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