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 "native_defs.h"
  36 #include <sys/param.h>
  37
  38 /* for struct iovec */
  39 #include <sys/uio.h>
  40
  41 #include "regs.h"
  42 #include "ptrace.h"
  43
  44 #if defined(SPARC64)
  45 # undef PTRACE_GETREGS
  46 # define PTRACE_GETREGS PTRACE_GETREGS64
  47 # undef PTRACE_SETREGS
  48 # define PTRACE_SETREGS PTRACE_SETREGS64
  49 #endif
  50
  51 #if defined SPARC64
  52 # include <asm/psrcompat.h>
  53 #elif defined SPARC
  54 # include <asm/psr.h>
  55 #endif
  56
  57 #ifdef IA64
  58 # include <asm/rse.h>
  59 #endif
  60
  61 #ifndef NT_PRSTATUS
  62 # define NT_PRSTATUS 1
  63 #endif
  64
  65 #ifndef NSIG
  66 # warning: NSIG is not defined, using 32
  67 # define NSIG 32
  68 #endif
  69
  70 #include "syscall.h"
  71
  72 /* Define these shorthand notations to simplify the syscallent files. */
  73 #define TD TRACE_DESC
  74 #define TF TRACE_FILE
  75 #define TI TRACE_IPC
  76 #define TN TRACE_NETWORK
  77 #define TP TRACE_PROCESS
  78 #define TS TRACE_SIGNAL
  79 #define TM TRACE_MEMORY
  80 #define NF SYSCALL_NEVER_FAILS
  81 #define MA MAX_ARGS
  82 #define SI STACKTRACE_INVALIDATE_CACHE
  83 #define SE STACKTRACE_CAPTURE_ON_ENTER
  84
  85 #define SEN_NAME(syscall_name) SEN_ ## syscall_name
  86 #define SEN(syscall_name) SEN_NAME(syscall_name), SYS_FUNC_NAME(syscall_name)
  87
  88 const struct_sysent sysent0[] = {
  89 #include "syscallent.h"
  90 };
  91
  92 #if SUPPORTED_PERSONALITIES > 1
  93 # include PERSONALITY1_INCLUDE_FUNCS
  94 static const struct_sysent sysent1[] = {
  95 # include "syscallent1.h"
  96 };
  97 #endif
  98
  99 #if SUPPORTED_PERSONALITIES > 2
 100 # include PERSONALITY2_INCLUDE_FUNCS
 101 static const struct_sysent sysent2[] = {
 102 # include "syscallent2.h"
 103 };
 104 #endif
 105
 106 /* Now undef them since short defines cause wicked namespace pollution. */
 107 #undef SEN
 108 #undef SEN_NAME
 109 #undef TD
 110 #undef TF
 111 #undef TI
 112 #undef TN
 113 #undef TP
 114 #undef TS
 115 #undef TM
 116 #undef NF
 117 #undef MA
 118 #undef SI
 119 #undef SE
 120
 121 /*
 122  * `ioctlent[012].h' files are automatically generated by the auxiliary
 123  * program `ioctlsort', such that the list is sorted by the `code' field.
 124  * This has the side-effect of resolving the _IO.. macros into
 125  * plain integers, eliminating the need to include here everything
 126  * in "/usr/include".
 127  */
 128
 129 const char *const errnoent0[] = {
 130 #include "errnoent.h"
 131 };
 132 const char *const signalent0[] = {
 133 #include "signalent.h"
 134 };
 135 const struct_ioctlent ioctlent0[] = {
 136 #include "ioctlent0.h"
 137 };
 138
 139 #if SUPPORTED_PERSONALITIES > 1
 140 static const char *const errnoent1[] = {
 141 # include "errnoent1.h"
 142 };
 143 static const char *const signalent1[] = {
 144 # include "signalent1.h"
 145 };
 146 static const struct_ioctlent ioctlent1[] = {
 147 # include "ioctlent1.h"
 148 };
 149 # include PERSONALITY0_INCLUDE_PRINTERS_DECLS
 150 static const struct_printers printers0 = {
 151 # include PERSONALITY0_INCLUDE_PRINTERS_DEFS
 152 };
 153 # include PERSONALITY1_INCLUDE_PRINTERS_DECLS
 154 static const struct_printers printers1 = {
 155 # include PERSONALITY1_INCLUDE_PRINTERS_DEFS
 156 };
 157 #endif
 158
 159 #if SUPPORTED_PERSONALITIES > 2
 160 static const char *const errnoent2[] = {
 161 # include "errnoent2.h"
 162 };
 163 static const char *const signalent2[] = {
 164 # include "signalent2.h"
 165 };
 166 static const struct_ioctlent ioctlent2[] = {
 167 # include "ioctlent2.h"
 168 };
 169 # include PERSONALITY2_INCLUDE_PRINTERS_DECLS
 170 static const struct_printers printers2 = {
 171 # include PERSONALITY2_INCLUDE_PRINTERS_DEFS
 172 };
 173 #endif
 174
 175 enum {
 176         nsyscalls0 = ARRAY_SIZE(sysent0)
 177 #if SUPPORTED_PERSONALITIES > 1
 178         , nsyscalls1 = ARRAY_SIZE(sysent1)
 179 # if SUPPORTED_PERSONALITIES > 2
 180         , nsyscalls2 = ARRAY_SIZE(sysent2)
 181 # endif
 182 #endif
 183 };
 184
 185 enum {
 186         nerrnos0 = ARRAY_SIZE(errnoent0)
 187 #if SUPPORTED_PERSONALITIES > 1
 188         , nerrnos1 = ARRAY_SIZE(errnoent1)
 189 # if SUPPORTED_PERSONALITIES > 2
 190         , nerrnos2 = ARRAY_SIZE(errnoent2)
 191 # endif
 192 #endif
 193 };
 194
 195 enum {
 196         nsignals0 = ARRAY_SIZE(signalent0)
 197 #if SUPPORTED_PERSONALITIES > 1
 198         , nsignals1 = ARRAY_SIZE(signalent1)
 199 # if SUPPORTED_PERSONALITIES > 2
 200         , nsignals2 = ARRAY_SIZE(signalent2)
 201 # endif
 202 #endif
 203 };
 204
 205 enum {
 206         nioctlents0 = ARRAY_SIZE(ioctlent0)
 207 #if SUPPORTED_PERSONALITIES > 1
 208         , nioctlents1 = ARRAY_SIZE(ioctlent1)
 209 # if SUPPORTED_PERSONALITIES > 2
 210         , nioctlents2 = ARRAY_SIZE(ioctlent2)
 211 # endif
 212 #endif
 213 };
 214
 215 #if SUPPORTED_PERSONALITIES > 1
 216 const struct_sysent *sysent = sysent0;
 217 const char *const *errnoent = errnoent0;
 218 const char *const *signalent = signalent0;
 219 const struct_ioctlent *ioctlent = ioctlent0;
 220 const struct_printers *printers = &printers0;
 221 #endif
 222
 223 unsigned nsyscalls = nsyscalls0;
 224 unsigned nerrnos = nerrnos0;
 225 unsigned nsignals = nsignals0;
 226 unsigned nioctlents = nioctlents0;
 227
 228 unsigned num_quals;
 229 qualbits_t *qual_vec[SUPPORTED_PERSONALITIES];
 230
 231 static const unsigned nsyscall_vec[SUPPORTED_PERSONALITIES] = {
 232         nsyscalls0,
 233 #if SUPPORTED_PERSONALITIES > 1
 234         nsyscalls1,
 235 #endif
 236 #if SUPPORTED_PERSONALITIES > 2
 237         nsyscalls2,
 238 #endif
 239 };
 240 static const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
 241         sysent0,
 242 #if SUPPORTED_PERSONALITIES > 1
 243         sysent1,
 244 #endif
 245 #if SUPPORTED_PERSONALITIES > 2
 246         sysent2,
 247 #endif
 248 };
 249
 250 enum {
 251         MAX_NSYSCALLS1 = (nsyscalls0
 252 #if SUPPORTED_PERSONALITIES > 1
 253                         > nsyscalls1 ? nsyscalls0 : nsyscalls1
 254 #endif
 255                         ),
 256         MAX_NSYSCALLS2 = (MAX_NSYSCALLS1
 257 #if SUPPORTED_PERSONALITIES > 2
 258                         > nsyscalls2 ? MAX_NSYSCALLS1 : nsyscalls2
 259 #endif
 260                         ),
 261         MAX_NSYSCALLS = MAX_NSYSCALLS2,
 262         /* We are ready for arches with up to 255 signals,
 263          * even though the largest known signo is on MIPS and it is 128.
 264          * The number of existing syscalls on all arches is
 265          * larger that 255 anyway, so it is just a pedantic matter.
 266          */
 267         MIN_QUALS = MAX_NSYSCALLS > 255 ? MAX_NSYSCALLS : 255
 268 };
 269
 270 #if SUPPORTED_PERSONALITIES > 1
 271 unsigned current_personality;
 272
 273 # ifndef current_wordsize
 274 unsigned current_wordsize;
 275 static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
 276         PERSONALITY0_WORDSIZE,
 277         PERSONALITY1_WORDSIZE,
 278 # if SUPPORTED_PERSONALITIES > 2
 279         PERSONALITY2_WORDSIZE,
 280 # endif
 281 };
 282 # endif
 283
 284 void
 285 set_personality(int personality)
 286 {
 287         nsyscalls = nsyscall_vec[personality];
 288         sysent = sysent_vec[personality];
 289
 290         switch (personality) {
 291         case 0:
 292                 errnoent = errnoent0;
 293                 nerrnos = nerrnos0;
 294                 ioctlent = ioctlent0;
 295                 nioctlents = nioctlents0;
 296                 signalent = signalent0;
 297                 nsignals = nsignals0;
 298                 printers = &printers0;
 299                 break;
 300
 301         case 1:
 302                 errnoent = errnoent1;
 303                 nerrnos = nerrnos1;
 304                 ioctlent = ioctlent1;
 305                 nioctlents = nioctlents1;
 306                 signalent = signalent1;
 307                 nsignals = nsignals1;
 308                 printers = &printers1;
 309                 break;
 310
 311 # if SUPPORTED_PERSONALITIES > 2
 312         case 2:
 313                 errnoent = errnoent2;
 314                 nerrnos = nerrnos2;
 315                 ioctlent = ioctlent2;
 316                 nioctlents = nioctlents2;
 317                 signalent = signalent2;
 318                 nsignals = nsignals2;
 319                 printers = &printers2;
 320                 break;
 321 # endif
 322         }
 323
 324         current_personality = personality;
 325 # ifndef current_wordsize
 326         current_wordsize = personality_wordsize[personality];
 327 # endif
 328 }
 329
 330 static void
 331 update_personality(struct tcb *tcp, unsigned int personality)
 332 {
 333         if (personality == current_personality)
 334                 return;
 335         set_personality(personality);
 336
 337         if (personality == tcp->currpers)
 338                 return;
 339         tcp->currpers = personality;
 340
 341 # undef PERSONALITY_NAMES
 342 # if defined POWERPC64
 343 #  define PERSONALITY_NAMES {"64 bit", "32 bit"}
 344 # elif defined X86_64
 345 #  define PERSONALITY_NAMES {"64 bit", "32 bit", "x32"}
 346 # elif defined X32
 347 #  define PERSONALITY_NAMES {"x32", "32 bit"}
 348 # elif defined AARCH64
 349 #  define PERSONALITY_NAMES {"32-bit", "AArch64"}
 350 # elif defined TILE
 351 #  define PERSONALITY_NAMES {"64-bit", "32-bit"}
 352 # endif
 353 # ifdef PERSONALITY_NAMES
 354         if (!qflag) {
 355                 static const char *const names[] = PERSONALITY_NAMES;
 356                 error_msg("[ Process PID=%d runs in %s mode. ]",
 357                           tcp->pid, names[personality]);
 358         }
 359 # endif
 360 }
 361 #endif
 362
 363 static int qual_syscall(), qual_signal(), qual_desc();
 364
 365 static const struct qual_options {
 366         unsigned int bitflag;
 367         const char *option_name;
 368         int (*qualify)(const char *, int, int);
 369         const char *argument_name;
 370 } qual_options[] = {
 371         { QUAL_TRACE,   "trace",        qual_syscall,   "system call"   },
 372         { QUAL_TRACE,   "t",            qual_syscall,   "system call"   },
 373         { QUAL_ABBREV,  "abbrev",       qual_syscall,   "system call"   },
 374         { QUAL_ABBREV,  "a",            qual_syscall,   "system call"   },
 375         { QUAL_VERBOSE, "verbose",      qual_syscall,   "system call"   },
 376         { QUAL_VERBOSE, "v",            qual_syscall,   "system call"   },
 377         { QUAL_RAW,     "raw",          qual_syscall,   "system call"   },
 378         { QUAL_RAW,     "x",            qual_syscall,   "system call"   },
 379         { QUAL_SIGNAL,  "signal",       qual_signal,    "signal"        },
 380         { QUAL_SIGNAL,  "signals",      qual_signal,    "signal"        },
 381         { QUAL_SIGNAL,  "s",            qual_signal,    "signal"        },
 382         { QUAL_READ,    "read",         qual_desc,      "descriptor"    },
 383         { QUAL_READ,    "reads",        qual_desc,      "descriptor"    },
 384         { QUAL_READ,    "r",            qual_desc,      "descriptor"    },
 385         { QUAL_WRITE,   "write",        qual_desc,      "descriptor"    },
 386         { QUAL_WRITE,   "writes",       qual_desc,      "descriptor"    },
 387         { QUAL_WRITE,   "w",            qual_desc,      "descriptor"    },
 388         { 0,            NULL,           NULL,           NULL            },
 389 };
 390
 391 static void
 392 reallocate_qual(const unsigned int n)
 393 {
 394         unsigned p;
 395         qualbits_t *qp;
 396         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 397                 qp = qual_vec[p] = xreallocarray(qual_vec[p], n,
 398                                                  sizeof(qualbits_t));
 399                 memset(&qp[num_quals], 0, (n - num_quals) * sizeof(qualbits_t));
 400         }
 401         num_quals = n;
 402 }
 403
 404 static void
 405 qualify_one(const unsigned int n, unsigned int bitflag, const int not, const int pers)
 406 {
 407         int p;
 408
 409         if (num_quals <= n)
 410                 reallocate_qual(n + 1);
 411
 412         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 413                 if (pers == p || pers < 0) {
 414                         if (not)
 415                                 qual_vec[p][n] &= ~bitflag;
 416                         else
 417                                 qual_vec[p][n] |= bitflag;
 418                 }
 419         }
 420 }
 421
 422 static int
 423 qual_syscall(const char *s, const unsigned int bitflag, const int not)
 424 {
 425         int p;
 426         unsigned int i;
 427         int rc = -1;
 428
 429         if (*s >= '0' && *s <= '9') {
 430                 i = string_to_uint(s);
 431                 if (i >= MAX_NSYSCALLS)
 432                         return -1;
 433                 qualify_one(i, bitflag, not, -1);
 434                 return 0;
 435         }
 436
 437         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 438                 for (i = 0; i < nsyscall_vec[p]; i++) {
 439                         if (sysent_vec[p][i].sys_name
 440                          && strcmp(s, sysent_vec[p][i].sys_name) == 0
 441                         ) {
 442                                 qualify_one(i, bitflag, not, p);
 443                                 rc = 0;
 444                         }
 445                 }
 446         }
 447
 448         return rc;
 449 }
 450
 451 static int
 452 qual_signal(const char *s, const unsigned int bitflag, const int not)
 453 {
 454         unsigned int i;
 455
 456         if (*s >= '0' && *s <= '9') {
 457                 int signo = string_to_uint(s);
 458                 if (signo < 0 || signo > 255)
 459                         return -1;
 460                 qualify_one(signo, bitflag, not, -1);
 461                 return 0;
 462         }
 463         if (strncasecmp(s, "SIG", 3) == 0)
 464                 s += 3;
 465         for (i = 0; i <= NSIG; i++) {
 466                 if (strcasecmp(s, signame(i) + 3) == 0) {
 467                         qualify_one(i, bitflag, not, -1);
 468                         return 0;
 469                 }
 470         }
 471         return -1;
 472 }
 473
 474 static int
 475 qual_desc(const char *s, const unsigned int bitflag, const int not)
 476 {
 477         if (*s >= '0' && *s <= '9') {
 478                 int desc = string_to_uint(s);
 479                 if (desc < 0 || desc > 0x7fff) /* paranoia */
 480                         return -1;
 481                 qualify_one(desc, bitflag, not, -1);
 482                 return 0;
 483         }
 484         return -1;
 485 }
 486
 487 static int
 488 lookup_class(const char *s)
 489 {
 490         if (strcmp(s, "file") == 0)
 491                 return TRACE_FILE;
 492         if (strcmp(s, "ipc") == 0)
 493                 return TRACE_IPC;
 494         if (strcmp(s, "network") == 0)
 495                 return TRACE_NETWORK;
 496         if (strcmp(s, "process") == 0)
 497                 return TRACE_PROCESS;
 498         if (strcmp(s, "signal") == 0)
 499                 return TRACE_SIGNAL;
 500         if (strcmp(s, "desc") == 0)
 501                 return TRACE_DESC;
 502         if (strcmp(s, "memory") == 0)
 503                 return TRACE_MEMORY;
 504         return -1;
 505 }
 506
 507 void
 508 qualify(const char *s)
 509 {
 510         const struct qual_options *opt;
 511         char *copy;
 512         const char *p;
 513         int not;
 514         unsigned int i;
 515
 516         if (num_quals == 0)
 517                 reallocate_qual(MIN_QUALS);
 518
 519         opt = &qual_options[0];
 520         for (i = 0; (p = qual_options[i].option_name); i++) {
 521                 unsigned int len = strlen(p);
 522                 if (strncmp(s, p, len) == 0 && s[len] == '=') {
 523                         opt = &qual_options[i];
 524                         s += len + 1;
 525                         break;
 526                 }
 527         }
 528         not = 0;
 529         if (*s == '!') {
 530                 not = 1;
 531                 s++;
 532         }
 533         if (strcmp(s, "none") == 0) {
 534                 not = 1 - not;
 535                 s = "all";
 536         }
 537         if (strcmp(s, "all") == 0) {
 538                 for (i = 0; i < num_quals; i++) {
 539                         qualify_one(i, opt->bitflag, not, -1);
 540                 }
 541                 return;
 542         }
 543         for (i = 0; i < num_quals; i++) {
 544                 qualify_one(i, opt->bitflag, !not, -1);
 545         }
 546         copy = xstrdup(s);
 547         for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
 548                 int n;
 549                 if (opt->bitflag == QUAL_TRACE && (n = lookup_class(p)) > 0) {
 550                         unsigned pers;
 551                         for (pers = 0; pers < SUPPORTED_PERSONALITIES; pers++) {
 552                                 for (i = 0; i < nsyscall_vec[pers]; i++)
 553                                         if (sysent_vec[pers][i].sys_flags & n)
 554                                                 qualify_one(i, opt->bitflag, not, pers);
 555                         }
 556                         continue;
 557                 }
 558                 if (opt->qualify(p, opt->bitflag, not)) {
 559                         error_msg_and_die("invalid %s '%s'",
 560                                 opt->argument_name, p);
 561                 }
 562         }
 563         free(copy);
 564         return;
 565 }
 566
 567 #ifdef SYS_socket_subcall
 568 static void
 569 decode_socket_subcall(struct tcb *tcp)
 570 {
 571         unsigned long addr;
 572         unsigned int n;
 573
 574         if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= SYS_socket_nsubcalls)
 575                 return;
 576
 577         tcp->scno = SYS_socket_subcall + tcp->u_arg[0];
 578         tcp->qual_flg = qual_flags[tcp->scno];
 579         tcp->s_ent = &sysent[tcp->scno];
 580         addr = tcp->u_arg[1];
 581         n = tcp->s_ent->nargs;
 582         if (sizeof(tcp->u_arg[0]) == current_wordsize) {
 583                 memset(tcp->u_arg, 0, n * sizeof(tcp->u_arg[0]));
 584                 (void) umoven(tcp, addr, n * sizeof(tcp->u_arg[0]), tcp->u_arg);
 585         } else {
 586                 unsigned int args[n];
 587                 unsigned int i;
 588
 589                 memset(args, 0, sizeof(args));
 590                 (void) umove(tcp, addr, &args);
 591                 for (i = 0; i < n; ++i)
 592                         tcp->u_arg[i] = args[i];
 593         }
 594 }
 595 #endif
 596
 597 #ifdef SYS_ipc_subcall
 598 static void
 599 decode_ipc_subcall(struct tcb *tcp)
 600 {
 601         unsigned int i, n;
 602
 603         if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= SYS_ipc_nsubcalls)
 604                 return;
 605
 606         tcp->scno = SYS_ipc_subcall + tcp->u_arg[0];
 607         tcp->qual_flg = qual_flags[tcp->scno];
 608         tcp->s_ent = &sysent[tcp->scno];
 609         n = tcp->s_ent->nargs;
 610         for (i = 0; i < n; i++)
 611                 tcp->u_arg[i] = tcp->u_arg[i + 1];
 612 }
 613 #endif
 614
 615 #ifdef LINUX_MIPSO32
 616 static void
 617 decode_mips_subcall(struct tcb *tcp)
 618 {
 619         if (!SCNO_IS_VALID(tcp->u_arg[0]))
 620                 return;
 621         tcp->scno = tcp->u_arg[0];
 622         tcp->qual_flg = qual_flags[tcp->scno];
 623         tcp->s_ent = &sysent[tcp->scno];
 624         memmove(&tcp->u_arg[0], &tcp->u_arg[1],
 625                 sizeof(tcp->u_arg) - sizeof(tcp->u_arg[0]));
 626         /*
 627          * Fetching the last arg of 7-arg syscalls (fadvise64_64
 628          * and sync_file_range) would require additional code,
 629          * see linux/mips/get_syscall_args.c
 630          */
 631 }
 632
 633 SYS_FUNC(syscall)
 634 {
 635         return printargs(tcp);
 636 }
 637 #endif
 638
 639 int
 640 printargs(struct tcb *tcp)
 641 {
 642         if (entering(tcp)) {
 643                 int i;
 644                 int n = tcp->s_ent->nargs;
 645                 for (i = 0; i < n; i++)
 646                         tprintf("%s%#lx", i ? ", " : "", tcp->u_arg[i]);
 647         }
 648         return 0;
 649 }
 650
 651 int
 652 printargs_lu(struct tcb *tcp)
 653 {
 654         if (entering(tcp)) {
 655                 int i;
 656                 int n = tcp->s_ent->nargs;
 657                 for (i = 0; i < n; i++)
 658                         tprintf("%s%lu", i ? ", " : "", tcp->u_arg[i]);
 659         }
 660         return 0;
 661 }
 662
 663 int
 664 printargs_ld(struct tcb *tcp)
 665 {
 666         if (entering(tcp)) {
 667                 int i;
 668                 int n = tcp->s_ent->nargs;
 669                 for (i = 0; i < n; i++)
 670                         tprintf("%s%ld", i ? ", " : "", tcp->u_arg[i]);
 671         }
 672         return 0;
 673 }
 674
 675 static void
 676 dumpio(struct tcb *tcp)
 677 {
 678         int sen;
 679
 680         if (syserror(tcp))
 681                 return;
 682         if ((unsigned long) tcp->u_arg[0] >= num_quals)
 683                 return;
 684         sen = tcp->s_ent->sen;
 685         if (SEN_printargs == sen)
 686                 return;
 687         if (qual_flags[tcp->u_arg[0]] & QUAL_READ) {
 688                 switch (sen) {
 689                 case SEN_read:
 690                 case SEN_pread:
 691                 case SEN_recv:
 692                 case SEN_recvfrom:
 693                         dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
 694                         return;
 695                 case SEN_readv:
 696                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 697                         return;
 698                 case SEN_recvmsg:
 699                         dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
 700                         return;
 701                 case SEN_recvmmsg:
 702                         dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
 703                         return;
 704                 }
 705         }
 706         if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE) {
 707                 switch (sen) {
 708                 case SEN_write:
 709                 case SEN_pwrite:
 710                 case SEN_send:
 711                 case SEN_sendto:
 712                         dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 713                         break;
 714                 case SEN_writev:
 715                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 716                         break;
 717                 case SEN_sendmsg:
 718                         dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
 719                         break;
 720                 case SEN_sendmmsg:
 721                         dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
 722                         break;
 723                 }
 724         }
 725 }
 726
 727 /*
 728  * Shuffle syscall numbers so that we don't have huge gaps in syscall table.
 729  * The shuffling should be an involution: shuffle_scno(shuffle_scno(n)) == n.
 730  */
 731 #if defined(ARM) || defined(AARCH64) /* So far only 32-bit ARM needs this */
 732 static long
 733 shuffle_scno(unsigned long scno)
 734 {
 735         if (scno < ARM_FIRST_SHUFFLED_SYSCALL)
 736                 return scno;
 737
 738         /* __ARM_NR_cmpxchg? Swap with LAST_ORDINARY+1 */
 739         if (scno == ARM_FIRST_SHUFFLED_SYSCALL)
 740                 return 0x000ffff0;
 741         if (scno == 0x000ffff0)
 742                 return ARM_FIRST_SHUFFLED_SYSCALL;
 743
 744 #define ARM_SECOND_SHUFFLED_SYSCALL (ARM_FIRST_SHUFFLED_SYSCALL + 1)
 745         /*
 746          * Is it ARM specific syscall?
 747          * Swap [0x000f0000, 0x000f0000 + LAST_SPECIAL] range
 748          * with [SECOND_SHUFFLED, SECOND_SHUFFLED + LAST_SPECIAL] range.
 749          */
 750         if (scno >= 0x000f0000 &&
 751             scno <= 0x000f0000 + ARM_LAST_SPECIAL_SYSCALL) {
 752                 return scno - 0x000f0000 + ARM_SECOND_SHUFFLED_SYSCALL;
 753         }
 754         if (scno <= ARM_SECOND_SHUFFLED_SYSCALL + ARM_LAST_SPECIAL_SYSCALL) {
 755                 return scno + 0x000f0000 - ARM_SECOND_SHUFFLED_SYSCALL;
 756         }
 757
 758         return scno;
 759 }
 760 #else
 761 # define shuffle_scno(scno) ((long)(scno))
 762 #endif
 763
 764 const char *
 765 syscall_name(long scno)
 766 {
 767         static char buf[sizeof("syscall_%lu") + sizeof(long)*3];
 768
 769         if (SCNO_IS_VALID(scno))
 770                 return sysent[scno].sys_name;
 771         else {
 772                 sprintf(buf, "syscall_%lu", shuffle_scno(scno));
 773                 return buf;
 774         }
 775 }
 776
 777 static long get_regs_error;
 778
 779 void
 780 clear_regs(void)
 781 {
 782         get_regs_error = -1;
 783 }
 784
 785 static int get_syscall_args(struct tcb *);
 786 static int get_syscall_result(struct tcb *);
 787
 788 static int
 789 trace_syscall_entering(struct tcb *tcp)
 790 {
 791         int res, scno_good;
 792
 793         scno_good = res = get_scno(tcp);
 794         if (res == 0)
 795                 return res;
 796         if (res == 1)
 797                 res = get_syscall_args(tcp);
 798
 799         if (res != 1) {
 800                 printleader(tcp);
 801                 if (scno_good != 1)
 802                         tprints("????" /* anti-trigraph gap */ "(");
 803                 else if (tcp->qual_flg & UNDEFINED_SCNO)
 804                         tprintf("%s(", syscall_name(tcp->scno));
 805                 else
 806                         tprintf("%s(", tcp->s_ent->sys_name);
 807                 /*
 808                  * " <unavailable>" will be added later by the code which
 809                  * detects ptrace errors.
 810                  */
 811                 goto ret;
 812         }
 813
 814 #ifdef LINUX_MIPSO32
 815         if (SEN_syscall == tcp->s_ent->sen)
 816                 decode_mips_subcall(tcp);
 817 #endif
 818
 819         if (   SEN_execve == tcp->s_ent->sen
 820 # if defined(SPARC) || defined(SPARC64)
 821             || SEN_execv == tcp->s_ent->sen
 822 # endif
 823            ) {
 824                 hide_log_until_execve = 0;
 825         }
 826
 827 #if defined(SYS_socket_subcall) || defined(SYS_ipc_subcall)
 828         switch (tcp->s_ent->sen) {
 829 # ifdef SYS_socket_subcall
 830                 case SEN_socketcall:
 831                         decode_socket_subcall(tcp);
 832                         break;
 833 # endif
 834 # ifdef SYS_ipc_subcall
 835                 case SEN_ipc:
 836                         decode_ipc_subcall(tcp);
 837                         break;
 838 # endif
 839         }
 840 #endif
 841
 842         if (!(tcp->qual_flg & QUAL_TRACE)
 843          || (tracing_paths && !pathtrace_match(tcp))
 844         ) {
 845                 tcp->flags |= TCB_INSYSCALL | TCB_FILTERED;
 846                 tcp->sys_func_rval = 0;
 847                 return 0;
 848         }
 849
 850         tcp->flags &= ~TCB_FILTERED;
 851
 852         if (cflag == CFLAG_ONLY_STATS || hide_log_until_execve) {
 853                 res = 0;
 854                 goto ret;
 855         }
 856
 857 #ifdef USE_LIBUNWIND
 858         if (stack_trace_enabled) {
 859                 if (tcp->s_ent->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)
 860                         unwind_capture_stacktrace(tcp);
 861         }
 862 #endif
 863
 864         printleader(tcp);
 865         if (tcp->qual_flg & UNDEFINED_SCNO)
 866                 tprintf("%s(", syscall_name(tcp->scno));
 867         else
 868                 tprintf("%s(", tcp->s_ent->sys_name);
 869         if ((tcp->qual_flg & QUAL_RAW) && SEN_exit != tcp->s_ent->sen)
 870                 res = printargs(tcp);
 871         else
 872                 res = tcp->s_ent->sys_func(tcp);
 873
 874         fflush(tcp->outf);
 875  ret:
 876         tcp->flags |= TCB_INSYSCALL;
 877         tcp->sys_func_rval = res;
 878         /* Measure the entrance time as late as possible to avoid errors. */
 879         if (Tflag || cflag)
 880                 gettimeofday(&tcp->etime, NULL);
 881         return res;
 882 }
 883
 884 static int
 885 trace_syscall_exiting(struct tcb *tcp)
 886 {
 887         int sys_res;
 888         struct timeval tv;
 889         int res;
 890         long u_error;
 891
 892         /* Measure the exit time as early as possible to avoid errors. */
 893         if (Tflag || cflag)
 894                 gettimeofday(&tv, NULL);
 895
 896 #ifdef USE_LIBUNWIND
 897         if (stack_trace_enabled) {
 898                 if (tcp->s_ent->sys_flags & STACKTRACE_INVALIDATE_CACHE)
 899                         unwind_cache_invalidate(tcp);
 900         }
 901 #endif
 902
 903 #if SUPPORTED_PERSONALITIES > 1
 904         update_personality(tcp, tcp->currpers);
 905 #endif
 906         res = (get_regs_error ? -1 : get_syscall_result(tcp));
 907         if (filtered(tcp) || hide_log_until_execve)
 908                 goto ret;
 909
 910         if (cflag) {
 911                 count_syscall(tcp, &tv);
 912                 if (cflag == CFLAG_ONLY_STATS) {
 913                         goto ret;
 914                 }
 915         }
 916
 917         /* If not in -ff mode, and printing_tcp != tcp,
 918          * then the log currently does not end with output
 919          * of _our syscall entry_, but with something else.
 920          * We need to say which syscall's return is this.
 921          *
 922          * Forced reprinting via TCB_REPRINT is used only by
 923          * "strace -ff -oLOG test/threaded_execve" corner case.
 924          * It's the only case when -ff mode needs reprinting.
 925          */
 926         if ((followfork < 2 && printing_tcp != tcp) || (tcp->flags & TCB_REPRINT)) {
 927                 tcp->flags &= ~TCB_REPRINT;
 928                 printleader(tcp);
 929                 if (tcp->qual_flg & UNDEFINED_SCNO)
 930                         tprintf("<... %s resumed> ", syscall_name(tcp->scno));
 931                 else
 932                         tprintf("<... %s resumed> ", tcp->s_ent->sys_name);
 933         }
 934         printing_tcp = tcp;
 935
 936         tcp->s_prev_ent = NULL;
 937         if (res != 1) {
 938                 /* There was error in one of prior ptrace ops */
 939                 tprints(") ");
 940                 tabto();
 941                 tprints("= ? <unavailable>\n");
 942                 line_ended();
 943                 tcp->flags &= ~TCB_INSYSCALL;
 944                 tcp->sys_func_rval = 0;
 945                 return res;
 946         }
 947         tcp->s_prev_ent = tcp->s_ent;
 948
 949         sys_res = 0;
 950         if (tcp->qual_flg & QUAL_RAW) {
 951                 /* sys_res = printargs(tcp); - but it's nop on sysexit */
 952         } else {
 953         /* FIXME: not_failing_only (IOW, option -z) is broken:
 954          * failure of syscall is known only after syscall return.
 955          * Thus we end up with something like this on, say, ENOENT:
 956          *     open("doesnt_exist", O_RDONLY <unfinished ...>
 957          *     {next syscall decode}
 958          * whereas the intended result is that open(...) line
 959          * is not shown at all.
 960          */
 961                 if (not_failing_only && tcp->u_error)
 962                         goto ret;       /* ignore failed syscalls */
 963                 if (tcp->sys_func_rval & RVAL_DECODED)
 964                         sys_res = tcp->sys_func_rval;
 965                 else
 966                         sys_res = tcp->s_ent->sys_func(tcp);
 967         }
 968
 969         tprints(") ");
 970         tabto();
 971         u_error = tcp->u_error;
 972         if (tcp->qual_flg & QUAL_RAW) {
 973                 if (u_error)
 974                         tprintf("= -1 (errno %ld)", u_error);
 975                 else
 976                         tprintf("= %#lx", tcp->u_rval);
 977         }
 978         else if (!(sys_res & RVAL_NONE) && u_error) {
 979                 switch (u_error) {
 980                 /* Blocked signals do not interrupt any syscalls.
 981                  * In this case syscalls don't return ERESTARTfoo codes.
 982                  *
 983                  * Deadly signals set to SIG_DFL interrupt syscalls
 984                  * and kill the process regardless of which of the codes below
 985                  * is returned by the interrupted syscall.
 986                  * In some cases, kernel forces a kernel-generated deadly
 987                  * signal to be unblocked and set to SIG_DFL (and thus cause
 988                  * death) if it is blocked or SIG_IGNed: for example, SIGSEGV
 989                  * or SIGILL. (The alternative is to leave process spinning
 990                  * forever on the faulty instruction - not useful).
 991                  *
 992                  * SIG_IGNed signals and non-deadly signals set to SIG_DFL
 993                  * (for example, SIGCHLD, SIGWINCH) interrupt syscalls,
 994                  * but kernel will always restart them.
 995                  */
 996                 case ERESTARTSYS:
 997                         /* Most common type of signal-interrupted syscall exit code.
 998                          * The system call will be restarted with the same arguments
 999                          * if SA_RESTART is set; otherwise, it will fail with EINTR.
1000                          */
1001                         tprints("= ? ERESTARTSYS (To be restarted if SA_RESTART is set)");
1002                         break;
1003                 case ERESTARTNOINTR:
1004                         /* Rare. For example, fork() returns this if interrupted.
1005                          * SA_RESTART is ignored (assumed set): the restart is unconditional.
1006                          */
1007                         tprints("= ? ERESTARTNOINTR (To be restarted)");
1008                         break;
1009                 case ERESTARTNOHAND:
1010                         /* pause(), rt_sigsuspend() etc use this code.
1011                          * SA_RESTART is ignored (assumed not set):
1012                          * syscall won't restart (will return EINTR instead)
1013                          * even after signal with SA_RESTART set. However,
1014                          * after SIG_IGN or SIG_DFL signal it will restart
1015                          * (thus the name "restart only if has no handler").
1016                          */
1017                         tprints("= ? ERESTARTNOHAND (To be restarted if no handler)");
1018                         break;
1019                 case ERESTART_RESTARTBLOCK:
1020                         /* Syscalls like nanosleep(), poll() which can't be
1021                          * restarted with their original arguments use this
1022                          * code. Kernel will execute restart_syscall() instead,
1023                          * which changes arguments before restarting syscall.
1024                          * SA_RESTART is ignored (assumed not set) similarly
1025                          * to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
1026                          * since restart data is saved in "restart block"
1027                          * in task struct, and if signal handler uses a syscall
1028                          * which in turn saves another such restart block,
1029                          * old data is lost and restart becomes impossible)
1030                          */
1031                         tprints("= ? ERESTART_RESTARTBLOCK (Interrupted by signal)");
1032                         break;
1033                 default:
1034                         if ((unsigned long) u_error < nerrnos
1035                             && errnoent[u_error])
1036                                 tprintf("= -1 %s (%s)", errnoent[u_error],
1037                                         strerror(u_error));
1038                         else
1039                                 tprintf("= -1 ERRNO_%lu (%s)", u_error,
1040                                         strerror(u_error));
1041                         break;
1042                 }
1043                 if ((sys_res & RVAL_STR) && tcp->auxstr)
1044                         tprintf(" (%s)", tcp->auxstr);
1045         }
1046         else {
1047                 if (sys_res & RVAL_NONE)
1048                         tprints("= ?");
1049                 else {
1050                         switch (sys_res & RVAL_MASK) {
1051                         case RVAL_HEX:
1052 #if SUPPORTED_PERSONALITIES > 1
1053                                 if (current_wordsize < sizeof(long))
1054                                         tprintf("= %#x",
1055                                                 (unsigned int) tcp->u_rval);
1056                                 else
1057 #endif
1058                                         tprintf("= %#lx", tcp->u_rval);
1059                                 break;
1060                         case RVAL_OCTAL:
1061                                 tprintf("= %#lo", tcp->u_rval);
1062                                 break;
1063                         case RVAL_UDECIMAL:
1064                                 tprintf("= %lu", tcp->u_rval);
1065                                 break;
1066                         case RVAL_DECIMAL:
1067                                 tprintf("= %ld", tcp->u_rval);
1068                                 break;
1069                         case RVAL_FD:
1070                                 if (show_fd_path) {
1071                                         tprints("= ");
1072                                         printfd(tcp, tcp->u_rval);
1073                                 }
1074                                 else
1075                                         tprintf("= %ld", tcp->u_rval);
1076                                 break;
1077 #if defined(LINUX_MIPSN32) || defined(X32)
1078                         /*
1079                         case RVAL_LHEX:
1080                                 tprintf("= %#llx", tcp->u_lrval);
1081                                 break;
1082                         case RVAL_LOCTAL:
1083                                 tprintf("= %#llo", tcp->u_lrval);
1084                                 break;
1085                         */
1086                         case RVAL_LUDECIMAL:
1087                                 tprintf("= %llu", tcp->u_lrval);
1088                                 break;
1089                         /*
1090                         case RVAL_LDECIMAL:
1091                                 tprintf("= %lld", tcp->u_lrval);
1092                                 break;
1093                         */
1094 #endif
1095                         default:
1096                                 error_msg("invalid rval format");
1097                                 break;
1098                         }
1099                 }
1100                 if ((sys_res & RVAL_STR) && tcp->auxstr)
1101                         tprintf(" (%s)", tcp->auxstr);
1102         }
1103         if (Tflag) {
1104                 tv_sub(&tv, &tv, &tcp->etime);
1105                 tprintf(" <%ld.%06ld>",
1106                         (long) tv.tv_sec, (long) tv.tv_usec);
1107         }
1108         tprints("\n");
1109         dumpio(tcp);
1110         line_ended();
1111
1112 #ifdef USE_LIBUNWIND
1113         if (stack_trace_enabled)
1114                 unwind_print_stacktrace(tcp);
1115 #endif
1116
1117  ret:
1118         tcp->flags &= ~TCB_INSYSCALL;
1119         tcp->sys_func_rval = 0;
1120         return 0;
1121 }
1122
1123 int
1124 trace_syscall(struct tcb *tcp)
1125 {
1126         return exiting(tcp) ?
1127                 trace_syscall_exiting(tcp) : trace_syscall_entering(tcp);
1128 }
1129
1130 bool
1131 is_erestart(struct tcb *tcp)
1132 {
1133         switch (tcp->u_error) {
1134                 case ERESTARTSYS:
1135                 case ERESTARTNOINTR:
1136                 case ERESTARTNOHAND:
1137                 case ERESTART_RESTARTBLOCK:
1138                         return true;
1139                 default:
1140                         return false;
1141         }
1142 }
1143
1144 static int saved_u_error;
1145
1146 void
1147 temporarily_clear_syserror(struct tcb *tcp)
1148 {
1149         saved_u_error = tcp->u_error;
1150         tcp->u_error = 0;
1151 }
1152
1153 void
1154 restore_cleared_syserror(struct tcb *tcp)
1155 {
1156         tcp->u_error = saved_u_error;
1157 }
1158
1159 #include "kernel_types.h"
1160
1161 /*
1162  * Check the syscall return value register value for whether it is
1163  * a negated errno code indicating an error, or a success return value.
1164  */
1165 static inline bool
1166 is_negated_errno(kernel_ulong_t val)
1167 {
1168         /* Linux kernel defines MAX_ERRNO to 4095. */
1169         kernel_ulong_t max = -(kernel_long_t) 4095;
1170
1171 #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
1172         if (current_wordsize < sizeof(val)) {
1173                 val = (uint32_t) val;
1174                 max = (uint32_t) max;
1175         }
1176 #elif defined X32
1177         /*
1178          * current_wordsize is 4 even in personality 0 (native X32)
1179          * but truncation _must not_ be done in it.
1180          * can't check current_wordsize here!
1181          */
1182         if (current_personality != 0) {
1183                 val = (uint32_t) val;
1184                 max = (uint32_t) max;
1185         }
1186 #endif
1187
1188         return val >= max;
1189 }
1190
1191 #include "arch_regs.c"
1192
1193 #ifdef HAVE_GETRVAL2
1194 # include "arch_getrval2.c"
1195 #endif
1196
1197 void
1198 print_pc(struct tcb *tcp)
1199 {
1200         const char *fmt;
1201         const char *bad;
1202
1203 #ifdef current_wordsize
1204 # define pc_wordsize current_wordsize
1205 #else
1206 # define pc_wordsize personality_wordsize[tcp->currpers]
1207 #endif
1208
1209         if (pc_wordsize == 4) {
1210                 fmt = "[%08lx] ";
1211                 bad = "[????????] ";
1212         } else {
1213                 fmt = "[%016lx] ";
1214                 bad = "[????????????????] ";
1215         }
1216
1217 #undef pc_wordsize
1218 #define PRINTBADPC tprints(bad)
1219
1220         if (get_regs_error) {
1221                 PRINTBADPC;
1222                 return;
1223         }
1224
1225 #include "print_pc.c"
1226 }
1227
1228 #if defined X86_64 || defined POWERPC
1229 # include "getregs_old.c"
1230 #endif
1231
1232 #if defined ARCH_REGS_FOR_GETREGSET
1233 static long
1234 get_regset(pid_t pid)
1235 {
1236 # ifdef ARCH_IOVEC_FOR_GETREGSET
1237         /* variable iovec */
1238         ARCH_IOVEC_FOR_GETREGSET.iov_len = sizeof(ARCH_REGS_FOR_GETREGSET);
1239         return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS,
1240                       &ARCH_IOVEC_FOR_GETREGSET);
1241 # else
1242         /* constant iovec */
1243         static struct iovec io = {
1244                 .iov_base = &ARCH_REGS_FOR_GETREGSET,
1245                 .iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
1246         };
1247         return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &io);
1248
1249 # endif
1250 }
1251 #endif /* ARCH_REGS_FOR_GETREGSET */
1252
1253 void
1254 get_regs(pid_t pid)
1255 {
1256 #ifdef ARCH_REGS_FOR_GETREGSET
1257 # ifdef X86_64
1258         /* Try PTRACE_GETREGSET first, fallback to PTRACE_GETREGS. */
1259         static int getregset_support;
1260
1261         if (getregset_support >= 0) {
1262                 get_regs_error = get_regset(pid);
1263                 if (getregset_support > 0)
1264                         return;
1265                 if (get_regs_error >= 0) {
1266                         getregset_support = 1;
1267                         return;
1268                 }
1269                 if (errno == EPERM || errno == ESRCH)
1270                         return;
1271                 getregset_support = -1;
1272         }
1273         getregs_old(pid);
1274 # else /* !X86_64 */
1275         /* Assume that PTRACE_GETREGSET works. */
1276         get_regs_error = get_regset(pid);
1277 # endif
1278 #elif defined ARCH_REGS_FOR_GETREGS
1279 # if defined SPARC || defined SPARC64
1280         /* SPARC systems have the meaning of data and addr reversed */
1281         get_regs_error = ptrace(PTRACE_GETREGS, pid, (char *)&ARCH_REGS_FOR_GETREGS, 0);
1282 # elif defined POWERPC
1283         static bool old_kernel = 0;
1284         if (old_kernel)
1285                 goto old;
1286         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
1287         if (get_regs_error && errno == EIO) {
1288                 old_kernel = 1;
1289  old:
1290                 get_regs_error = getregs_old(pid);
1291         }
1292 # else
1293         /* Assume that PTRACE_GETREGS works. */
1294         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &ARCH_REGS_FOR_GETREGS);
1295 # endif
1296
1297 #else /* !ARCH_REGS_FOR_GETREGSET && !ARCH_REGS_FOR_GETREGS */
1298 #  warning get_regs is not implemented for this architecture yet
1299         get_regs_error = 0;
1300 #endif
1301 }
1302
1303 /* Returns:
1304  * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
1305  * 1: ok, continue in trace_syscall_entering().
1306  * other: error, trace_syscall_entering() should print error indicator
1307  *    ("????" etc) and bail out.
1308  */
1309 int
1310 get_scno(struct tcb *tcp)
1311 {
1312         if (get_regs_error)
1313                 return -1;
1314
1315         long scno = 0;
1316
1317 #include "get_scno.c"
1318
1319         tcp->scno = scno;
1320         if (SCNO_IS_VALID(tcp->scno)) {
1321                 tcp->s_ent = &sysent[scno];
1322                 tcp->qual_flg = qual_flags[scno];
1323         } else {
1324                 static const struct_sysent unknown = {
1325                         .nargs = MAX_ARGS,
1326                         .sys_flags = 0,
1327                         .sys_func = printargs,
1328                         .sys_name = "system call",
1329                 };
1330                 tcp->s_ent = &unknown;
1331                 tcp->qual_flg = UNDEFINED_SCNO | QUAL_RAW | DEFAULT_QUAL_FLAGS;
1332                 if (debug_flag)
1333                         error_msg("pid %d invalid syscall %ld", tcp->pid, scno);
1334         }
1335         return 1;
1336 }
1337
1338 /* Return -1 on error or 1 on success (never 0!) */
1339 static int
1340 get_syscall_args(struct tcb *tcp)
1341 {
1342 #include "get_syscall_args.c"
1343         return 1;
1344 }
1345
1346 static void
1347 get_error(struct tcb *tcp)
1348 {
1349         const bool check_errno = !(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS);
1350         tcp->u_error = 0;
1351
1352 #include "get_error.c"
1353 }
1354
1355 /* Returns:
1356  * 1: ok, continue in trace_syscall_exiting().
1357  * -1: error, trace_syscall_exiting() should print error indicator
1358  *    ("????" etc) and bail out.
1359  */
1360 static int
1361 get_syscall_result(struct tcb *tcp)
1362 {
1363 #if defined ARCH_REGS_FOR_GETREGSET || defined ARCH_REGS_FOR_GETREGS
1364         /* already done by get_regs */
1365 #else
1366 # include "get_syscall_result.c"
1367 #endif
1368         get_error(tcp);
1369         return 1;
1370 }