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 lookup_class(const char *s)
 423 {
 424         if (strcmp(s, "file") == 0)
 425                 return TRACE_FILE;
 426         if (strcmp(s, "ipc") == 0)
 427                 return TRACE_IPC;
 428         if (strcmp(s, "network") == 0)
 429                 return TRACE_NETWORK;
 430         if (strcmp(s, "process") == 0)
 431                 return TRACE_PROCESS;
 432         if (strcmp(s, "signal") == 0)
 433                 return TRACE_SIGNAL;
 434         if (strcmp(s, "desc") == 0)
 435                 return TRACE_DESC;
 436         if (strcmp(s, "memory") == 0)
 437                 return TRACE_MEMORY;
 438         return -1;
 439 }
 440
 441 static int
 442 qual_syscall(const char *s, const unsigned int bitflag, const int not)
 443 {
 444         unsigned int p;
 445         unsigned int i;
 446         int n;
 447         int rc = -1;
 448
 449         if ((n = lookup_class(s)) >= 0) {
 450                 for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
 451                         for (i = 0; i < nsyscall_vec[p]; ++i) {
 452                                 if ((sysent_vec[p][i].sys_flags & n) == n) {
 453                                         qualify_one(i, bitflag, not, p);
 454                                 }
 455                         }
 456                 }
 457                 return 0;
 458         }
 459
 460         if (*s >= '0' && *s <= '9') {
 461                 i = string_to_uint(s);
 462                 if (i >= MAX_NSYSCALLS)
 463                         return -1;
 464                 qualify_one(i, bitflag, not, -1);
 465                 return 0;
 466         }
 467
 468         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 469                 for (i = 0; i < nsyscall_vec[p]; i++) {
 470                         if (sysent_vec[p][i].sys_name
 471                          && strcmp(s, sysent_vec[p][i].sys_name) == 0
 472                         ) {
 473                                 qualify_one(i, bitflag, not, p);
 474                                 rc = 0;
 475                         }
 476                 }
 477         }
 478
 479         return rc;
 480 }
 481
 482 static int
 483 qual_signal(const char *s, const unsigned int bitflag, const int not)
 484 {
 485         unsigned int i;
 486
 487         if (*s >= '0' && *s <= '9') {
 488                 int signo = string_to_uint(s);
 489                 if (signo < 0 || signo > 255)
 490                         return -1;
 491                 qualify_one(signo, bitflag, not, -1);
 492                 return 0;
 493         }
 494         if (strncasecmp(s, "SIG", 3) == 0)
 495                 s += 3;
 496         for (i = 0; i <= NSIG; i++) {
 497                 if (strcasecmp(s, signame(i) + 3) == 0) {
 498                         qualify_one(i, bitflag, not, -1);
 499                         return 0;
 500                 }
 501         }
 502         return -1;
 503 }
 504
 505 static int
 506 qual_desc(const char *s, const unsigned int bitflag, const int not)
 507 {
 508         if (*s >= '0' && *s <= '9') {
 509                 int desc = string_to_uint(s);
 510                 if (desc < 0 || desc > 0x7fff) /* paranoia */
 511                         return -1;
 512                 qualify_one(desc, bitflag, not, -1);
 513                 return 0;
 514         }
 515         return -1;
 516 }
 517
 518 void
 519 qualify(const char *s)
 520 {
 521         const struct qual_options *opt;
 522         char *copy;
 523         const char *p;
 524         int not;
 525         unsigned int i;
 526
 527         if (num_quals == 0)
 528                 reallocate_qual(MIN_QUALS);
 529
 530         opt = &qual_options[0];
 531         for (i = 0; (p = qual_options[i].option_name); i++) {
 532                 unsigned int len = strlen(p);
 533                 if (strncmp(s, p, len) == 0 && s[len] == '=') {
 534                         opt = &qual_options[i];
 535                         s += len + 1;
 536                         break;
 537                 }
 538         }
 539         not = 0;
 540         if (*s == '!') {
 541                 not = 1;
 542                 s++;
 543         }
 544         if (strcmp(s, "none") == 0) {
 545                 not = 1 - not;
 546                 s = "all";
 547         }
 548         if (strcmp(s, "all") == 0) {
 549                 for (i = 0; i < num_quals; i++) {
 550                         qualify_one(i, opt->bitflag, not, -1);
 551                 }
 552                 return;
 553         }
 554         for (i = 0; i < num_quals; i++) {
 555                 qualify_one(i, opt->bitflag, !not, -1);
 556         }
 557         copy = xstrdup(s);
 558         for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
 559                 if (opt->qualify(p, opt->bitflag, not)) {
 560                         error_msg_and_die("invalid %s '%s'",
 561                                 opt->argument_name, p);
 562                 }
 563         }
 564         free(copy);
 565         return;
 566 }
 567
 568 #ifdef SYS_socket_subcall
 569 static void
 570 decode_socket_subcall(struct tcb *tcp)
 571 {
 572         const int call = tcp->u_arg[0];
 573
 574         if (call < 1 || call >= SYS_socket_nsubcalls)
 575                 return;
 576
 577         const unsigned long scno = SYS_socket_subcall + call;
 578         const unsigned int nargs = sysent[scno].nargs;
 579         uint64_t buf[nargs];
 580
 581         if (umoven(tcp, tcp->u_arg[1], nargs * current_wordsize, buf) < 0)
 582                 return;
 583
 584         tcp->scno = scno;
 585         tcp->qual_flg = qual_flags[scno];
 586         tcp->s_ent = &sysent[scno];
 587
 588         unsigned int i;
 589         for (i = 0; i < nargs; ++i)
 590                 tcp->u_arg[i] = (sizeof(uint32_t) == current_wordsize)
 591                                 ? ((uint32_t *) (void *) buf)[i] : buf[i];
 592 }
 593 #endif
 594
 595 #ifdef SYS_ipc_subcall
 596 static void
 597 decode_ipc_subcall(struct tcb *tcp)
 598 {
 599         unsigned int call = tcp->u_arg[0];
 600         const unsigned int version = call >> 16;
 601
 602         if (version) {
 603 # if defined S390 || defined S390X
 604                 return;
 605 # else
 606 #  ifdef SPARC64
 607                 if (current_wordsize == 8)
 608                         return;
 609 #  endif
 610                 set_tcb_priv_ulong(tcp, version);
 611                 call &= 0xffff;
 612 # endif
 613         }
 614
 615         switch (call) {
 616                 case  1: case  2: case  3: case  4:
 617                 case 11: case 12: case 13: case 14:
 618                 case 21: case 22: case 23: case 24:
 619                         break;
 620                 default:
 621                         return;
 622         }
 623
 624         tcp->scno = SYS_ipc_subcall + call;
 625         tcp->qual_flg = qual_flags[tcp->scno];
 626         tcp->s_ent = &sysent[tcp->scno];
 627
 628         const unsigned int n = tcp->s_ent->nargs;
 629         unsigned int i;
 630         for (i = 0; i < n; i++)
 631                 tcp->u_arg[i] = tcp->u_arg[i + 1];
 632 }
 633 #endif
 634
 635 #ifdef LINUX_MIPSO32
 636 static void
 637 decode_mips_subcall(struct tcb *tcp)
 638 {
 639         if (!SCNO_IS_VALID(tcp->u_arg[0]))
 640                 return;
 641         tcp->scno = tcp->u_arg[0];
 642         tcp->qual_flg = qual_flags[tcp->scno];
 643         tcp->s_ent = &sysent[tcp->scno];
 644         memmove(&tcp->u_arg[0], &tcp->u_arg[1],
 645                 sizeof(tcp->u_arg) - sizeof(tcp->u_arg[0]));
 646         /*
 647          * Fetching the last arg of 7-arg syscalls (fadvise64_64
 648          * and sync_file_range) requires additional code,
 649          * see linux/mips/get_syscall_args.c
 650          */
 651         if (tcp->s_ent->nargs == MAX_ARGS) {
 652                 if (umoven(tcp,
 653                            mips_REG_SP + MAX_ARGS * sizeof(tcp->u_arg[0]),
 654                            sizeof(tcp->u_arg[0]),
 655                            &tcp->u_arg[MAX_ARGS - 1]) < 0)
 656                 tcp->u_arg[MAX_ARGS - 1] = 0;
 657         }
 658 }
 659 #endif /* LINUX_MIPSO32 */
 660
 661 static void
 662 dumpio(struct tcb *tcp)
 663 {
 664         int sen;
 665
 666         if (syserror(tcp))
 667                 return;
 668         if ((unsigned long) tcp->u_arg[0] >= num_quals)
 669                 return;
 670         sen = tcp->s_ent->sen;
 671         if (SEN_printargs == sen)
 672                 return;
 673         if (qual_flags[tcp->u_arg[0]] & QUAL_READ) {
 674                 switch (sen) {
 675                 case SEN_read:
 676                 case SEN_pread:
 677                 case SEN_recv:
 678                 case SEN_recvfrom:
 679                         dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
 680                         return;
 681                 case SEN_readv:
 682                 case SEN_preadv:
 683                 case SEN_preadv2:
 684                         dumpiov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1],
 685                                      tcp->u_rval);
 686                         return;
 687                 case SEN_recvmsg:
 688                         dumpiov_in_msghdr(tcp, tcp->u_arg[1], tcp->u_rval);
 689                         return;
 690                 case SEN_recvmmsg:
 691                         dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
 692                         return;
 693                 }
 694         }
 695         if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE) {
 696                 switch (sen) {
 697                 case SEN_write:
 698                 case SEN_pwrite:
 699                 case SEN_send:
 700                 case SEN_sendto:
 701                         dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
 702                         break;
 703                 case SEN_writev:
 704                 case SEN_pwritev:
 705                 case SEN_pwritev2:
 706                 case SEN_vmsplice:
 707                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
 708                         break;
 709                 case SEN_sendmsg:
 710                         dumpiov_in_msghdr(tcp, tcp->u_arg[1],
 711                                           (unsigned long) -1L);
 712                         break;
 713                 case SEN_sendmmsg:
 714                         dumpiov_in_mmsghdr(tcp, tcp->u_arg[1]);
 715                         break;
 716                 }
 717         }
 718 }
 719
 720 /*
 721  * Shuffle syscall numbers so that we don't have huge gaps in syscall table.
 722  * The shuffling should be an involution: shuffle_scno(shuffle_scno(n)) == n.
 723  */
 724 #if defined(ARM) || defined(AARCH64) /* So far only 32-bit ARM needs this */
 725 static long
 726 shuffle_scno(unsigned long scno)
 727 {
 728         if (scno < ARM_FIRST_SHUFFLED_SYSCALL)
 729                 return scno;
 730
 731         /* __ARM_NR_cmpxchg? Swap with LAST_ORDINARY+1 */
 732         if (scno == ARM_FIRST_SHUFFLED_SYSCALL)
 733                 return 0x000ffff0;
 734         if (scno == 0x000ffff0)
 735                 return ARM_FIRST_SHUFFLED_SYSCALL;
 736
 737 #define ARM_SECOND_SHUFFLED_SYSCALL (ARM_FIRST_SHUFFLED_SYSCALL + 1)
 738         /*
 739          * Is it ARM specific syscall?
 740          * Swap [0x000f0000, 0x000f0000 + LAST_SPECIAL] range
 741          * with [SECOND_SHUFFLED, SECOND_SHUFFLED + LAST_SPECIAL] range.
 742          */
 743         if (scno >= 0x000f0000 &&
 744             scno <= 0x000f0000 + ARM_LAST_SPECIAL_SYSCALL) {
 745                 return scno - 0x000f0000 + ARM_SECOND_SHUFFLED_SYSCALL;
 746         }
 747         if (scno <= ARM_SECOND_SHUFFLED_SYSCALL + ARM_LAST_SPECIAL_SYSCALL) {
 748                 return scno + 0x000f0000 - ARM_SECOND_SHUFFLED_SYSCALL;
 749         }
 750
 751         return scno;
 752 }
 753 #else
 754 # define shuffle_scno(scno) ((long)(scno))
 755 #endif
 756
 757 const char *
 758 syscall_name(long scno)
 759 {
 760         static char buf[sizeof("syscall_%lu") + sizeof(long)*3];
 761
 762         if (SCNO_IS_VALID(scno))
 763                 return sysent[scno].sys_name;
 764         else {
 765                 sprintf(buf, "syscall_%lu", scno);
 766                 return buf;
 767         }
 768 }
 769
 770 const char *
 771 err_name(unsigned long err)
 772 {
 773         if ((err < nerrnos) && errnoent[err])
 774                 return errnoent[err];
 775
 776         return NULL;
 777 }
 778
 779 static long get_regs_error;
 780
 781 void
 782 clear_regs(void)
 783 {
 784         get_regs_error = -1;
 785 }
 786
 787 static int get_syscall_args(struct tcb *);
 788 static int get_syscall_result(struct tcb *);
 789 static int arch_get_scno(struct tcb *tcp);
 790 static void get_error(struct tcb *, const bool);
 791 #if defined X86_64 || defined POWERPC
 792 static int getregs_old(pid_t);
 793 #endif
 794
 795 static int
 796 trace_syscall_entering(struct tcb *tcp)
 797 {
 798         int res, scno_good;
 799
 800         scno_good = res = get_scno(tcp);
 801         if (res == 0)
 802                 return res;
 803         if (res == 1)
 804                 res = get_syscall_args(tcp);
 805
 806         if (res != 1) {
 807                 printleader(tcp);
 808                 tprintf("%s(", scno_good == 1 ? tcp->s_ent->sys_name : "????");
 809                 /*
 810                  * " <unavailable>" will be added later by the code which
 811                  * detects ptrace errors.
 812                  */
 813                 goto ret;
 814         }
 815
 816 #ifdef LINUX_MIPSO32
 817         if (SEN_syscall == tcp->s_ent->sen)
 818                 decode_mips_subcall(tcp);
 819 #endif
 820
 821         if (   SEN_execve == tcp->s_ent->sen
 822 # if defined(SPARC) || defined(SPARC64)
 823             || SEN_execv == tcp->s_ent->sen
 824 # endif
 825            ) {
 826                 hide_log_until_execve = 0;
 827         }
 828
 829 #if defined(SYS_socket_subcall) || defined(SYS_ipc_subcall)
 830         switch (tcp->s_ent->sen) {
 831 # ifdef SYS_socket_subcall
 832                 case SEN_socketcall:
 833                         decode_socket_subcall(tcp);
 834                         break;
 835 # endif
 836 # ifdef SYS_ipc_subcall
 837                 case SEN_ipc:
 838                         decode_ipc_subcall(tcp);
 839                         break;
 840 # endif
 841         }
 842 #endif
 843
 844         if (!(tcp->qual_flg & QUAL_TRACE)
 845          || (tracing_paths && !pathtrace_match(tcp))
 846         ) {
 847                 tcp->flags |= TCB_INSYSCALL | TCB_FILTERED;
 848                 tcp->sys_func_rval = 0;
 849                 return 0;
 850         }
 851
 852         tcp->flags &= ~TCB_FILTERED;
 853
 854         if (cflag == CFLAG_ONLY_STATS || hide_log_until_execve) {
 855                 res = 0;
 856                 goto ret;
 857         }
 858
 859 #ifdef USE_LIBUNWIND
 860         if (stack_trace_enabled) {
 861                 if (tcp->s_ent->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)
 862                         unwind_capture_stacktrace(tcp);
 863         }
 864 #endif
 865
 866         printleader(tcp);
 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         unsigned 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                 tprintf("<... %s resumed> ", tcp->s_ent->sys_name);
 929         }
 930         printing_tcp = tcp;
 931
 932         tcp->s_prev_ent = NULL;
 933         if (res != 1) {
 934                 /* There was error in one of prior ptrace ops */
 935                 tprints(") ");
 936                 tabto();
 937                 tprints("= ? <unavailable>\n");
 938                 line_ended();
 939                 tcp->flags &= ~TCB_INSYSCALL;
 940                 tcp->sys_func_rval = 0;
 941                 free_tcb_priv_data(tcp);
 942                 return res;
 943         }
 944         tcp->s_prev_ent = tcp->s_ent;
 945
 946         sys_res = 0;
 947         if (tcp->qual_flg & QUAL_RAW) {
 948                 /* sys_res = printargs(tcp); - but it's nop on sysexit */
 949         } else {
 950         /* FIXME: not_failing_only (IOW, option -z) is broken:
 951          * failure of syscall is known only after syscall return.
 952          * Thus we end up with something like this on, say, ENOENT:
 953          *     open("doesnt_exist", O_RDONLY <unfinished ...>
 954          *     {next syscall decode}
 955          * whereas the intended result is that open(...) line
 956          * is not shown at all.
 957          */
 958                 if (not_failing_only && tcp->u_error)
 959                         goto ret;       /* ignore failed syscalls */
 960                 if (tcp->sys_func_rval & RVAL_DECODED)
 961                         sys_res = tcp->sys_func_rval;
 962                 else
 963                         sys_res = tcp->s_ent->sys_func(tcp);
 964         }
 965
 966         tprints(") ");
 967         tabto();
 968         u_error = tcp->u_error;
 969         if (tcp->qual_flg & QUAL_RAW) {
 970                 if (u_error)
 971                         tprintf("= -1 (errno %lu)", u_error);
 972                 else
 973                         tprintf("= %#lx", tcp->u_rval);
 974         }
 975         else if (!(sys_res & RVAL_NONE) && u_error) {
 976                 switch (u_error) {
 977                 /* Blocked signals do not interrupt any syscalls.
 978                  * In this case syscalls don't return ERESTARTfoo codes.
 979                  *
 980                  * Deadly signals set to SIG_DFL interrupt syscalls
 981                  * and kill the process regardless of which of the codes below
 982                  * is returned by the interrupted syscall.
 983                  * In some cases, kernel forces a kernel-generated deadly
 984                  * signal to be unblocked and set to SIG_DFL (and thus cause
 985                  * death) if it is blocked or SIG_IGNed: for example, SIGSEGV
 986                  * or SIGILL. (The alternative is to leave process spinning
 987                  * forever on the faulty instruction - not useful).
 988                  *
 989                  * SIG_IGNed signals and non-deadly signals set to SIG_DFL
 990                  * (for example, SIGCHLD, SIGWINCH) interrupt syscalls,
 991                  * but kernel will always restart them.
 992                  */
 993                 case ERESTARTSYS:
 994                         /* Most common type of signal-interrupted syscall exit code.
 995                          * The system call will be restarted with the same arguments
 996                          * if SA_RESTART is set; otherwise, it will fail with EINTR.
 997                          */
 998                         tprints("= ? ERESTARTSYS (To be restarted if SA_RESTART is set)");
 999                         break;
1000                 case ERESTARTNOINTR:
1001                         /* Rare. For example, fork() returns this if interrupted.
1002                          * SA_RESTART is ignored (assumed set): the restart is unconditional.
1003                          */
1004                         tprints("= ? ERESTARTNOINTR (To be restarted)");
1005                         break;
1006                 case ERESTARTNOHAND:
1007                         /* pause(), rt_sigsuspend() etc use this code.
1008                          * SA_RESTART is ignored (assumed not set):
1009                          * syscall won't restart (will return EINTR instead)
1010                          * even after signal with SA_RESTART set. However,
1011                          * after SIG_IGN or SIG_DFL signal it will restart
1012                          * (thus the name "restart only if has no handler").
1013                          */
1014                         tprints("= ? ERESTARTNOHAND (To be restarted if no handler)");
1015                         break;
1016                 case ERESTART_RESTARTBLOCK:
1017                         /* Syscalls like nanosleep(), poll() which can't be
1018                          * restarted with their original arguments use this
1019                          * code. Kernel will execute restart_syscall() instead,
1020                          * which changes arguments before restarting syscall.
1021                          * SA_RESTART is ignored (assumed not set) similarly
1022                          * to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
1023                          * since restart data is saved in "restart block"
1024                          * in task struct, and if signal handler uses a syscall
1025                          * which in turn saves another such restart block,
1026                          * old data is lost and restart becomes impossible)
1027                          */
1028                         tprints("= ? ERESTART_RESTARTBLOCK (Interrupted by signal)");
1029                         break;
1030                 default:
1031                         if (u_error < nerrnos && errnoent[u_error])
1032                                 tprintf("= -1 %s (%s)", errnoent[u_error],
1033                                         strerror(u_error));
1034                         else
1035                                 tprintf("= -1 ERRNO_%lu (%s)", u_error,
1036                                         strerror(u_error));
1037                         break;
1038                 }
1039                 if ((sys_res & RVAL_STR) && tcp->auxstr)
1040                         tprintf(" (%s)", tcp->auxstr);
1041         }
1042         else {
1043                 if (sys_res & RVAL_NONE)
1044                         tprints("= ?");
1045                 else {
1046                         switch (sys_res & RVAL_MASK) {
1047                         case RVAL_HEX:
1048 #if SUPPORTED_PERSONALITIES > 1
1049                                 if (current_wordsize < sizeof(long))
1050                                         tprintf("= %#x",
1051                                                 (unsigned int) tcp->u_rval);
1052                                 else
1053 #endif
1054                                         tprintf("= %#lx", tcp->u_rval);
1055                                 break;
1056                         case RVAL_OCTAL:
1057                                 tprints("= ");
1058                                 print_numeric_long_umask(tcp->u_rval);
1059                                 break;
1060                         case RVAL_UDECIMAL:
1061 #if SUPPORTED_PERSONALITIES > 1
1062                                 if (current_wordsize < sizeof(long))
1063                                         tprintf("= %u",
1064                                                 (unsigned int) tcp->u_rval);
1065                                 else
1066 #endif
1067                                         tprintf("= %lu", tcp->u_rval);
1068                                 break;
1069                         case RVAL_DECIMAL:
1070                                 tprintf("= %ld", tcp->u_rval);
1071                                 break;
1072                         case RVAL_FD:
1073                                 if (show_fd_path) {
1074                                         tprints("= ");
1075                                         printfd(tcp, tcp->u_rval);
1076                                 }
1077                                 else
1078                                         tprintf("= %ld", tcp->u_rval);
1079                                 break;
1080 #if HAVE_STRUCT_TCB_EXT_ARG
1081                         /*
1082                         case RVAL_LHEX:
1083                                 tprintf("= %#llx", tcp->u_lrval);
1084                                 break;
1085                         case RVAL_LOCTAL:
1086                                 tprintf("= %#llo", tcp->u_lrval);
1087                                 break;
1088                         */
1089                         case RVAL_LUDECIMAL:
1090                                 tprintf("= %llu", tcp->u_lrval);
1091                                 break;
1092                         /*
1093                         case RVAL_LDECIMAL:
1094                                 tprintf("= %lld", tcp->u_lrval);
1095                                 break;
1096                         */
1097 #endif /* HAVE_STRUCT_TCB_EXT_ARG */
1098                         default:
1099                                 error_msg("invalid rval format");
1100                                 break;
1101                         }
1102                 }
1103                 if ((sys_res & RVAL_STR) && tcp->auxstr)
1104                         tprintf(" (%s)", tcp->auxstr);
1105         }
1106         if (Tflag) {
1107                 tv_sub(&tv, &tv, &tcp->etime);
1108                 tprintf(" <%ld.%06ld>",
1109                         (long) tv.tv_sec, (long) tv.tv_usec);
1110         }
1111         tprints("\n");
1112         dumpio(tcp);
1113         line_ended();
1114
1115 #ifdef USE_LIBUNWIND
1116         if (stack_trace_enabled)
1117                 unwind_print_stacktrace(tcp);
1118 #endif
1119
1120  ret:
1121         tcp->flags &= ~TCB_INSYSCALL;
1122         tcp->sys_func_rval = 0;
1123         free_tcb_priv_data(tcp);
1124         return 0;
1125 }
1126
1127 int
1128 trace_syscall(struct tcb *tcp)
1129 {
1130         return exiting(tcp) ?
1131                 trace_syscall_exiting(tcp) : trace_syscall_entering(tcp);
1132 }
1133
1134 bool
1135 is_erestart(struct tcb *tcp)
1136 {
1137         switch (tcp->u_error) {
1138                 case ERESTARTSYS:
1139                 case ERESTARTNOINTR:
1140                 case ERESTARTNOHAND:
1141                 case ERESTART_RESTARTBLOCK:
1142                         return true;
1143                 default:
1144                         return false;
1145         }
1146 }
1147
1148 static unsigned long saved_u_error;
1149
1150 void
1151 temporarily_clear_syserror(struct tcb *tcp)
1152 {
1153         saved_u_error = tcp->u_error;
1154         tcp->u_error = 0;
1155 }
1156
1157 void
1158 restore_cleared_syserror(struct tcb *tcp)
1159 {
1160         tcp->u_error = saved_u_error;
1161 }
1162
1163 #include "kernel_types.h"
1164
1165 /*
1166  * Check the syscall return value register value for whether it is
1167  * a negated errno code indicating an error, or a success return value.
1168  */
1169 static inline bool
1170 is_negated_errno(kernel_ulong_t val)
1171 {
1172         /* Linux kernel defines MAX_ERRNO to 4095. */
1173         kernel_ulong_t max = -(kernel_long_t) 4095;
1174
1175 #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
1176         if (current_wordsize < sizeof(val)) {
1177                 val = (uint32_t) val;
1178                 max = (uint32_t) max;
1179         }
1180 #elif defined X32
1181         /*
1182          * current_wordsize is 4 even in personality 0 (native X32)
1183          * but truncation _must not_ be done in it.
1184          * can't check current_wordsize here!
1185          */
1186         if (current_personality != 0) {
1187                 val = (uint32_t) val;
1188                 max = (uint32_t) max;
1189         }
1190 #endif
1191
1192         return val >= max;
1193 }
1194
1195 #include "arch_regs.c"
1196
1197 #ifdef HAVE_GETRVAL2
1198 # include "arch_getrval2.c"
1199 #endif
1200
1201 void
1202 print_pc(struct tcb *tcp)
1203 {
1204 #if defined ARCH_PC_REG
1205 # define ARCH_GET_PC 0
1206 #elif defined ARCH_PC_PEEK_ADDR
1207         long pc;
1208 # define ARCH_PC_REG pc
1209 # define ARCH_GET_PC upeek(tcp->pid, ARCH_PC_PEEK_ADDR, &pc)
1210 #else
1211 # error Neither ARCH_PC_REG nor ARCH_PC_PEEK_ADDR is defined
1212 #endif
1213         if (get_regs_error || ARCH_GET_PC)
1214                 tprints(current_wordsize == 4 ? "[????????] "
1215                                               : "[????????????????] ");
1216         else
1217                 tprintf(current_wordsize == 4 ? "[%08lx] " : "[%016lx] ",
1218                         (unsigned long) ARCH_PC_REG);
1219 }
1220
1221 #if defined ARCH_REGS_FOR_GETREGSET
1222 static long
1223 get_regset(pid_t pid)
1224 {
1225 # ifdef ARCH_IOVEC_FOR_GETREGSET
1226         /* variable iovec */
1227         ARCH_IOVEC_FOR_GETREGSET.iov_len = sizeof(ARCH_REGS_FOR_GETREGSET);
1228         return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS,
1229                       &ARCH_IOVEC_FOR_GETREGSET);
1230 # else
1231         /* constant iovec */
1232         static struct iovec io = {
1233                 .iov_base = &ARCH_REGS_FOR_GETREGSET,
1234                 .iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
1235         };
1236         return ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &io);
1237
1238 # endif
1239 }
1240 #endif /* ARCH_REGS_FOR_GETREGSET */
1241
1242 void
1243 get_regs(pid_t pid)
1244 {
1245 #undef USE_GET_SYSCALL_RESULT_REGS
1246 #ifdef ARCH_REGS_FOR_GETREGSET
1247 # ifdef X86_64
1248         /* Try PTRACE_GETREGSET first, fallback to PTRACE_GETREGS. */
1249         static int getregset_support;
1250
1251         if (getregset_support >= 0) {
1252                 get_regs_error = get_regset(pid);
1253                 if (getregset_support > 0)
1254                         return;
1255                 if (get_regs_error >= 0) {
1256                         getregset_support = 1;
1257                         return;
1258                 }
1259                 if (errno == EPERM || errno == ESRCH)
1260                         return;
1261                 getregset_support = -1;
1262         }
1263         get_regs_error = getregs_old(pid);
1264 # else /* !X86_64 */
1265         /* Assume that PTRACE_GETREGSET works. */
1266         get_regs_error = get_regset(pid);
1267 # endif
1268 #elif defined ARCH_REGS_FOR_GETREGS
1269 # if defined SPARC || defined SPARC64
1270         /* SPARC systems have the meaning of data and addr reversed */
1271         get_regs_error =
1272                 ptrace(PTRACE_GETREGS, pid, (void *) &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 struct sysent_buf {
1296         struct tcb *tcp;
1297         struct_sysent ent;
1298         char buf[sizeof("syscall_%lu") + sizeof(long) * 3];
1299 };
1300
1301 static void
1302 free_sysent_buf(void *ptr)
1303 {
1304         struct sysent_buf *s = ptr;
1305         s->tcp->s_prev_ent = s->tcp->s_ent = NULL;
1306         free(ptr);
1307 }
1308
1309 /*
1310  * Returns:
1311  * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
1312  * 1: ok, continue in trace_syscall_entering().
1313  * other: error, trace_syscall_entering() should print error indicator
1314  *    ("????" etc) and bail out.
1315  */
1316 int
1317 get_scno(struct tcb *tcp)
1318 {
1319         if (get_regs_error)
1320                 return -1;
1321
1322         int rc = arch_get_scno(tcp);
1323         if (rc != 1)
1324                 return rc;
1325
1326         if (SCNO_IS_VALID(tcp->scno)) {
1327                 tcp->s_ent = &sysent[tcp->scno];
1328                 tcp->qual_flg = qual_flags[tcp->scno];
1329         } else {
1330                 struct sysent_buf *s = xcalloc(1, sizeof(*s));
1331
1332                 s->tcp = tcp;
1333                 s->ent.nargs = MAX_ARGS;
1334                 s->ent.sen = SEN_printargs;
1335                 s->ent.sys_func = printargs;
1336                 s->ent.sys_name = s->buf;
1337                 sprintf(s->buf, "syscall_%lu", shuffle_scno(tcp->scno));
1338
1339                 tcp->s_ent = &s->ent;
1340                 tcp->qual_flg = QUAL_RAW | DEFAULT_QUAL_FLAGS;
1341
1342                 set_tcb_priv_data(tcp, s, free_sysent_buf);
1343
1344                 if (debug_flag)
1345                         error_msg("pid %d invalid syscall %ld", tcp->pid, tcp->scno);
1346         }
1347         return 1;
1348 }
1349
1350 #ifdef USE_GET_SYSCALL_RESULT_REGS
1351 static int get_syscall_result_regs(struct tcb *);
1352 #endif
1353
1354 /* Returns:
1355  * 1: ok, continue in trace_syscall_exiting().
1356  * -1: error, trace_syscall_exiting() should print error indicator
1357  *    ("????" etc) and bail out.
1358  */
1359 static int
1360 get_syscall_result(struct tcb *tcp)
1361 {
1362 #ifdef USE_GET_SYSCALL_RESULT_REGS
1363         if (get_syscall_result_regs(tcp))
1364                 return -1;
1365 #endif
1366         tcp->u_error = 0;
1367         get_error(tcp, !(tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS));
1368
1369         return 1;
1370 }
1371
1372 #include "get_scno.c"
1373 #include "get_syscall_args.c"
1374 #ifdef USE_GET_SYSCALL_RESULT_REGS
1375 # include "get_syscall_result.c"
1376 #endif
1377 #include "get_error.c"
1378 #if defined X86_64 || defined POWERPC
1379 # include "getregs_old.c"
1380 #endif