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

   1 /*
   2  * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
   3  * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   4  * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
   5  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   6  * Copyright (c) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   7  *                     Linux for s390 port by D.J. Barrow
   8  *                    <barrow_dj@mail.yahoo.com,djbarrow@de.ibm.com>
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include "defs.h"
  35 #include <sys/user.h>
  36 #include <sys/param.h>
  37
  38 #ifdef HAVE_SYS_REG_H
  39 # include <sys/reg.h>
  40 #elif defined(HAVE_LINUX_PTRACE_H)
  41 # undef PTRACE_SYSCALL
  42 # ifdef HAVE_STRUCT_IA64_FPREG
  43 #  define ia64_fpreg XXX_ia64_fpreg
  44 # endif
  45 # ifdef HAVE_STRUCT_PT_ALL_USER_REGS
  46 #  define pt_all_user_regs XXX_pt_all_user_regs
  47 # endif
  48 # ifdef HAVE_STRUCT_PTRACE_PEEKSIGINFO_ARGS
  49 #  define ptrace_peeksiginfo_args XXX_ptrace_peeksiginfo_args
  50 # endif
  51 # include <linux/ptrace.h>
  52 # undef ptrace_peeksiginfo_args
  53 # undef ia64_fpreg
  54 # undef pt_all_user_regs
  55 #endif
  56
  57 #if defined(SPARC64)
  58 # undef PTRACE_GETREGS
  59 # define PTRACE_GETREGS PTRACE_GETREGS64
  60 # undef PTRACE_SETREGS
  61 # define PTRACE_SETREGS PTRACE_SETREGS64
  62 #endif
  63
  64 #if defined(IA64)
  65 # include <asm/ptrace_offsets.h>
  66 # include <asm/rse.h>
  67 #endif
  68
  69 /* for struct iovec */
  70 #include <sys/uio.h>
  71 /* for NT_PRSTATUS */
  72 #ifdef HAVE_ELF_H
  73 # include <elf.h>
  74 #endif
  75
  76 #if defined(AARCH64)
  77 # include <asm/ptrace.h>
  78 #endif
  79
  80 #if defined(XTENSA)
  81 # include <asm/ptrace.h>
  82 #endif
  83
  84 #ifndef NSIG
  85 # warning: NSIG is not defined, using 32
  86 # define NSIG 32
  87 #endif
  88
  89 #include "syscall.h"
  90
  91 /* Define these shorthand notations to simplify the syscallent files. */
  92 #define TD TRACE_DESC
  93 #define TF TRACE_FILE
  94 #define TI TRACE_IPC
  95 #define TN TRACE_NETWORK
  96 #define TP TRACE_PROCESS
  97 #define TS TRACE_SIGNAL
  98 #define TM TRACE_MEMORY
  99 #define NF SYSCALL_NEVER_FAILS
 100 #define MA MAX_ARGS
 101
 102 const struct_sysent sysent0[] = {
 103 #include "syscallent.h"
 104 };
 105
 106 #if SUPPORTED_PERSONALITIES > 1
 107 static const struct_sysent sysent1[] = {
 108 # include "syscallent1.h"
 109 };
 110 #endif
 111
 112 #if SUPPORTED_PERSONALITIES > 2
 113 static const struct_sysent sysent2[] = {
 114 # include "syscallent2.h"
 115 };
 116 #endif
 117
 118 /* Now undef them since short defines cause wicked namespace pollution. */
 119 #undef TD
 120 #undef TF
 121 #undef TI
 122 #undef TN
 123 #undef TP
 124 #undef TS
 125 #undef TM
 126 #undef NF
 127 #undef MA
 128
 129 /*
 130  * `ioctlent.h' may be generated from `ioctlent.raw' by the auxiliary
 131  * program `ioctlsort', such that the list is sorted by the `code' field.
 132  * This has the side-effect of resolving the _IO.. macros into
 133  * plain integers, eliminating the need to include here everything
 134  * in "/usr/include".
 135  */
 136
 137 const char *const errnoent0[] = {
 138 #include "errnoent.h"
 139 };
 140 const char *const signalent0[] = {
 141 #include "signalent.h"
 142 };
 143 const struct_ioctlent ioctlent0[] = {
 144 #include "ioctlent.h"
 145 };
 146
 147 #if SUPPORTED_PERSONALITIES > 1
 148 static const char *const errnoent1[] = {
 149 # include "errnoent1.h"
 150 };
 151 static const char *const signalent1[] = {
 152 # include "signalent1.h"
 153 };
 154 static const struct_ioctlent ioctlent1[] = {
 155 # include "ioctlent1.h"
 156 };
 157 #endif
 158
 159 #if SUPPORTED_PERSONALITIES > 2
 160 static const char *const errnoent2[] = {
 161 # include "errnoent2.h"
 162 };
 163 static const char *const signalent2[] = {
 164 # include "signalent2.h"
 165 };
 166 static const struct_ioctlent ioctlent2[] = {
 167 # include "ioctlent2.h"
 168 };
 169 #endif
 170
 171 enum {
 172         nsyscalls0 = ARRAY_SIZE(sysent0)
 173 #if SUPPORTED_PERSONALITIES > 1
 174         , nsyscalls1 = ARRAY_SIZE(sysent1)
 175 # if SUPPORTED_PERSONALITIES > 2
 176         , nsyscalls2 = ARRAY_SIZE(sysent2)
 177 # endif
 178 #endif
 179 };
 180
 181 enum {
 182         nerrnos0 = ARRAY_SIZE(errnoent0)
 183 #if SUPPORTED_PERSONALITIES > 1
 184         , nerrnos1 = ARRAY_SIZE(errnoent1)
 185 # if SUPPORTED_PERSONALITIES > 2
 186         , nerrnos2 = ARRAY_SIZE(errnoent2)
 187 # endif
 188 #endif
 189 };
 190
 191 enum {
 192         nsignals0 = ARRAY_SIZE(signalent0)
 193 #if SUPPORTED_PERSONALITIES > 1
 194         , nsignals1 = ARRAY_SIZE(signalent1)
 195 # if SUPPORTED_PERSONALITIES > 2
 196         , nsignals2 = ARRAY_SIZE(signalent2)
 197 # endif
 198 #endif
 199 };
 200
 201 enum {
 202         nioctlents0 = ARRAY_SIZE(ioctlent0)
 203 #if SUPPORTED_PERSONALITIES > 1
 204         , nioctlents1 = ARRAY_SIZE(ioctlent1)
 205 # if SUPPORTED_PERSONALITIES > 2
 206         , nioctlents2 = ARRAY_SIZE(ioctlent2)
 207 # endif
 208 #endif
 209 };
 210
 211 #if SUPPORTED_PERSONALITIES > 1
 212 const struct_sysent *sysent = sysent0;
 213 const char *const *errnoent = errnoent0;
 214 const char *const *signalent = signalent0;
 215 const struct_ioctlent *ioctlent = ioctlent0;
 216 #endif
 217 unsigned nsyscalls = nsyscalls0;
 218 unsigned nerrnos = nerrnos0;
 219 unsigned nsignals = nsignals0;
 220 unsigned nioctlents = nioctlents0;
 221
 222 unsigned num_quals;
 223 qualbits_t *qual_vec[SUPPORTED_PERSONALITIES];
 224
 225 static const unsigned nsyscall_vec[SUPPORTED_PERSONALITIES] = {
 226         nsyscalls0,
 227 #if SUPPORTED_PERSONALITIES > 1
 228         nsyscalls1,
 229 #endif
 230 #if SUPPORTED_PERSONALITIES > 2
 231         nsyscalls2,
 232 #endif
 233 };
 234 static const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
 235         sysent0,
 236 #if SUPPORTED_PERSONALITIES > 1
 237         sysent1,
 238 #endif
 239 #if SUPPORTED_PERSONALITIES > 2
 240         sysent2,
 241 #endif
 242 };
 243
 244 enum {
 245         MAX_NSYSCALLS1 = (nsyscalls0
 246 #if SUPPORTED_PERSONALITIES > 1
 247                         > nsyscalls1 ? nsyscalls0 : nsyscalls1
 248 #endif
 249                         ),
 250         MAX_NSYSCALLS2 = (MAX_NSYSCALLS1
 251 #if SUPPORTED_PERSONALITIES > 2
 252                         > nsyscalls2 ? MAX_NSYSCALLS1 : nsyscalls2
 253 #endif
 254                         ),
 255         MAX_NSYSCALLS = MAX_NSYSCALLS2,
 256         /* We are ready for arches with up to 255 signals,
 257          * even though the largest known signo is on MIPS and it is 128.
 258          * The number of existing syscalls on all arches is
 259          * larger that 255 anyway, so it is just a pedantic matter.
 260          */
 261         MIN_QUALS = MAX_NSYSCALLS > 255 ? MAX_NSYSCALLS : 255
 262 };
 263
 264 #if SUPPORTED_PERSONALITIES > 1
 265 unsigned current_personality;
 266
 267 # ifndef current_wordsize
 268 unsigned current_wordsize;
 269 static const int personality_wordsize[SUPPORTED_PERSONALITIES] = {
 270         PERSONALITY0_WORDSIZE,
 271         PERSONALITY1_WORDSIZE,
 272 # if SUPPORTED_PERSONALITIES > 2
 273         PERSONALITY2_WORDSIZE,
 274 # endif
 275 };
 276 # endif
 277
 278 void
 279 set_personality(int personality)
 280 {
 281         nsyscalls = nsyscall_vec[personality];
 282         sysent = sysent_vec[personality];
 283
 284         switch (personality) {
 285         case 0:
 286                 errnoent = errnoent0;
 287                 nerrnos = nerrnos0;
 288                 ioctlent = ioctlent0;
 289                 nioctlents = nioctlents0;
 290                 signalent = signalent0;
 291                 nsignals = nsignals0;
 292                 break;
 293
 294         case 1:
 295                 errnoent = errnoent1;
 296                 nerrnos = nerrnos1;
 297                 ioctlent = ioctlent1;
 298                 nioctlents = nioctlents1;
 299                 signalent = signalent1;
 300                 nsignals = nsignals1;
 301                 break;
 302
 303 # if SUPPORTED_PERSONALITIES > 2
 304         case 2:
 305                 errnoent = errnoent2;
 306                 nerrnos = nerrnos2;
 307                 ioctlent = ioctlent2;
 308                 nioctlents = nioctlents2;
 309                 signalent = signalent2;
 310                 nsignals = nsignals2;
 311                 break;
 312 # endif
 313         }
 314
 315         current_personality = personality;
 316 # ifndef current_wordsize
 317         current_wordsize = personality_wordsize[personality];
 318 # endif
 319 }
 320
 321 static void
 322 update_personality(struct tcb *tcp, int personality)
 323 {
 324         if (personality == current_personality)
 325                 return;
 326         set_personality(personality);
 327
 328         if (personality == tcp->currpers)
 329                 return;
 330         tcp->currpers = personality;
 331
 332 # if defined(POWERPC64)
 333         if (!qflag) {
 334                 static const char *const names[] = {"64 bit", "32 bit"};
 335                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 336                         tcp->pid, names[personality]);
 337         }
 338 # elif defined(X86_64)
 339         if (!qflag) {
 340                 static const char *const names[] = {"64 bit", "32 bit", "x32"};
 341                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 342                         tcp->pid, names[personality]);
 343         }
 344 # elif defined(X32)
 345         if (!qflag) {
 346                 static const char *const names[] = {"x32", "32 bit"};
 347                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 348                         tcp->pid, names[personality]);
 349         }
 350 # elif defined(AARCH64)
 351         if (!qflag) {
 352                 static const char *const names[] = {"32-bit", "AArch64"};
 353                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 354                         tcp->pid, names[personality]);
 355         }
 356 # elif defined(TILE)
 357         if (!qflag) {
 358                 static const char *const names[] = {"64-bit", "32-bit"};
 359                 fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
 360                         tcp->pid, names[personality]);
 361         }
 362 # endif
 363 }
 364 #endif
 365
 366 static int qual_syscall(), qual_signal(), qual_desc();
 367
 368 static const struct qual_options {
 369         int bitflag;
 370         const char *option_name;
 371         int (*qualify)(const char *, int, int);
 372         const char *argument_name;
 373 } qual_options[] = {
 374         { QUAL_TRACE,   "trace",        qual_syscall,   "system call"   },
 375         { QUAL_TRACE,   "t",            qual_syscall,   "system call"   },
 376         { QUAL_ABBREV,  "abbrev",       qual_syscall,   "system call"   },
 377         { QUAL_ABBREV,  "a",            qual_syscall,   "system call"   },
 378         { QUAL_VERBOSE, "verbose",      qual_syscall,   "system call"   },
 379         { QUAL_VERBOSE, "v",            qual_syscall,   "system call"   },
 380         { QUAL_RAW,     "raw",          qual_syscall,   "system call"   },
 381         { QUAL_RAW,     "x",            qual_syscall,   "system call"   },
 382         { QUAL_SIGNAL,  "signal",       qual_signal,    "signal"        },
 383         { QUAL_SIGNAL,  "signals",      qual_signal,    "signal"        },
 384         { QUAL_SIGNAL,  "s",            qual_signal,    "signal"        },
 385         { QUAL_READ,    "read",         qual_desc,      "descriptor"    },
 386         { QUAL_READ,    "reads",        qual_desc,      "descriptor"    },
 387         { QUAL_READ,    "r",            qual_desc,      "descriptor"    },
 388         { QUAL_WRITE,   "write",        qual_desc,      "descriptor"    },
 389         { QUAL_WRITE,   "writes",       qual_desc,      "descriptor"    },
 390         { QUAL_WRITE,   "w",            qual_desc,      "descriptor"    },
 391         { 0,            NULL,           NULL,           NULL            },
 392 };
 393
 394 static void
 395 reallocate_qual(int n)
 396 {
 397         unsigned p;
 398         qualbits_t *qp;
 399         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 400                 qp = qual_vec[p] = realloc(qual_vec[p], n * sizeof(qualbits_t));
 401                 if (!qp)
 402                         die_out_of_memory();
 403                 memset(&qp[num_quals], 0, (n - num_quals) * sizeof(qualbits_t));
 404         }
 405         num_quals = n;
 406 }
 407
 408 static void
 409 qualify_one(int n, int bitflag, int not, int pers)
 410 {
 411         unsigned p;
 412
 413         if (num_quals <= n)
 414                 reallocate_qual(n + 1);
 415
 416         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 417                 if (pers == p || pers < 0) {
 418                         if (not)
 419                                 qual_vec[p][n] &= ~bitflag;
 420                         else
 421                                 qual_vec[p][n] |= bitflag;
 422                 }
 423         }
 424 }
 425
 426 static int
 427 qual_syscall(const char *s, int bitflag, int not)
 428 {
 429         unsigned p;
 430         unsigned i;
 431         int rc = -1;
 432
 433         if (*s >= '0' && *s <= '9') {
 434                 i = string_to_uint(s);
 435                 if (i >= MAX_NSYSCALLS)
 436                         return -1;
 437                 qualify_one(i, bitflag, not, -1);
 438                 return 0;
 439         }
 440
 441         for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
 442                 for (i = 0; i < nsyscall_vec[p]; i++) {
 443                         if (sysent_vec[p][i].sys_name
 444                          && strcmp(s, sysent_vec[p][i].sys_name) == 0
 445                         ) {
 446                                 qualify_one(i, bitflag, not, p);
 447                                 rc = 0;
 448                         }
 449                 }
 450         }
 451
 452         return rc;
 453 }
 454
 455 static int
 456 qual_signal(const char *s, int bitflag, int not)
 457 {
 458         int i;
 459
 460         if (*s >= '0' && *s <= '9') {
 461                 int signo = string_to_uint(s);
 462                 if (signo < 0 || signo > 255)
 463                         return -1;
 464                 qualify_one(signo, bitflag, not, -1);
 465                 return 0;
 466         }
 467         if (strncasecmp(s, "SIG", 3) == 0)
 468                 s += 3;
 469         for (i = 0; i <= NSIG; i++) {
 470                 if (strcasecmp(s, signame(i) + 3) == 0) {
 471                         qualify_one(i, bitflag, not, -1);
 472                         return 0;
 473                 }
 474         }
 475         return -1;
 476 }
 477
 478 static int
 479 qual_desc(const char *s, int bitflag, int not)
 480 {
 481         if (*s >= '0' && *s <= '9') {
 482                 int desc = string_to_uint(s);
 483                 if (desc < 0 || desc > 0x7fff) /* paranoia */
 484                         return -1;
 485                 qualify_one(desc, bitflag, not, -1);
 486                 return 0;
 487         }
 488         return -1;
 489 }
 490
 491 static int
 492 lookup_class(const char *s)
 493 {
 494         if (strcmp(s, "file") == 0)
 495                 return TRACE_FILE;
 496         if (strcmp(s, "ipc") == 0)
 497                 return TRACE_IPC;
 498         if (strcmp(s, "network") == 0)
 499                 return TRACE_NETWORK;
 500         if (strcmp(s, "process") == 0)
 501                 return TRACE_PROCESS;
 502         if (strcmp(s, "signal") == 0)
 503                 return TRACE_SIGNAL;
 504         if (strcmp(s, "desc") == 0)
 505                 return TRACE_DESC;
 506         if (strcmp(s, "memory") == 0)
 507                 return TRACE_MEMORY;
 508         return -1;
 509 }
 510
 511 void
 512 qualify(const char *s)
 513 {
 514         const struct qual_options *opt;
 515         int not;
 516         char *copy;
 517         const char *p;
 518         int i, n;
 519
 520         if (num_quals == 0)
 521                 reallocate_qual(MIN_QUALS);
 522
 523         opt = &qual_options[0];
 524         for (i = 0; (p = qual_options[i].option_name); i++) {
 525                 n = strlen(p);
 526                 if (strncmp(s, p, n) == 0 && s[n] == '=') {
 527                         opt = &qual_options[i];
 528                         s += n + 1;
 529                         break;
 530                 }
 531         }
 532         not = 0;
 533         if (*s == '!') {
 534                 not = 1;
 535                 s++;
 536         }
 537         if (strcmp(s, "none") == 0) {
 538                 not = 1 - not;
 539                 s = "all";
 540         }
 541         if (strcmp(s, "all") == 0) {
 542                 for (i = 0; i < num_quals; i++) {
 543                         qualify_one(i, opt->bitflag, not, -1);
 544                 }
 545                 return;
 546         }
 547         for (i = 0; i < num_quals; i++) {
 548                 qualify_one(i, opt->bitflag, !not, -1);
 549         }
 550         copy = strdup(s);
 551         if (!copy)
 552                 die_out_of_memory();
 553         for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
 554                 if (opt->bitflag == QUAL_TRACE && (n = lookup_class(p)) > 0) {
 555                         unsigned pers;
 556                         for (pers = 0; pers < SUPPORTED_PERSONALITIES; pers++) {
 557                                 for (i = 0; i < nsyscall_vec[pers]; i++)
 558                                         if (sysent_vec[pers][i].sys_flags & n)
 559                                                 qualify_one(i, opt->bitflag, not, pers);
 560                         }
 561                         continue;
 562                 }
 563                 if (opt->qualify(p, opt->bitflag, not)) {
 564                         error_msg_and_die("invalid %s '%s'",
 565                                 opt->argument_name, p);
 566                 }
 567         }
 568         free(copy);
 569         return;
 570 }
 571
 572 #ifdef SYS_socket_subcall
 573 static void
 574 decode_socket_subcall(struct tcb *tcp)
 575 {
 576         unsigned long addr;
 577         unsigned int i, n, size;
 578
 579         if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= SYS_socket_nsubcalls)
 580                 return;
 581
 582         tcp->scno = SYS_socket_subcall + tcp->u_arg[0];
 583         tcp->qual_flg = qual_flags[tcp->scno];
 584         tcp->s_ent = &sysent[tcp->scno];
 585         addr = tcp->u_arg[1];
 586         size = current_wordsize;
 587         n = tcp->s_ent->nargs;
 588         for (i = 0; i < n; ++i) {
 589                 if (size == sizeof(int)) {
 590                         unsigned int arg;
 591                         if (umove(tcp, addr, &arg) < 0)
 592                                 arg = 0;
 593                         tcp->u_arg[i] = arg;
 594                 }
 595                 else {
 596                         unsigned long arg;
 597                         if (umove(tcp, addr, &arg) < 0)
 598                                 arg = 0;
 599                         tcp->u_arg[i] = arg;
 600                 }
 601                 addr += size;
 602         }
 603 }
 604 #endif
 605
 606 #ifdef SYS_ipc_subcall
 607 static void
 608 decode_ipc_subcall(struct tcb *tcp)
 609 {
 610         unsigned int i, n;
 611
 612         if (tcp->u_arg[0] < 0 || tcp->u_arg[0] >= SYS_ipc_nsubcalls)
 613                 return;
 614
 615         tcp->scno = SYS_ipc_subcall + tcp->u_arg[0];
 616         tcp->qual_flg = qual_flags[tcp->scno];
 617         tcp->s_ent = &sysent[tcp->scno];
 618         n = tcp->s_ent->nargs;
 619         for (i = 0; i < n; i++)
 620                 tcp->u_arg[i] = tcp->u_arg[i + 1];
 621 }
 622 #endif
 623
 624 int
 625 printargs(struct tcb *tcp)
 626 {
 627         if (entering(tcp)) {
 628                 int i;
 629                 int n = tcp->s_ent->nargs;
 630                 for (i = 0; i < n; i++)
 631                         tprintf("%s%#lx", i ? ", " : "", tcp->u_arg[i]);
 632         }
 633         return 0;
 634 }
 635
 636 int
 637 printargs_lu(struct tcb *tcp)
 638 {
 639         if (entering(tcp)) {
 640                 int i;
 641                 int n = tcp->s_ent->nargs;
 642                 for (i = 0; i < n; i++)
 643                         tprintf("%s%lu", i ? ", " : "", tcp->u_arg[i]);
 644         }
 645         return 0;
 646 }
 647
 648 int
 649 printargs_ld(struct tcb *tcp)
 650 {
 651         if (entering(tcp)) {
 652                 int i;
 653                 int n = tcp->s_ent->nargs;
 654                 for (i = 0; i < n; i++)
 655                         tprintf("%s%ld", i ? ", " : "", tcp->u_arg[i]);
 656         }
 657         return 0;
 658 }
 659
 660 #if defined(SPARC) || defined(SPARC64) || defined(IA64) || defined(SH)
 661 long
 662 getrval2(struct tcb *tcp)
 663 {
 664         long val;
 665
 666 # if defined(SPARC) || defined(SPARC64)
 667         val = sparc_regs.u_regs[U_REG_O1];
 668 # elif defined(SH)
 669         if (upeek(tcp->pid, 4*(REG_REG0+1), &val) < 0)
 670                 return -1;
 671 # elif defined(IA64)
 672         if (upeek(tcp->pid, PT_R9, &val) < 0)
 673                 return -1;
 674 # endif
 675
 676         return val;
 677 }
 678 #endif
 679
 680 #if defined(I386)
 681 static struct user_regs_struct i386_regs;
 682 /* Cast suppresses signedness warning (.esp is long, not unsigned long) */
 683 uint32_t *const i386_esp_ptr = (uint32_t*)&i386_regs.esp;
 684 # define ARCH_REGS_FOR_GETREGSET i386_regs
 685 #elif defined(X86_64) || defined(X32)
 686 /*
 687  * On i386, pt_regs and user_regs_struct are the same,
 688  * but on 64 bit x86, user_regs_struct has six more fields:
 689  * fs_base, gs_base, ds, es, fs, gs.
 690  * PTRACE_GETREGS fills them too, so struct pt_regs would overflow.
 691  */
 692 struct i386_user_regs_struct {
 693         uint32_t ebx;
 694         uint32_t ecx;
 695         uint32_t edx;
 696         uint32_t esi;
 697         uint32_t edi;
 698         uint32_t ebp;
 699         uint32_t eax;
 700         uint32_t xds;
 701         uint32_t xes;
 702         uint32_t xfs;
 703         uint32_t xgs;
 704         uint32_t orig_eax;
 705         uint32_t eip;
 706         uint32_t xcs;
 707         uint32_t eflags;
 708         uint32_t esp;
 709         uint32_t xss;
 710 };
 711 static union {
 712         struct user_regs_struct      x86_64_r;
 713         struct i386_user_regs_struct i386_r;
 714 } x86_regs_union;
 715 # define x86_64_regs x86_regs_union.x86_64_r
 716 # define i386_regs   x86_regs_union.i386_r
 717 uint32_t *const i386_esp_ptr = &i386_regs.esp;
 718 static struct iovec x86_io = {
 719         .iov_base = &x86_regs_union
 720 };
 721 #elif defined(IA64)
 722 bool ia64_ia32mode = 0; /* not static */
 723 static long ia64_r8, ia64_r10;
 724 #elif defined(POWERPC)
 725 struct pt_regs ppc_regs;
 726 #elif defined(M68K)
 727 static long m68k_d0;
 728 #elif defined(BFIN)
 729 static long bfin_r0;
 730 #elif defined(ARM)
 731 struct pt_regs arm_regs; /* not static */
 732 # define ARCH_REGS_FOR_GETREGSET arm_regs
 733 #elif defined(AARCH64)
 734 static union {
 735         struct user_pt_regs aarch64_r;
 736         struct arm_pt_regs  arm_r;
 737 } arm_regs_union;
 738 # define aarch64_regs arm_regs_union.aarch64_r
 739 # define arm_regs     arm_regs_union.arm_r
 740 static struct iovec aarch64_io = {
 741         .iov_base = &arm_regs_union
 742 };
 743 #elif defined(ALPHA)
 744 static long alpha_r0;
 745 static long alpha_a3;
 746 #elif defined(AVR32)
 747 static struct pt_regs avr32_regs;
 748 #elif defined(SPARC) || defined(SPARC64)
 749 struct pt_regs sparc_regs; /* not static */
 750 #elif defined(LINUX_MIPSN32)
 751 static long long mips_a3;
 752 static long long mips_r2;
 753 #elif defined(MIPS)
 754 static long mips_a3;
 755 static long mips_r2;
 756 #elif defined(S390) || defined(S390X)
 757 static long s390_gpr2;
 758 #elif defined(HPPA)
 759 static long hppa_r28;
 760 #elif defined(SH)
 761 static long sh_r0;
 762 #elif defined(SH64)
 763 static long sh64_r9;
 764 #elif defined(CRISV10) || defined(CRISV32)
 765 static long cris_r10;
 766 #elif defined(TILE)
 767 struct pt_regs tile_regs;
 768 #elif defined(MICROBLAZE)
 769 static long microblaze_r3;
 770 #elif defined(OR1K)
 771 static struct user_regs_struct or1k_regs;
 772 # define ARCH_REGS_FOR_GETREGSET or1k_regs
 773 #elif defined(METAG)
 774 static struct user_gp_regs metag_regs;
 775 # define ARCH_REGS_FOR_GETREGSET metag_regs
 776 #elif defined(XTENSA)
 777 static long xtensa_a2;
 778 # elif defined(ARC)
 779 static struct user_regs_struct arc_regs;
 780 # define ARCH_REGS_FOR_GETREGSET arc_regs
 781 #endif
 782
 783 void
 784 print_pc(struct tcb *tcp)
 785 {
 786 #define PRINTBADPC tprintf(sizeof(long) == 4 ? "[????????] " : \
 787                            sizeof(long) == 8 ? "[????????????????] " : \
 788                            NULL /* crash */)
 789         if (get_regs_error) {
 790                 PRINTBADPC;
 791                 return;
 792         }
 793 #if defined(I386)
 794         tprintf("[%08lx] ", i386_regs.eip);
 795 #elif defined(S390) || defined(S390X)
 796         long psw;
 797         if (upeek(tcp->pid, PT_PSWADDR, &psw) < 0) {
 798                 PRINTBADPC;
 799                 return;
 800         }
 801 # ifdef S390
 802         tprintf("[%08lx] ", psw);
 803 # elif S390X
 804         tprintf("[%016lx] ", psw);
 805 # endif
 806 #elif defined(X86_64) || defined(X32)
 807         if (x86_io.iov_len == sizeof(i386_regs)) {
 808                 tprintf("[%08x] ", (unsigned) i386_regs.eip);
 809         } else {
 810 # if defined(X86_64)
 811                 tprintf("[%016lx] ", (unsigned long) x86_64_regs.rip);
 812 # elif defined(X32)
 813                 /* Note: this truncates 64-bit rip to 32 bits */
 814                 tprintf("[%08lx] ", (unsigned long) x86_64_regs.rip);
 815 # endif
 816         }
 817 #elif defined(IA64)
 818         long ip;
 819         if (upeek(tcp->pid, PT_B0, &ip) < 0) {
 820                 PRINTBADPC;
 821                 return;
 822         }
 823         tprintf("[%08lx] ", ip);
 824 #elif defined(POWERPC)
 825         long pc = ppc_regs.nip;
 826 # ifdef POWERPC64
 827         tprintf("[%016lx] ", pc);
 828 # else
 829         tprintf("[%08lx] ", pc);
 830 # endif
 831 #elif defined(M68K)
 832         long pc;
 833         if (upeek(tcp->pid, 4*PT_PC, &pc) < 0) {
 834                 tprints("[????????] ");
 835                 return;
 836         }
 837         tprintf("[%08lx] ", pc);
 838 #elif defined(ALPHA)
 839         long pc;
 840         if (upeek(tcp->pid, REG_PC, &pc) < 0) {
 841                 tprints("[????????????????] ");
 842                 return;
 843         }
 844         tprintf("[%08lx] ", pc);
 845 #elif defined(SPARC)
 846         tprintf("[%08lx] ", sparc_regs.pc);
 847 #elif defined(SPARC64)
 848         tprintf("[%08lx] ", sparc_regs.tpc);
 849 #elif defined(HPPA)
 850         long pc;
 851         if (upeek(tcp->pid, PT_IAOQ0, &pc) < 0) {
 852                 tprints("[????????] ");
 853                 return;
 854         }
 855         tprintf("[%08lx] ", pc);
 856 #elif defined(MIPS)
 857         long pc;
 858         if (upeek(tcp->pid, REG_EPC, &pc) < 0) {
 859                 tprints("[????????] ");
 860                 return;
 861         }
 862         tprintf("[%08lx] ", pc);
 863 #elif defined(SH)
 864         long pc;
 865         if (upeek(tcp->pid, 4*REG_PC, &pc) < 0) {
 866                 tprints("[????????] ");
 867                 return;
 868         }
 869         tprintf("[%08lx] ", pc);
 870 #elif defined(SH64)
 871         long pc;
 872         if (upeek(tcp->pid, REG_PC, &pc) < 0) {
 873                 tprints("[????????????????] ");
 874                 return;
 875         }
 876         tprintf("[%08lx] ", pc);
 877 #elif defined(ARM)
 878         tprintf("[%08lx] ", arm_regs.ARM_pc);
 879 #elif defined(AARCH64)
 880         /* tprintf("[%016lx] ", aarch64_regs.regs[???]); */
 881 #elif defined(AVR32)
 882         tprintf("[%08lx] ", avr32_regs.pc);
 883 #elif defined(BFIN)
 884         long pc;
 885         if (upeek(tcp->pid, PT_PC, &pc) < 0) {
 886                 PRINTBADPC;
 887                 return;
 888         }
 889         tprintf("[%08lx] ", pc);
 890 #elif defined(CRISV10)
 891         long pc;
 892         if (upeek(tcp->pid, 4*PT_IRP, &pc) < 0) {
 893                 PRINTBADPC;
 894                 return;
 895         }
 896         tprintf("[%08lx] ", pc);
 897 #elif defined(CRISV32)
 898         long pc;
 899         if (upeek(tcp->pid, 4*PT_ERP, &pc) < 0) {
 900                 PRINTBADPC;
 901                 return;
 902         }
 903         tprintf("[%08lx] ", pc);
 904 #elif defined(TILE)
 905 # ifdef _LP64
 906         tprintf("[%016lx] ", (unsigned long) tile_regs.pc);
 907 # else
 908         tprintf("[%08lx] ", (unsigned long) tile_regs.pc);
 909 # endif
 910 #elif defined(OR1K)
 911         tprintf("[%08lx] ", or1k_regs.pc);
 912 #elif defined(METAG)
 913         tprintf("[%08lx] ", metag_regs.pc);
 914 #elif defined(XTENSA)
 915         long pc;
 916         if (upeek(tcp->pid, REG_PC, &pc) < 0) {
 917                 PRINTBADPC;
 918                 return;
 919         }
 920         tprintf("[%08lx] ", pc);
 921 #elif defined(ARC)
 922         tprintf("[%08lx] ", arc_regs.efa);
 923 #endif /* architecture */
 924 }
 925
 926 /* Shuffle syscall numbers so that we don't have huge gaps in syscall table.
 927  * The shuffling should be reversible: shuffle_scno(shuffle_scno(n)) == n.
 928  */
 929 #if defined(ARM) || defined(AARCH64) /* So far only 32-bit ARM needs this */
 930 static long
 931 shuffle_scno(unsigned long scno)
 932 {
 933         if (scno <= ARM_LAST_ORDINARY_SYSCALL)
 934                 return scno;
 935
 936         /* __ARM_NR_cmpxchg? Swap with LAST_ORDINARY+1 */
 937         if (scno == 0x000ffff0)
 938                 return ARM_LAST_ORDINARY_SYSCALL+1;
 939         if (scno == ARM_LAST_ORDINARY_SYSCALL+1)
 940                 return 0x000ffff0;
 941
 942         /* Is it ARM specific syscall?
 943          * Swap with [LAST_ORDINARY+2, LAST_ORDINARY+2 + LAST_SPECIAL] range.
 944          */
 945         if (scno >= 0x000f0000
 946          && scno <= 0x000f0000 + ARM_LAST_SPECIAL_SYSCALL
 947         ) {
 948                 return scno - 0x000f0000 + (ARM_LAST_ORDINARY_SYSCALL+2);
 949         }
 950         if (/* scno >= ARM_LAST_ORDINARY_SYSCALL+2 - always true */ 1
 951          && scno <= (ARM_LAST_ORDINARY_SYSCALL+2) + ARM_LAST_SPECIAL_SYSCALL
 952         ) {
 953                 return scno + 0x000f0000 - (ARM_LAST_ORDINARY_SYSCALL+2);
 954         }
 955
 956         return scno;
 957 }
 958 #else
 959 # define shuffle_scno(scno) ((long)(scno))
 960 #endif
 961
 962 static char*
 963 undefined_scno_name(struct tcb *tcp)
 964 {
 965         static char buf[sizeof("syscall_%lu") + sizeof(long)*3];
 966
 967         sprintf(buf, "syscall_%lu", shuffle_scno(tcp->scno));
 968         return buf;
 969 }
 970
 971 #ifdef POWERPC
 972 /*
 973  * PTRACE_GETREGS was added to the PowerPC kernel in v2.6.23,
 974  * we provide a slow fallback for old kernels.
 975  */
 976 static int powerpc_getregs_old(pid_t pid)
 977 {
 978         int i;
 979         long r;
 980
 981         if (iflag) {
 982                 r = upeek(pid, sizeof(long) * PT_NIP, (long *)&ppc_regs.nip);
 983                 if (r)
 984                         goto out;
 985         }
 986 #ifdef POWERPC64 /* else we never use it */
 987         r = upeek(pid, sizeof(long) * PT_MSR, (long *)&ppc_regs.msr);
 988         if (r)
 989                 goto out;
 990 #endif
 991         r = upeek(pid, sizeof(long) * PT_CCR, (long *)&ppc_regs.ccr);
 992         if (r)
 993                 goto out;
 994         r = upeek(pid, sizeof(long) * PT_ORIG_R3, (long *)&ppc_regs.orig_gpr3);
 995         if (r)
 996                 goto out;
 997         for (i = 0; i <= 8; i++) {
 998                 r = upeek(pid, sizeof(long) * (PT_R0 + i),
 999                           (long *)&ppc_regs.gpr[i]);
1000                 if (r)
1001                         goto out;
1002         }
1003  out:
1004         return r;
1005 }
1006 #endif
1007
1008 #ifndef get_regs
1009 long get_regs_error;
1010
1011 #if defined(PTRACE_GETREGSET) && defined(NT_PRSTATUS)
1012 static void get_regset(pid_t pid)
1013 {
1014 /* constant iovec */
1015 # if defined(ARM) \
1016   || defined(I386) \
1017   || defined(METAG) \
1018   || defined(OR1K) \
1019   || defined(ARC)
1020         static struct iovec io = {
1021                 .iov_base = &ARCH_REGS_FOR_GETREGSET,
1022                 .iov_len = sizeof(ARCH_REGS_FOR_GETREGSET)
1023         };
1024         get_regs_error = ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &io);
1025
1026 /* variable iovec */
1027 # elif defined(X86_64) || defined(X32)
1028         /* x86_io.iov_base = &x86_regs_union; - already is */
1029         x86_io.iov_len = sizeof(x86_regs_union);
1030         get_regs_error = ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &x86_io);
1031 # elif defined(AARCH64)
1032         /* aarch64_io.iov_base = &arm_regs_union; - already is */
1033         aarch64_io.iov_len = sizeof(arm_regs_union);
1034         get_regs_error = ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &aarch64_io);
1035 # else
1036 #  warning both PTRACE_GETREGSET and NT_PRSTATUS are available but not yet used
1037 # endif
1038 }
1039 #endif /* PTRACE_GETREGSET && NT_PRSTATUS */
1040
1041 void
1042 get_regs(pid_t pid)
1043 {
1044 /* PTRACE_GETREGSET only */
1045 # if defined(METAG) || defined(OR1K) || defined(X32) || defined(AARCH64) || defined(ARC)
1046         get_regset(pid);
1047
1048 /* PTRACE_GETREGS only */
1049 # elif defined(AVR32)
1050         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &avr32_regs);
1051 # elif defined(TILE)
1052         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &tile_regs);
1053 # elif defined(SPARC) || defined(SPARC64)
1054         get_regs_error = ptrace(PTRACE_GETREGS, pid, (char *)&sparc_regs, 0);
1055 # elif defined(POWERPC)
1056         static bool old_kernel = 0;
1057         if (old_kernel)
1058                 goto old;
1059         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, (long) &ppc_regs);
1060         if (get_regs_error && errno == EIO) {
1061                 old_kernel = 1;
1062  old:
1063                 get_regs_error = powerpc_getregs_old(pid);
1064         }
1065
1066 /* try PTRACE_GETREGSET first, fallback to PTRACE_GETREGS */
1067 # else
1068 #  if defined(PTRACE_GETREGSET) && defined(NT_PRSTATUS)
1069         static int getregset_support;
1070
1071         if (getregset_support >= 0) {
1072                 get_regset(pid);
1073                 if (getregset_support > 0)
1074                         return;
1075                 if (get_regs_error >= 0) {
1076                         getregset_support = 1;
1077                         return;
1078                 }
1079                 if (errno == EPERM || errno == ESRCH)
1080                         return;
1081                 getregset_support = -1;
1082         }
1083 #  endif /* PTRACE_GETREGSET && NT_PRSTATUS */
1084 #  if defined(ARM)
1085         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &arm_regs);
1086 #  elif defined(I386)
1087         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &i386_regs);
1088 #  elif defined(X86_64)
1089         /* Use old method, with unreliable heuristical detection of 32-bitness. */
1090         x86_io.iov_len = sizeof(x86_64_regs);
1091         get_regs_error = ptrace(PTRACE_GETREGS, pid, NULL, &x86_64_regs);
1092         if (!get_regs_error && x86_64_regs.cs == 0x23) {
1093                 x86_io.iov_len = sizeof(i386_regs);
1094                 /*
1095                  * The order is important: i386_regs and x86_64_regs
1096                  * are overlaid in memory!
1097                  */
1098                 i386_regs.ebx = x86_64_regs.rbx;
1099                 i386_regs.ecx = x86_64_regs.rcx;
1100                 i386_regs.edx = x86_64_regs.rdx;
1101                 i386_regs.esi = x86_64_regs.rsi;
1102                 i386_regs.edi = x86_64_regs.rdi;
1103                 i386_regs.ebp = x86_64_regs.rbp;
1104                 i386_regs.eax = x86_64_regs.rax;
1105                 /* i386_regs.xds = x86_64_regs.ds; unused by strace */
1106                 /* i386_regs.xes = x86_64_regs.es; ditto... */
1107                 /* i386_regs.xfs = x86_64_regs.fs; */
1108                 /* i386_regs.xgs = x86_64_regs.gs; */
1109                 i386_regs.orig_eax = x86_64_regs.orig_rax;
1110                 i386_regs.eip = x86_64_regs.rip;
1111                 /* i386_regs.xcs = x86_64_regs.cs; */
1112                 /* i386_regs.eflags = x86_64_regs.eflags; */
1113                 i386_regs.esp = x86_64_regs.rsp;
1114                 /* i386_regs.xss = x86_64_regs.ss; */
1115         }
1116 #  else
1117 #   error unhandled architecture
1118 #  endif /* ARM || I386 || X86_64 */
1119 # endif
1120 }
1121 #endif /* !get_regs */
1122
1123 /* Returns:
1124  * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
1125  * 1: ok, continue in trace_syscall_entering().
1126  * other: error, trace_syscall_entering() should print error indicator
1127  *    ("????" etc) and bail out.
1128  */
1129 static int
1130 get_scno(struct tcb *tcp)
1131 {
1132         long scno = 0;
1133
1134 #if defined(S390) || defined(S390X)
1135         if (upeek(tcp->pid, PT_GPR2, &s390_gpr2) < 0)
1136                 return -1;
1137
1138         if (s390_gpr2 != -ENOSYS) {
1139                 /*
1140                  * Since kernel version 2.5.44 the scno gets passed in gpr2.
1141                  */
1142                 scno = s390_gpr2;
1143         } else {
1144                 /*
1145                  * Old style of "passing" the scno via the SVC instruction.
1146                  */
1147                 long psw;
1148                 long opcode, offset_reg, tmp;
1149                 void *svc_addr;
1150                 static const int gpr_offset[16] = {
1151                                 PT_GPR0,  PT_GPR1,  PT_ORIGGPR2, PT_GPR3,
1152                                 PT_GPR4,  PT_GPR5,  PT_GPR6,     PT_GPR7,
1153                                 PT_GPR8,  PT_GPR9,  PT_GPR10,    PT_GPR11,
1154                                 PT_GPR12, PT_GPR13, PT_GPR14,    PT_GPR15
1155                 };
1156
1157                 if (upeek(tcp->pid, PT_PSWADDR, &psw) < 0)
1158                         return -1;
1159                 errno = 0;
1160                 opcode = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)(psw - sizeof(long)), 0);
1161                 if (errno) {
1162                         perror_msg("peektext(psw-oneword)");
1163                         return -1;
1164                 }
1165
1166                 /*
1167                  *  We have to check if the SVC got executed directly or via an
1168                  *  EXECUTE instruction. In case of EXECUTE it is necessary to do
1169                  *  instruction decoding to derive the system call number.
1170                  *  Unfortunately the opcode sizes of EXECUTE and SVC are differently,
1171                  *  so that this doesn't work if a SVC opcode is part of an EXECUTE
1172                  *  opcode. Since there is no way to find out the opcode size this
1173                  *  is the best we can do...
1174                  */
1175                 if ((opcode & 0xff00) == 0x0a00) {
1176                         /* SVC opcode */
1177                         scno = opcode & 0xff;
1178                 }
1179                 else {
1180                         /* SVC got executed by EXECUTE instruction */
1181
1182                         /*
1183                          *  Do instruction decoding of EXECUTE. If you really want to
1184                          *  understand this, read the Principles of Operations.
1185                          */
1186                         svc_addr = (void *) (opcode & 0xfff);
1187
1188                         tmp = 0;
1189                         offset_reg = (opcode & 0x000f0000) >> 16;
1190                         if (offset_reg && (upeek(tcp->pid, gpr_offset[offset_reg], &tmp) < 0))
1191                                 return -1;
1192                         svc_addr += tmp;
1193
1194                         tmp = 0;
1195                         offset_reg = (opcode & 0x0000f000) >> 12;
1196                         if (offset_reg && (upeek(tcp->pid, gpr_offset[offset_reg], &tmp) < 0))
1197                                 return -1;
1198                         svc_addr += tmp;
1199
1200                         scno = ptrace(PTRACE_PEEKTEXT, tcp->pid, svc_addr, 0);
1201                         if (errno)
1202                                 return -1;
1203 # if defined(S390X)
1204                         scno >>= 48;
1205 # else
1206                         scno >>= 16;
1207 # endif
1208                         tmp = 0;
1209                         offset_reg = (opcode & 0x00f00000) >> 20;
1210                         if (offset_reg && (upeek(tcp->pid, gpr_offset[offset_reg], &tmp) < 0))
1211                                 return -1;
1212
1213                         scno = (scno | tmp) & 0xff;
1214                 }
1215         }
1216 #elif defined(POWERPC)
1217         scno = ppc_regs.gpr[0];
1218 # ifdef POWERPC64
1219         int currpers;
1220
1221         /*
1222          * Check for 64/32 bit mode.
1223          * Embedded implementations covered by Book E extension of PPC use
1224          * bit 0 (CM) of 32-bit Machine state register (MSR).
1225          * Other implementations use bit 0 (SF) of 64-bit MSR.
1226          */
1227         currpers = (ppc_regs.msr & 0x8000000080000000) ? 0 : 1;
1228         update_personality(tcp, currpers);
1229 # endif
1230 #elif defined(AVR32)
1231         scno = avr32_regs.r8;
1232 #elif defined(BFIN)
1233         if (upeek(tcp->pid, PT_ORIG_P0, &scno))
1234                 return -1;
1235 #elif defined(I386)
1236         scno = i386_regs.orig_eax;
1237 #elif defined(X86_64) || defined(X32)
1238 # ifndef __X32_SYSCALL_BIT
1239 #  define __X32_SYSCALL_BIT     0x40000000
1240 # endif
1241         int currpers;
1242 # if 1
1243         /* GETREGSET of NT_PRSTATUS tells us regset size,
1244          * which unambiguously detects i386.
1245          *
1246          * Linux kernel distinguishes x86-64 and x32 processes
1247          * solely by looking at __X32_SYSCALL_BIT:
1248          * arch/x86/include/asm/compat.h::is_x32_task():
1249          * if (task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)
1250          *         return true;
1251          */
1252         if (x86_io.iov_len == sizeof(i386_regs)) {
1253                 scno = i386_regs.orig_eax;
1254                 currpers = 1;
1255         } else {
1256                 scno = x86_64_regs.orig_rax;
1257                 currpers = 0;
1258                 if (scno & __X32_SYSCALL_BIT) {
1259                         scno -= __X32_SYSCALL_BIT;
1260                         currpers = 2;
1261                 }
1262         }
1263 # elif 0
1264         /* cs = 0x33 for long mode (native 64 bit and x32)
1265          * cs = 0x23 for compatibility mode (32 bit)
1266          * ds = 0x2b for x32 mode (x86-64 in 32 bit)
1267          */
1268         scno = x86_64_regs.orig_rax;
1269         switch (x86_64_regs.cs) {
1270                 case 0x23: currpers = 1; break;
1271                 case 0x33:
1272                         if (x86_64_regs.ds == 0x2b) {
1273                                 currpers = 2;
1274                                 scno &= ~__X32_SYSCALL_BIT;
1275                         } else
1276                                 currpers = 0;
1277                         break;
1278                 default:
1279                         fprintf(stderr, "Unknown value CS=0x%08X while "
1280                                  "detecting personality of process "
1281                                  "PID=%d\n", (int)x86_64_regs.cs, tcp->pid);
1282                         currpers = current_personality;
1283                         break;
1284         }
1285 # elif 0
1286         /* This version analyzes the opcode of a syscall instruction.
1287          * (int 0x80 on i386 vs. syscall on x86-64)
1288          * It works, but is too complicated, and strictly speaking, unreliable.
1289          */
1290         unsigned long call, rip = x86_64_regs.rip;
1291         /* sizeof(syscall) == sizeof(int 0x80) == 2 */
1292         rip -= 2;
1293         errno = 0;
1294         call = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)rip, (char *)0);
1295         if (errno)
1296                 fprintf(stderr, "ptrace_peektext failed: %s\n",
1297                                 strerror(errno));
1298         switch (call & 0xffff) {
1299                 /* x86-64: syscall = 0x0f 0x05 */
1300                 case 0x050f: currpers = 0; break;
1301                 /* i386: int 0x80 = 0xcd 0x80 */
1302                 case 0x80cd: currpers = 1; break;
1303                 default:
1304                         currpers = current_personality;
1305                         fprintf(stderr,
1306                                 "Unknown syscall opcode (0x%04X) while "
1307                                 "detecting personality of process "
1308                                 "PID=%d\n", (int)call, tcp->pid);
1309                         break;
1310         }
1311 # endif
1312
1313 # ifdef X32
1314         /* If we are built for a x32 system, then personality 0 is x32
1315          * (not x86_64), and stracing of x86_64 apps is not supported.
1316          * Stracing of i386 apps is still supported.
1317          */
1318         if (currpers == 0) {
1319                 fprintf(stderr, "syscall_%lu(...) in unsupported "
1320                                 "64-bit mode of process PID=%d\n",
1321                         scno, tcp->pid);
1322                 return 0;
1323         }
1324         currpers &= ~2; /* map 2,1 to 0,1 */
1325 # endif
1326         update_personality(tcp, currpers);
1327 #elif defined(IA64)
1328 #       define IA64_PSR_IS      ((long)1 << 34)
1329         long psr;
1330         if (upeek(tcp->pid, PT_CR_IPSR, &psr) >= 0)
1331                 ia64_ia32mode = ((psr & IA64_PSR_IS) != 0);
1332         if (ia64_ia32mode) {
1333                 if (upeek(tcp->pid, PT_R1, &scno) < 0)
1334                         return -1;
1335         } else {
1336                 if (upeek(tcp->pid, PT_R15, &scno) < 0)
1337                         return -1;
1338         }
1339 #elif defined(AARCH64)
1340         switch (aarch64_io.iov_len) {
1341                 case sizeof(aarch64_regs):
1342                         /* We are in 64-bit mode */
1343                         scno = aarch64_regs.regs[8];
1344                         update_personality(tcp, 1);
1345                         break;
1346                 case sizeof(arm_regs):
1347                         /* We are in 32-bit mode */
1348                         /* Note: we don't support OABI, unlike 32-bit ARM build */
1349                         scno = arm_regs.ARM_r7;
1350                         scno = shuffle_scno(scno);
1351                         update_personality(tcp, 0);
1352                         break;
1353         }
1354 #elif defined(ARM)
1355         if (arm_regs.ARM_ip != 0) {
1356                 /* It is not a syscall entry */
1357                 fprintf(stderr, "pid %d stray syscall exit\n", tcp->pid);
1358                 tcp->flags |= TCB_INSYSCALL;
1359                 return 0;
1360         }
1361         /* Note: we support only 32-bit CPUs, not 26-bit */
1362
1363 # if !defined(__ARM_EABI__) || ENABLE_ARM_OABI
1364         if (arm_regs.ARM_cpsr & 0x20)
1365                 /* Thumb mode */
1366                 goto scno_in_r7;
1367         /* ARM mode */
1368         /* Check EABI/OABI by examining SVC insn's low 24 bits */
1369         errno = 0;
1370         scno = ptrace(PTRACE_PEEKTEXT, tcp->pid, (void *)(arm_regs.ARM_pc - 4), NULL);
1371         if (errno)
1372                 return -1;
1373         /* EABI syscall convention? */
1374         if (scno != 0xef000000) {
1375                 /* No, it's OABI */
1376                 if ((scno & 0x0ff00000) != 0x0f900000) {
1377                         fprintf(stderr, "pid %d unknown syscall trap 0x%08lx\n",
1378                                 tcp->pid, scno);
1379                         return -1;
1380                 }
1381                 /* Fixup the syscall number */
1382                 scno &= 0x000fffff;
1383         } else {
1384  scno_in_r7:
1385                 scno = arm_regs.ARM_r7;
1386         }
1387 # else /* __ARM_EABI__ || !ENABLE_ARM_OABI */
1388         scno = arm_regs.ARM_r7;
1389 # endif
1390         scno = shuffle_scno(scno);
1391 #elif defined(M68K)
1392         if (upeek(tcp->pid, 4*PT_ORIG_D0, &scno) < 0)
1393                 return -1;
1394 #elif defined(LINUX_MIPSN32)
1395         unsigned long long regs[38];
1396
1397         if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (long) &regs) < 0)
1398                 return -1;
1399         mips_a3 = regs[REG_A3];
1400         mips_r2 = regs[REG_V0];
1401
1402         scno = mips_r2;
1403         if (!SCNO_IN_RANGE(scno)) {
1404                 if (mips_a3 == 0 || mips_a3 == -1) {
1405                         if (debug_flag)
1406                                 fprintf(stderr, "stray syscall exit: v0 = %ld\n", scno);
1407                         return 0;
1408                 }
1409         }
1410 #elif defined(MIPS)
1411         if (upeek(tcp->pid, REG_A3, &mips_a3) < 0)
1412                 return -1;
1413         if (upeek(tcp->pid, REG_V0, &scno) < 0)
1414                 return -1;
1415
1416         if (!SCNO_IN_RANGE(scno)) {
1417                 if (mips_a3 == 0 || mips_a3 == -1) {
1418                         if (debug_flag)
1419                                 fprintf(stderr, "stray syscall exit: v0 = %ld\n", scno);
1420                         return 0;
1421                 }
1422         }
1423 #elif defined(ALPHA)
1424         if (upeek(tcp->pid, REG_A3, &alpha_a3) < 0)
1425                 return -1;
1426         if (upeek(tcp->pid, REG_R0, &scno) < 0)
1427                 return -1;
1428
1429         /*
1430          * Do some sanity checks to figure out if it's
1431          * really a syscall entry
1432          */
1433         if (!SCNO_IN_RANGE(scno)) {
1434                 if (alpha_a3 == 0 || alpha_a3 == -1) {
1435                         if (debug_flag)
1436                                 fprintf(stderr, "stray syscall exit: r0 = %ld\n", scno);
1437                         return 0;
1438                 }
1439         }
1440 #elif defined(SPARC) || defined(SPARC64)
1441         /* Disassemble the syscall trap. */
1442         /* Retrieve the syscall trap instruction. */
1443         unsigned long trap;
1444         errno = 0;
1445 # if defined(SPARC64)
1446         trap = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)sparc_regs.tpc, 0);
1447         trap >>= 32;
1448 # else
1449         trap = ptrace(PTRACE_PEEKTEXT, tcp->pid, (char *)sparc_regs.pc, 0);
1450 # endif
1451         if (errno)
1452                 return -1;
1453
1454         /* Disassemble the trap to see what personality to use. */
1455         switch (trap) {
1456         case 0x91d02010:
1457                 /* Linux/SPARC syscall trap. */
1458                 update_personality(tcp, 0);
1459                 break;
1460         case 0x91d0206d:
1461                 /* Linux/SPARC64 syscall trap. */
1462                 update_personality(tcp, 2);
1463                 break;
1464         case 0x91d02000:
1465                 /* SunOS syscall trap. (pers 1) */
1466                 fprintf(stderr, "syscall: SunOS no support\n");
1467                 return -1;
1468         case 0x91d02008:
1469                 /* Solaris 2.x syscall trap. (per 2) */
1470                 update_personality(tcp, 1);
1471                 break;
1472         case 0x91d02009:
1473                 /* NetBSD/FreeBSD syscall trap. */
1474                 fprintf(stderr, "syscall: NetBSD/FreeBSD not supported\n");
1475                 return -1;
1476         case 0x91d02027:
1477                 /* Solaris 2.x gettimeofday */
1478                 update_personality(tcp, 1);
1479                 break;
1480         default:
1481 # if defined(SPARC64)
1482                 fprintf(stderr, "syscall: unknown syscall trap %08lx %016lx\n", trap, sparc_regs.tpc);
1483 # else
1484                 fprintf(stderr, "syscall: unknown syscall trap %08lx %08lx\n", trap, sparc_regs.pc);
1485 # endif
1486                 return -1;
1487         }
1488
1489         /* Extract the system call number from the registers. */
1490         if (trap == 0x91d02027)
1491                 scno = 156;
1492         else
1493                 scno = sparc_regs.u_regs[U_REG_G1];
1494         if (scno == 0) {
1495                 scno = sparc_regs.u_regs[U_REG_O0];
1496                 memmove(&sparc_regs.u_regs[U_REG_O0], &sparc_regs.u_regs[U_REG_O1], 7*sizeof(sparc_regs.u_regs[0]));
1497         }
1498 #elif defined(HPPA)
1499         if (upeek(tcp->pid, PT_GR20, &scno) < 0)
1500                 return -1;
1501 #elif defined(SH)
1502         /*
1503          * In the new syscall ABI, the system call number is in R3.
1504          */
1505         if (upeek(tcp->pid, 4*(REG_REG0+3), &scno) < 0)
1506                 return -1;
1507
1508         if (scno < 0) {
1509                 /* Odd as it may seem, a glibc bug has been known to cause
1510                    glibc to issue bogus negative syscall numbers.  So for
1511                    our purposes, make strace print what it *should* have been */
1512                 long correct_scno = (scno & 0xff);
1513                 if (debug_flag)
1514                         fprintf(stderr,
1515                                 "Detected glibc bug: bogus system call"
1516                                 " number = %ld, correcting to %ld\n",
1517                                 scno,
1518                                 correct_scno);
1519                 scno = correct_scno;
1520         }
1521 #elif defined(SH64)
1522         if (upeek(tcp->pid, REG_SYSCALL, &scno) < 0)
1523                 return -1;
1524         scno &= 0xFFFF;
1525 #elif defined(CRISV10) || defined(CRISV32)
1526         if (upeek(tcp->pid, 4*PT_R9, &scno) < 0)
1527                 return -1;
1528 #elif defined(TILE)
1529         int currpers;
1530         scno = tile_regs.regs[10];
1531 # ifdef __tilepro__
1532         currpers = 1;
1533 # else
1534 #  ifndef PT_FLAGS_COMPAT
1535 #   define PT_FLAGS_COMPAT 0x10000  /* from Linux 3.8 on */
1536 #  endif
1537         if (tile_regs.flags & PT_FLAGS_COMPAT)
1538                 currpers = 1;
1539         else
1540                 currpers = 0;
1541 # endif
1542         update_personality(tcp, currpers);
1543 #elif defined(MICROBLAZE)
1544         if (upeek(tcp->pid, 0, &scno) < 0)
1545                 return -1;
1546 #elif defined(OR1K)
1547         scno = or1k_regs.gpr[11];
1548 #elif defined(METAG)
1549         scno = metag_regs.dx[0][1];     /* syscall number in D1Re0 (D1.0) */
1550 #elif defined(XTENSA)
1551         if (upeek(tcp->pid, SYSCALL_NR, &scno) < 0)
1552                 return -1;
1553 # elif defined(ARC)
1554         scno = arc_regs.scratch.r8;
1555 #endif
1556
1557         tcp->scno = scno;
1558         if (SCNO_IS_VALID(tcp->scno)) {
1559                 tcp->s_ent = &sysent[scno];
1560                 tcp->qual_flg = qual_flags[scno];
1561         } else {
1562                 static const struct_sysent unknown = {
1563                         .nargs = MAX_ARGS,
1564                         .sys_flags = 0,
1565                         .sys_func = printargs,
1566                         .sys_name = "unknown", /* not used */
1567                 };
1568                 tcp->s_ent = &unknown;
1569                 tcp->qual_flg = UNDEFINED_SCNO | QUAL_RAW | DEFAULT_QUAL_FLAGS;
1570         }
1571         return 1;
1572 }
1573
1574 /* Called at each syscall entry.
1575  * Returns:
1576  * 0: "ignore this ptrace stop", bail out of trace_syscall_entering() silently.
1577  * 1: ok, continue in trace_syscall_entering().
1578  * other: error, trace_syscall_entering() should print error indicator
1579  *    ("????" etc) and bail out.
1580  */
1581 static int
1582 syscall_fixup_on_sysenter(struct tcb *tcp)
1583 {
1584         /* A common case of "not a syscall entry" is post-execve SIGTRAP */
1585 #if defined(I386)
1586         if (i386_regs.eax != -ENOSYS) {
1587                 if (debug_flag)
1588                         fprintf(stderr, "not a syscall entry (eax = %ld)\n", i386_regs.eax);
1589                 return 0;
1590         }
1591 #elif defined(X86_64) || defined(X32)
1592         {
1593                 long rax;
1594                 if (x86_io.iov_len == sizeof(i386_regs)) {
1595                         /* Sign extend from 32 bits */
1596                         rax = (int32_t)i386_regs.eax;
1597                 } else {
1598                         /* Note: in X32 build, this truncates 64 to 32 bits */
1599                         rax = x86_64_regs.rax;
1600                 }
1601                 if (rax != -ENOSYS) {
1602                         if (debug_flag)
1603                                 fprintf(stderr, "not a syscall entry (rax = %ld)\n", rax);
1604                         return 0;
1605                 }
1606         }
1607 #elif defined(M68K)
1608         /* TODO? Eliminate upeek's in arches below like we did in x86 */
1609         if (upeek(tcp->pid, 4*PT_D0, &m68k_d0) < 0)
1610                 return -1;
1611         if (m68k_d0 != -ENOSYS) {
1612                 if (debug_flag)
1613                         fprintf(stderr, "not a syscall entry (d0 = %ld)\n", m68k_d0);
1614                 return 0;
1615         }
1616 #elif defined(IA64)
1617         if (upeek(tcp->pid, PT_R10, &ia64_r10) < 0)
1618                 return -1;
1619         if (upeek(tcp->pid, PT_R8, &ia64_r8) < 0)
1620                 return -1;
1621         if (ia64_ia32mode && ia64_r8 != -ENOSYS) {
1622                 if (debug_flag)
1623                         fprintf(stderr, "not a syscall entry (r8 = %ld)\n", ia64_r8);
1624                 return 0;
1625         }
1626 #elif defined(CRISV10) || defined(CRISV32)
1627         if (upeek(tcp->pid, 4*PT_R10, &cris_r10) < 0)
1628                 return -1;
1629         if (cris_r10 != -ENOSYS) {
1630                 if (debug_flag)
1631                         fprintf(stderr, "not a syscall entry (r10 = %ld)\n", cris_r10);
1632                 return 0;
1633         }
1634 #elif defined(MICROBLAZE)
1635         if (upeek(tcp->pid, 3 * 4, &microblaze_r3) < 0)
1636                 return -1;
1637         if (microblaze_r3 != -ENOSYS) {
1638                 if (debug_flag)
1639                         fprintf(stderr, "not a syscall entry (r3 = %ld)\n", microblaze_r3);
1640                 return 0;
1641         }
1642 #endif
1643         return 1;
1644 }
1645
1646 static void
1647 internal_fork(struct tcb *tcp)
1648 {
1649 #if defined S390 || defined S390X || defined CRISV10 || defined CRISV32
1650 # define ARG_FLAGS      1
1651 #else
1652 # define ARG_FLAGS      0
1653 #endif
1654 #ifndef CLONE_UNTRACED
1655 # define CLONE_UNTRACED 0x00800000
1656 #endif
1657         if ((ptrace_setoptions
1658             & (PTRACE_O_TRACECLONE | PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK))
1659            == (PTRACE_O_TRACECLONE | PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK))
1660                 return;
1661
1662         if (!followfork)
1663                 return;
1664
1665         if (entering(tcp)) {
1666                 /*
1667                  * We won't see the new child if clone is called with
1668                  * CLONE_UNTRACED, so we keep the same logic with that option
1669                  * and don't trace it.
1670                  */
1671                 if ((tcp->s_ent->sys_func == sys_clone)
1672                  && (tcp->u_arg[ARG_FLAGS] & CLONE_UNTRACED)
1673                 )
1674                         return;
1675                 setbpt(tcp);
1676         } else {
1677                 if (tcp->flags & TCB_BPTSET)
1678                         clearbpt(tcp);
1679         }
1680 }
1681
1682 #if defined(TCB_WAITEXECVE)
1683 static void
1684 internal_exec(struct tcb *tcp)
1685 {
1686         /* Maybe we have post-execve SIGTRAP suppressed? */
1687         if (ptrace_setoptions & PTRACE_O_TRACEEXEC)
1688                 return; /* yes, no need to do anything */
1689
1690         if (exiting(tcp) && syserror(tcp))
1691                 /* Error in execve, no post-execve SIGTRAP expected */
1692                 tcp->flags &= ~TCB_WAITEXECVE;
1693         else
1694                 tcp->flags |= TCB_WAITEXECVE;
1695 }
1696 #endif
1697
1698 static void
1699 syscall_fixup_for_fork_exec(struct tcb *tcp)
1700 {
1701         /*
1702          * We must always trace a few critical system calls in order to
1703          * correctly support following forks in the presence of tracing
1704          * qualifiers.
1705          */
1706         int (*func)();
1707
1708         func = tcp->s_ent->sys_func;
1709
1710         if (   sys_fork == func
1711             || sys_clone == func
1712            ) {
1713                 internal_fork(tcp);
1714                 return;
1715         }
1716
1717 #if defined(TCB_WAITEXECVE)
1718         if (   sys_execve == func
1719 # if defined(SPARC) || defined(SPARC64)
1720             || sys_execv == func
1721 # endif
1722            ) {
1723                 internal_exec(tcp);
1724                 return;
1725         }
1726 #endif
1727 }
1728
1729 /* Return -1 on error or 1 on success (never 0!) */
1730 static int
1731 get_syscall_args(struct tcb *tcp)
1732 {
1733         int i, nargs;
1734
1735         nargs = tcp->s_ent->nargs;
1736
1737 #if defined(S390) || defined(S390X)
1738         for (i = 0; i < nargs; ++i)
1739                 if (upeek(tcp->pid, i==0 ? PT_ORIGGPR2 : PT_GPR2 + i*sizeof(long), &tcp->u_arg[i]) < 0)
1740                         return -1;
1741 #elif defined(ALPHA)
1742         for (i = 0; i < nargs; ++i)
1743                 if (upeek(tcp->pid, REG_A0+i, &tcp->u_arg[i]) < 0)
1744                         return -1;
1745 #elif defined(IA64)
1746         if (!ia64_ia32mode) {
1747                 unsigned long *out0, cfm, sof, sol;
1748                 long rbs_end;
1749                 /* be backwards compatible with kernel < 2.4.4... */
1750 #               ifndef PT_RBS_END
1751 #                 define PT_RBS_END     PT_AR_BSP
1752 #               endif
1753
1754                 if (upeek(tcp->pid, PT_RBS_END, &rbs_end) < 0)
1755                         return -1;
1756                 if (upeek(tcp->pid, PT_CFM, (long *) &cfm) < 0)
1757                         return -1;
1758
1759                 sof = (cfm >> 0) & 0x7f;
1760                 sol = (cfm >> 7) & 0x7f;
1761                 out0 = ia64_rse_skip_regs((unsigned long *) rbs_end, -sof + sol);
1762
1763                 for (i = 0; i < nargs; ++i) {
1764                         if (umoven(tcp, (unsigned long) ia64_rse_skip_regs(out0, i),
1765                                    sizeof(long), (char *) &tcp->u_arg[i]) < 0)
1766                                 return -1;
1767                 }
1768         } else {
1769                 static const int argreg[MAX_ARGS] = { PT_R11 /* EBX = out0 */,
1770                                                       PT_R9  /* ECX = out1 */,
1771                                                       PT_R10 /* EDX = out2 */,
1772                                                       PT_R14 /* ESI = out3 */,
1773                                                       PT_R15 /* EDI = out4 */,
1774                                                       PT_R13 /* EBP = out5 */};
1775
1776                 for (i = 0; i < nargs; ++i) {
1777                         if (upeek(tcp->pid, argreg[i], &tcp->u_arg[i]) < 0)
1778                                 return -1;
1779                         /* truncate away IVE sign-extension */
1780                         tcp->u_arg[i] &= 0xffffffff;
1781                 }
1782         }
1783 #elif defined(LINUX_MIPSN32) || defined(LINUX_MIPSN64)
1784         /* N32 and N64 both use up to six registers.  */
1785         unsigned long long regs[38];
1786
1787         if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (long) &regs) < 0)
1788                 return -1;
1789
1790         for (i = 0; i < nargs; ++i) {
1791                 tcp->u_arg[i] = regs[REG_A0 + i];
1792 # if defined(LINUX_MIPSN32)
1793                 tcp->ext_arg[i] = regs[REG_A0 + i];
1794 # endif
1795         }
1796 #elif defined(MIPS)
1797         if (nargs > 4) {
1798                 long sp;
1799
1800                 if (upeek(tcp->pid, REG_SP, &sp) < 0)
1801                         return -1;
1802                 for (i = 0; i < 4; ++i)
1803                         if (upeek(tcp->pid, REG_A0 + i, &tcp->u_arg[i]) < 0)
1804                                 return -1;
1805                 umoven(tcp, sp + 16, (nargs - 4) * sizeof(tcp->u_arg[0]),
1806                        (char *)(tcp->u_arg + 4));
1807         } else {
1808                 for (i = 0; i < nargs; ++i)
1809                         if (upeek(tcp->pid, REG_A0 + i, &tcp->u_arg[i]) < 0)
1810                                 return -1;
1811         }
1812 #elif defined(POWERPC)
1813         (void)i;
1814         (void)nargs;
1815         tcp->u_arg[0] = ppc_regs.orig_gpr3;
1816         tcp->u_arg[1] = ppc_regs.gpr[4];
1817         tcp->u_arg[2] = ppc_regs.gpr[5];
1818         tcp->u_arg[3] = ppc_regs.gpr[6];
1819         tcp->u_arg[4] = ppc_regs.gpr[7];
1820         tcp->u_arg[5] = ppc_regs.gpr[8];
1821 #elif defined(SPARC) || defined(SPARC64)
1822         for (i = 0; i < nargs; ++i)
1823                 tcp->u_arg[i] = sparc_regs.u_regs[U_REG_O0 + i];
1824 #elif defined(HPPA)
1825         for (i = 0; i < nargs; ++i)
1826                 if (upeek(tcp->pid, PT_GR26-4*i, &tcp->u_arg[i]) < 0)
1827                         return -1;
1828 #elif defined(ARM) || defined(AARCH64)
1829 # if defined(AARCH64)
1830         if (tcp->currpers == 1)
1831                 for (i = 0; i < nargs; ++i)
1832                         tcp->u_arg[i] = aarch64_regs.regs[i];
1833         else
1834 # endif
1835         for (i = 0; i < nargs; ++i)
1836                 tcp->u_arg[i] = arm_regs.uregs[i];
1837 #elif defined(AVR32)
1838         (void)i;
1839         (void)nargs;
1840         tcp->u_arg[0] = avr32_regs.r12;
1841         tcp->u_arg[1] = avr32_regs.r11;
1842         tcp->u_arg[2] = avr32_regs.r10;
1843         tcp->u_arg[3] = avr32_regs.r9;
1844         tcp->u_arg[4] = avr32_regs.r5;
1845         tcp->u_arg[5] = avr32_regs.r3;
1846 #elif defined(BFIN)
1847         static const int argreg[MAX_ARGS] = { PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5 };
1848
1849         for (i = 0; i < nargs; ++i)
1850                 if (upeek(tcp->pid, argreg[i], &tcp->u_arg[i]) < 0)
1851                         return -1;
1852 #elif defined(SH)
1853         static const int syscall_regs[MAX_ARGS] = {
1854                 4 * (REG_REG0+4), 4 * (REG_REG0+5), 4 * (REG_REG0+6),
1855                 4 * (REG_REG0+7), 4 * (REG_REG0  ), 4 * (REG_REG0+1)
1856         };
1857
1858         for (i = 0; i < nargs; ++i)
1859                 if (upeek(tcp->pid, syscall_regs[i], &tcp->u_arg[i]) < 0)
1860                         return -1;
1861 #elif defined(SH64)
1862         int i;
1863         /* Registers used by SH5 Linux system calls for parameters */
1864         static const int syscall_regs[MAX_ARGS] = { 2, 3, 4, 5, 6, 7 };
1865
1866         for (i = 0; i < nargs; ++i)
1867                 if (upeek(tcp->pid, REG_GENERAL(syscall_regs[i]), &tcp->u_arg[i]) < 0)
1868                         return -1;
1869 #elif defined(I386)
1870         (void)i;
1871         (void)nargs;
1872         tcp->u_arg[0] = i386_regs.ebx;
1873         tcp->u_arg[1] = i386_regs.ecx;
1874         tcp->u_arg[2] = i386_regs.edx;
1875         tcp->u_arg[3] = i386_regs.esi;
1876         tcp->u_arg[4] = i386_regs.edi;
1877         tcp->u_arg[5] = i386_regs.ebp;
1878 #elif defined(X86_64) || defined(X32)
1879         (void)i;
1880         (void)nargs;
1881         if (x86_io.iov_len != sizeof(i386_regs)) {
1882                 /* x86-64 or x32 ABI */
1883                 tcp->u_arg[0] = x86_64_regs.rdi;
1884                 tcp->u_arg[1] = x86_64_regs.rsi;
1885                 tcp->u_arg[2] = x86_64_regs.rdx;
1886                 tcp->u_arg[3] = x86_64_regs.r10;
1887                 tcp->u_arg[4] = x86_64_regs.r8;
1888                 tcp->u_arg[5] = x86_64_regs.r9;
1889 #  ifdef X32
1890                 tcp->ext_arg[0] = x86_64_regs.rdi;
1891                 tcp->ext_arg[1] = x86_64_regs.rsi;
1892                 tcp->ext_arg[2] = x86_64_regs.rdx;
1893                 tcp->ext_arg[3] = x86_64_regs.r10;
1894                 tcp->ext_arg[4] = x86_64_regs.r8;
1895                 tcp->ext_arg[5] = x86_64_regs.r9;
1896 #  endif
1897         } else {
1898                 /* i386 ABI */
1899                 /* Zero-extend from 32 bits */
1900                 /* Use widen_to_long(tcp->u_arg[N]) in syscall handlers
1901                  * if you need to use *sign-extended* parameter.
1902                  */
1903                 tcp->u_arg[0] = (long)(uint32_t)i386_regs.ebx;
1904                 tcp->u_arg[1] = (long)(uint32_t)i386_regs.ecx;
1905                 tcp->u_arg[2] = (long)(uint32_t)i386_regs.edx;
1906                 tcp->u_arg[3] = (long)(uint32_t)i386_regs.esi;
1907                 tcp->u_arg[4] = (long)(uint32_t)i386_regs.edi;
1908                 tcp->u_arg[5] = (long)(uint32_t)i386_regs.ebp;
1909         }
1910 #elif defined(MICROBLAZE)
1911         for (i = 0; i < nargs; ++i)
1912                 if (upeek(tcp->pid, (5 + i) * 4, &tcp->u_arg[i]) < 0)
1913                         return -1;
1914 #elif defined(CRISV10) || defined(CRISV32)
1915         static const int crisregs[MAX_ARGS] = {
1916                 4*PT_ORIG_R10, 4*PT_R11, 4*PT_R12,
1917                 4*PT_R13     , 4*PT_MOF, 4*PT_SRP
1918         };
1919
1920         for (i = 0; i < nargs; ++i)
1921                 if (upeek(tcp->pid, crisregs[i], &tcp->u_arg[i]) < 0)
1922                         return -1;
1923 #elif defined(TILE)
1924         for (i = 0; i < nargs; ++i)
1925                 tcp->u_arg[i] = tile_regs.regs[i];
1926 #elif defined(M68K)
1927         for (i = 0; i < nargs; ++i)
1928                 if (upeek(tcp->pid, (i < 5 ? i : i + 2)*4, &tcp->u_arg[i]) < 0)
1929                         return -1;
1930 #elif defined(OR1K)
1931         (void)nargs;
1932         for (i = 0; i < 6; ++i)
1933                 tcp->u_arg[i] = or1k_regs.gpr[3 + i];
1934 #elif defined(METAG)
1935         for (i = 0; i < nargs; i++)
1936                 /* arguments go backwards from D1Ar1 (D1.3) */
1937                 tcp->u_arg[i] = ((unsigned long *)&metag_regs.dx[3][1])[-i];
1938 #elif defined(XTENSA)
1939         /* arg0: a6, arg1: a3, arg2: a4, arg3: a5, arg4: a8, arg5: a9 */
1940         static const int xtensaregs[MAX_ARGS] = { 6, 3, 4, 5, 8, 9 };
1941         for (i = 0; i < nargs; ++i)
1942                 if (upeek(tcp->pid, REG_A_BASE + xtensaregs[i], &tcp->u_arg[i]) < 0)
1943                         return -1;
1944 # elif defined(ARC)
1945         long *arc_args = &arc_regs.scratch.r0;
1946         for (i = 0; i < nargs; ++i)
1947                 tcp->u_arg[i] = *arc_args--;
1948
1949 #else /* Other architecture (32bits specific) */
1950         for (i = 0; i < nargs; ++i)
1951                 if (upeek(tcp->pid, i*4, &tcp->u_arg[i]) < 0)
1952                         return -1;
1953 #endif
1954         return 1;
1955 }
1956
1957 static int
1958 trace_syscall_entering(struct tcb *tcp)
1959 {
1960         int res, scno_good;
1961
1962 #if defined TCB_WAITEXECVE
1963         if (tcp->flags & TCB_WAITEXECVE) {
1964                 /* This is the post-execve SIGTRAP. */
1965                 tcp->flags &= ~TCB_WAITEXECVE;
1966                 return 0;
1967         }
1968 #endif
1969
1970         scno_good = res = (get_regs_error ? -1 : get_scno(tcp));
1971         if (res == 0)
1972                 return res;
1973         if (res == 1) {
1974                 res = syscall_fixup_on_sysenter(tcp);
1975                 if (res == 0)
1976                         return res;
1977                 if (res == 1)
1978                         res = get_syscall_args(tcp);
1979         }
1980
1981         if (res != 1) {
1982                 printleader(tcp);
1983                 if (scno_good != 1)
1984                         tprints("????" /* anti-trigraph gap */ "(");
1985                 else if (tcp->qual_flg & UNDEFINED_SCNO)
1986                         tprintf("%s(", undefined_scno_name(tcp));
1987                 else
1988                         tprintf("%s(", tcp->s_ent->sys_name);
1989                 /*
1990                  * " <unavailable>" will be added later by the code which
1991                  * detects ptrace errors.
1992                  */
1993                 goto ret;
1994         }
1995
1996         if (   sys_execve == tcp->s_ent->sys_func
1997 # if defined(SPARC) || defined(SPARC64)
1998             || sys_execv == tcp->s_ent->sys_func
1999 # endif
2000            ) {
2001                 hide_log_until_execve = 0;
2002         }
2003
2004 #if defined(SYS_socket_subcall) || defined(SYS_ipc_subcall)
2005         while (1) {
2006 # ifdef SYS_socket_subcall
2007                 if (tcp->s_ent->sys_func == sys_socketcall) {
2008                         decode_socket_subcall(tcp);
2009                         break;
2010                 }
2011 # endif
2012 # ifdef SYS_ipc_subcall
2013                 if (tcp->s_ent->sys_func == sys_ipc) {
2014                         decode_ipc_subcall(tcp);
2015                         break;
2016                 }
2017 # endif
2018                 break;
2019         }
2020 #endif
2021
2022         if (need_fork_exec_workarounds)
2023                 syscall_fixup_for_fork_exec(tcp);
2024
2025         if (!(tcp->qual_flg & QUAL_TRACE)
2026          || (tracing_paths && !pathtrace_match(tcp))
2027         ) {
2028                 tcp->flags |= TCB_INSYSCALL | TCB_FILTERED;
2029                 return 0;
2030         }
2031
2032         tcp->flags &= ~TCB_FILTERED;
2033
2034         if (cflag == CFLAG_ONLY_STATS || hide_log_until_execve) {
2035                 res = 0;
2036                 goto ret;
2037         }
2038
2039         printleader(tcp);
2040         if (tcp->qual_flg & UNDEFINED_SCNO)
2041                 tprintf("%s(", undefined_scno_name(tcp));
2042         else
2043                 tprintf("%s(", tcp->s_ent->sys_name);
2044         if ((tcp->qual_flg & QUAL_RAW) && tcp->s_ent->sys_func != sys_exit)
2045                 res = printargs(tcp);
2046         else
2047                 res = tcp->s_ent->sys_func(tcp);
2048
2049         fflush(tcp->outf);
2050  ret:
2051         tcp->flags |= TCB_INSYSCALL;
2052         /* Measure the entrance time as late as possible to avoid errors. */
2053         if (Tflag || cflag)
2054                 gettimeofday(&tcp->etime, NULL);
2055         return res;
2056 }
2057
2058 /* Returns:
2059  * 1: ok, continue in trace_syscall_exiting().
2060  * -1: error, trace_syscall_exiting() should print error indicator
2061  *    ("????" etc) and bail out.
2062  */
2063 static int
2064 get_syscall_result(struct tcb *tcp)
2065 {
2066 #if defined(S390) || defined(S390X)
2067         if (upeek(tcp->pid, PT_GPR2, &s390_gpr2) < 0)
2068                 return -1;
2069 #elif defined(POWERPC)
2070         /* already done by get_regs */
2071 #elif defined(AVR32)
2072         /* already done by get_regs */
2073 #elif defined(BFIN)
2074         if (upeek(tcp->pid, PT_R0, &bfin_r0) < 0)
2075                 return -1;
2076 #elif defined(I386)
2077         /* already done by get_regs */
2078 #elif defined(X86_64) || defined(X32)
2079         /* already done by get_regs */
2080 #elif defined(IA64)
2081 #       define IA64_PSR_IS      ((long)1 << 34)
2082         long psr;
2083         if (upeek(tcp->pid, PT_CR_IPSR, &psr) >= 0)
2084                 ia64_ia32mode = ((psr & IA64_PSR_IS) != 0);
2085         if (upeek(tcp->pid, PT_R8, &ia64_r8) < 0)
2086                 return -1;
2087         if (upeek(tcp->pid, PT_R10, &ia64_r10) < 0)
2088                 return -1;
2089 #elif defined(ARM)
2090         /* already done by get_regs */
2091 #elif defined(AARCH64)
2092         /* register reading already done by get_regs */
2093
2094         /* Used to do this, but we did it on syscall entry already: */
2095         /* We are in 64-bit mode (personality 1) if register struct is aarch64_regs,
2096          * else it's personality 0.
2097          */
2098         /*update_personality(tcp, aarch64_io.iov_len == sizeof(aarch64_regs));*/
2099 #elif defined(M68K)
2100         if (upeek(tcp->pid, 4*PT_D0, &m68k_d0) < 0)
2101                 return -1;
2102 #elif defined(LINUX_MIPSN32)
2103         unsigned long long regs[38];
2104
2105         if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (long) &regs) < 0)
2106                 return -1;
2107         mips_a3 = regs[REG_A3];
2108         mips_r2 = regs[REG_V0];
2109 #elif defined(MIPS)
2110         if (upeek(tcp->pid, REG_A3, &mips_a3) < 0)
2111                 return -1;
2112         if (upeek(tcp->pid, REG_V0, &mips_r2) < 0)
2113                 return -1;
2114 #elif defined(ALPHA)
2115         if (upeek(tcp->pid, REG_A3, &alpha_a3) < 0)
2116                 return -1;
2117         if (upeek(tcp->pid, REG_R0, &alpha_r0) < 0)
2118                 return -1;
2119 #elif defined(SPARC) || defined(SPARC64)
2120         /* already done by get_regs */
2121 #elif defined(HPPA)
2122         if (upeek(tcp->pid, PT_GR28, &hppa_r28) < 0)
2123                 return -1;
2124 #elif defined(SH)
2125         /* new syscall ABI returns result in R0 */
2126         if (upeek(tcp->pid, 4*REG_REG0, (long *)&sh_r0) < 0)
2127                 return -1;
2128 #elif defined(SH64)
2129         /* ABI defines result returned in r9 */
2130         if (upeek(tcp->pid, REG_GENERAL(9), (long *)&sh64_r9) < 0)
2131                 return -1;
2132 #elif defined(CRISV10) || defined(CRISV32)
2133         if (upeek(tcp->pid, 4*PT_R10, &cris_r10) < 0)
2134                 return -1;
2135 #elif defined(TILE)
2136         /* already done by get_regs */
2137 #elif defined(MICROBLAZE)
2138         if (upeek(tcp->pid, 3 * 4, &microblaze_r3) < 0)
2139                 return -1;
2140 #elif defined(OR1K)
2141         /* already done by get_regs */
2142 #elif defined(METAG)
2143         /* already done by get_regs */
2144 #elif defined(XTENSA)
2145         if (upeek(tcp->pid, REG_A_BASE + 2, &xtensa_a2) < 0)
2146                 return -1;
2147 #elif defined(ARC)
2148         /* already done by get_regs */
2149 #endif
2150         return 1;
2151 }
2152
2153 /* Called at each syscall exit */
2154 static void
2155 syscall_fixup_on_sysexit(struct tcb *tcp)
2156 {
2157 #if defined(S390) || defined(S390X)
2158         if ((tcp->flags & TCB_WAITEXECVE)
2159                  && (s390_gpr2 == -ENOSYS || s390_gpr2 == tcp->scno)) {
2160                 /*
2161                  * Return from execve.
2162                  * Fake a return value of zero.  We leave the TCB_WAITEXECVE
2163                  * flag set for the post-execve SIGTRAP to see and reset.
2164                  */
2165                 s390_gpr2 = 0;
2166         }
2167 #endif
2168 }
2169
2170 /*
2171  * Check the syscall return value register value for whether it is
2172  * a negated errno code indicating an error, or a success return value.
2173  */
2174 static inline int
2175 is_negated_errno(unsigned long int val)
2176 {
2177         unsigned long int max = -(long int) nerrnos;
2178 #if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
2179         if (current_wordsize < sizeof(val)) {
2180                 val = (unsigned int) val;
2181                 max = (unsigned int) max;
2182         }
2183 #endif
2184         return val > max;
2185 }
2186
2187 #if defined(X32)
2188 static inline int
2189 is_negated_errno_x32(unsigned long long val)
2190 {
2191         unsigned long long max = -(long long) nerrnos;
2192         /*
2193          * current_wordsize is 4 even in personality 0 (native X32)
2194          * but truncation _must not_ be done in it.
2195          * can't check current_wordsize here!
2196          */
2197         if (current_personality != 0) {
2198                 val = (uint32_t) val;
2199                 max = (uint32_t) max;
2200         }
2201         return val > max;
2202 }
2203 #endif
2204
2205 /* Returns:
2206  * 1: ok, continue in trace_syscall_exiting().
2207  * -1: error, trace_syscall_exiting() should print error indicator
2208  *    ("????" etc) and bail out.
2209  */
2210 static void
2211 get_error(struct tcb *tcp)
2212 {
2213         int u_error = 0;
2214         int check_errno = 1;
2215         if (tcp->s_ent->sys_flags & SYSCALL_NEVER_FAILS) {
2216                 check_errno = 0;
2217         }
2218 #if defined(S390) || defined(S390X)
2219         if (check_errno && is_negated_errno(s390_gpr2)) {
2220                 tcp->u_rval = -1;
2221                 u_error = -s390_gpr2;
2222         }
2223         else {
2224                 tcp->u_rval = s390_gpr2;
2225         }
2226 #elif defined(I386)
2227         if (check_errno && is_negated_errno(i386_regs.eax)) {
2228                 tcp->u_rval = -1;
2229                 u_error = -i386_regs.eax;
2230         }
2231         else {
2232                 tcp->u_rval = i386_regs.eax;
2233         }
2234 #elif defined(X86_64)
2235         long rax;
2236         if (x86_io.iov_len == sizeof(i386_regs)) {
2237                 /* Sign extend from 32 bits */
2238                 rax = (int32_t)i386_regs.eax;
2239         } else {
2240                 rax = x86_64_regs.rax;
2241         }
2242         if (check_errno && is_negated_errno(rax)) {
2243                 tcp->u_rval = -1;
2244                 u_error = -rax;
2245         }
2246         else {
2247                 tcp->u_rval = rax;
2248         }
2249 #elif defined(X32)
2250         /* In X32, return value is 64-bit (llseek uses one).
2251          * Using merely "long rax" would not work.
2252          */
2253         long long rax;
2254         if (x86_io.iov_len == sizeof(i386_regs)) {
2255                 /* Sign extend from 32 bits */
2256                 rax = (int32_t)i386_regs.eax;
2257         } else {
2258                 rax = x86_64_regs.rax;
2259         }
2260         /* Careful: is_negated_errno() works only on longs */
2261         if (check_errno && is_negated_errno_x32(rax)) {
2262                 tcp->u_rval = -1;
2263                 u_error = -rax;
2264         }
2265         else {
2266                 tcp->u_rval = rax; /* truncating */
2267                 tcp->u_lrval = rax;
2268         }
2269 #elif defined(IA64)
2270         if (ia64_ia32mode) {
2271                 int err;
2272
2273                 err = (int)ia64_r8;
2274                 if (check_errno && is_negated_errno(err)) {
2275                         tcp->u_rval = -1;
2276                         u_error = -err;
2277                 }
2278                 else {
2279                         tcp->u_rval = err;
2280                 }
2281         } else {
2282                 if (check_errno && ia64_r10) {
2283                         tcp->u_rval = -1;
2284                         u_error = ia64_r8;
2285                 } else {
2286                         tcp->u_rval = ia64_r8;
2287                 }
2288         }
2289 #elif defined(MIPS)
2290         if (check_errno && mips_a3) {
2291                 tcp->u_rval = -1;
2292                 u_error = mips_r2;
2293         } else {
2294                 tcp->u_rval = mips_r2;
2295 # if defined(LINUX_MIPSN32)
2296                 tcp->u_lrval = mips_r2;
2297 # endif
2298         }
2299 #elif defined(POWERPC)
2300         if (check_errno && (ppc_regs.ccr & 0x10000000)) {
2301                 tcp->u_rval = -1;
2302                 u_error = ppc_regs.gpr[3];
2303         }
2304         else {
2305                 tcp->u_rval = ppc_regs.gpr[3];
2306         }
2307 #elif defined(M68K)
2308         if (check_errno && is_negated_errno(m68k_d0)) {
2309                 tcp->u_rval = -1;
2310                 u_error = -m68k_d0;
2311         }
2312         else {
2313                 tcp->u_rval = m68k_d0;
2314         }
2315 #elif defined(ARM) || defined(AARCH64)
2316 # if defined(AARCH64)
2317         if (tcp->currpers == 1) {
2318                 if (check_errno && is_negated_errno(aarch64_regs.regs[0])) {
2319                         tcp->u_rval = -1;
2320                         u_error = -aarch64_regs.regs[0];
2321                 }
2322                 else {
2323                         tcp->u_rval = aarch64_regs.regs[0];
2324                 }
2325         }
2326         else
2327 # endif
2328         {
2329                 if (check_errno && is_negated_errno(arm_regs.ARM_r0)) {
2330                         tcp->u_rval = -1;
2331                         u_error = -arm_regs.ARM_r0;
2332                 }
2333                 else {
2334                         tcp->u_rval = arm_regs.ARM_r0;
2335                 }
2336         }
2337 #elif defined(AVR32)
2338         if (check_errno && avr32_regs.r12 && (unsigned) -avr32_regs.r12 < nerrnos) {
2339                 tcp->u_rval = -1;
2340                 u_error = -avr32_regs.r12;
2341         }
2342         else {
2343                 tcp->u_rval = avr32_regs.r12;
2344         }
2345 #elif defined(BFIN)
2346         if (check_errno && is_negated_errno(bfin_r0)) {
2347                 tcp->u_rval = -1;
2348                 u_error = -bfin_r0;
2349         } else {
2350                 tcp->u_rval = bfin_r0;
2351         }
2352 #elif defined(ALPHA)
2353         if (check_errno && alpha_a3) {
2354                 tcp->u_rval = -1;
2355                 u_error = alpha_r0;
2356         }
2357         else {
2358                 tcp->u_rval = alpha_r0;
2359         }
2360 #elif defined(SPARC)
2361         if (check_errno && sparc_regs.psr & PSR_C) {
2362                 tcp->u_rval = -1;
2363                 u_error = sparc_regs.u_regs[U_REG_O0];
2364         }
2365         else {
2366                 tcp->u_rval = sparc_regs.u_regs[U_REG_O0];
2367         }
2368 #elif defined(SPARC64)
2369         if (check_errno && sparc_regs.tstate & 0x1100000000UL) {
2370                 tcp->u_rval = -1;
2371                 u_error = sparc_regs.u_regs[U_REG_O0];
2372         }
2373         else {
2374                 tcp->u_rval = sparc_regs.u_regs[U_REG_O0];
2375         }
2376 #elif defined(HPPA)
2377         if (check_errno && is_negated_errno(hppa_r28)) {
2378                 tcp->u_rval = -1;
2379                 u_error = -hppa_r28;
2380         }
2381         else {
2382                 tcp->u_rval = hppa_r28;
2383         }
2384 #elif defined(SH)
2385         if (check_errno && is_negated_errno(sh_r0)) {
2386                 tcp->u_rval = -1;
2387                 u_error = -sh_r0;
2388         }
2389         else {
2390                 tcp->u_rval = sh_r0;
2391         }
2392 #elif defined(SH64)
2393         if (check_errno && is_negated_errno(sh64_r9)) {
2394                 tcp->u_rval = -1;
2395                 u_error = -sh64_r9;
2396         }
2397         else {
2398                 tcp->u_rval = sh64_r9;
2399         }
2400 #elif defined(METAG)
2401         /* result pointer in D0Re0 (D0.0) */
2402         if (check_errno && is_negated_errno(metag_regs.dx[0][0])) {
2403                 tcp->u_rval = -1;
2404                 u_error = -metag_regs.dx[0][0];
2405         }
2406         else {
2407                 tcp->u_rval = metag_regs.dx[0][0];
2408         }
2409 #elif defined(CRISV10) || defined(CRISV32)
2410         if (check_errno && cris_r10 && (unsigned) -cris_r10 < nerrnos) {
2411                 tcp->u_rval = -1;
2412                 u_error = -cris_r10;
2413         }
2414         else {
2415                 tcp->u_rval = cris_r10;
2416         }
2417 #elif defined(TILE)
2418         /*
2419          * The standard tile calling convention returns the value (or negative
2420          * errno) in r0, and zero (or positive errno) in r1.
2421          * Until at least kernel 3.8, however, the r1 value is not reflected
2422          * in ptregs at this point, so we use r0 here.
2423          */
2424         if (check_errno && is_negated_errno(tile_regs.regs[0])) {
2425                 tcp->u_rval = -1;
2426                 u_error = -tile_regs.regs[0];
2427         } else {
2428                 tcp->u_rval = tile_regs.regs[0];
2429         }
2430 #elif defined(MICROBLAZE)
2431         if (check_errno && is_negated_errno(microblaze_r3)) {
2432                 tcp->u_rval = -1;
2433                 u_error = -microblaze_r3;
2434         }
2435         else {
2436                 tcp->u_rval = microblaze_r3;
2437         }
2438 #elif defined(OR1K)
2439         if (check_errno && is_negated_errno(or1k_regs.gpr[11])) {
2440                 tcp->u_rval = -1;
2441                 u_error = -or1k_regs.gpr[11];
2442         }
2443         else {
2444                 tcp->u_rval = or1k_regs.gpr[11];
2445         }
2446 #elif defined(XTENSA)
2447         if (check_errno && is_negated_errno(xtensa_a2)) {
2448                 tcp->u_rval = -1;
2449                 u_error = -xtensa_a2;
2450         }
2451         else {
2452                 tcp->u_rval = xtensa_a2;
2453         }
2454 #elif defined(ARC)
2455         if (check_errno && is_negated_errno(arc_regs.scratch.r0)) {
2456                 tcp->u_rval = -1;
2457                 u_error = -arc_regs.scratch.r0;
2458         }
2459         else {
2460                 tcp->u_rval = arc_regs.scratch.r0;
2461         }
2462 #endif
2463         tcp->u_error = u_error;
2464 }
2465
2466 static void
2467 dumpio(struct tcb *tcp)
2468 {
2469         int (*func)();
2470
2471         if (syserror(tcp))
2472                 return;
2473         if ((unsigned long) tcp->u_arg[0] >= num_quals)
2474                 return;
2475         func = tcp->s_ent->sys_func;
2476         if (func == printargs)
2477                 return;
2478         if (qual_flags[tcp->u_arg[0]] & QUAL_READ) {
2479                 if (func == sys_read ||
2480                     func == sys_pread ||
2481                     func == sys_recv ||
2482                     func == sys_recvfrom)
2483                         dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
2484                 else if (func == sys_readv)
2485                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
2486                 return;
2487         }
2488         if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE) {
2489                 if (func == sys_write ||
2490                     func == sys_pwrite ||
2491                     func == sys_send ||
2492                     func == sys_sendto)
2493                         dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
2494                 else if (func == sys_writev)
2495                         dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
2496                 return;
2497         }
2498 }
2499
2500 static int
2501 trace_syscall_exiting(struct tcb *tcp)
2502 {
2503         int sys_res;
2504         struct timeval tv;
2505         int res;
2506         long u_error;
2507
2508         /* Measure the exit time as early as possible to avoid errors. */
2509         if (Tflag || cflag)
2510                 gettimeofday(&tv, NULL);
2511
2512 #if SUPPORTED_PERSONALITIES > 1
2513         update_personality(tcp, tcp->currpers);
2514 #endif
2515         res = (get_regs_error ? -1 : get_syscall_result(tcp));
2516         if (res == 1) {
2517                 syscall_fixup_on_sysexit(tcp); /* never fails */
2518                 get_error(tcp); /* never fails */
2519                 if (need_fork_exec_workarounds)
2520                         syscall_fixup_for_fork_exec(tcp);
2521                 if (filtered(tcp) || hide_log_until_execve)
2522                         goto ret;
2523         }
2524
2525         if (cflag) {
2526                 count_syscall(tcp, &tv);
2527                 if (cflag == CFLAG_ONLY_STATS) {
2528                         goto ret;
2529                 }
2530         }
2531
2532         /* If not in -ff mode, and printing_tcp != tcp,
2533          * then the log currently does not end with output
2534          * of _our syscall entry_, but with something else.
2535          * We need to say which syscall's return is this.
2536          *
2537          * Forced reprinting via TCB_REPRINT is used only by
2538          * "strace -ff -oLOG test/threaded_execve" corner case.
2539          * It's the only case when -ff mode needs reprinting.
2540          */
2541         if ((followfork < 2 && printing_tcp != tcp) || (tcp->flags & TCB_REPRINT)) {
2542                 tcp->flags &= ~TCB_REPRINT;
2543                 printleader(tcp);
2544                 if (tcp->qual_flg & UNDEFINED_SCNO)
2545                         tprintf("<... %s resumed> ", undefined_scno_name(tcp));
2546                 else
2547                         tprintf("<... %s resumed> ", tcp->s_ent->sys_name);
2548         }
2549         printing_tcp = tcp;
2550
2551         if (res != 1) {
2552                 /* There was error in one of prior ptrace ops */
2553                 tprints(") ");
2554                 tabto();
2555                 tprints("= ? <unavailable>\n");
2556                 line_ended();
2557                 tcp->flags &= ~TCB_INSYSCALL;
2558                 return res;
2559         }
2560
2561         sys_res = 0;
2562         if (tcp->qual_flg & QUAL_RAW) {
2563                 /* sys_res = printargs(tcp); - but it's nop on sysexit */
2564         } else {
2565         /* FIXME: not_failing_only (IOW, option -z) is broken:
2566          * failure of syscall is known only after syscall return.
2567          * Thus we end up with something like this on, say, ENOENT:
2568          *     open("doesnt_exist", O_RDONLY <unfinished ...>
2569          *     {next syscall decode}
2570          * whereas the intended result is that open(...) line
2571          * is not shown at all.
2572          */
2573                 if (not_failing_only && tcp->u_error)
2574                         goto ret;       /* ignore failed syscalls */
2575                 sys_res = tcp->s_ent->sys_func(tcp);
2576         }
2577
2578         tprints(") ");
2579         tabto();
2580         u_error = tcp->u_error;
2581         if (tcp->qual_flg & QUAL_RAW) {
2582                 if (u_error)
2583                         tprintf("= -1 (errno %ld)", u_error);
2584                 else
2585                         tprintf("= %#lx", tcp->u_rval);
2586         }
2587         else if (!(sys_res & RVAL_NONE) && u_error) {
2588                 switch (u_error) {
2589                 /* Blocked signals do not interrupt any syscalls.
2590                  * In this case syscalls don't return ERESTARTfoo codes.
2591                  *
2592                  * Deadly signals set to SIG_DFL interrupt syscalls
2593                  * and kill the process regardless of which of the codes below
2594                  * is returned by the interrupted syscall.
2595                  * In some cases, kernel forces a kernel-generated deadly
2596                  * signal to be unblocked and set to SIG_DFL (and thus cause
2597                  * death) if it is blocked or SIG_IGNed: for example, SIGSEGV
2598                  * or SIGILL. (The alternative is to leave process spinning
2599                  * forever on the faulty instruction - not useful).
2600                  *
2601                  * SIG_IGNed signals and non-deadly signals set to SIG_DFL
2602                  * (for example, SIGCHLD, SIGWINCH) interrupt syscalls,
2603                  * but kernel will always restart them.
2604                  */
2605                 case ERESTARTSYS:
2606                         /* Most common type of signal-interrupted syscall exit code.
2607                          * The system call will be restarted with the same arguments
2608                          * if SA_RESTART is set; otherwise, it will fail with EINTR.
2609                          */
2610                         tprints("= ? ERESTARTSYS (To be restarted if SA_RESTART is set)");
2611                         break;
2612                 case ERESTARTNOINTR:
2613                         /* Rare. For example, fork() returns this if interrupted.
2614                          * SA_RESTART is ignored (assumed set): the restart is unconditional.
2615                          */
2616                         tprints("= ? ERESTARTNOINTR (To be restarted)");
2617                         break;
2618                 case ERESTARTNOHAND:
2619                         /* pause(), rt_sigsuspend() etc use this code.
2620                          * SA_RESTART is ignored (assumed not set):
2621                          * syscall won't restart (will return EINTR instead)
2622                          * even after signal with SA_RESTART set. However,
2623                          * after SIG_IGN or SIG_DFL signal it will restart
2624                          * (thus the name "restart only if has no handler").
2625                          */
2626                         tprints("= ? ERESTARTNOHAND (To be restarted if no handler)");
2627                         break;
2628                 case ERESTART_RESTARTBLOCK:
2629                         /* Syscalls like nanosleep(), poll() which can't be
2630                          * restarted with their original arguments use this
2631                          * code. Kernel will execute restart_syscall() instead,
2632                          * which changes arguments before restarting syscall.
2633                          * SA_RESTART is ignored (assumed not set) similarly
2634                          * to ERESTARTNOHAND. (Kernel can't honor SA_RESTART
2635                          * since restart data is saved in "restart block"
2636                          * in task struct, and if signal handler uses a syscall
2637                          * which in turn saves another such restart block,
2638                          * old data is lost and restart becomes impossible)
2639                          */
2640                         tprints("= ? ERESTART_RESTARTBLOCK (Interrupted by signal)");
2641                         break;
2642                 default:
2643                         if (u_error < 0)
2644                                 tprintf("= -1 E??? (errno %ld)", u_error);
2645                         else if (u_error < nerrnos)
2646                                 tprintf("= -1 %s (%s)", errnoent[u_error],
2647                                         strerror(u_error));
2648                         else
2649                                 tprintf("= -1 ERRNO_%ld (%s)", u_error,
2650                                         strerror(u_error));
2651                         break;
2652                 }
2653                 if ((sys_res & RVAL_STR) && tcp->auxstr)
2654                         tprintf(" (%s)", tcp->auxstr);
2655         }
2656         else {
2657                 if (sys_res & RVAL_NONE)
2658                         tprints("= ?");
2659                 else {
2660                         switch (sys_res & RVAL_MASK) {
2661                         case RVAL_HEX:
2662                                 tprintf("= %#lx", tcp->u_rval);
2663                                 break;
2664                         case RVAL_OCTAL:
2665                                 tprintf("= %#lo", tcp->u_rval);
2666                                 break;
2667                         case RVAL_UDECIMAL:
2668                                 tprintf("= %lu", tcp->u_rval);
2669                                 break;
2670                         case RVAL_DECIMAL:
2671                                 tprintf("= %ld", tcp->u_rval);
2672                                 break;
2673 #if defined(LINUX_MIPSN32) || defined(X32)
2674                         /*
2675                         case RVAL_LHEX:
2676                                 tprintf("= %#llx", tcp->u_lrval);
2677                                 break;
2678                         case RVAL_LOCTAL:
2679                                 tprintf("= %#llo", tcp->u_lrval);
2680                                 break;
2681                         */
2682                         case RVAL_LUDECIMAL:
2683                                 tprintf("= %llu", tcp->u_lrval);
2684                                 break;
2685                         /*
2686                         case RVAL_LDECIMAL:
2687                                 tprintf("= %lld", tcp->u_lrval);
2688                                 break;
2689                         */
2690 #endif
2691                         default:
2692                                 fprintf(stderr,
2693                                         "invalid rval format\n");
2694                                 break;
2695                         }
2696                 }
2697                 if ((sys_res & RVAL_STR) && tcp->auxstr)
2698                         tprintf(" (%s)", tcp->auxstr);
2699         }
2700         if (Tflag) {
2701                 tv_sub(&tv, &tv, &tcp->etime);
2702                 tprintf(" <%ld.%06ld>",
2703                         (long) tv.tv_sec, (long) tv.tv_usec);
2704         }
2705         tprints("\n");
2706         dumpio(tcp);
2707         line_ended();
2708
2709  ret:
2710         tcp->flags &= ~TCB_INSYSCALL;
2711         return 0;
2712 }
2713
2714 int
2715 trace_syscall(struct tcb *tcp)
2716 {
2717         return exiting(tcp) ?
2718                 trace_syscall_exiting(tcp) : trace_syscall_entering(tcp);
2719 }