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) 2001-2018 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 "nsig.h"
37 #include "xstring.h"
38 
39 /* The libc headers do not define this constant since it should only be
40    used by the implementation.  So we define it here.  */
41 #ifndef SA_RESTORER
42 # ifdef ASM_SA_RESTORER
43 #  define SA_RESTORER ASM_SA_RESTORER
44 # endif
45 #endif
46 
47 /*
48  * Some architectures define SA_RESTORER in their headers,
49  * but do not actually have sa_restorer.
50  *
51  * Some architectures, otherwise, do not define SA_RESTORER in their headers,
52  * but actually have sa_restorer.
53  */
54 #ifdef HAVE_ARCH_SA_RESTORER
55 # define HAVE_SA_RESTORER HAVE_ARCH_SA_RESTORER
56 #else /* !HAVE_ARCH_SA_RESTORER */
57 # ifdef SA_RESTORER
58 #  define HAVE_SA_RESTORER 1
59 # else
60 #  define HAVE_SA_RESTORER 0
61 # endif
62 #endif /* HAVE_ARCH_SA_RESTORER */
63 
64 #include "xlat/sa_handler_values.h"
65 #include "xlat/sigact_flags.h"
66 #include "xlat/sigprocmaskcmds.h"
67 
68 /* Anonymous realtime signals. */
69 #ifndef ASM_SIGRTMIN
70 /* Linux kernel >= 3.18 defines SIGRTMIN to 32 on all architectures. */
71 # define ASM_SIGRTMIN 32
72 #endif
73 #ifndef ASM_SIGRTMAX
74 /* Under glibc 2.1, SIGRTMAX et al are functions, but __SIGRTMAX is a
75    constant.  This is what we want.  Otherwise, just use SIGRTMAX. */
76 # ifdef SIGRTMAX
77 #  ifndef __SIGRTMAX
78 #   define __SIGRTMAX SIGRTMAX
79 #  endif
80 # endif
81 # ifdef __SIGRTMAX
82 #  define ASM_SIGRTMAX __SIGRTMAX
83 # endif
84 #endif
85 
86 /* Note on the size of sigset_t:
87  *
88  * In glibc, sigset_t is an array with space for 1024 bits (!),
89  * even though all arches supported by Linux have only 64 signals
90  * except MIPS, which has 128. IOW, it is 128 bytes long.
91  *
92  * In-kernel sigset_t is sized correctly (it is either 64 or 128 bit long).
93  * However, some old syscall return only 32 lower bits (one word).
94  * Example: sys_sigpending vs sys_rt_sigpending.
95  *
96  * Be aware of this fact when you try to
97  *     memcpy(&tcp->u_arg[1], &something, sizeof(sigset_t))
98  * - sizeof(sigset_t) is much bigger than you think,
99  * it may overflow tcp->u_arg[] array, and it may try to copy more data
100  * than is really available in <something>.
101  * Similarly,
102  *     umoven(tcp, addr, sizeof(sigset_t), &sigset)
103  * may be a bad idea: it'll try to read much more data than needed
104  * to fetch a sigset_t.
105  * Use NSIG_BYTES as a size instead.
106  */
107 
108 static const char *
get_sa_handler_str(kernel_ulong_t handler)109 get_sa_handler_str(kernel_ulong_t handler)
110 {
111 	return xlookup(sa_handler_values, handler);
112 }
113 
114 static void
print_sa_handler(kernel_ulong_t handler)115 print_sa_handler(kernel_ulong_t handler)
116 {
117 	const char *sa_handler_str = get_sa_handler_str(handler);
118 
119 	if (sa_handler_str)
120 		print_xlat_ex(handler, sa_handler_str, XLAT_STYLE_DEFAULT);
121 	else
122 		printaddr(handler);
123 }
124 
125 const char *
signame(const int sig)126 signame(const int sig)
127 {
128 	static char buf[sizeof("SIGRT_%u") + sizeof(int)*3];
129 
130 	if (sig >= 0) {
131 		const unsigned int s = sig;
132 
133 		if (s < nsignals)
134 			return signalent[s];
135 #ifdef ASM_SIGRTMAX
136 		if (s >= ASM_SIGRTMIN && s <= (unsigned int) ASM_SIGRTMAX) {
137 			xsprintf(buf, "SIGRT_%u", s - ASM_SIGRTMIN);
138 			return buf;
139 		}
140 #endif
141 	}
142 	xsprintf(buf, "%d", sig);
143 	return buf;
144 }
145 
146 static unsigned int
popcount32(const uint32_t * a,unsigned int size)147 popcount32(const uint32_t *a, unsigned int size)
148 {
149 	unsigned int count = 0;
150 
151 	for (; size; ++a, --size) {
152 		uint32_t x = *a;
153 
154 #ifdef HAVE___BUILTIN_POPCOUNT
155 		count += __builtin_popcount(x);
156 #else
157 		for (; x; ++count)
158 			x &= x - 1;
159 #endif
160 	}
161 
162 	return count;
163 }
164 
165 const char *
sprintsigmask_n(const char * prefix,const void * sig_mask,unsigned int bytes)166 sprintsigmask_n(const char *prefix, const void *sig_mask, unsigned int bytes)
167 {
168 	/*
169 	 * The maximum number of signal names to be printed
170 	 * is NSIG_BYTES * 8 * 2 / 3.
171 	 * Most of signal names have length 7,
172 	 * average length of signal names is less than 7.
173 	 * The length of prefix string does not exceed 16.
174 	 */
175 	static char outstr[128 + 8 * (NSIG_BYTES * 8 * 2 / 3)];
176 
177 	char *s;
178 	const uint32_t *mask;
179 	uint32_t inverted_mask[NSIG_BYTES / 4];
180 	unsigned int size;
181 	int i;
182 	char sep;
183 
184 	s = stpcpy(outstr, prefix);
185 
186 	mask = sig_mask;
187 	/* length of signal mask in 4-byte words */
188 	size = (bytes >= NSIG_BYTES) ? NSIG_BYTES / 4 : (bytes + 3) / 4;
189 
190 	/* check whether 2/3 or more bits are set */
191 	if (popcount32(mask, size) >= size * (4 * 8) * 2 / 3) {
192 		/* show those signals that are NOT in the mask */
193 		unsigned int j;
194 		for (j = 0; j < size; ++j)
195 			inverted_mask[j] = ~mask[j];
196 		mask = inverted_mask;
197 		*s++ = '~';
198 	}
199 
200 	sep = '[';
201 	for (i = 0; (i = next_set_bit(mask, i, size * (4 * 8))) >= 0; ) {
202 		++i;
203 		*s++ = sep;
204 		if ((unsigned) i < nsignals) {
205 			s = stpcpy(s, signalent[i] + 3);
206 		}
207 #ifdef ASM_SIGRTMAX
208 		else if (i >= ASM_SIGRTMIN && i <= ASM_SIGRTMAX) {
209 			s = xappendstr(outstr, s, "RT_%u", i - ASM_SIGRTMIN);
210 		}
211 #endif
212 		else {
213 			s = xappendstr(outstr, s, "%u", i);
214 		}
215 		sep = ' ';
216 	}
217 	if (sep == '[')
218 		*s++ = sep;
219 	*s++ = ']';
220 	*s = '\0';
221 	return outstr;
222 }
223 
224 #define sprintsigmask_val(prefix, mask) \
225 	sprintsigmask_n((prefix), &(mask), sizeof(mask))
226 
227 #define tprintsigmask_val(prefix, mask) \
228 	tprints(sprintsigmask_n((prefix), &(mask), sizeof(mask)))
229 
230 static const char *
sprint_old_sigmask_val(const char * const prefix,const unsigned long mask)231 sprint_old_sigmask_val(const char *const prefix, const unsigned long mask)
232 {
233 #if defined(current_wordsize) || !defined(WORDS_BIGENDIAN)
234 	return sprintsigmask_n(prefix, &mask, current_wordsize);
235 #else /* !current_wordsize && WORDS_BIGENDIAN */
236 	if (current_wordsize == sizeof(mask)) {
237 		return sprintsigmask_val(prefix, mask);
238 	} else {
239 		uint32_t mask32 = mask;
240 		return sprintsigmask_val(prefix, mask32);
241 	}
242 #endif
243 }
244 
245 #define tprint_old_sigmask_val(prefix, mask) \
246 	tprints(sprint_old_sigmask_val((prefix), (mask)))
247 
248 void
printsignal(int nr)249 printsignal(int nr)
250 {
251 	tprints(signame(nr));
252 }
253 
254 static void
print_sigset_addr_len_limit(struct tcb * const tcp,const kernel_ulong_t addr,const kernel_ulong_t len,const unsigned int min_len)255 print_sigset_addr_len_limit(struct tcb *const tcp, const kernel_ulong_t addr,
256 			    const kernel_ulong_t len, const unsigned int min_len)
257 {
258 	/*
259 	 * Here len is usually equal to NSIG_BYTES or current_wordsize.
260 	 * But we code this defensively:
261 	 */
262 	if (len < min_len || len > NSIG_BYTES) {
263 		printaddr(addr);
264 		return;
265 	}
266 	int mask[NSIG_BYTES / sizeof(int)] = {};
267 	if (umoven_or_printaddr(tcp, addr, len, mask))
268 		return;
269 	tprints(sprintsigmask_n("", mask, len));
270 }
271 
272 void
print_sigset_addr_len(struct tcb * const tcp,const kernel_ulong_t addr,const kernel_ulong_t len)273 print_sigset_addr_len(struct tcb *const tcp, const kernel_ulong_t addr,
274 		      const kernel_ulong_t len)
275 {
276 	print_sigset_addr_len_limit(tcp, addr, len, current_wordsize);
277 }
278 
279 void
print_sigset_addr(struct tcb * const tcp,const kernel_ulong_t addr)280 print_sigset_addr(struct tcb *const tcp, const kernel_ulong_t addr)
281 {
282 	print_sigset_addr_len_limit(tcp, addr, NSIG_BYTES, NSIG_BYTES);
283 }
284 
SYS_FUNC(ssetmask)285 SYS_FUNC(ssetmask)
286 {
287 	if (entering(tcp)) {
288 		tprint_old_sigmask_val("", (unsigned) tcp->u_arg[0]);
289 	} else if (!syserror(tcp)) {
290 		tcp->auxstr = sprint_old_sigmask_val("old mask ",
291 						     (unsigned) tcp->u_rval);
292 		return RVAL_HEX | RVAL_STR;
293 	}
294 	return 0;
295 }
296 
297 struct old_sigaction {
298 	/* sa_handler may be a libc #define, need to use other name: */
299 #if defined MIPS
300 	unsigned int sa_flags;
301 	unsigned long sa_handler__;
302 	unsigned long sa_mask;
303 #elif defined ALPHA
304 	unsigned long sa_handler__;
305 	unsigned long sa_mask;
306 	unsigned int sa_flags;
307 #else
308 	unsigned long sa_handler__;
309 	unsigned long sa_mask;
310 	unsigned long sa_flags;
311 	unsigned long sa_restorer;
312 #endif
313 }
314 #ifdef ALPHA
315 	ATTRIBUTE_PACKED
316 #endif
317 ;
318 
319 static void
decode_old_sigaction(struct tcb * const tcp,const kernel_ulong_t addr)320 decode_old_sigaction(struct tcb *const tcp, const kernel_ulong_t addr)
321 {
322 	struct old_sigaction sa;
323 
324 #ifndef current_wordsize
325 	if (current_wordsize < sizeof(sa.sa_handler__)) {
326 		struct old_sigaction32 {
327 			uint32_t sa_handler__;
328 			uint32_t sa_mask;
329 			uint32_t sa_flags;
330 			uint32_t sa_restorer;
331 		} sa32;
332 
333 		if (umove_or_printaddr(tcp, addr, &sa32))
334 			return;
335 
336 		memset(&sa, 0, sizeof(sa));
337 		sa.sa_handler__ = sa32.sa_handler__;
338 		sa.sa_flags = sa32.sa_flags;
339 		sa.sa_restorer = sa32.sa_restorer;
340 		sa.sa_mask = sa32.sa_mask;
341 	} else
342 #endif
343 	if (umove_or_printaddr(tcp, addr, &sa))
344 		return;
345 
346 	tprints("{sa_handler=");
347 	print_sa_handler(sa.sa_handler__);
348 	tprints(", sa_mask=");
349 	tprint_old_sigmask_val("", sa.sa_mask);
350 	tprints(", sa_flags=");
351 	printflags(sigact_flags, sa.sa_flags, "SA_???");
352 #if !(defined ALPHA || defined MIPS)
353 	if (sa.sa_flags & 0x04000000U) {
354 		tprints(", sa_restorer=");
355 		printaddr(sa.sa_restorer);
356 	}
357 #endif
358 	tprints("}");
359 }
360 
SYS_FUNC(sigaction)361 SYS_FUNC(sigaction)
362 {
363 	if (entering(tcp)) {
364 		int signo = tcp->u_arg[0];
365 #if defined SPARC || defined SPARC64
366 		if (signo < 0) {
367 			tprints("-");
368 			signo = -signo;
369 		}
370 #endif
371 		printsignal(signo);
372 		tprints(", ");
373 		decode_old_sigaction(tcp, tcp->u_arg[1]);
374 		tprints(", ");
375 	} else
376 		decode_old_sigaction(tcp, tcp->u_arg[2]);
377 	return 0;
378 }
379 
SYS_FUNC(signal)380 SYS_FUNC(signal)
381 {
382 	if (entering(tcp)) {
383 		printsignal(tcp->u_arg[0]);
384 		tprints(", ");
385 		print_sa_handler(tcp->u_arg[1]);
386 		return 0;
387 	} else if (!syserror(tcp)) {
388 		tcp->auxstr = get_sa_handler_str(tcp->u_rval);
389 		return RVAL_HEX | RVAL_STR;
390 	}
391 	return 0;
392 }
393 
SYS_FUNC(sgetmask)394 SYS_FUNC(sgetmask)
395 {
396 	if (exiting(tcp) && !syserror(tcp)) {
397 		tcp->auxstr = sprint_old_sigmask_val("mask ", tcp->u_rval);
398 		return RVAL_HEX | RVAL_STR;
399 	}
400 	return 0;
401 }
402 
SYS_FUNC(sigsuspend)403 SYS_FUNC(sigsuspend)
404 {
405 #ifdef MIPS
406 	print_sigset_addr_len(tcp, tcp->u_arg[tcp->s_ent->nargs - 1],
407 			      current_wordsize);
408 #else
409 	tprint_old_sigmask_val("", tcp->u_arg[tcp->s_ent->nargs - 1]);
410 #endif
411 
412 	return RVAL_DECODED;
413 }
414 
415 #ifdef ALPHA
416 /*
417  * The OSF/1 sigprocmask is different: it doesn't pass in two pointers,
418  * but rather passes in the new bitmask as an argument and then returns
419  * the old bitmask.  This "works" because we only have 64 signals to worry
420  * about.  If you want more, use of the rt_sigprocmask syscall is required.
421  *
422  * Alpha:
423  *	old = osf_sigprocmask(how, new);
424  * Everyone else:
425  *	ret = sigprocmask(how, &new, &old, ...);
426  */
SYS_FUNC(osf_sigprocmask)427 SYS_FUNC(osf_sigprocmask)
428 {
429 	if (entering(tcp)) {
430 		printxval(sigprocmaskcmds, tcp->u_arg[0], "SIG_???");
431 		tprintsigmask_val(", ", tcp->u_arg[1]);
432 	} else if (!syserror(tcp)) {
433 		tcp->auxstr = sprintsigmask_val("old mask ", tcp->u_rval);
434 		return RVAL_HEX | RVAL_STR;
435 	}
436 	return 0;
437 }
438 
439 #else /* !ALPHA */
440 
441 /* "Old" sigprocmask, which operates with word-sized signal masks */
SYS_FUNC(sigprocmask)442 SYS_FUNC(sigprocmask)
443 {
444 	if (entering(tcp)) {
445 		printxval(sigprocmaskcmds, tcp->u_arg[0], "SIG_???");
446 		tprints(", ");
447 		print_sigset_addr_len(tcp, tcp->u_arg[1], current_wordsize);
448 		tprints(", ");
449 	} else {
450 		print_sigset_addr_len(tcp, tcp->u_arg[2], current_wordsize);
451 	}
452 	return 0;
453 }
454 #endif /* !ALPHA */
455 
SYS_FUNC(kill)456 SYS_FUNC(kill)
457 {
458 	tprintf("%d, %s",
459 		(int) tcp->u_arg[0],
460 		signame(tcp->u_arg[1]));
461 
462 	return RVAL_DECODED;
463 }
464 
SYS_FUNC(tgkill)465 SYS_FUNC(tgkill)
466 {
467 	tprintf("%d, %d, %s",
468 		(int) tcp->u_arg[0],
469 		(int) tcp->u_arg[1],
470 		signame(tcp->u_arg[2]));
471 
472 	return RVAL_DECODED;
473 }
474 
SYS_FUNC(sigpending)475 SYS_FUNC(sigpending)
476 {
477 	if (exiting(tcp))
478 		print_sigset_addr_len(tcp, tcp->u_arg[0], current_wordsize);
479 	return 0;
480 }
481 
SYS_FUNC(rt_sigprocmask)482 SYS_FUNC(rt_sigprocmask)
483 {
484 	/* Note: arg[3] is the length of the sigset. Kernel requires NSIG_BYTES */
485 	if (entering(tcp)) {
486 		printxval(sigprocmaskcmds, tcp->u_arg[0], "SIG_???");
487 		tprints(", ");
488 		print_sigset_addr_len(tcp, tcp->u_arg[1], tcp->u_arg[3]);
489 		tprints(", ");
490 	} else {
491 		print_sigset_addr_len(tcp, tcp->u_arg[2], tcp->u_arg[3]);
492 		tprintf(", %" PRI_klu, tcp->u_arg[3]);
493 	}
494 	return 0;
495 }
496 
497 /* Structure describing the action to be taken when a signal arrives.  */
498 struct new_sigaction {
499 	/* sa_handler may be a libc #define, need to use other name: */
500 #ifdef MIPS
501 	unsigned int sa_flags;
502 	unsigned long sa_handler__;
503 #else
504 	unsigned long sa_handler__;
505 	unsigned long sa_flags;
506 #endif /* !MIPS */
507 #if HAVE_SA_RESTORER
508 	unsigned long sa_restorer;
509 #endif
510 	/* Kernel treats sa_mask as an array of longs. */
511 	unsigned long sa_mask[NSIG / sizeof(long)];
512 };
513 /* Same for i386-on-x86_64 and similar cases */
514 struct new_sigaction32 {
515 	uint32_t sa_handler__;
516 	uint32_t sa_flags;
517 #if HAVE_SA_RESTORER
518 	uint32_t sa_restorer;
519 #endif
520 	uint32_t sa_mask[2 * (NSIG / sizeof(long))];
521 };
522 
523 static void
decode_new_sigaction(struct tcb * const tcp,const kernel_ulong_t addr)524 decode_new_sigaction(struct tcb *const tcp, const kernel_ulong_t addr)
525 {
526 	struct new_sigaction sa;
527 
528 #ifndef current_wordsize
529 	if (current_wordsize < sizeof(sa.sa_handler__)) {
530 		struct new_sigaction32 sa32;
531 
532 		if (umove_or_printaddr(tcp, addr, &sa32))
533 			return;
534 
535 		memset(&sa, 0, sizeof(sa));
536 		sa.sa_handler__ = sa32.sa_handler__;
537 		sa.sa_flags     = sa32.sa_flags;
538 #if HAVE_SA_RESTORER && defined SA_RESTORER
539 		sa.sa_restorer  = sa32.sa_restorer;
540 #endif
541 		/* Kernel treats sa_mask as an array of longs.
542 		 * For 32-bit process, "long" is uint32_t, thus, for example,
543 		 * 32th bit in sa_mask will end up as bit 0 in sa_mask[1].
544 		 * But for (64-bit) kernel, 32th bit in sa_mask is
545 		 * 32th bit in 0th (64-bit) long!
546 		 * For little-endian, it's the same.
547 		 * For big-endian, we swap 32-bit words.
548 		 */
549 		sa.sa_mask[0] = ULONG_LONG(sa32.sa_mask[0], sa32.sa_mask[1]);
550 	} else
551 #endif
552 	if (umove_or_printaddr(tcp, addr, &sa))
553 		return;
554 
555 	tprints("{sa_handler=");
556 	print_sa_handler(sa.sa_handler__);
557 	tprints(", sa_mask=");
558 	/*
559 	 * Sigset size is in tcp->u_arg[4] (SPARC)
560 	 * or in tcp->u_arg[3] (all other),
561 	 * but kernel won't handle sys_rt_sigaction
562 	 * with wrong sigset size (just returns EINVAL instead).
563 	 * We just fetch the right size, which is NSIG_BYTES.
564 	 */
565 	tprintsigmask_val("", sa.sa_mask);
566 	tprints(", sa_flags=");
567 
568 	printflags(sigact_flags, sa.sa_flags, "SA_???");
569 #if HAVE_SA_RESTORER && defined SA_RESTORER
570 	if (sa.sa_flags & SA_RESTORER) {
571 		tprints(", sa_restorer=");
572 		printaddr(sa.sa_restorer);
573 	}
574 #endif
575 	tprints("}");
576 }
577 
SYS_FUNC(rt_sigaction)578 SYS_FUNC(rt_sigaction)
579 {
580 	if (entering(tcp)) {
581 		printsignal(tcp->u_arg[0]);
582 		tprints(", ");
583 		decode_new_sigaction(tcp, tcp->u_arg[1]);
584 		tprints(", ");
585 	} else {
586 		decode_new_sigaction(tcp, tcp->u_arg[2]);
587 #if defined(SPARC) || defined(SPARC64)
588 		tprintf(", %#" PRI_klx ", %" PRI_klu, tcp->u_arg[3], tcp->u_arg[4]);
589 #elif defined(ALPHA)
590 		tprintf(", %" PRI_klu ", %#" PRI_klx, tcp->u_arg[3], tcp->u_arg[4]);
591 #else
592 		tprintf(", %" PRI_klu, tcp->u_arg[3]);
593 #endif
594 	}
595 	return 0;
596 }
597 
SYS_FUNC(rt_sigpending)598 SYS_FUNC(rt_sigpending)
599 {
600 	if (exiting(tcp)) {
601 		/*
602 		 * One of the few syscalls where sigset size (arg[1])
603 		 * is allowed to be <= NSIG_BYTES, not strictly ==.
604 		 * This allows non-rt sigpending() syscall
605 		 * to reuse rt_sigpending() code in kernel.
606 		 */
607 		print_sigset_addr_len_limit(tcp, tcp->u_arg[0],
608 					    tcp->u_arg[1], 1);
609 		tprintf(", %" PRI_klu, tcp->u_arg[1]);
610 	}
611 	return 0;
612 }
613 
SYS_FUNC(rt_sigsuspend)614 SYS_FUNC(rt_sigsuspend)
615 {
616 	/* NB: kernel requires arg[1] == NSIG_BYTES */
617 	print_sigset_addr_len(tcp, tcp->u_arg[0], tcp->u_arg[1]);
618 	tprintf(", %" PRI_klu, tcp->u_arg[1]);
619 
620 	return RVAL_DECODED;
621 }
622 
623 static void
print_sigqueueinfo(struct tcb * const tcp,const int sig,const kernel_ulong_t addr)624 print_sigqueueinfo(struct tcb *const tcp, const int sig,
625 		   const kernel_ulong_t addr)
626 {
627 	printsignal(sig);
628 	tprints(", ");
629 	printsiginfo_at(tcp, addr);
630 }
631 
SYS_FUNC(rt_sigqueueinfo)632 SYS_FUNC(rt_sigqueueinfo)
633 {
634 	tprintf("%d, ", (int) tcp->u_arg[0]);
635 	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
636 
637 	return RVAL_DECODED;
638 }
639 
SYS_FUNC(rt_tgsigqueueinfo)640 SYS_FUNC(rt_tgsigqueueinfo)
641 {
642 	tprintf("%d, %d, ", (int) tcp->u_arg[0], (int) tcp->u_arg[1]);
643 	print_sigqueueinfo(tcp, tcp->u_arg[2], tcp->u_arg[3]);
644 
645 	return RVAL_DECODED;
646 }
647 
SYS_FUNC(rt_sigtimedwait)648 SYS_FUNC(rt_sigtimedwait)
649 {
650 	/* NB: kernel requires arg[3] == NSIG_BYTES */
651 	if (entering(tcp)) {
652 		print_sigset_addr_len(tcp, tcp->u_arg[0], tcp->u_arg[3]);
653 		tprints(", ");
654 		if (!(tcp->u_arg[1] && verbose(tcp))) {
655 			/*
656 			 * This is the only "return" parameter,
657 			 * if we are not going to fetch it on exit,
658 			 * decode all parameters on entry.
659 			 */
660 			printaddr(tcp->u_arg[1]);
661 			tprints(", ");
662 			print_timespec(tcp, tcp->u_arg[2]);
663 			tprintf(", %" PRI_klu, tcp->u_arg[3]);
664 		} else {
665 			char *sts = xstrdup(sprint_timespec(tcp, tcp->u_arg[2]));
666 			set_tcb_priv_data(tcp, sts, free);
667 		}
668 	} else {
669 		if (tcp->u_arg[1] && verbose(tcp)) {
670 			printsiginfo_at(tcp, tcp->u_arg[1]);
671 			tprints(", ");
672 			tprints(get_tcb_priv_data(tcp));
673 			tprintf(", %" PRI_klu, tcp->u_arg[3]);
674 		}
675 
676 		if (!syserror(tcp) && tcp->u_rval) {
677 			tcp->auxstr = signame(tcp->u_rval);
678 			return RVAL_STR;
679 		}
680 	}
681 	return 0;
682 }
683 
SYS_FUNC(restart_syscall)684 SYS_FUNC(restart_syscall)
685 {
686 	tprintf("<... resuming interrupted %s ...>",
687 		tcp->s_prev_ent ? tcp->s_prev_ent->sys_name : "system call");
688 
689 	return RVAL_DECODED;
690 }
691