granicus.if.org Git - strace/blob - syscall.c

   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  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include "defs.h"
  35 #include <sys/param.h>
  36
  37 /* for struct iovec */
  38 #include <sys/uio.h>
  39
  40 #include "regs.h"
  41 #include "ptrace.h"
  42
  43 #if defined(SPARC64)
  44 # undef PTRACE_GETREGS
  45 # define PTRACE_GETREGS PTRACE_GETREGS64
  46 # undef PTRACE_SETREGS
  47 # define PTRACE_SETREGS PTRACE_SETREGS64
  48 #endif
  49
  50 #if defined SPARC64
  51 # include <asm/psrcompat.h>
  52 #elif defined SPARC
  53 # include <asm/psr.h>
  54 #endif
  55
  56 #ifndef NT_PRSTATUS
  57 # define NT_PRSTATUS 1
  58 #endif
  59
  60 #ifndef NSIG
  61 # warning: NSIG is not defined, using 32
  62 # define NSIG 32
  63 #endif
  64
  65 #include "syscall.h"
  66
  67 /* Define these shorthand notations to simplify the syscallent files. */
  68 #define TD TRACE_DESC
  69 #define TF TRACE_FILE
  70 #define TI TRACE_IPC
  71 #define TN TRACE_NETWORK
  72 #define TP TRACE_PROCESS
  73 #define TS TRACE_SIGNAL
  74 #define TM TRACE_MEMORY
  75 #define NF SYSCALL_NEVER_FAILS
  76 #define MA MAX_ARGS
  77 #define SI STACKTRACE_INVALIDATE_CACHE
  78 #define SE STACKTRACE_CAPTURE_ON_ENTER
  79
  80 const struct_sysent sysent0[] = {
  81 #include "syscallent.h"
  82 };
  83
  84 #if SUPPORTED_PERSONALITIES > 1
  85 static const struct_sysent sysent1[] = {
  86 # include "syscallent1.h"
  87 };
  88 #endif
  89
  90 #if SUPPORTED_PERSONALITIES > 2
  91 static const struct_sysent sysent2[] = {
  92 # include "syscallent2.h"
  93 };
  94 #endif
  95
  96 /* Now undef them since short defines cause wicked namespace pollution. */
  97 #undef TD
  98 #undef TF
  99 #undef TI
 100 #undef TN
 101 #undef TP
 102 #undef TS
 103 #undef TM
 104 #undef NF
 105 #undef MA
 106 #undef SI
 107 #undef SE
 108
 109 /*
 110  * `ioctlent[012].h' files are automatically generated by the auxiliary
 111  * program `ioctlsort', such that the list is sorted by the `code' field.
 112  * This has the side-effect of resolving the _IO.. macros into
 113  * plain integers, eliminating the need to include here everything
 114  * in "/usr/include".
 115  */
 116
 117 const char *const errnoent0[] = {
 118 #include "errnoent.h"
 119 };
 120 const char *const signalent0[] = {
 121 #include "signalent.h"
 122 };
 123 const struct_ioctlent ioctlent0[] = {
 124 #include "ioctlent0.h"
 125 };
 126
 127 #if SUPPORTED_PERSONALITIES > 1
 128 static const char *const errnoent1[] = {
 129 # include "errnoent1.h"
 130 };
 131 static const char *const signalent1[] = {
 132 # include "signalent1.h"
 133 };
 134 static const struct_ioctlent ioctlent1[] = {
 135 # include "ioctlent1.h"
 136 };
 137 #endif
 138
 139 #if SUPPORTED_PERSONALITIES > 2
 140 static const char *const errnoent2[] = {
 141 # include "errnoent2.h"
 142 };
 143 static const char *const signalent2[] = {
 144 # include "signalent2.h"
 145 };
 146 static const struct_ioctlent ioctlent2[] = {
 147 # include "ioctlent2.h"
 148 };
 149 #endif
 150
 151 enum {
 152         nsyscalls0 = ARRAY_SIZE(sysent0)
 153 #if SUPPORTED_PERSONALITIES > 1
 154         , nsyscalls1 = ARRAY_SIZE(sysent1)
 155 # if SUPPORTED_PERSONALITIES > 2
 156         , nsyscalls2 = ARRAY_SIZE(sysent2)
 157 # endif
 158 #endif
 159 };
 160
 161 enum {
 162         nerrnos0 = ARRAY_SIZE(errnoent0)
 163 #if SUPPORTED_PERSONALITIES > 1
 164         , nerrnos1 = ARRAY_SIZE(errnoent1)
 165 # if SUPPORTED_PERSONALITIES > 2
 166         , nerrnos2 = ARRAY_SIZE(errnoent2)
 167 # endif
 168 #endif
 169 };
 170
 171 enum {
 172         nsignals0 = ARRAY_SIZE(signalent0)
 173 #if SUPPORTED_PERSONALITIES > 1
 174         , nsignals1 = ARRAY_SIZE(signalent1)
 175 # if SUPPORTED_PERSONALITIES > 2
 176         , nsignals2 = ARRAY_SIZE(signalent2)
 177 # endif
 178 #endif
 179 };
 180
 181 enum {
 182         nioctlents0 = ARRAY_SIZE(ioctlent0)
 183 #if SUPPORTED_PERSONALITIES > 1
 184         , nioctlents1 = ARRAY_SIZE(ioctlent1)
 185 # if SUPPORTED_PERSONALITIES > 2
 186         , nioctlents2 = ARRAY_SIZE(ioctlent2)
 187 # endif
 188 #endif
 189 };
 190
 191 #if SUPPORTED_PERSONALITIES > 1
 192 const struct_sysent *sysent = sysent0;
 193 const char *const *errnoent = errnoent0;
 194 const char *const *signalent = signalent0;
 195 const struct_ioctlent *ioctlent = ioctlent0;
 196 #endif
 197 unsigned nsyscalls = nsyscalls0;
 198 unsigned nerrnos = nerrnos0;
 199 unsigned nsignals = nsignals0;
 200 unsigned nioctlents = nioctlents0;
 201
 202 unsigned num_quals;
 203 qualbits_t *qual_vec[SUPPORTED_PERSONALITIES];
 204
 205 static const unsigned nsyscall_vec[SUPPORTED_PERSONALITIES] = {
 206         nsyscalls0,
 207 #if SUPPORTED_PERSONALITIES > 1
 208         nsyscalls1,
 209 #endif
 210 #if SUPPORTED_PERSONALITIES > 2
 211         nsyscalls2,
 212 #endif
 213 };
 214 static const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
 215         sysent0,
 216 #if SUPPORTED_PERSONALITIES > 1
 217         sysent1,
 218 #endif
 219 #if SUPPORTED_PERSONALITIES > 2
 220         sysent2,
 221 #endif
 222 };
 223
 224 enum {
 225         MAX_NSYSCALLS1 = (nsyscalls0
 226 #if SUPPORTED_PERSONALITIES > 1
 227                         > nsyscalls1 ? nsyscalls0 : nsyscalls1
 228 #endif
 229                         ),
 230         MAX_NSYSCALLS2 = (MAX_NSYSCALLS1
 231 #if SUPPORTED_PERSONALITIES > 2
 232                         > nsyscalls2 ? MAX_NSYSCALLS1 : nsyscalls2
 233 #endif
 234                         ),
 235         MAX_NSYSCALLS = MAX_NSYSCALLS2,
 236         /* We are ready for arches with up to 255 signals,
 237          * even though the largest known signo is on MIPS and it is 128.
 238          * The number of existing syscalls on all arches is
 239          * larger that 255 anyway, so it is just a pedantic matter.
 240          */
 241         MIN_QUALS = MAX_NSYSCALLS > 255 ? MAX_NSYSCALLS : 255
 242 };
 243
 244 #if SUPPORTED_PERSONALITIES > 1
 245 unsigned current_personality;
 246
 247 # ifndef current_wordsize
 248 unsigned current_wordsize;
 249 static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
 250         PERSONALITY0_WORDSIZE,
 251         PERSONALITY1_WORDSIZE,
 252 # if SUPPORTED_PERSONALITIES > 2
 253         PERSONALITY2_WORDSIZE,
 254 # endif
 255 };
 256 # endif
 257
 258 void
 259 set_personality(int personality)
 260 {
 261         nsyscalls = nsyscall_vec[personality];
 262         sysent = sysent_vec[personality];
 263
 264         switch (personality) {
 265         case 0:
 266                 errnoent = errnoent0;
 267                 nerrnos = nerrnos0;
 268                 ioctlent = ioctlent0;
 269                 nioctlents = nioctlents0;
 270                 signalent = signalent0;
 271                 nsignals = nsignals0;
 272                 break;
 273
 274         case 1:
 275                 errnoent = errnoent1;
 276                 nerrnos = nerrnos1;
 277                 ioctlent = ioctlent1;
 278                 nioctlents = nioctlents1;
 279                 signalent = signalent1;
 280                 nsignals = nsignals1;
 281                 break;
 282
 283 # if SUPPORTED_PERSONALITIES > 2
 284         case 2:
 285                 errnoent = errnoent2;
 286                 nerrnos = nerrnos2;
 287                 ioctlent = ioctlent2;
 288                 nioctlents = nioctlents2;
 289                 signalent = signalent2;
 290                 nsignals = nsignals2;
 291                 break;
 292 # endif
 293         }
 294
 295         current_personality = personality;
 296 # ifndef current_wordsize
 297         current_wordsize = personality_wordsize[personality];
 298 # endif
 299 }
 300
 301 static void
 302 update_personality(struct tcb *tcp, unsigned int personality)
 303 {
 304         if (personality == current_personality)
 305                 return;
 306         set_personality(personality);
 307
 308         if (personality == tcp->currpers)
 309                 return;
 310         tcp->currpers = personality;
 311
 312 # if defined(POWERPC64)
 313         if (!qflag) {
 314                 static const char *const names[] = {"64 bit", "32 bit"};
 315                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 316                         tcp->pid, names[personality]);
 317         }
 318 # elif defined(X86_64)
 319         if (!qflag) {
 320                 static const char *const names[] = {"64 bit", "32 bit", "x32"};
 321                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 322                         tcp->pid, names[personality]);
 323         }
 324 # elif defined(X32)
 325         if (!qflag) {
 326                 static const char *const names[] = {"x32", "32 bit"};
 327                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 328                         tcp->pid, names[personality]);
 329         }
 330 # elif defined(AARCH64)
 331         if (!qflag) {
 332                 static const char *const names[] = {"32-bit", "AArch64"};
 333                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 334                         tcp->pid, names[personality]);
 335         }
 336 # elif defined(TILE)
 337         if (!qflag) {
 338                 static const char *const names[] = {"64-bit", "32-bit"};
 339                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 340                         tcp->pid, names[personality]);
 341         }
 342 # endif
 343 }
 344 #endif
 345
 346 static int qual_syscall(), qual_signal(), qual_desc();
 347
 348 static const struct qual_options {
 349         unsigned int bitflag;
 350         const char *option_name;
 351         int (*qualify)(const char *, int, int);
 352         const char *argument_name;
 353 } qual_options[] = {
 354         { QUAL_TRACE,   "trace",        qual_syscall,   "system call"   },
 355         { QUAL_TRACE,   "t",            qual_syscall,   "system call"   },
 356         { QUAL_ABBREV,  "abbrev",       qual_syscall,   "system call"   },
 357         { QUAL_ABBREV,  "a",            qual_syscall,   "system call"   },
 358         { QUAL_VERBOSE, "verbose",      qual_syscall,   "system call"   },
 359         { QUAL_VERBOSE, "v",            qual_syscall,   "system call"   },
 360         { QUAL_RAW,     "raw",          qual_syscall,   "system call"   },
 361         { QUAL_RAW,     "x",            qual_syscall,   "system call"   },
 362         { QUAL_SIGNAL,  "signal",       qual_signal,    "signal"        },
 363         { QUAL_SIGNAL,  "signals",      qual_signal,    "signal"        },
 364         { QUAL_SIGNAL,  "s",            qual_signal,    "signal"        },
 365         { QUAL_READ,    "read",         qual_desc,      "descriptor"    },
 366         { QUAL_READ,    "reads",        qual_desc,      "descriptor"    },
 367         { QUAL_READ,    "r",            qual_desc,      "descriptor"    },
 368         { QUAL_WRITE,   "write",        qual_desc,      "descriptor"    },
 369         { QUAL_WRITE,   "writes",       qual_desc,      "descriptor"    },
 370         { QUAL_WRITE,   "w",            qual_desc,      "descriptor"    },
 371         { 0,            NULL,           NULL,           NULL            },
 372 };
 373
 374 static void
 375 reallocate_qual(const unsigned int n)
 376 {
 377         unsigned p;
 378         qualbits_t *qp;
 379         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 380                 qp = qual_vec[p] = realloc(qual_vec[p], n * sizeof(qualbits_t));
 381                 if (!qp)
 382                         die_out_of_memory();
 383                 memset(&qp[num_quals], 0, (n - num_quals) * sizeof(qualbits_t));
 384         }
 385         num_quals = n;
 386 }
 387
 388 static void
 389 qualify_one(const unsigned int n, unsigned int bitflag, const int not, const int pers)
 390 {
 391         int p;
 392
 393         if (num_quals <= n)
 394                 reallocate_qual(n + 1);
 395
 396         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 397                 if (pers == p || pers < 0) {
 398                         if (not)
 399                                 qual_vec[p][n] &= ~bitflag;
 400                         else
 401                                 qual_vec[p][n] |= bitflag;
 402                 }
 403         }
 404 }
 405
 406 static int
 407 qual_syscall(const char *s, const unsigned int bitflag, const int not)
 408 {
 409         int p;
 410         unsigned int i;
 411         int rc = -1;
 412
 413         if (*s >= '0' && *s <= '9') {
 414                 i = string_to_uint(s);
 415                 if (i >= MAX_NSYSCALLS)
 416                         return -1;
 417                 qualify_one(i, bitflag, not, -1);
 418                 return 0;
 419         }
 420
 421         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 422                 for (i = 0; i < nsyscall_vec[p]; i++) {
 423                         if (sysent_vec[p][i].sys_name
 424                          && strcmp(s, sysent_vec[p][i].sys_name) == 0
 425                         ) {
 426                                 qualify_one(i, bitflag, not, p);
 427                                 rc = 0;
 428                         }
 429                 }
 430         }
 431
 432         return rc;
 433 }
 434
 435 static int
 436 qual_signal(const char *s, const unsigned int bitflag, const int not)
 437 {
 438         unsigned int i;
 439
 440         if (*s >= '0' && *s <= '9') {
 441                 int signo = string_to_uint(s);
 442                 if (signo < 0 || signo > 255)
 443                         return -1;
 444                 qualify_one(signo, bitflag, not, -1);
 445                 return 0;
 446         }
 447         if (strncasecmp(s, "SIG", 3) == 0)
 448                 s += 3;
 449         for (i = 0; i <= NSIG; i++) {
 450                 if (strcasecmp(s, signame(i) + 3) == 0) {
 451                         qualify_one(i, bitflag, not, -1);
 452                         return 0;
 453                 }
 454         }
 455         return -1;
 456 }
 457
 458 static int
 459 qual_desc(const char *s, const unsigned int bitflag, const int not)
 460 {
 461         if (*s >= '0' && *s <= '9') {
 462                 int desc = string_to_uint(s);
 463                 if (desc < 0 || desc > 0x7fff) /* paranoia */
 464                         return -1;
 465                 qualify_one(desc, bitflag, not, -1);
 466                 return 0;
 467         }
 468         return -1;
 469 }
 470
 471 static int
 472 lookup_class(const char *s)
 473 {
 474         if (strcmp(s, "file") == 0)
 475                 return TRACE_FILE;
 476         if (strcmp(s, "ipc") == 0)
 477                 return TRACE_IPC;
 478         if (strcmp(s, "network") == 0)
 479                 return TRACE_NETWORK;
 480         if (strcmp(s, "process") == 0)
 481                 return TRACE_PROCESS;
 482         if (strcmp(s, "signal") == 0)
 483                 return TRACE_SIGNAL;
 484         if (strcmp(s, "desc") == 0)
 485                 return TRACE_DESC;
 486         if (strcmp(s, "memory") == 0)
 487                 return TRACE_MEMORY;
 488         return -1;
 489 }
 490
 491 void
 492 qualify(const char *s)
 493 {
 494         const struct qual_options *opt;
 495         char *copy;
 496         const char *p;
 497         int not;
 498         unsigned int i;
 499
 500         if (num_quals == 0)
 501                 reallocate_qual(MIN_QUALS);
 502
 503         opt = &qual_options[0];
 504         for (i = 0; (p = qual_options[i].option_name); i++) {
 505                 unsigned int len = strlen(p);
 506                 if (strncmp(s, p, len) == 0 && s[len] == '=') {
 507                         opt = &qual_options[i];
 508                         s += len + 1;
 509                         break;
 510                 }
 511         }
 512         not = 0;
 513         if (*s == '!') {
 514                 not = 1;
 515                 s++;
 516         }
 517         if (strcmp(s, "none") == 0) {
 518                 not = 1 - not;
 519                 s = "all";
 520         }
 521         if (strcmp(s, "all") == 0) {
 522                 for (i = 0; i < num_quals; i++) {
 523                         qualify_one(i, opt->bitflag, not, -1);
 524                 }
 525                 return;
 526         }
 527         for (i = 0; i < num_quals; i++) {
 528                 qualify_one(i, opt->bitflag, !not, -1);
 529         }
 530         copy = strdup(s);
 531         if (!copy)
 532                 die_out_of_memory();
 533         for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
 534                 int n;
 535                 if (opt->bitflag == QUAL_TRACE && (n = lookup_class(p)) > 0) {
 536                         unsigned pers;
 537                         for (pers = 0; pers < SUPPORTED_PERSONALITIES; pers++) {
 538                                 for (i = 0; i < nsyscall_vec[pers]; i++)
 539                                         if (sysent_vec[pers][i].sys_flags & n)
 540                                                 qualify_one(i, opt->bitflag, not, pers);
 541                         }
 542                         continue;
 543                 }
 544                 if (opt->qualify(p, opt->bitflag, not)) {
 545                         error_msg_and_die("invalid %s '%s'",
 546                                 opt->argument_name, p);
 547                 }
 548         }
 549         free(copy);
 550         return;
 551 }
 552
 553 #ifdef SYS_socket_subcall
 554 static void
 555 decode_socket_subcall(struct tcb *tcp)
 556 {
 557         unsigned long addr;
 558         unsigned int i, n, size;
 559
 560         if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= SYS_socket_nsubcalls)
 561                 return;
 562
 563         tcp->scno = SYS_socket_subcall + tcp->u_arg[0];
 564         tcp->qual_flg = qual_flags[tcp->scno];
 565         tcp->s_ent = &sysent[tcp->scno];
 566         addr = tcp->u_arg[1];
 567         size = current_wordsize;
 568         n = tcp->s_ent->nargs;
 569         for (i = 0; i < n; ++i) {
 570                 if (size == sizeof(int)) {
 571                         unsigned int arg;
 572                         if (umove(tcp, addr, &arg) < 0)
 573                                 arg = 0;
 574                         tcp->u_arg[i] = arg;
 575                 }
 576                 else {
 577                         unsigned long arg;
 578                         if (umove(tcp, addr, &arg) < 0)
 579                                 arg = 0;
 580                         tcp->u_arg[i] = arg;
 581                 }
 582                 addr += size;
 583         }
 584 }
 585 #endif
 586
 587 #ifdef SYS_ipc_subcall
 588 static void
 589 decode_ipc_subcall(struct tcb *tcp)
 590 {
 591         unsigned int i, n;
 592
 593         if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= SYS_ipc_nsubcalls)
 594                 return;
 595
 596         tcp->scno = SYS_ipc_subcall + tcp->u_arg[0];
 597         tcp->qual_flg = qual_flags[tcp->scno];
 598         tcp->s_ent = &sysent[tcp->scno];
 599         n = tcp->s_ent->nargs;
 600         for (i = 0; i < n; i++)
 601                 tcp->u_arg[i] = tcp->u_arg[i + 1];
 602 }
 603 #endif
 604
 605 int
 606 printargs(struct tcb *tcp)
 607 {
 608         if (entering(tcp)) {
 609                 int i;
 610                 int n = tcp->s_ent->nargs;
 611                 for (i = 0; i < n; i++)
 612                         tprintf("%s%#lx", i ? ", " : "", tcp->u_arg[i]);
 613         }
 614         return 0;
 615 }
 616
 617 int
 618 printargs_lu(struct tcb *tcp)
 619 {
 620         if (entering(tcp)) {
 621                 int i;
 622                 int n = tcp->s_ent->nargs;
 623                 for (i = 0; i < n; i++)
 624                         tprintf("%s%lu", i ? ", " : "", tcp->u_arg[i]);
 625         }
 626         return 0;
 627 }
 628
 629 int
 630 printargs_ld(struct tcb *tcp)
 631 {
 632         if (entering(tcp)) {
 633                 int i;
 634                 int n = tcp->s_ent->nargs;
 635                 for (i = 0; i < n; i++)
 636                         tprintf("%s%ld", i ? ", " : "", tcp->u_arg[i]);
 637         }
 638         return 0;
 639 }
 640
 641 #if defined(SPARC) || defined(SPARC64) || defined(IA64) || defined(SH)
 642 long
 643 getrval2(struct tcb *tcp)
 644 {
 645         long val;
 646
 647 # if defined(SPARC) || defined(SPARC64)
 648         val = sparc_regs.u_regs[U_REG_O1];
 649 # elif defined(SH)
 650         if (upeek(tcp->pid, 4*(REG_REG0+1), &val) < 0)
 651                 return -1;
 652 # elif defined(IA64)
 653         if (upeek(tcp->pid, PT_R9, &val) < 0)
 654                 return -1;
 655 # endif
 656
 657         return val;
 658 }
 659 #endif
 660
 661 #if defined(I386)
 662 static struct user_regs_struct i386_regs;
 663 long *const i386_esp_ptr = &i386_regs.esp;
 664 # define ARCH_REGS_FOR_GETREGS i386_regs
 665 #elif defined(X86_64) || defined(X32)
 666 /*
 667  * On i386, pt_regs and user_regs_struct are the same,
 668  * but on 64 bit x86, user_regs_struct has six more fields:
 669  * fs_base, gs_base, ds, es, fs, gs.
 670  * PTRACE_GETREGS fills them too, so struct pt_regs would overflow.
 671  */
 672 struct i386_user_regs_struct {
 673         uint32_t ebx;
 674         uint32_t ecx;
 675         uint32_t edx;
 676         uint32_t esi;
 677         uint32_t edi;
 678         uint32_t ebp;
 679         uint32_t eax;
 680         uint32_t xds;
 681         uint32_t xes;
 682         uint32_t xfs;
 683         uint32_t xgs;
 684         uint32_t orig_eax;
 685         uint32_t eip;
 686         uint32_t xcs;
 687         uint32_t eflags;
 688         uint32_t esp;
 689         uint32_t xss;
 690 };
 691 static union {
 692         struct user_regs_struct      x86_64_r;
 693         struct i386_user_regs_struct i386_r;
 694 } x86_regs_union;
 695 # define x86_64_regs x86_regs_union.x86_64_r
 696 # define i386_regs   x86_regs_union.i386_r
 697 uint32_t *const i386_esp_ptr = &i386_regs.esp;
 698 static struct iovec x86_io = {
 699         .iov_base = &x86_regs_union
 700 };
 701 # define ARCH_REGS_FOR_GETREGSET x86_regs_union
 702 # define ARCH_IOVEC_FOR_GETREGSET x86_io
 703 #elif defined(IA64)
 704 static bool ia64_ia32mode;
 705 static long ia64_r8, ia64_r10;
 706 #elif defined(POWERPC)
 707 struct pt_regs ppc_regs; /* not static */
 708 # define ARCH_REGS_FOR_GETREGS ppc_regs
 709 #elif defined(M68K)
 710 static long m68k_d0;
 711 #elif defined(BFIN)
 712 static long bfin_r0;
 713 #elif defined(ARM)
 714 struct pt_regs arm_regs; /* not static */
 715 # define ARCH_REGS_FOR_GETREGS arm_regs
 716 #elif defined(AARCH64)
 717 struct arm_pt_regs {
 718         int uregs[18];
 719 };
 720 # define ARM_cpsr       uregs[16]
 721 # define ARM_pc         uregs[15]
 722 # define ARM_lr         uregs[14]
 723 # define ARM_sp         uregs[13]
 724 # define ARM_ip         uregs[12]
 725 # define ARM_fp         uregs[11]
 726 # define ARM_r10        uregs[10]
 727 # define ARM_r9         uregs[9]
 728 # define ARM_r8         uregs[8]
 729 # define ARM_r7         uregs[7]
 730 # define ARM_r6         uregs[6]
 731 # define ARM_r5         uregs[5]
 732 # define ARM_r4         uregs[4]
 733 # define ARM_r3         uregs[3]
 734 # define ARM_r2         uregs[2]
 735 # define ARM_r1         uregs[1]
 736 # define ARM_r0         uregs[0]
 737 # define ARM_ORIG_r0    uregs[17]
 738 static union {
 739         struct user_pt_regs aarch64_r;
 740         struct arm_pt_regs  arm_r;
 741 } arm_regs_union;
 742 # define aarch64_regs arm_regs_union.aarch64_r
 743 # define arm_regs     arm_regs_union.arm_r
 744 static struct iovec aarch64_io = {
 745         .iov_base = &arm_regs_union
 746 };
 747 # define ARCH_REGS_FOR_GETREGSET arm_regs_union
 748 # define ARCH_IOVEC_FOR_GETREGSET aarch64_io
 749 #elif defined(ALPHA)
 750 static long alpha_r0;
 751 static long alpha_a3;
 752 #elif defined(AVR32)
 753 static struct pt_regs avr32_regs;
 754 # define ARCH_REGS_FOR_GETREGS avr32_regs
 755 #elif defined(SPARC) || defined(SPARC64)
 756 struct pt_regs sparc_regs; /* not static */
 757 # define ARCH_REGS_FOR_GETREGS sparc_regs
 758 #elif defined(MIPS)
 759 struct mips_regs mips_regs; /* not static */
 760 /* PTRACE_GETREGS on MIPS is available since linux v2.6.15. */
 761 # define ARCH_REGS_FOR_GETREGS mips_regs
 762 #elif defined(S390) || defined(S390X)
 763 static long s390_gpr2;
 764 #elif defined(HPPA)
 765 static long hppa_r28;
 766 #elif defined(SH)
 767 static long sh_r0;
 768 #elif defined(SH64)
 769 static long sh64_r9;
 770 #elif defined(CRISV10) || defined(CRISV32)
 771 static long cris_r10;
 772 #elif defined(TILE)
 773 struct pt_regs tile_regs; /* not static */
 774 # define ARCH_REGS_FOR_GETREGS tile_regs
 775 #elif defined(MICROBLAZE)
 776 static long microblaze_r3;
 777 #elif defined(OR1K)
 778 static struct user_regs_struct or1k_regs;
 779 # define ARCH_REGS_FOR_GETREGSET or1k_regs
 780 #elif defined(METAG)
 781 static struct user_gp_regs metag_regs;
 782 # define ARCH_REGS_FOR_GETREGSET metag_regs
 783 #elif defined(XTENSA)
 784 static long xtensa_a2;
 785 # elif defined(ARC)
 786 static struct user_regs_struct arc_regs;
 787 # define ARCH_REGS_FOR_GETREGSET arc_regs
 788 #endif
 789
 790 static long get_regs_error;
 791
 792 void
 793 print_pc(struct tcb *tcp)
 794 {
 795         const char *fmt;
 796         const char *bad;
 797
 798 #ifdef current_wordsize
 799 # define pc_wordsize current_wordsize
 800 #else
 801 # define pc_wordsize personality_wordsize[tcp->currpers]
 802 #endif
 803
 804         if (pc_wordsize == 4) {
 805                 fmt = "[%08lx] ";
 806                 bad = "[????????] ";
 807         } else {
 808                 fmt = "[%016lx] ";
 809                 bad = "[????????????????] ";
 810         }
 811
 812 #undef pc_wordsize
 813 #define PRINTBADPC tprints(bad)
 814
 815         if (get_regs_error) {
 816                 PRINTBADPC;
 817                 return;
 818         }
 819
 820 #if defined(I386)
 821         tprintf(fmt, i386_regs.eip);
 822 #elif defined(X86_64) || defined(X32)
 823         if (x86_io.iov_len == sizeof(i386_regs))
 824                 tprintf(fmt, (unsigned long) i386_regs.eip);
 825         else
 826                 tprintf(fmt, (unsigned long) x86_64_regs.rip);
 827 #elif defined(S390) || defined(S390X)
 828         long psw;
 829         if (upeek(tcp->pid, PT_PSWADDR, &psw) < 0) {
 830                 PRINTBADPC;
 831                 return;
 832         }
 833         tprintf(fmt, psw);
 834 #elif defined(IA64)
 835         long ip;
 836         if (upeek(tcp->pid, PT_B0, &ip) < 0) {
 837                 PRINTBADPC;
 838                 return;
 839         }
 840         tprintf(fmt, ip);
 841 #elif defined(POWERPC)
 842         tprintf(fmt, ppc_regs.nip);
 843 #elif defined(M68K)
 844         long pc;
 845         if (upeek(tcp->pid, 4*PT_PC, &pc) < 0) {
 846                 PRINTBADPC;
 847                 return;
 848         }
 849         tprintf(fmt, pc);
 850 #elif defined(ALPHA)
 851         long pc;
 852         if (upeek(tcp->pid, REG_PC, &pc) < 0) {
 853                 PRINTBADPC;
 854                 return;
 855         }
 856         tprintf(fmt, pc);
 857 #elif defined(SPARC)
 858         tprintf(fmt, sparc_regs.pc);
 859 #elif defined(SPARC64)
 860         tprintf(fmt, sparc_regs.tpc);
 861 #elif defined(HPPA)
 862         long pc;
 863         if (upeek(tcp->pid, PT_IAOQ0, &pc) < 0) {
 864                 PRINTBADPC;
 865                 return;
 866         }
 867         tprintf(fmt, pc);
 868 #elif defined MIPS
 869         tprintf(fmt, (unsigned long) mips_REG_EPC);
 870 #elif defined(SH)
 871         long pc;
 872         if (upeek(tcp->pid, 4*REG_PC, &pc) < 0) {
 873                 PRINTBADPC;
 874                 return;
 875         }
 876         tprintf(fmt, pc);
 877 #elif defined(SH64)
 878         long pc;
 879         if (upeek(tcp->pid, REG_PC, &pc) < 0) {
 880                 PRINTBADPC;
 881                 return;
 882         }
 883         tprintf(fmt, pc);
 884 #elif defined(ARM)
 885         tprintf(fmt, arm_regs.ARM_pc);
 886 #elif defined(AVR32)
 887         tprintf(fmt, avr32_regs.pc);
 888 #elif defined(BFIN)
 889         long pc;
 890         if (upeek(tcp->pid, PT_PC, &pc) < 0) {
 891                 PRINTBADPC;
 892                 return;
 893         }
 894         tprintf(fmt, pc);
 895 #elif defined(CRISV10)
 896         long pc;
 897         if (upeek(tcp->pid, 4*PT_IRP, &pc) < 0) {
 898                 PRINTBADPC;
 899                 return;
 900         }
 901         tprintf(fmt, pc);
 902 #elif defined(CRISV32)
 903         long pc;
 904         if (upeek(tcp->pid, 4*PT_ERP, &pc) < 0) {
 905                 PRINTBADPC;
 906                 return;
 907         }
 908         tprintf(fmt, pc);
 909 #elif defined(TILE)
 910         tprintf(fmt, (unsigned long) tile_regs.pc);
 911 #elif defined(OR1K)
 912         tprintf(fmt, or1k_regs.pc);
 913 #elif defined(METAG)
 914         tprintf(fmt, metag_regs.pc);
 915 #elif defined(XTENSA)
 916         long pc;
 917         if (upeek(tcp->pid, REG_PC, &pc) < 0) {
 918                 PRINTBADPC;
 919                 return;
 920         }
 921         tprintf(fmt, pc);
 922 #elif defined(ARC)
 923         tprintf(fmt, arc_regs.efa);
 924 #else
 925 # warning print_pc is not implemented for this architecture
 926         PRINTBADPC;
 927 #endif /* architecture */
 928 }
 929
 930 /*
 931  * Shuffle syscall numbers so that we don't have huge gaps in syscall table.
 932  * The shuffling should be an involution: shuffle_scno(shuffle_scno(n)) == n.
 933  */
 934 #if defined(ARM) || defined(AARCH64) /* So far only 32-bit ARM needs this */
 935 static long
 936 shuffle_scno(unsigned long scno)
 937 {
 938         if (scno < ARM_FIRST_SHUFFLED_SYSCALL)
 939                 return scno;
 940
 941         /* __ARM_NR_cmpxchg? Swap with LAST_ORDINARY+1 */
 942         if (scno == ARM_FIRST_SHUFFLED_SYSCALL)
 943                 return 0x000ffff0;
 944         if (scno == 0x000ffff0)
 945                 return ARM_FIRST_SHUFFLED_SYSCALL;
 946
 947 #define ARM_SECOND_SHUFFLED_SYSCALL (ARM_FIRST_SHUFFLED_SYSCALL + 1)
 948         /*
 949          * Is it ARM specific syscall?
 950          * Swap [0x000f0000, 0x000f0000 + LAST_SPECIAL] range
 951          * with [SECOND_SHUFFLED, SECOND_SHUFFLED + LAST_SPECIAL] range.
 952          */
 953         if (scno >= 0x000f0000 &&
 954             scno <= 0x000f0000 + ARM_LAST_SPECIAL_SYSCALL) {
 955                 return scno - 0x000f0000 + ARM_SECOND_SHUFFLED_SYSCALL;
 956         }
 957         if (scno <= ARM_SECOND_SHUFFLED_SYSCALL + ARM_LAST_SPECIAL_SYSCALL) {
 958                 return scno + 0x000f0000 - ARM_SECOND_SHUFFLED_SYSCALL;
 959         }
 960
 961         return scno;
 962 }
 963 #else
 964 # define shuffle_scno(scno) ((long)(scno))
 965 #endif
 966
 967 static char*
 968 undefined_scno_name(struct tcb *tcp)
 969 {
 970         static char buf[sizeof("syscall_%lu") + sizeof(long)*3];
 971
 972         sprintf(buf, "syscall_%lu", shuffle_scno(tcp->scno));
 973         return buf;
 974 }
 975
 976 #ifdef POWERPC
 977 /*
 978  * PTRACE_GETREGS was added to the PowerPC kernel in v2.6.23,
 979  * we provide a slow fallback for old kernels.
 980  */
 981 static int powerpc_getregs_old(pid_t pid)
 982 {
 983         int i;
 984         long r;
 985
 986         if (iflag) {
 987                 r = upeek(pid, sizeof(long) * PT_NIP, (long *)&ppc_regs.nip);
 988                 if (r)
 989                         goto out;
 990         }
 991 #ifdef POWERPC64 /* else we never use it */
 992         r = upeek(pid, sizeof(long) * PT_MSR, (long *)&ppc_regs.msr);
 993         if (r)
 994                 goto out;
 995 #endif
 996         r = upeek(pid, sizeof(long) * PT_CCR, (long *)&ppc_regs.ccr);
 997         if (r)
 998                 goto out;
 999         r = upeek(pid, sizeof(long) * PT_ORIG_R3, (long *)&ppc_regs.orig_gpr3);
1000         if (r)
1001                 goto out;
1002         for (i = 0; i <= 8; i++) {
1003                 r = upeek(pid, sizeof(long) * (PT_R0 + i),
1004                           (long *)&ppc_regs.gpr[i]);
1005                 if (r)
1006                         goto out;
1007         }
1008  out:
1009         return r;
1010 }
1011 #endif
1012
1013 void
1014 clear_regs(void)
1015 {
1016         get_regs_error = -1;
1017 }
1018
1019 #if defined ARCH_REGS_FOR_GETREGSET
1020 static long
1021 get_regset(pid_t pid)
1022 {
1023 # ifdef ARCH_IOVEC_FOR_GETREGSET
1024         /* variable iovec */
1025         ARCH_IOVEC_FOR_GETREGSET.iov_len = sizeof(ARCH_REGS_FOR_GETREGSET);
1026         return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS,
1027                       &ARCH_IOVEC_FOR_GETREGSET);
1028 # else
1029         /* constant iovec */
1030         static struct iovec io = {
1031                 .iov_base = &ARCH_REGS_FOR_GETREGSET,
1032                 .iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
1033         };
1034         return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &io);
1035
1036 # endif
1037 }
1038 #endif /* ARCH_REGS_FOR_GETREGSET */
1039
1040 void
1041 get_regs(pid_t pid)
1042 {
1043 #ifdef ARCH_REGS_FOR_GETREGSET
1044 # ifdef X86_64
1045         /* Try PTRACE_GETREGSET first, fallback to PTRACE_GETREGS. */
1046         static int getregset_support;
1047
1048         if (getregset_support >= 0) {
1049                 get_regs_error = get_regset(pid);
1050                 if (getregset_support > 0)
1051                         return;
1052                 if (get_regs_error >= 0) {
1053                         getregset_support = 1;
1054                         return;
1055                 }
1056                 if (errno == EPERM || errno == ESRCH)
1057                         return;
1058                 getregset_support = -1;
1059         }
1060         /* Use old method, with unreliable heuristical detection of 32-bitness. */
1061         x86_io.iov_len = sizeof(x86_64_regs);
1062         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &x86_64_regs);
1063         if (!get_regs_error && x86_64_regs.cs == 0x23) {
1064                 x86_io.iov_len = sizeof(i386_regs);
1065                 /*
1066                  * The order is important: i386_regs and x86_64_regs
1067                  * are overlaid in memory!
1068                  */
1069                 i386_regs.ebx = x86_64_regs.rbx;
1070                 i386_regs.ecx = x86_64_regs.rcx;
1071                 i386_regs.edx = x86_64_regs.rdx;
1072                 i386_regs.esi = x86_64_regs.rsi;
1073                 i386_regs.edi = x86_64_regs.rdi;
1074                 i386_regs.ebp = x86_64_regs.rbp;
1075                 i386_regs.eax = x86_64_regs.rax;
1076                 /* i386_regs.xds = x86_64_regs.ds; unused by strace */
1077                 /* i386_regs.xes = x86_64_regs.es; ditto... */
1078                 /* i386_regs.xfs = x86_64_regs.fs; */
1079                 /* i386_regs.xgs = x86_64_regs.gs; */
1080                 i386_regs.orig_eax = x86_64_regs.orig_rax;
1081                 i386_regs.eip = x86_64_regs.rip;
1082                 /* i386_regs.xcs = x86_64_regs.cs; */
1083                 /* i386_regs.eflags = x86_64_regs.eflags; */
1084                 i386_regs.esp = x86_64_regs.rsp;
1085                 /* i386_regs.xss = x86_64_regs.ss; */
1086         }
1087 # else /* !X86_64 */
1088         /* Assume that PTRACE_GETREGSET works. */
1089         get_regs_error = get_regset(pid);
1090 # endif
1091 #elif defined ARCH_REGS_FOR_GETREGS
1092 # if defined SPARC || defined SPARC64
1093         /* SPARC systems have the meaning of data and addr reversed */
1094         get_regs_error = ptrace(PTRACE_GETREGS, pid, (char *)&ARCH_REGS_FOR_GETREGS, 0);
1095 # elif defined POWERPC
1096         static bool old_kernel = 0;
1097         if (old_kernel)
1098                 goto old;
1099         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
1100         if (get_regs_error && errno == EIO) {
1101                 old_kernel = 1;
1102  old:
1103                 get_regs_error = powerpc_getregs_old(pid);
1104         }
1105 # else
1106         /* Assume that PTRACE_GETREGS works. */
1107         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
1108 # endif
1109
1110 #else /* !ARCH_REGS_FOR_GETREGSET && !ARCH_REGS_FOR_GETREGS */
1111 #  warning get_regs is not implemented for this architecture yet
1112         get_regs_error = 0;
1113 #endif
1114 }
1115
1116 /* Returns:
1117  * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
1118  * 1: ok, continue in trace_syscall_entering().
1119  * other: error, trace_syscall_entering() should print error indicator
1120  *    ("????" etc) and bail out.
1121  */
1122 static int
1123 get_scno(struct tcb *tcp)
1124 {
1125         long scno = 0;
1126
1127 #if defined(S390) || defined(S390X)
1128         if (upeek(tcp->pid, PT_GPR2, &s390_gpr2) < 0)
1129                 return -1;
1130
1131         if (s390_gpr2 != -ENOSYS) {
1132                 /*
1133                  * Since kernel version 2.5.44 the scno gets passed in gpr2.
1134                  */
1135                 scno = s390_gpr2;
1136         } else {
1137                 /*
1138                  * Old style of "passing" the scno via the SVC instruction.
1139                  */
1140                 long psw;
1141                 long opcode, offset_reg, tmp;
1142                 void *svc_addr;
1143                 static const int gpr_offset[16] = {
1144                                 PT_GPR0,  PT_GPR1,  PT_ORIGGPR2, PT_GPR3,
1145                                 PT_GPR4,  PT_GPR5,  PT_GPR6,     PT_GPR7,
1146                                 PT_GPR8,  PT_GPR9,  PT_GPR10,    PT_GPR11,
1147                                 PT_GPR12, PT_GPR13, PT_GPR14,    PT_GPR15
1148                 };
1149
1150                 if (upeek(tcp->pid, PT_PSWADDR, &psw) < 0)
1151                         return -1;
1152                 errno = 0;
1153                 opcode = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)(psw - sizeof(long)), 0);
1154                 if (errno) {
1155                         perror_msg("peektext(psw-oneword)");
1156                         return -1;
1157                 }
1158
1159                 /*
1160                  *  We have to check if the SVC got executed directly or via an
1161                  *  EXECUTE instruction. In case of EXECUTE it is necessary to do
1162                  *  instruction decoding to derive the system call number.
1163                  *  Unfortunately the opcode sizes of EXECUTE and SVC are differently,
1164                  *  so that this doesn't work if a SVC opcode is part of an EXECUTE
1165                  *  opcode. Since there is no way to find out the opcode size this
1166                  *  is the best we can do...
1167                  */
1168                 if ((opcode & 0xff00) == 0x0a00) {
1169                         /* SVC opcode */
1170                         scno = opcode & 0xff;
1171                 }
1172                 else {
1173                         /* SVC got executed by EXECUTE instruction */
1174
1175                         /*
1176                          *  Do instruction decoding of EXECUTE. If you really want to
1177                          *  understand this, read the Principles of Operations.
1178                          */
1179                         svc_addr = (void *) (opcode & 0xfff);
1180
1181                         tmp = 0;
1182                         offset_reg = (opcode & 0x000f0000) >> 16;
1183                         if (offset_reg && (upeek(tcp->pid, gpr_offset[offset_reg], &tmp) < 0))
1184                                 return -1;
1185                         svc_addr += tmp;
1186
1187                         tmp = 0;
1188                         offset_reg = (opcode & 0x0000f000) >> 12;
1189                         if (offset_reg && (upeek(tcp->pid, gpr_offset[offset_reg], &tmp) < 0))
1190                                 return -1;
1191                         svc_addr += tmp;
1192
1193                         scno = ptrace(PTRACE_PEEKTEXT, tcp->pid, svc_addr, 0);
1194                         if (errno)
1195                                 return -1;
1196 # if defined(S390X)
1197                         scno >>= 48;
1198 # else
1199                         scno >>= 16;
1200 # endif
1201                         tmp = 0;
1202                         offset_reg = (opcode & 0x00f00000) >> 20;
1203                         if (offset_reg && (upeek(tcp->pid, gpr_offset[offset_reg], &tmp) < 0))
1204                                 return -1;
1205
1206                         scno = (scno | tmp) & 0xff;
1207                 }
1208         }
1209 #elif defined(POWERPC)
1210         scno = ppc_regs.gpr[0];
1211 # ifdef POWERPC64
1212         unsigned int currpers;
1213
1214         /*
1215          * Check for 64/32 bit mode.
1216          * Embedded implementations covered by Book E extension of PPC use
1217          * bit 0 (CM) of 32-bit Machine state register (MSR).
1218          * Other implementations use bit 0 (SF) of 64-bit MSR.
1219          */
1220         currpers = (ppc_regs.msr & 0x8000000080000000) ? 0 : 1;
1221         update_personality(tcp, currpers);
1222 # endif
1223 #elif defined(AVR32)
1224         scno = avr32_regs.r8;
1225 #elif defined(BFIN)
1226         if (upeek(tcp->pid, PT_ORIG_P0, &scno))
1227                 return -1;
1228 #elif defined(I386)
1229         scno = i386_regs.orig_eax;
1230 #elif defined(X86_64) || defined(X32)
1231 # ifndef __X32_SYSCALL_BIT
1232 #  define __X32_SYSCALL_BIT     0x40000000
1233 # endif
1234         unsigned int currpers;
1235 # if 1
1236         /* GETREGSET of NT_PRSTATUS tells us regset size,
1237          * which unambiguously detects i386.
1238          *
1239          * Linux kernel distinguishes x86-64 and x32 processes
1240          * solely by looking at __X32_SYSCALL_BIT:
1241          * arch/x86/include/asm/compat.h::is_x32_task():
1242          * if (task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)
1243          *         return true;
1244          */
1245         if (x86_io.iov_len == sizeof(i386_regs)) {
1246                 scno = i386_regs.orig_eax;
1247                 currpers = 1;
1248         } else {
1249                 scno = x86_64_regs.orig_rax;
1250                 currpers = 0;
1251                 if (scno & __X32_SYSCALL_BIT) {
1252                         /*
1253                          * Syscall number -1 requires special treatment:
1254                          * it might be a side effect of SECCOMP_RET_ERRNO
1255                          * filtering that sets orig_rax to -1
1256                          * in some versions of linux kernel.
1257                          * If that is the case, then
1258                          * __X32_SYSCALL_BIT logic does not apply.
1259                          */
1260                         if ((long long) x86_64_regs.orig_rax != -1) {
1261                                 scno -= __X32_SYSCALL_BIT;
1262                                 currpers = 2;
1263                         } else {
1264 #  ifdef X32
1265                                 currpers = 2;
1266 #  endif
1267                         }
1268                 }
1269         }
1270 # elif 0
1271         /* cs = 0x33 for long mode (native 64 bit and x32)
1272          * cs = 0x23 for compatibility mode (32 bit)
1273          * ds = 0x2b for x32 mode (x86-64 in 32 bit)
1274          */
1275         scno = x86_64_regs.orig_rax;
1276         switch (x86_64_regs.cs) {
1277                 case 0x23: currpers = 1; break;
1278                 case 0x33:
1279                         if (x86_64_regs.ds == 0x2b) {
1280                                 currpers = 2;
1281                                 scno &= ~__X32_SYSCALL_BIT;
1282                         } else
1283                                 currpers = 0;
1284                         break;
1285                 default:
1286                         fprintf(stderr, "Unknown value CS=0x%08X while "
1287                                  "detecting personality of process "
1288                                  "PID=%d\n", (int)x86_64_regs.cs, tcp->pid);
1289                         currpers = current_personality;
1290                         break;
1291         }
1292 # elif 0
1293         /* This version analyzes the opcode of a syscall instruction.
1294          * (int 0x80 on i386 vs. syscall on x86-64)
1295          * It works, but is too complicated, and strictly speaking, unreliable.
1296          */
1297         unsigned long call, rip = x86_64_regs.rip;
1298         /* sizeof(syscall) == sizeof(int 0x80) == 2 */
1299         rip -= 2;
1300         errno = 0;
1301         call = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)rip, (char *)0);
1302         if (errno)
1303                 fprintf(stderr, "ptrace_peektext failed: %s\n",
1304                                 strerror(errno));
1305         switch (call & 0xffff) {
1306                 /* x86-64: syscall = 0x0f 0x05 */
1307                 case 0x050f: currpers = 0; break;
1308                 /* i386: int 0x80 = 0xcd 0x80 */
1309                 case 0x80cd: currpers = 1; break;
1310                 default:
1311                         currpers = current_personality;
1312                         fprintf(stderr,
1313                                 "Unknown syscall opcode (0x%04X) while "
1314                                 "detecting personality of process "
1315                                 "PID=%d\n", (int)call, tcp->pid);
1316                         break;
1317         }
1318 # endif
1319
1320 # ifdef X32
1321         /* If we are built for a x32 system, then personality 0 is x32
1322          * (not x86_64), and stracing of x86_64 apps is not supported.
1323          * Stracing of i386 apps is still supported.
1324          */
1325         if (currpers == 0) {
1326                 fprintf(stderr, "syscall_%lu(...) in unsupported "
1327                                 "64-bit mode of process PID=%d\n",
1328                         scno, tcp->pid);
1329                 return 0;
1330         }
1331         currpers &= ~2; /* map 2,1 to 0,1 */
1332 # endif
1333         update_personality(tcp, currpers);
1334 #elif defined(IA64)
1335 #       define IA64_PSR_IS      ((long)1 << 34)
1336         long psr;
1337         if (upeek(tcp->pid, PT_CR_IPSR, &psr) >= 0)
1338                 ia64_ia32mode = ((psr & IA64_PSR_IS) != 0);
1339         if (ia64_ia32mode) {
1340                 if (upeek(tcp->pid, PT_R1, &scno) < 0)
1341                         return -1;
1342         } else {
1343                 if (upeek(tcp->pid, PT_R15, &scno) < 0)
1344                         return -1;
1345         }
1346 #elif defined(AARCH64)
1347         switch (aarch64_io.iov_len) {
1348                 case sizeof(aarch64_regs):
1349                         /* We are in 64-bit mode */
1350                         scno = aarch64_regs.regs[8];
1351                         update_personality(tcp, 1);
1352                         break;
1353                 case sizeof(arm_regs):
1354                         /* We are in 32-bit mode */
1355                         /* Note: we don't support OABI, unlike 32-bit ARM build */
1356                         scno = arm_regs.ARM_r7;
1357                         scno = shuffle_scno(scno);
1358                         update_personality(tcp, 0);
1359                         break;
1360         }
1361 #elif defined(ARM)
1362         if (arm_regs.ARM_ip != 0) {
1363                 /* It is not a syscall entry */
1364                 fprintf(stderr, "pid %d stray syscall exit\n", tcp->pid);
1365                 tcp->flags |= TCB_INSYSCALL;
1366                 return 0;
1367         }
1368         /* Note: we support only 32-bit CPUs, not 26-bit */
1369
1370 # if !defined(__ARM_EABI__) || ENABLE_ARM_OABI
1371         if (arm_regs.ARM_cpsr & 0x20)
1372                 /* Thumb mode */
1373                 goto scno_in_r7;
1374         /* ARM mode */
1375         /* Check EABI/OABI by examining SVC insn's low 24 bits */
1376         errno = 0;
1377         scno = ptrace(PTRACE_PEEKTEXT, tcp->pid, (void *)(arm_regs.ARM_pc - 4), NULL);
1378         if (errno)
1379                 return -1;
1380         /* EABI syscall convention? */
1381         if ((unsigned long) scno != 0xef000000) {
1382                 /* No, it's OABI */
1383                 if ((scno & 0x0ff00000) != 0x0f900000) {
1384                         fprintf(stderr, "pid %d unknown syscall trap 0x%08lx\n",
1385                                 tcp->pid, scno);
1386                         return -1;
1387                 }
1388                 /* Fixup the syscall number */
1389                 scno &= 0x000fffff;
1390         } else {
1391  scno_in_r7:
1392                 scno = arm_regs.ARM_r7;
1393         }
1394 # else /* __ARM_EABI__ || !ENABLE_ARM_OABI */
1395         scno = arm_regs.ARM_r7;
1396 # endif
1397         scno = shuffle_scno(scno);
1398 #elif defined(M68K)
1399         if (upeek(tcp->pid, 4*PT_ORIG_D0, &scno) < 0)
1400                 return -1;
1401 #elif defined(MIPS)
1402         scno = mips_REG_V0;
1403
1404         if (!SCNO_IN_RANGE(scno)) {
1405                 if (mips_REG_A3 == 0 || mips_REG_A3 == -1) {
1406                         if (debug_flag)
1407                                 fprintf(stderr, "stray syscall exit: v0 = %ld\n", scno);
1408                         return 0;
1409                 }
1410         }
1411 #elif defined(ALPHA)
1412         if (upeek(tcp->pid, REG_A3, &alpha_a3) < 0)
1413                 return -1;
1414         if (upeek(tcp->pid, REG_R0, &scno) < 0)
1415                 return -1;
1416
1417         /*
1418          * Do some sanity checks to figure out if it's
1419          * really a syscall entry
1420          */
1421         if (!SCNO_IN_RANGE(scno)) {
1422                 if (alpha_a3 == 0 || alpha_a3 == -1) {
1423                         if (debug_flag)
1424                                 fprintf(stderr, "stray syscall exit: r0 = %ld\n", scno);
1425                         return 0;
1426                 }
1427         }
1428 #elif defined(SPARC) || defined(SPARC64)
1429         /* Disassemble the syscall trap. */
1430         /* Retrieve the syscall trap instruction. */
1431         unsigned long trap;
1432         errno = 0;
1433 # if defined(SPARC64)
1434         trap = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)sparc_regs.tpc, 0);
1435         trap >>= 32;
1436 # else
1437         trap = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)sparc_regs.pc, 0);
1438 # endif
1439         if (errno)
1440                 return -1;
1441
1442         /* Disassemble the trap to see what personality to use. */
1443         switch (trap) {
1444         case 0x91d02010:
1445                 /* Linux/SPARC syscall trap. */
1446                 update_personality(tcp, 0);
1447                 break;
1448         case 0x91d0206d:
1449                 /* Linux/SPARC64 syscall trap. */
1450                 update_personality(tcp, 2);
1451                 break;
1452         case 0x91d02000:
1453                 /* SunOS syscall trap. (pers 1) */
1454                 fprintf(stderr, "syscall: SunOS no support\n");
1455                 return -1;
1456         case 0x91d02008:
1457                 /* Solaris 2.x syscall trap. (per 2) */
1458                 update_personality(tcp, 1);
1459                 break;
1460         case 0x91d02009:
1461                 /* NetBSD/FreeBSD syscall trap. */
1462                 fprintf(stderr, "syscall: NetBSD/FreeBSD not supported\n");
1463                 return -1;
1464         case 0x91d02027:
1465                 /* Solaris 2.x gettimeofday */
1466                 update_personality(tcp, 1);
1467                 break;
1468         default:
1469 # if defined(SPARC64)
1470                 fprintf(stderr, "syscall: unknown syscall trap %08lx %016lx\n", trap, sparc_regs.tpc);
1471 # else
1472                 fprintf(stderr, "syscall: unknown syscall trap %08lx %08lx\n", trap, sparc_regs.pc);
1473 # endif
1474                 return -1;
1475         }
1476
1477         /* Extract the system call number from the registers. */
1478         if (trap == 0x91d02027)
1479                 scno = 156;
1480         else
1481                 scno = sparc_regs.u_regs[U_REG_G1];
1482         if (scno == 0) {
1483                 scno = sparc_regs.u_regs[U_REG_O0];
1484                 memmove(&sparc_regs.u_regs[U_REG_O0], &sparc_regs.u_regs[U_REG_O1], 7*sizeof(sparc_regs.u_regs[0]));
1485         }
1486 #elif defined(HPPA)
1487         if (upeek(tcp->pid, PT_GR20, &scno) < 0)
1488                 return -1;
1489 #elif defined(SH)
1490         /*
1491          * In the new syscall ABI, the system call number is in R3.
1492          */
1493         if (upeek(tcp->pid, 4*(REG_REG0+3), &scno) < 0)
1494                 return -1;
1495
1496         if (scno < 0) {
1497                 /* Odd as it may seem, a glibc bug has been known to cause
1498                    glibc to issue bogus negative syscall numbers.  So for
1499                    our purposes, make strace print what it *should* have been */
1500                 long correct_scno = (scno & 0xff);
1501                 if (debug_flag)
1502                         fprintf(stderr,
1503                                 "Detected glibc bug: bogus system call"
1504                                 " number = %ld, correcting to %ld\n",
1505                                 scno,
1506                                 correct_scno);
1507                 scno = correct_scno;
1508         }
1509 #elif defined(SH64)
1510         if (upeek(tcp->pid, REG_SYSCALL, &scno) < 0)
1511                 return -1;
1512         scno &= 0xFFFF;
1513 #elif defined(CRISV10) || defined(CRISV32)
1514         if (upeek(tcp->pid, 4*PT_R9, &scno) < 0)
1515                 return -1;
1516 #elif defined(TILE)
1517         unsigned int currpers;
1518         scno = tile_regs.regs[10];
1519 # ifdef __tilepro__
1520         currpers = 1;
1521 # else
1522 #  ifndef PT_FLAGS_COMPAT
1523 #   define PT_FLAGS_COMPAT 0x10000  /* from Linux 3.8 on */
1524 #  endif
1525         if (tile_regs.flags & PT_FLAGS_COMPAT)
1526                 currpers = 1;
1527         else
1528                 currpers = 0;
1529 # endif
1530         update_personality(tcp, currpers);
1531 #elif defined(MICROBLAZE)
1532         if (upeek(tcp->pid, 0, &scno) < 0)
1533                 return -1;
1534 #elif defined(OR1K)
1535         scno = or1k_regs.gpr[11];
1536 #elif defined(METAG)
1537         scno = metag_regs.dx[0][1];     /* syscall number in D1Re0 (D1.0) */
1538 #elif defined(XTENSA)
1539         if (upeek(tcp->pid, SYSCALL_NR, &scno) < 0)
1540                 return -1;
1541 # elif defined(ARC)
1542         scno = arc_regs.scratch.r8;
1543 #endif
1544
1545         tcp->scno = scno;
1546         if (SCNO_IS_VALID(tcp->scno)) {
1547                 tcp->s_ent = &sysent[scno];
1548                 tcp->qual_flg = qual_flags[scno];
1549         } else {
1550                 static const struct_sysent unknown = {
1551                         .nargs = MAX_ARGS,
1552                         .sys_flags = 0,
1553                         .sys_func = printargs,
1554                         .sys_name = "unknown", /* not used */
1555                 };
1556                 tcp->s_ent = &unknown;
1557                 tcp->qual_flg = UNDEFINED_SCNO | QUAL_RAW | DEFAULT_QUAL_FLAGS;
1558         }
1559         return 1;
1560 }
1561
1562 /*
1563  * Cannot rely on __kernel_[u]long_t being defined,
1564  * it is quite a recent feature of <asm/posix_types.h>.
1565  */
1566 #ifdef __kernel_long_t
1567 typedef __kernel_long_t kernel_long_t;
1568 typedef __kernel_ulong_t kernel_ulong_t;
1569 #else
1570 # ifdef X32
1571 typedef long long kernel_long_t;
1572 typedef unsigned long long kernel_ulong_t;
1573 # else
1574 typedef long kernel_long_t;
1575 typedef unsigned long kernel_ulong_t;
1576 # endif
1577 #endif
1578
1579 /*
1580  * Check the syscall return value register value for whether it is
1581  * a negated errno code indicating an error, or a success return value.
1582  */
1583 static inline bool
1584 is_negated_errno(kernel_ulong_t val)
1585 {
1586         /* Linux kernel defines MAX_ERRNO to 4095. */
1587         kernel_ulong_t max = -(kernel_long_t) 4095;
1588
1589 #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
1590         if (current_wordsize < sizeof(val)) {
1591                 val = (uint32_t) val;
1592                 max = (uint32_t) max;
1593         }
1594 #elif defined X32
1595         /*
1596          * current_wordsize is 4 even in personality 0 (native X32)
1597          * but truncation _must not_ be done in it.
1598          * can't check current_wordsize here!
1599          */
1600         if (current_personality != 0) {
1601                 val = (uint32_t) val;
1602                 max = (uint32_t) max;
1603         }
1604 #endif
1605
1606         return val >= max;
1607 }
1608
1609 /* Return -1 on error or 1 on success (never 0!) */
1610 static int
1611 get_syscall_args(struct tcb *tcp)
1612 {
1613         int i, nargs;
1614
1615         nargs = tcp->s_ent->nargs;
1616
1617 #if defined(S390) || defined(S390X)
1618         for (i = 0; i < nargs; ++i)
1619                 if (upeek(tcp->pid, i==0 ? PT_ORIGGPR2 : PT_GPR2 + i*sizeof(long), &tcp->u_arg[i]) < 0)
1620                         return -1;
1621 #elif defined(ALPHA)
1622         for (i = 0; i < nargs; ++i)
1623                 if (upeek(tcp->pid, REG_A0+i, &tcp->u_arg[i]) < 0)
1624                         return -1;
1625 #elif defined(IA64)
1626         if (!ia64_ia32mode) {
1627                 unsigned long *out0, cfm, sof, sol;
1628                 long rbs_end;
1629                 /* be backwards compatible with kernel < 2.4.4... */
1630 #               ifndef PT_RBS_END
1631 #                 define PT_RBS_END     PT_AR_BSP
1632 #               endif
1633
1634                 if (upeek(tcp->pid, PT_RBS_END, &rbs_end) < 0)
1635                         return -1;
1636                 if (upeek(tcp->pid, PT_CFM, (long *) &cfm) < 0)
1637                         return -1;
1638
1639                 sof = (cfm >> 0) & 0x7f;
1640                 sol = (cfm >> 7) & 0x7f;
1641                 out0 = ia64_rse_skip_regs((unsigned long *) rbs_end, -sof + sol);
1642
1643                 for (i = 0; i < nargs; ++i) {
1644                         if (umoven(tcp, (unsigned long) ia64_rse_skip_regs(out0, i),
1645                                    sizeof(long), (char *) &tcp->u_arg[i]) < 0)
1646                                 return -1;
1647                 }
1648         } else {
1649                 static const int argreg[MAX_ARGS] = { PT_R11 /* EBX = out0 */,
1650                                                       PT_R9  /* ECX = out1 */,
1651                                                       PT_R10 /* EDX = out2 */,
1652                                                       PT_R14 /* ESI = out3 */,
1653                                                       PT_R15 /* EDI = out4 */,
1654                                                       PT_R13 /* EBP = out5 */};
1655
1656                 for (i = 0; i < nargs; ++i) {
1657                         if (upeek(tcp->pid, argreg[i], &tcp->u_arg[i]) < 0)
1658                                 return -1;
1659                         /* truncate away IVE sign-extension */
1660                         tcp->u_arg[i] &= 0xffffffff;
1661                 }
1662         }
1663 #elif defined LINUX_MIPSN64
1664         (void)i;
1665         (void)nargs;
1666         tcp->u_arg[0] = mips_REG_A0;
1667         tcp->u_arg[1] = mips_REG_A1;
1668         tcp->u_arg[2] = mips_REG_A2;
1669         tcp->u_arg[3] = mips_REG_A3;
1670         tcp->u_arg[4] = mips_REG_A4;
1671         tcp->u_arg[5] = mips_REG_A5;
1672 #elif defined LINUX_MIPSN32
1673         (void)i;
1674         (void)nargs;
1675         tcp->u_arg[0] = tcp->ext_arg[0] = mips_REG_A0;
1676         tcp->u_arg[1] = tcp->ext_arg[1] = mips_REG_A1;
1677         tcp->u_arg[2] = tcp->ext_arg[2] = mips_REG_A2;
1678         tcp->u_arg[3] = tcp->ext_arg[3] = mips_REG_A3;
1679         tcp->u_arg[4] = tcp->ext_arg[4] = mips_REG_A4;
1680         tcp->u_arg[5] = tcp->ext_arg[5] = mips_REG_A5;
1681 #elif defined LINUX_MIPSO32
1682         (void)i;
1683         (void)nargs;
1684         tcp->u_arg[0] = mips_REG_A0;
1685         tcp->u_arg[1] = mips_REG_A1;
1686         tcp->u_arg[2] = mips_REG_A2;
1687         tcp->u_arg[3] = mips_REG_A3;
1688         if (nargs > 4) {
1689                 umoven(tcp, mips_REG_SP + 4 * 4,
1690                        (nargs - 4) * sizeof(tcp->u_arg[0]),
1691                        (char *)(tcp->u_arg + 4));
1692         }
1693 #elif defined(POWERPC)
1694         (void)i;
1695         (void)nargs;
1696         tcp->u_arg[0] = ppc_regs.orig_gpr3;
1697         tcp->u_arg[1] = ppc_regs.gpr[4];
1698         tcp->u_arg[2] = ppc_regs.gpr[5];
1699         tcp->u_arg[3] = ppc_regs.gpr[6];
1700         tcp->u_arg[4] = ppc_regs.gpr[7];
1701         tcp->u_arg[5] = ppc_regs.gpr[8];
1702 #elif defined(SPARC) || defined(SPARC64)
1703         for (i = 0; i < nargs; ++i)
1704                 tcp->u_arg[i] = sparc_regs.u_regs[U_REG_O0 + i];
1705 #elif defined(HPPA)
1706         for (i = 0; i < nargs; ++i)
1707                 if (upeek(tcp->pid, PT_GR26-4*i, &tcp->u_arg[i]) < 0)
1708                         return -1;
1709 #elif defined(ARM) || defined(AARCH64)
1710 # if defined(AARCH64)
1711         if (tcp->currpers == 1)
1712                 for (i = 0; i < nargs; ++i)
1713                         tcp->u_arg[i] = aarch64_regs.regs[i];
1714         else
1715 # endif
1716         for (i = 0; i < nargs; ++i)
1717                 tcp->u_arg[i] = arm_regs.uregs[i];
1718 #elif defined(AVR32)
1719         (void)i;
1720         (void)nargs;
1721         tcp->u_arg[0] = avr32_regs.r12;
1722         tcp->u_arg[1] = avr32_regs.r11;
1723         tcp->u_arg[2] = avr32_regs.r10;
1724         tcp->u_arg[3] = avr32_regs.r9;
1725         tcp->u_arg[4] = avr32_regs.r5;
1726         tcp->u_arg[5] = avr32_regs.r3;
1727 #elif defined(BFIN)
1728         static const int argreg[MAX_ARGS] = { PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5 };
1729
1730         for (i = 0; i < nargs; ++i)
1731                 if (upeek(tcp->pid, argreg[i], &tcp->u_arg[i]) < 0)
1732                         return -1;
1733 #elif defined(SH)
1734         static const int syscall_regs[MAX_ARGS] = {
1735                 4 * (REG_REG0+4), 4 * (REG_REG0+5), 4 * (REG_REG0+6),
1736                 4 * (REG_REG0+7), 4 * (REG_REG0  ), 4 * (REG_REG0+1)
1737         };
1738
1739         for (i = 0; i < nargs; ++i)
1740                 if (upeek(tcp->pid, syscall_regs[i], &tcp->u_arg[i]) < 0)
1741                         return -1;
1742 #elif defined(SH64)
1743         int i;
1744         /* Registers used by SH5 Linux system calls for parameters */
1745         static const int syscall_regs[MAX_ARGS] = { 2, 3, 4, 5, 6, 7 };
1746
1747         for (i = 0; i < nargs; ++i)
1748                 if (upeek(tcp->pid, REG_GENERAL(syscall_regs[i]), &tcp->u_arg[i]) < 0)
1749                         return -1;
1750 #elif defined(I386)
1751         (void)i;
1752         (void)nargs;
1753         tcp->u_arg[0] = i386_regs.ebx;
1754         tcp->u_arg[1] = i386_regs.ecx;
1755         tcp->u_arg[2] = i386_regs.edx;
1756         tcp->u_arg[3] = i386_regs.esi;
1757         tcp->u_arg[4] = i386_regs.edi;
1758         tcp->u_arg[5] = i386_regs.ebp;
1759 #elif defined(X86_64) || defined(X32)
1760         (void)i;
1761         (void)nargs;
1762         if (x86_io.iov_len != sizeof(i386_regs)) {
1763                 /* x86-64 or x32 ABI */
1764                 tcp->u_arg[0] = x86_64_regs.rdi;
1765                 tcp->u_arg[1] = x86_64_regs.rsi;
1766                 tcp->u_arg[2] = x86_64_regs.rdx;
1767                 tcp->u_arg[3] = x86_64_regs.r10;
1768                 tcp->u_arg[4] = x86_64_regs.r8;
1769                 tcp->u_arg[5] = x86_64_regs.r9;
1770 #  ifdef X32
1771                 tcp->ext_arg[0] = x86_64_regs.rdi;
1772                 tcp->ext_arg[1] = x86_64_regs.rsi;
1773                 tcp->ext_arg[2] = x86_64_regs.rdx;
1774                 tcp->ext_arg[3] = x86_64_regs.r10;
1775                 tcp->ext_arg[4] = x86_64_regs.r8;
1776                 tcp->ext_arg[5] = x86_64_regs.r9;
1777 #  endif
1778         } else {
1779                 /* i386 ABI */
1780                 /* Zero-extend from 32 bits */
1781                 /* Use widen_to_long(tcp->u_arg[N]) in syscall handlers
1782                  * if you need to use *sign-extended* parameter.
1783                  */
1784                 tcp->u_arg[0] = (long)(uint32_t)i386_regs.ebx;
1785                 tcp->u_arg[1] = (long)(uint32_t)i386_regs.ecx;
1786                 tcp->u_arg[2] = (long)(uint32_t)i386_regs.edx;
1787                 tcp->u_arg[3] = (long)(uint32_t)i386_regs.esi;
1788                 tcp->u_arg[4] = (long)(uint32_t)i386_regs.edi;
1789                 tcp->u_arg[5] = (long)(uint32_t)i386_regs.ebp;
1790         }
1791 #elif defined(MICROBLAZE)
1792         for (i = 0; i < nargs; ++i)
1793                 if (upeek(tcp->pid, (5 + i) * 4, &tcp->u_arg[i]) < 0)
1794                         return -1;
1795 #elif defined(CRISV10) || defined(CRISV32)
1796         static const int crisregs[MAX_ARGS] = {
1797                 4*PT_ORIG_R10, 4*PT_R11, 4*PT_R12,
1798                 4*PT_R13     , 4*PT_MOF, 4*PT_SRP
1799         };
1800
1801         for (i = 0; i < nargs; ++i)
1802                 if (upeek(tcp->pid, crisregs[i], &tcp->u_arg[i]) < 0)
1803                         return -1;
1804 #elif defined(TILE)
1805         for (i = 0; i < nargs; ++i)
1806                 tcp->u_arg[i] = tile_regs.regs[i];
1807 #elif defined(M68K)
1808         for (i = 0; i < nargs; ++i)
1809                 if (upeek(tcp->pid, (i < 5 ? i : i + 2)*4, &tcp->u_arg[i]) < 0)
1810                         return -1;
1811 #elif defined(OR1K)
1812         (void)nargs;
1813         for (i = 0; i < 6; ++i)
1814                 tcp->u_arg[i] = or1k_regs.gpr[3 + i];
1815 #elif defined(METAG)
1816         for (i = 0; i < nargs; i++)
1817                 /* arguments go backwards from D1Ar1 (D1.3) */
1818                 tcp->u_arg[i] = ((unsigned long *)&metag_regs.dx[3][1])[-i];
1819 #elif defined(XTENSA)
1820         /* arg0: a6, arg1: a3, arg2: a4, arg3: a5, arg4: a8, arg5: a9 */
1821         static const int xtensaregs[MAX_ARGS] = { 6, 3, 4, 5, 8, 9 };
1822         for (i = 0; i < nargs; ++i)
1823                 if (upeek(tcp->pid, REG_A_BASE + xtensaregs[i], &tcp->u_arg[i]) < 0)
1824                         return -1;
1825 # elif defined(ARC)
1826         long *arc_args = &arc_regs.scratch.r0;
1827         for (i = 0; i < nargs; ++i)
1828                 tcp->u_arg[i] = *arc_args--;
1829
1830 #else /* Other architecture (32bits specific) */
1831         for (i = 0; i < nargs; ++i)
1832                 if (upeek(tcp->pid, i*4, &tcp->u_arg[i]) < 0)
1833                         return -1;
1834 #endif
1835         return 1;
1836 }
1837
1838 static int
1839 trace_syscall_entering(struct tcb *tcp)
1840 {
1841         int res, scno_good;
1842
1843         scno_good = res = (get_regs_error ? -1 : get_scno(tcp));
1844         if (res == 0)
1845                 return res;
1846         if (res == 1)
1847                 res = get_syscall_args(tcp);
1848
1849         if (res != 1) {
1850                 printleader(tcp);
1851                 if (scno_good != 1)
1852                         tprints("????" /* anti-trigraph gap */ "(");
1853                 else if (tcp->qual_flg & UNDEFINED_SCNO)
1854                         tprintf("%s(", undefined_scno_name(tcp));
1855                 else
1856                         tprintf("%s(", tcp->s_ent->sys_name);
1857                 /*
1858                  * " <unavailable>" will be added later by the code which
1859                  * detects ptrace errors.
1860                  */
1861                 goto ret;
1862         }
1863
1864         if (   sys_execve == tcp->s_ent->sys_func
1865 # if defined(SPARC) || defined(SPARC64)
1866             || sys_execv == tcp->s_ent->sys_func
1867 # endif
1868            ) {
1869                 hide_log_until_execve = 0;
1870         }
1871
1872 #if defined(SYS_socket_subcall) || defined(SYS_ipc_subcall)
1873         while (1) {
1874 # ifdef SYS_socket_subcall
1875                 if (tcp->s_ent->sys_func == sys_socketcall) {
1876                         decode_socket_subcall(tcp);
1877                         break;
1878                 }
1879 # endif
1880 # ifdef SYS_ipc_subcall
1881                 if (tcp->s_ent->sys_func == sys_ipc) {
1882                         decode_ipc_subcall(tcp);
1883                         break;
1884                 }
1885 # endif
1886                 break;
1887         }
1888 #endif
1889
1890         if (!(tcp->qual_flg & QUAL_TRACE)
1891          || (tracing_paths && !pathtrace_match(tcp))
1892         ) {
1893                 tcp->flags |= TCB_INSYSCALL | TCB_FILTERED;
1894                 return 0;
1895         }
1896
1897         tcp->flags &= ~TCB_FILTERED;
1898
1899         if (cflag == CFLAG_ONLY_STATS || hide_log_until_execve) {
1900                 res = 0;
1901                 goto ret;
1902         }
1903
1904 #ifdef USE_LIBUNWIND
1905         if (stack_trace_enabled) {
1906                 if (tcp->s_ent->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)
1907                         unwind_capture_stacktrace(tcp);
1908         }
1909 #endif
1910
1911         printleader(tcp);
1912         if (tcp->qual_flg & UNDEFINED_SCNO)
1913                 tprintf("%s(", undefined_scno_name(tcp));
1914         else
1915                 tprintf("%s(", tcp->s_ent->sys_name);
1916         if ((tcp->qual_flg & QUAL_RAW) && tcp->s_ent->sys_func != sys_exit)
1917                 res = printargs(tcp);
1918         else
1919                 res = tcp->s_ent->sys_func(tcp);
1920
1921         fflush(tcp->outf);
1922  ret:
1923         tcp->flags |= TCB_INSYSCALL;
1924         /* Measure the entrance time as late as possible to avoid errors. */
1925         if (Tflag || cflag)
1926                 gettimeofday(&tcp->etime, NULL);
1927         return res;
1928 }
1929
1930 /* Returns:
1931  * 1: ok, continue in trace_syscall_exiting().
1932  * -1: error, trace_syscall_exiting() should print error indicator
1933  *    ("????" etc) and bail out.
1934  */
1935 static int
1936 get_syscall_result(struct tcb *tcp)
1937 {
1938 #if defined ARCH_REGS_FOR_GETREGSET || defined ARCH_REGS_FOR_GETREGS
1939         /* already done by get_regs */
1940 #elif defined(S390) || defined(S390X)
1941         if (upeek(tcp->pid, PT_GPR2, &s390_gpr2) < 0)
1942                 return -1;
1943 #elif defined(BFIN)
1944         if (upeek(tcp->pid, PT_R0, &bfin_r0) < 0)
1945                 return -1;
1946 #elif defined(IA64)
1947 #       define IA64_PSR_IS      ((long)1 << 34)
1948         long psr;
1949         if (upeek(tcp->pid, PT_CR_IPSR, &psr) >= 0)
1950                 ia64_ia32mode = ((psr & IA64_PSR_IS) != 0);
1951         if (upeek(tcp->pid, PT_R8, &ia64_r8) < 0)
1952                 return -1;
1953         if (upeek(tcp->pid, PT_R10, &ia64_r10) < 0)
1954                 return -1;
1955 #elif defined(M68K)
1956         if (upeek(tcp->pid, 4*PT_D0, &m68k_d0) < 0)
1957                 return -1;
1958 #elif defined(ALPHA)
1959         if (upeek(tcp->pid, REG_A3, &alpha_a3) < 0)
1960                 return -1;
1961         if (upeek(tcp->pid, REG_R0, &alpha_r0) < 0)
1962                 return -1;
1963 #elif defined(HPPA)
1964         if (upeek(tcp->pid, PT_GR28, &hppa_r28) < 0)
1965                 return -1;
1966 #elif defined(SH)
1967         /* new syscall ABI returns result in R0 */
1968         if (upeek(tcp->pid, 4*REG_REG0, (long *)&sh_r0) < 0)
1969                 return -1;
1970 #elif defined(SH64)
1971         /* ABI defines result returned in r9 */
1972         if (upeek(tcp->pid, REG_GENERAL(9), (long *)&sh64_r9) < 0)
1973                 return -1;
1974 #elif defined(CRISV10) || defined(CRISV32)
1975         if (upeek(tcp->pid, 4*PT_R10, &cris_r10) < 0)
1976                 return -1;
1977 #elif defined(MICROBLAZE)
1978         if (upeek(tcp->pid, 3 * 4, &microblaze_r3) < 0)
1979                 return -1;
1980 #elif defined(XTENSA)
1981         if (upeek(tcp->pid, REG_A_BASE + 2, &xtensa_a2) < 0)
1982                 return -1;
1983 #else
1984 # error get_syscall_result is not implemented for this architecture
1985 #endif
1986         return 1;
1987 }
1988
1989 /* Returns:
1990  * 1: ok, continue in trace_syscall_exiting().
1991  * -1: error, trace_syscall_exiting() should print error indicator
1992  *    ("????" etc) and bail out.
1993  */
1994 static void
1995 get_error(struct tcb *tcp)
1996 {
1997         int u_error = 0;
1998         int check_errno = 1;
1999         if (tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS) {
2000                 check_errno = 0;
2001         }
2002 #if defined(S390) || defined(S390X)
2003         if (check_errno && is_negated_errno(s390_gpr2)) {
2004                 tcp->u_rval = -1;
2005                 u_error = -s390_gpr2;
2006         }
2007         else {
2008                 tcp->u_rval = s390_gpr2;
2009         }
2010 #elif defined(I386)
2011         if (check_errno && is_negated_errno(i386_regs.eax)) {
2012                 tcp->u_rval = -1;
2013                 u_error = -i386_regs.eax;
2014         }
2015         else {
2016                 tcp->u_rval = i386_regs.eax;
2017         }
2018 #elif defined(X86_64) || defined(X32)
2019         /*
2020          * In X32, return value is 64-bit (llseek uses one).
2021          * Using merely "long rax" would not work.
2022          */
2023         kernel_long_t rax;
2024
2025         if (x86_io.iov_len == sizeof(i386_regs)) {
2026                 /* Sign extend from 32 bits */
2027                 rax = (int32_t) i386_regs.eax;
2028         } else {
2029                 rax = x86_64_regs.rax;
2030         }
2031         if (check_errno && is_negated_errno(rax)) {
2032                 tcp->u_rval = -1;
2033                 u_error = -rax;
2034         }
2035         else {
2036                 tcp->u_rval = rax;
2037 # ifdef X32
2038                 /* tcp->u_rval contains a truncated value */
2039                 tcp->u_lrval = rax;
2040 # endif
2041         }
2042 #elif defined(IA64)
2043         if (ia64_ia32mode) {
2044                 int err;
2045
2046                 err = (int)ia64_r8;
2047                 if (check_errno && is_negated_errno(err)) {
2048                         tcp->u_rval = -1;
2049                         u_error = -err;
2050                 }
2051                 else {
2052                         tcp->u_rval = err;
2053                 }
2054         } else {
2055                 if (check_errno && ia64_r10) {
2056                         tcp->u_rval = -1;
2057                         u_error = ia64_r8;
2058                 } else {
2059                         tcp->u_rval = ia64_r8;
2060                 }
2061         }
2062 #elif defined(MIPS)
2063         if (check_errno && mips_REG_A3) {
2064                 tcp->u_rval = -1;
2065                 u_error = mips_REG_V0;
2066         } else {
2067 # if defined LINUX_MIPSN32
2068                 tcp->u_lrval = mips_REG_V0;
2069 # endif
2070                 tcp->u_rval = mips_REG_V0;
2071         }
2072 #elif defined(POWERPC)
2073         if (check_errno && (ppc_regs.ccr & 0x10000000)) {
2074                 tcp->u_rval = -1;
2075                 u_error = ppc_regs.gpr[3];
2076         }
2077         else {
2078                 tcp->u_rval = ppc_regs.gpr[3];
2079         }
2080 #elif defined(M68K)
2081         if (check_errno && is_negated_errno(m68k_d0)) {
2082                 tcp->u_rval = -1;
2083                 u_error = -m68k_d0;
2084         }
2085         else {
2086                 tcp->u_rval = m68k_d0;
2087         }
2088 #elif defined(ARM) || defined(AARCH64)
2089 # if defined(AARCH64)
2090         if (tcp->currpers == 1) {
2091                 if (check_errno && is_negated_errno(aarch64_regs.regs[0])) {
2092                         tcp->u_rval = -1;
2093                         u_error = -aarch64_regs.regs[0];
2094                 }
2095                 else {
2096                         tcp->u_rval = aarch64_regs.regs[0];
2097                 }
2098         }
2099         else
2100 # endif
2101         {
2102                 if (check_errno && is_negated_errno(arm_regs.ARM_r0)) {
2103                         tcp->u_rval = -1;
2104                         u_error = -arm_regs.ARM_r0;
2105                 }
2106                 else {
2107                         tcp->u_rval = arm_regs.ARM_r0;
2108                 }
2109         }
2110 #elif defined(AVR32)
2111         if (check_errno && avr32_regs.r12 && (unsigned) -avr32_regs.r12 < nerrnos) {
2112                 tcp->u_rval = -1;
2113                 u_error = -avr32_regs.r12;
2114         }
2115         else {
2116                 tcp->u_rval = avr32_regs.r12;
2117         }
2118 #elif defined(BFIN)
2119         if (check_errno && is_negated_errno(bfin_r0)) {
2120                 tcp->u_rval = -1;
2121                 u_error = -bfin_r0;
2122         } else {
2123                 tcp->u_rval = bfin_r0;
2124         }
2125 #elif defined(ALPHA)
2126         if (check_errno && alpha_a3) {
2127                 tcp->u_rval = -1;
2128                 u_error = alpha_r0;
2129         }
2130         else {
2131                 tcp->u_rval = alpha_r0;
2132         }
2133 #elif defined(SPARC)
2134         if (check_errno && sparc_regs.psr & PSR_C) {
2135                 tcp->u_rval = -1;
2136                 u_error = sparc_regs.u_regs[U_REG_O0];
2137         }
2138         else {
2139                 tcp->u_rval = sparc_regs.u_regs[U_REG_O0];
2140         }
2141 #elif defined(SPARC64)
2142         if (check_errno && sparc_regs.tstate & 0x1100000000UL) {
2143                 tcp->u_rval = -1;
2144                 u_error = sparc_regs.u_regs[U_REG_O0];
2145         }
2146         else {
2147                 tcp->u_rval = sparc_regs.u_regs[U_REG_O0];
2148         }
2149 #elif defined(HPPA)
2150         if (check_errno && is_negated_errno(hppa_r28)) {
2151                 tcp->u_rval = -1;
2152                 u_error = -hppa_r28;
2153         }
2154         else {
2155                 tcp->u_rval = hppa_r28;
2156         }
2157 #elif defined(SH)
2158         if (check_errno && is_negated_errno(sh_r0)) {
2159                 tcp->u_rval = -1;
2160                 u_error = -sh_r0;
2161         }
2162         else {
2163                 tcp->u_rval = sh_r0;
2164         }
2165 #elif defined(SH64)
2166         if (check_errno && is_negated_errno(sh64_r9)) {
2167                 tcp->u_rval = -1;
2168                 u_error = -sh64_r9;
2169         }
2170         else {
2171                 tcp->u_rval = sh64_r9;
2172         }
2173 #elif defined(METAG)
2174         /* result pointer in D0Re0 (D0.0) */
2175         if (check_errno && is_negated_errno(metag_regs.dx[0][0])) {
2176                 tcp->u_rval = -1;
2177                 u_error = -metag_regs.dx[0][0];
2178         }
2179         else {
2180                 tcp->u_rval = metag_regs.dx[0][0];
2181         }
2182 #elif defined(CRISV10) || defined(CRISV32)
2183         if (check_errno && cris_r10 && (unsigned) -cris_r10 < nerrnos) {
2184                 tcp->u_rval = -1;
2185                 u_error = -cris_r10;
2186         }
2187         else {
2188                 tcp->u_rval = cris_r10;
2189         }
2190 #elif defined(TILE)
2191         /*
2192          * The standard tile calling convention returns the value (or negative
2193          * errno) in r0, and zero (or positive errno) in r1.
2194          * Until at least kernel 3.8, however, the r1 value is not reflected
2195          * in ptregs at this point, so we use r0 here.
2196          */
2197         if (check_errno && is_negated_errno(tile_regs.regs[0])) {
2198                 tcp->u_rval = -1;
2199                 u_error = -tile_regs.regs[0];
2200         } else {
2201                 tcp->u_rval = tile_regs.regs[0];
2202         }
2203 #elif defined(MICROBLAZE)
2204         if (check_errno && is_negated_errno(microblaze_r3)) {
2205                 tcp->u_rval = -1;
2206                 u_error = -microblaze_r3;
2207         }
2208         else {
2209                 tcp->u_rval = microblaze_r3;
2210         }
2211 #elif defined(OR1K)
2212         if (check_errno && is_negated_errno(or1k_regs.gpr[11])) {
2213                 tcp->u_rval = -1;
2214                 u_error = -or1k_regs.gpr[11];
2215         }
2216         else {
2217                 tcp->u_rval = or1k_regs.gpr[11];
2218         }
2219 #elif defined(XTENSA)
2220         if (check_errno && is_negated_errno(xtensa_a2)) {
2221                 tcp->u_rval = -1;
2222                 u_error = -xtensa_a2;
2223         }
2224         else {
2225                 tcp->u_rval = xtensa_a2;
2226         }
2227 #elif defined(ARC)
2228         if (check_errno && is_negated_errno(arc_regs.scratch.r0)) {
2229                 tcp->u_rval = -1;
2230                 u_error = -arc_regs.scratch.r0;
2231         }
2232         else {
2233                 tcp->u_rval = arc_regs.scratch.r0;
2234         }
2235 #endif
2236         tcp->u_error = u_error;
2237 }
2238
2239 static void
2240 dumpio(struct tcb *tcp)
2241 {
2242         int (*func)();
2243
2244         if (syserror(tcp))
2245                 return;
2246         if ((unsigned long) tcp->u_arg[0] >= num_quals)
2247                 return;
2248         func = tcp->s_ent->sys_func;
2249         if (func == printargs)
2250                 return;
2251         if (qual_flags[tcp->u_arg[0]] & QUAL_READ) {
2252                 if (func == sys_read ||
2253                     func == sys_pread ||
2254                     func == sys_recv ||
2255                     func == sys_recvfrom) {
2256                         dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
2257                         return;
2258                 } else if (func == sys_readv) {
2259                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
2260                         return;
2261 #if HAVE_SENDMSG
2262                 } else if (func == sys_recvmsg) {
2263                         dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
2264                         return;
2265                 } else if (func == sys_recvmmsg) {
2266                         dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
2267                         return;
2268 #endif
2269                 }
2270         }
2271         if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE) {
2272                 if (func == sys_write ||
2273                     func == sys_pwrite ||
2274                     func == sys_send ||
2275                     func == sys_sendto)
2276                         dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
2277                 else if (func == sys_writev)
2278                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
2279 #if HAVE_SENDMSG
2280                 else if (func == sys_sendmsg)
2281                         dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
2282                 else if (func == sys_sendmmsg)
2283                         dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
2284 #endif
2285         }
2286 }
2287
2288 static int
2289 trace_syscall_exiting(struct tcb *tcp)
2290 {
2291         int sys_res;
2292         struct timeval tv;
2293         int res;
2294         long u_error;
2295
2296         /* Measure the exit time as early as possible to avoid errors. */
2297         if (Tflag || cflag)
2298                 gettimeofday(&tv, NULL);
2299
2300 #ifdef USE_LIBUNWIND
2301         if (stack_trace_enabled) {
2302                 if (tcp->s_ent->sys_flags & STACKTRACE_INVALIDATE_CACHE)
2303                         unwind_cache_invalidate(tcp);
2304         }
2305 #endif
2306
2307 #if SUPPORTED_PERSONALITIES > 1
2308         update_personality(tcp, tcp->currpers);
2309 #endif
2310         res = (get_regs_error ? -1 : get_syscall_result(tcp));
2311         if (res == 1) {
2312                 get_error(tcp); /* never fails */
2313                 if (filtered(tcp) || hide_log_until_execve)
2314                         goto ret;
2315         }
2316
2317         if (cflag) {
2318                 count_syscall(tcp, &tv);
2319                 if (cflag == CFLAG_ONLY_STATS) {
2320                         goto ret;
2321                 }
2322         }
2323
2324         /* If not in -ff mode, and printing_tcp != tcp,
2325          * then the log currently does not end with output
2326          * of _our syscall entry_, but with something else.
2327          * We need to say which syscall's return is this.
2328          *
2329          * Forced reprinting via TCB_REPRINT is used only by
2330          * "strace -ff -oLOG test/threaded_execve" corner case.
2331          * It's the only case when -ff mode needs reprinting.
2332          */
2333         if ((followfork < 2 && printing_tcp != tcp) || (tcp->flags & TCB_REPRINT)) {
2334                 tcp->flags &= ~TCB_REPRINT;
2335                 printleader(tcp);
2336                 if (tcp->qual_flg & UNDEFINED_SCNO)
2337                         tprintf("<... %s resumed> ", undefined_scno_name(tcp));
2338                 else
2339                         tprintf("<... %s resumed> ", tcp->s_ent->sys_name);
2340         }
2341         printing_tcp = tcp;
2342
2343         if (res != 1) {
2344                 /* There was error in one of prior ptrace ops */
2345                 tprints(") ");
2346                 tabto();
2347                 tprints("= ? <unavailable>\n");
2348                 line_ended();
2349                 tcp->flags &= ~TCB_INSYSCALL;
2350                 return res;
2351         }
2352
2353         sys_res = 0;
2354         if (tcp->qual_flg & QUAL_RAW) {
2355                 /* sys_res = printargs(tcp); - but it's nop on sysexit */
2356         } else {
2357         /* FIXME: not_failing_only (IOW, option -z) is broken:
2358          * failure of syscall is known only after syscall return.
2359          * Thus we end up with something like this on, say, ENOENT:
2360          *     open("doesnt_exist", O_RDONLY <unfinished ...>
2361          *     {next syscall decode}
2362          * whereas the intended result is that open(...) line
2363          * is not shown at all.
2364          */
2365                 if (not_failing_only && tcp->u_error)
2366                         goto ret;       /* ignore failed syscalls */
2367                 sys_res = tcp->s_ent->sys_func(tcp);
2368         }
2369
2370         tprints(") ");
2371         tabto();
2372         u_error = tcp->u_error;
2373         if (tcp->qual_flg & QUAL_RAW) {
2374                 if (u_error)
2375                         tprintf("= -1 (errno %ld)", u_error);
2376                 else
2377                         tprintf("= %#lx", tcp->u_rval);
2378         }
2379         else if (!(sys_res & RVAL_NONE) && u_error) {
2380                 switch (u_error) {
2381                 /* Blocked signals do not interrupt any syscalls.
2382                  * In this case syscalls don't return ERESTARTfoo codes.
2383                  *
2384                  * Deadly signals set to SIG_DFL interrupt syscalls
2385                  * and kill the process regardless of which of the codes below
2386                  * is returned by the interrupted syscall.
2387                  * In some cases, kernel forces a kernel-generated deadly
2388                  * signal to be unblocked and set to SIG_DFL (and thus cause
2389                  * death) if it is blocked or SIG_IGNed: for example, SIGSEGV
2390                  * or SIGILL. (The alternative is to leave process spinning
2391                  * forever on the faulty instruction - not useful).
2392                  *
2393                  * SIG_IGNed signals and non-deadly signals set to SIG_DFL
2394                  * (for example, SIGCHLD, SIGWINCH) interrupt syscalls,
2395                  * but kernel will always restart them.
2396                  */
2397                 case ERESTARTSYS:
2398                         /* Most common type of signal-interrupted syscall exit code.
2399                          * The system call will be restarted with the same arguments
2400                          * if SA_RESTART is set; otherwise, it will fail with EINTR.
2401                          */
2402                         tprints("= ? ERESTARTSYS (To be restarted if SA_RESTART is set)");
2403                         break;
2404                 case ERESTARTNOINTR:
2405                         /* Rare. For example, fork() returns this if interrupted.
2406                          * SA_RESTART is ignored (assumed set): the restart is unconditional.
2407                          */
2408                         tprints("= ? ERESTARTNOINTR (To be restarted)");
2409                         break;
2410                 case ERESTARTNOHAND:
2411                         /* pause(), rt_sigsuspend() etc use this code.
2412                          * SA_RESTART is ignored (assumed not set):
2413                          * syscall won't restart (will return EINTR instead)
2414                          * even after signal with SA_RESTART set. However,
2415                          * after SIG_IGN or SIG_DFL signal it will restart
2416                          * (thus the name "restart only if has no handler").
2417                          */
2418                         tprints("= ? ERESTARTNOHAND (To be restarted if no handler)");
2419                         break;
2420                 case ERESTART_RESTARTBLOCK:
2421                         /* Syscalls like nanosleep(), poll() which can't be
2422                          * restarted with their original arguments use this
2423                          * code. Kernel will execute restart_syscall() instead,
2424                          * which changes arguments before restarting syscall.
2425                          * SA_RESTART is ignored (assumed not set) similarly
2426                          * to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
2427                          * since restart data is saved in "restart block"
2428                          * in task struct, and if signal handler uses a syscall
2429                          * which in turn saves another such restart block,
2430                          * old data is lost and restart becomes impossible)
2431                          */
2432                         tprints("= ? ERESTART_RESTARTBLOCK (Interrupted by signal)");
2433                         break;
2434                 default:
2435                         if ((unsigned long) u_error < nerrnos
2436                             && errnoent[u_error])
2437                                 tprintf("= -1 %s (%s)", errnoent[u_error],
2438                                         strerror(u_error));
2439                         else
2440                                 tprintf("= -1 ERRNO_%lu (%s)", u_error,
2441                                         strerror(u_error));
2442                         break;
2443                 }
2444                 if ((sys_res & RVAL_STR) && tcp->auxstr)
2445                         tprintf(" (%s)", tcp->auxstr);
2446         }
2447         else {
2448                 if (sys_res & RVAL_NONE)
2449                         tprints("= ?");
2450                 else {
2451                         switch (sys_res & RVAL_MASK) {
2452                         case RVAL_HEX:
2453 #if SUPPORTED_PERSONALITIES > 1
2454                                 if (current_wordsize < sizeof(long))
2455                                         tprintf("= %#x",
2456                                                 (unsigned int) tcp->u_rval);
2457                                 else
2458 #endif
2459                                         tprintf("= %#lx", tcp->u_rval);
2460                                 break;
2461                         case RVAL_OCTAL:
2462                                 tprintf("= %#lo", tcp->u_rval);
2463                                 break;
2464                         case RVAL_UDECIMAL:
2465                                 tprintf("= %lu", tcp->u_rval);
2466                                 break;
2467                         case RVAL_DECIMAL:
2468                                 tprintf("= %ld", tcp->u_rval);
2469                                 break;
2470                         case RVAL_FD:
2471                                 if (show_fd_path) {
2472                                         tprints("= ");
2473                                         printfd(tcp, tcp->u_rval);
2474                                 }
2475                                 else
2476                                         tprintf("= %ld", tcp->u_rval);
2477                                 break;
2478 #if defined(LINUX_MIPSN32) || defined(X32)
2479                         /*
2480                         case RVAL_LHEX:
2481                                 tprintf("= %#llx", tcp->u_lrval);
2482                                 break;
2483                         case RVAL_LOCTAL:
2484                                 tprintf("= %#llo", tcp->u_lrval);
2485                                 break;
2486                         */
2487                         case RVAL_LUDECIMAL:
2488                                 tprintf("= %llu", tcp->u_lrval);
2489                                 break;
2490                         /*
2491                         case RVAL_LDECIMAL:
2492                                 tprintf("= %lld", tcp->u_lrval);
2493                                 break;
2494                         */
2495 #endif
2496                         default:
2497                                 fprintf(stderr,
2498                                         "invalid rval format\n");
2499                                 break;
2500                         }
2501                 }
2502                 if ((sys_res & RVAL_STR) && tcp->auxstr)
2503                         tprintf(" (%s)", tcp->auxstr);
2504         }
2505         if (Tflag) {
2506                 tv_sub(&tv, &tv, &tcp->etime);
2507                 tprintf(" <%ld.%06ld>",
2508                         (long) tv.tv_sec, (long) tv.tv_usec);
2509         }
2510         tprints("\n");
2511         dumpio(tcp);
2512         line_ended();
2513
2514 #ifdef USE_LIBUNWIND
2515         if (stack_trace_enabled)
2516                 unwind_print_stacktrace(tcp);
2517 #endif
2518
2519  ret:
2520         tcp->flags &= ~TCB_INSYSCALL;
2521         return 0;
2522 }
2523
2524 int
2525 trace_syscall(struct tcb *tcp)
2526 {
2527         return exiting(tcp) ?
2528                 trace_syscall_exiting(tcp) : trace_syscall_entering(tcp);
2529 }