD
1072 # define ptrace_setregset_or_setregs ptrace_setregs
1073 static int
ptrace_setregs(pid_t pid)1074 ptrace_setregs(pid_t pid)
1075 {
1076 # if defined SPARC || defined SPARC64
1077 /* SPARC systems have the meaning of data and addr reversed */
1078 return ptrace(PTRACE_SETREGS, pid, (void *) &ARCH_REGS_FOR_GETREGS, 0);
1079 # else
1080 return ptrace(PTRACE_SETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
1081 # endif
1082 }
1083 # endif /* !HAVE_GETREGS_OLD */
1084
1085 #endif /* ARCH_REGS_FOR_GETREGSET || ARCH_REGS_FOR_GETREGS */
1086
1087 #ifdef ptrace_getregset_or_getregs
1088 static long get_regs_error;
1089 #endif
1090
1091 void
clear_regs(struct tcb * tcp)1092 clear_regs(struct tcb *tcp)
1093 {
1094 #ifdef ptrace_getregset_or_getregs
1095 get_regs_error = -1;
1096 #endif
1097 }
1098
1099 static long
get_regs(struct tcb * const tcp)1100 get_regs(struct tcb *const tcp)
1101 {
1102 #ifdef ptrace_getregset_or_getregs
1103
1104 if (get_regs_error != -1)
1105 return get_regs_error;
1106
1107 # ifdef HAVE_GETREGS_OLD
1108 /*
1109 * Try PTRACE_GETREGSET/PTRACE_GETREGS first,
1110 * fallback to getregs_old.
1111 */
1112 static int use_getregs_old;
1113 if (use_getregs_old < 0) {
1114 return get_regs_error = ptrace_getregset_or_getregs(tcp->pid);
1115 } else if (use_getregs_old == 0) {
1116 get_regs_error = ptrace_getregset_or_getregs(tcp->pid);
1117 if (get_regs_error >= 0) {
1118 use_getregs_old = -1;
1119 return get_regs_error;
1120 }
1121 if (errno == EPERM || errno == ESRCH)
1122 return get_regs_error;
1123 use_getregs_old = 1;
1124 }
1125 return get_regs_error = getregs_old(tcp);
1126 # else /* !HAVE_GETREGS_OLD */
1127 /* Assume that PTRACE_GETREGSET/PTRACE_GETREGS works. */
1128 get_regs_error = ptrace_getregset_or_getregs(tcp->pid);
1129
1130 # if defined ARCH_PERSONALITY_0_IOV_SIZE
1131 if (get_regs_error)
1132 return get_regs_error;
1133
1134 switch (ARCH_IOVEC_FOR_GETREGSET.iov_len) {
1135 case ARCH_PERSONALITY_0_IOV_SIZE:
1136 update_personality(tcp, 0);
1137 break;
1138 case ARCH_PERSONALITY_1_IOV_SIZE:
1139 update_personality(tcp, 1);
1140 break;
1141 default: {
1142 static bool printed = false;
1143
1144 if (!printed) {
1145 error_msg("Unsupported regset size returned by "
1146 "PTRACE_GETREGSET: %zu",
1147 ARCH_IOVEC_FOR_GETREGSET.iov_len);
1148
1149 printed = true;
1150 }
1151
1152 update_personality(tcp, 0);
1153 }
1154 }
1155 # endif /* ARCH_PERSONALITY_0_IOV_SIZE */
1156
1157 return get_regs_error;
1158
1159 # endif /* !HAVE_GETREGS_OLD */
1160
1161 #else /* !ptrace_getregset_or_getregs */
1162
1163 # warning get_regs is not implemented for this architecture yet
1164 return 0;
1165
1166 #endif /* !ptrace_getregset_or_getregs */
1167 }
1168
1169 #ifdef ptrace_setregset_or_setregs
1170 static int
set_regs(pid_t pid)1171 set_regs(pid_t pid)
1172 {
1173 return ptrace_setregset_or_setregs(pid);
1174 }
1175 #endif /* ptrace_setregset_or_setregs */
1176
1177 struct sysent_buf {
1178 struct tcb *tcp;
1179 struct_sysent ent;
1180 char buf[sizeof("syscall_0x") + sizeof(kernel_ulong_t) * 2];
1181 };
1182
1183 static void
free_sysent_buf(void * ptr)1184 free_sysent_buf(void *ptr)
1185 {
1186 struct sysent_buf *s = ptr;
1187 s->tcp->s_prev_ent = s->tcp->s_ent = NULL;
1188 free(ptr);
1189 }
1190
1191 /*
1192 * Returns:
1193 * 0: "ignore this ptrace stop", syscall_entering_decode() should return a "bail
1194 * out silently" code.
1195 * 1: ok, continue in syscall_entering_decode().
1196 * other: error, syscall_entering_decode() should print error indicator
1197 * ("????" etc) and return an appropriate code.
1198 */
1199 int
get_scno(struct tcb * tcp)1200 get_scno(struct tcb *tcp)
1201 {
1202 if (get_regs(tcp) < 0)
1203 return -1;
1204
1205 int rc = arch_get_scno(tcp);
1206 if (rc != 1)
1207 return rc;
1208
1209 tcp->scno = shuffle_scno(tcp->scno);
1210
1211 if (scno_is_valid(tcp->scno)) {
1212 tcp->s_ent = &sysent[tcp->scno];
1213 tcp->qual_flg = qual_flags(tcp->scno);
1214 } else {
1215 struct sysent_buf *s = xcalloc(1, sizeof(*s));
1216
1217 s->tcp = tcp;
1218 s->ent.nargs = MAX_ARGS;
1219 s->ent.sen = SEN_printargs;
1220 s->ent.sys_func = printargs;
1221 s->ent.sys_name = s->buf;
1222 xsprintf(s->buf, "syscall_%#" PRI_klx, shuffle_scno(tcp->scno));
1223
1224 tcp->s_ent = &s->ent;
1225 tcp->qual_flg = QUAL_RAW | DEFAULT_QUAL_FLAGS;
1226
1227 set_tcb_priv_data(tcp, s, free_sysent_buf);
1228
1229 debug_msg("pid %d invalid syscall %#" PRI_klx,
1230 tcp->pid, shuffle_scno(tcp->scno));
1231 }
1232
1233 /*
1234 * We refrain from argument decoding during recovering
1235 * as tracee memory mappings has changed and the registers
1236 * are very likely pointing to garbage already.
1237 */
1238 if (recovering(tcp))
1239 tcp->qual_flg |= QUAL_RAW;
1240
1241 return 1;
1242 }
1243
1244 #ifdef ptrace_getregset_or_getregs
1245 # define get_syscall_result_regs get_regs
1246 #else
1247 static int get_syscall_result_regs(struct tcb *);
1248 #endif
1249
1250 /* Returns:
1251 * 1: ok, continue in syscall_exiting_trace().
1252 * -1: error, syscall_exiting_trace() should print error indicator
1253 * ("????" etc) and bail out.
1254 */
1255 static int
get_syscall_result(struct tcb * tcp)1256 get_syscall_result(struct tcb *tcp)
1257 {
1258 if (get_syscall_result_regs(tcp) < 0)
1259 return -1;
1260 tcp->u_error = 0;
1261 get_error(tcp,
1262 (!(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS)
1263 || syscall_tampered(tcp))
1264 && !syscall_tampered_nofail(tcp));
1265
1266 return 1;
1267 }
1268
1269 #include "get_scno.c"
1270 #include "set_scno.c"
1271 #include "get_syscall_args.c"
1272 #ifndef ptrace_getregset_or_getregs
1273 # include "get_syscall_result.c"
1274 #endif
1275 #include "get_error.c"
1276 #include "set_error.c"
1277 #ifdef HAVE_GETREGS_OLD
1278 # include "getregs_old.c"
1279 #endif
1280 #include "shuffle_scno.c"
1281
1282 const char *
syscall_name(kernel_ulong_t scno)1283 syscall_name(kernel_ulong_t scno)
1284 {
1285 return scno_is_valid(scno) ? sysent[scno].sys_name : NULL;
1286 }
1287