syscall_emul.cc revision 6029
1/* 2 * Copyright (c) 2003-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Steve Reinhardt 29 * Ali Saidi 30 */ 31 32#include <fcntl.h> 33#include <unistd.h> 34 35#include <string> 36#include <iostream> 37 38#include "sim/syscall_emul.hh" 39#include "base/chunk_generator.hh" 40#include "base/trace.hh" 41#include "cpu/thread_context.hh" 42#include "cpu/base.hh" 43#include "mem/page_table.hh" 44#include "sim/process.hh" 45#include "sim/system.hh" 46 47#include "sim/sim_exit.hh" 48 49using namespace std; 50using namespace TheISA; 51 52void 53SyscallDesc::doSyscall(int callnum, LiveProcess *process, ThreadContext *tc) 54{ 55 DPRINTFR(SyscallVerbose, "%d: %s: syscall %s called w/arguments %d,%d,%d,%d\n", 56 curTick,tc->getCpuPtr()->name(), name, 57 process->getSyscallArg(tc, 0), process->getSyscallArg(tc, 1), 58 process->getSyscallArg(tc, 2), process->getSyscallArg(tc, 3)); 59 60 SyscallReturn retval = (*funcPtr)(this, callnum, process, tc); 61 62 DPRINTFR(SyscallVerbose, "%d: %s: syscall %s returns %d\n", 63 curTick,tc->getCpuPtr()->name(), name, retval.value()); 64 65 if (!(flags & SyscallDesc::SuppressReturnValue)) 66 process->setSyscallReturn(tc, retval); 67} 68 69 70SyscallReturn 71unimplementedFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 72 ThreadContext *tc) 73{ 74 fatal("syscall %s (#%d) unimplemented.", desc->name, callnum); 75 76 return 1; 77} 78 79 80SyscallReturn 81ignoreFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 82 ThreadContext *tc) 83{ 84 warn("ignoring syscall %s(%d, %d, ...)", desc->name, 85 process->getSyscallArg(tc, 0), process->getSyscallArg(tc, 1)); 86 87 return 0; 88} 89 90 91SyscallReturn 92exitFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 93 ThreadContext *tc) 94{ 95 if (process->system->numRunningContexts() == 1) { 96 // Last running context... exit simulator 97 exitSimLoop("target called exit()", 98 process->getSyscallArg(tc, 0) & 0xff); 99 } else { 100 // other running threads... just halt this one 101 tc->halt(); 102 } 103 104 return 1; 105} 106 107 108SyscallReturn 109getpagesizeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 110{ 111 return (int)VMPageSize; 112} 113 114 115SyscallReturn 116brkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 117{ 118 // change brk addr to first arg 119 Addr new_brk = p->getSyscallArg(tc, 0); 120 121 // in Linux at least, brk(0) returns the current break value 122 // (note that the syscall and the glibc function have different behavior) 123 if (new_brk == 0) 124 return p->brk_point; 125 126 if (new_brk > p->brk_point) { 127 // might need to allocate some new pages 128 for (ChunkGenerator gen(p->brk_point, new_brk - p->brk_point, 129 VMPageSize); !gen.done(); gen.next()) { 130 if (!p->pTable->translate(gen.addr())) 131 p->pTable->allocate(roundDown(gen.addr(), VMPageSize), 132 VMPageSize); 133 } 134 } 135 136 p->brk_point = new_brk; 137 DPRINTF(SyscallVerbose, "Break Point changed to: %#X\n", p->brk_point); 138 return p->brk_point; 139} 140 141 142SyscallReturn 143closeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 144{ 145 int target_fd = p->getSyscallArg(tc, 0); 146 int status = close(p->sim_fd(target_fd)); 147 if (status >= 0) 148 p->free_fd(target_fd); 149 return status; 150} 151 152 153SyscallReturn 154readFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 155{ 156 int fd = p->sim_fd(p->getSyscallArg(tc, 0)); 157 int nbytes = p->getSyscallArg(tc, 2); 158 BufferArg bufArg(p->getSyscallArg(tc, 1), nbytes); 159 160 int bytes_read = read(fd, bufArg.bufferPtr(), nbytes); 161 162 if (bytes_read != -1) 163 bufArg.copyOut(tc->getMemPort()); 164 165 return bytes_read; 166} 167 168SyscallReturn 169writeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 170{ 171 int fd = p->sim_fd(p->getSyscallArg(tc, 0)); 172 int nbytes = p->getSyscallArg(tc, 2); 173 BufferArg bufArg(p->getSyscallArg(tc, 1), nbytes); 174 175 bufArg.copyIn(tc->getMemPort()); 176 177 int bytes_written = write(fd, bufArg.bufferPtr(), nbytes); 178 179 fsync(fd); 180 181 return bytes_written; 182} 183 184 185SyscallReturn 186lseekFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 187{ 188 int fd = p->sim_fd(p->getSyscallArg(tc, 0)); 189 uint64_t offs = p->getSyscallArg(tc, 1); 190 int whence = p->getSyscallArg(tc, 2); 191 192 off_t result = lseek(fd, offs, whence); 193 194 return (result == (off_t)-1) ? -errno : result; 195} 196 197 198SyscallReturn 199_llseekFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 200{ 201 int fd = p->sim_fd(p->getSyscallArg(tc, 0)); 202 uint64_t offset_high = p->getSyscallArg(tc, 1); 203 uint32_t offset_low = p->getSyscallArg(tc, 2); 204 Addr result_ptr = p->getSyscallArg(tc, 3); 205 int whence = p->getSyscallArg(tc, 4); 206 207 uint64_t offset = (offset_high << 32) | offset_low; 208 209 uint64_t result = lseek(fd, offset, whence); 210 result = TheISA::htog(result); 211 212 if (result == (off_t)-1) { 213 //The seek failed. 214 return -errno; 215 } else { 216 //The seek succeeded. 217 //Copy "result" to "result_ptr" 218 //XXX We'll assume that the size of loff_t is 64 bits on the 219 //target platform 220 BufferArg result_buf(result_ptr, sizeof(result)); 221 memcpy(result_buf.bufferPtr(), &result, sizeof(result)); 222 result_buf.copyOut(tc->getMemPort()); 223 return 0; 224 } 225 226 227 return (result == (off_t)-1) ? -errno : result; 228} 229 230 231SyscallReturn 232munmapFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 233{ 234 // given that we don't really implement mmap, munmap is really easy 235 return 0; 236} 237 238 239const char *hostname = "m5.eecs.umich.edu"; 240 241SyscallReturn 242gethostnameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 243{ 244 int name_len = p->getSyscallArg(tc, 1); 245 BufferArg name(p->getSyscallArg(tc, 0), name_len); 246 247 strncpy((char *)name.bufferPtr(), hostname, name_len); 248 249 name.copyOut(tc->getMemPort()); 250 251 return 0; 252} 253 254SyscallReturn 255getcwdFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 256{ 257 int result = 0; 258 unsigned long size = p->getSyscallArg(tc, 1); 259 BufferArg buf(p->getSyscallArg(tc, 0), size); 260 261 // Is current working directory defined? 262 string cwd = p->getcwd(); 263 if (!cwd.empty()) { 264 if (cwd.length() >= size) { 265 // Buffer too small 266 return -ERANGE; 267 } 268 strncpy((char *)buf.bufferPtr(), cwd.c_str(), size); 269 result = cwd.length(); 270 } 271 else { 272 if (getcwd((char *)buf.bufferPtr(), size) != NULL) { 273 result = strlen((char *)buf.bufferPtr()); 274 } 275 else { 276 result = -1; 277 } 278 } 279 280 buf.copyOut(tc->getMemPort()); 281 282 return (result == -1) ? -errno : result; 283} 284 285 286SyscallReturn 287readlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 288{ 289 string path; 290 291 if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, 0))) 292 return (TheISA::IntReg)-EFAULT; 293 294 // Adjust path for current working directory 295 path = p->fullPath(path); 296 297 size_t bufsiz = p->getSyscallArg(tc, 2); 298 BufferArg buf(p->getSyscallArg(tc, 1), bufsiz); 299 300 int result = readlink(path.c_str(), (char *)buf.bufferPtr(), bufsiz); 301 302 buf.copyOut(tc->getMemPort()); 303 304 return (result == -1) ? -errno : result; 305} 306 307SyscallReturn 308unlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 309{ 310 string path; 311 312 if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, 0))) 313 return (TheISA::IntReg)-EFAULT; 314 315 // Adjust path for current working directory 316 path = p->fullPath(path); 317 318 int result = unlink(path.c_str()); 319 return (result == -1) ? -errno : result; 320} 321 322 323SyscallReturn 324mkdirFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 325{ 326 string path; 327 328 if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, 0))) 329 return (TheISA::IntReg)-EFAULT; 330 331 // Adjust path for current working directory 332 path = p->fullPath(path); 333 334 mode_t mode = p->getSyscallArg(tc, 1); 335 336 int result = mkdir(path.c_str(), mode); 337 return (result == -1) ? -errno : result; 338} 339 340SyscallReturn 341renameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 342{ 343 string old_name; 344 345 if (!tc->getMemPort()->tryReadString(old_name, p->getSyscallArg(tc, 0))) 346 return -EFAULT; 347 348 string new_name; 349 350 if (!tc->getMemPort()->tryReadString(new_name, p->getSyscallArg(tc, 1))) 351 return -EFAULT; 352 353 // Adjust path for current working directory 354 old_name = p->fullPath(old_name); 355 new_name = p->fullPath(new_name); 356 357 int64_t result = rename(old_name.c_str(), new_name.c_str()); 358 return (result == -1) ? -errno : result; 359} 360 361SyscallReturn 362truncateFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 363{ 364 string path; 365 366 if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, 0))) 367 return -EFAULT; 368 369 off_t length = p->getSyscallArg(tc, 1); 370 371 // Adjust path for current working directory 372 path = p->fullPath(path); 373 374 int result = truncate(path.c_str(), length); 375 return (result == -1) ? -errno : result; 376} 377 378SyscallReturn 379ftruncateFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 380{ 381 int fd = process->sim_fd(process->getSyscallArg(tc, 0)); 382 383 if (fd < 0) 384 return -EBADF; 385 386 off_t length = process->getSyscallArg(tc, 1); 387 388 int result = ftruncate(fd, length); 389 return (result == -1) ? -errno : result; 390} 391 392SyscallReturn 393umaskFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 394{ 395 // Letting the simulated program change the simulator's umask seems like 396 // a bad idea. Compromise by just returning the current umask but not 397 // changing anything. 398 mode_t oldMask = umask(0); 399 umask(oldMask); 400 return (int)oldMask; 401} 402 403SyscallReturn 404chownFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 405{ 406 string path; 407 408 if (!tc->getMemPort()->tryReadString(path, p->getSyscallArg(tc, 0))) 409 return -EFAULT; 410 411 /* XXX endianess */ 412 uint32_t owner = p->getSyscallArg(tc, 1); 413 uid_t hostOwner = owner; 414 uint32_t group = p->getSyscallArg(tc, 2); 415 gid_t hostGroup = group; 416 417 // Adjust path for current working directory 418 path = p->fullPath(path); 419 420 int result = chown(path.c_str(), hostOwner, hostGroup); 421 return (result == -1) ? -errno : result; 422} 423 424SyscallReturn 425fchownFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 426{ 427 int fd = process->sim_fd(process->getSyscallArg(tc, 0)); 428 429 if (fd < 0) 430 return -EBADF; 431 432 /* XXX endianess */ 433 uint32_t owner = process->getSyscallArg(tc, 1); 434 uid_t hostOwner = owner; 435 uint32_t group = process->getSyscallArg(tc, 2); 436 gid_t hostGroup = group; 437 438 int result = fchown(fd, hostOwner, hostGroup); 439 return (result == -1) ? -errno : result; 440} 441 442 443SyscallReturn 444dupFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 445{ 446 int fd = process->sim_fd(process->getSyscallArg(tc, 0)); 447 if (fd < 0) 448 return -EBADF; 449 450 Process::FdMap *fdo = process->sim_fd_obj(process->getSyscallArg(tc, 0)); 451 452 int result = dup(fd); 453 return (result == -1) ? -errno : process->alloc_fd(result, fdo->filename, fdo->flags, fdo->mode, false); 454} 455 456 457SyscallReturn 458fcntlFunc(SyscallDesc *desc, int num, LiveProcess *process, 459 ThreadContext *tc) 460{ 461 int fd = process->getSyscallArg(tc, 0); 462 463 if (fd < 0 || process->sim_fd(fd) < 0) 464 return -EBADF; 465 466 int cmd = process->getSyscallArg(tc, 1); 467 switch (cmd) { 468 case 0: // F_DUPFD 469 // if we really wanted to support this, we'd need to do it 470 // in the target fd space. 471 warn("fcntl(%d, F_DUPFD) not supported, error returned\n", fd); 472 return -EMFILE; 473 474 case 1: // F_GETFD (get close-on-exec flag) 475 case 2: // F_SETFD (set close-on-exec flag) 476 return 0; 477 478 case 3: // F_GETFL (get file flags) 479 case 4: // F_SETFL (set file flags) 480 // not sure if this is totally valid, but we'll pass it through 481 // to the underlying OS 482 warn("fcntl(%d, %d) passed through to host\n", fd, cmd); 483 return fcntl(process->sim_fd(fd), cmd); 484 // return 0; 485 486 case 7: // F_GETLK (get lock) 487 case 8: // F_SETLK (set lock) 488 case 9: // F_SETLKW (set lock and wait) 489 // don't mess with file locking... just act like it's OK 490 warn("File lock call (fcntl(%d, %d)) ignored.\n", fd, cmd); 491 return 0; 492 493 default: 494 warn("Unknown fcntl command %d\n", cmd); 495 return 0; 496 } 497} 498 499SyscallReturn 500fcntl64Func(SyscallDesc *desc, int num, LiveProcess *process, 501 ThreadContext *tc) 502{ 503 int fd = process->getSyscallArg(tc, 0); 504 505 if (fd < 0 || process->sim_fd(fd) < 0) 506 return -EBADF; 507 508 int cmd = process->getSyscallArg(tc, 1); 509 switch (cmd) { 510 case 33: //F_GETLK64 511 warn("fcntl64(%d, F_GETLK64) not supported, error returned\n", fd); 512 return -EMFILE; 513 514 case 34: // F_SETLK64 515 case 35: // F_SETLKW64 516 warn("fcntl64(%d, F_SETLK(W)64) not supported, error returned\n", fd); 517 return -EMFILE; 518 519 default: 520 // not sure if this is totally valid, but we'll pass it through 521 // to the underlying OS 522 warn("fcntl64(%d, %d) passed through to host\n", fd, cmd); 523 return fcntl(process->sim_fd(fd), cmd); 524 // return 0; 525 } 526} 527 528SyscallReturn 529pipePseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 530 ThreadContext *tc) 531{ 532 int fds[2], sim_fds[2]; 533 int pipe_retval = pipe(fds); 534 535 if (pipe_retval < 0) { 536 // error 537 return pipe_retval; 538 } 539 540 sim_fds[0] = process->alloc_fd(fds[0], "PIPE-READ", O_WRONLY, -1, true); 541 sim_fds[1] = process->alloc_fd(fds[1], "PIPE-WRITE", O_RDONLY, -1, true); 542 543 process->setReadPipeSource(sim_fds[0], sim_fds[1]); 544 // Alpha Linux convention for pipe() is that fd[0] is returned as 545 // the return value of the function, and fd[1] is returned in r20. 546 tc->setIntReg(SyscallPseudoReturnReg, sim_fds[1]); 547 return sim_fds[0]; 548} 549 550 551SyscallReturn 552getpidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 553 ThreadContext *tc) 554{ 555 // Make up a PID. There's no interprocess communication in 556 // fake_syscall mode, so there's no way for a process to know it's 557 // not getting a unique value. 558 559 tc->setIntReg(SyscallPseudoReturnReg, process->ppid()); 560 return process->pid(); 561} 562 563 564SyscallReturn 565getuidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 566 ThreadContext *tc) 567{ 568 // Make up a UID and EUID... it shouldn't matter, and we want the 569 // simulation to be deterministic. 570 571 // EUID goes in r20. 572 tc->setIntReg(SyscallPseudoReturnReg, process->euid()); //EUID 573 return process->uid(); // UID 574} 575 576 577SyscallReturn 578getgidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 579 ThreadContext *tc) 580{ 581 // Get current group ID. EGID goes in r20. 582 tc->setIntReg(SyscallPseudoReturnReg, process->egid()); //EGID 583 return process->gid(); 584} 585 586 587SyscallReturn 588setuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 589 ThreadContext *tc) 590{ 591 // can't fathom why a benchmark would call this. 592 warn("Ignoring call to setuid(%d)\n", process->getSyscallArg(tc, 0)); 593 return 0; 594} 595 596SyscallReturn 597getpidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 598 ThreadContext *tc) 599{ 600 // Make up a PID. There's no interprocess communication in 601 // fake_syscall mode, so there's no way for a process to know it's 602 // not getting a unique value. 603 604 tc->setIntReg(SyscallPseudoReturnReg, process->ppid()); //PID 605 return process->pid(); 606} 607 608SyscallReturn 609getppidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 610 ThreadContext *tc) 611{ 612 return process->ppid(); 613} 614 615SyscallReturn 616getuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 617 ThreadContext *tc) 618{ 619 return process->uid(); // UID 620} 621 622SyscallReturn 623geteuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 624 ThreadContext *tc) 625{ 626 return process->euid(); // UID 627} 628 629SyscallReturn 630getgidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 631 ThreadContext *tc) 632{ 633 return process->gid(); 634} 635 636SyscallReturn 637getegidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 638 ThreadContext *tc) 639{ 640 return process->egid(); 641} 642 643 644