syscall_emul.cc revision 3669:3607aaed36b6
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 46#include "sim/sim_exit.hh" 47 48using namespace std; 49using namespace TheISA; 50 51void 52SyscallDesc::doSyscall(int callnum, LiveProcess *process, ThreadContext *tc) 53{ 54 DPRINTFR(SyscallVerbose, "%d: %s: syscall %s called w/arguments %d,%d,%d,%d\n", 55 curTick,tc->getCpuPtr()->name(), name, 56 tc->getSyscallArg(0),tc->getSyscallArg(1), 57 tc->getSyscallArg(2),tc->getSyscallArg(3)); 58 59 SyscallReturn retval = (*funcPtr)(this, callnum, process, tc); 60 61 DPRINTFR(SyscallVerbose, "%d: %s: syscall %s returns %d\n", 62 curTick,tc->getCpuPtr()->name(), name, retval.value()); 63 64 if (!(flags & SyscallDesc::SuppressReturnValue)) 65 tc->setSyscallReturn(retval); 66} 67 68 69SyscallReturn 70unimplementedFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 71 ThreadContext *tc) 72{ 73 fatal("syscall %s (#%d) unimplemented.", desc->name, callnum); 74 75 return 1; 76} 77 78 79SyscallReturn 80ignoreFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 81 ThreadContext *tc) 82{ 83 warn("ignoring syscall %s(%d, %d, ...)", desc->name, 84 tc->getSyscallArg(0), tc->getSyscallArg(1)); 85 86 return 0; 87} 88 89 90SyscallReturn 91exitFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 92 ThreadContext *tc) 93{ 94 if (tc->exit()) { 95 exitSimLoop("target called exit()", tc->getSyscallArg(0) & 0xff); 96 } 97 98 return 1; 99} 100 101 102SyscallReturn 103getpagesizeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 104{ 105 return (int)VMPageSize; 106} 107 108 109SyscallReturn 110obreakFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 111{ 112 Addr junk; 113 114 // change brk addr to first arg 115 Addr new_brk = tc->getSyscallArg(0); 116 if (new_brk != 0) { 117 for (ChunkGenerator gen(p->brk_point, new_brk - p->brk_point, 118 VMPageSize); !gen.done(); gen.next()) { 119 if (!p->pTable->translate(gen.addr(), junk)) 120 p->pTable->allocate(roundDown(gen.addr(), VMPageSize), 121 VMPageSize); 122 } 123 p->brk_point = new_brk; 124 } 125 DPRINTF(SyscallVerbose, "Break Point changed to: %#X\n", p->brk_point); 126 return p->brk_point; 127} 128 129 130SyscallReturn 131closeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 132{ 133 int target_fd = tc->getSyscallArg(0); 134 int status = close(p->sim_fd(target_fd)); 135 if (status >= 0) 136 p->free_fd(target_fd); 137 return status; 138} 139 140 141SyscallReturn 142readFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 143{ 144 int fd = p->sim_fd(tc->getSyscallArg(0)); 145 int nbytes = tc->getSyscallArg(2); 146 BufferArg bufArg(tc->getSyscallArg(1), nbytes); 147 148 int bytes_read = read(fd, bufArg.bufferPtr(), nbytes); 149 150 if (bytes_read != -1) 151 bufArg.copyOut(tc->getMemPort()); 152 153 return bytes_read; 154} 155 156SyscallReturn 157writeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 158{ 159 int fd = p->sim_fd(tc->getSyscallArg(0)); 160 int nbytes = tc->getSyscallArg(2); 161 BufferArg bufArg(tc->getSyscallArg(1), nbytes); 162 163 bufArg.copyIn(tc->getMemPort()); 164 165 int bytes_written = write(fd, bufArg.bufferPtr(), nbytes); 166 167 fsync(fd); 168 169 return bytes_written; 170} 171 172 173SyscallReturn 174lseekFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 175{ 176 int fd = p->sim_fd(tc->getSyscallArg(0)); 177 uint64_t offs = tc->getSyscallArg(1); 178 int whence = tc->getSyscallArg(2); 179 180 off_t result = lseek(fd, offs, whence); 181 182 return (result == (off_t)-1) ? -errno : result; 183} 184 185 186SyscallReturn 187munmapFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 188{ 189 // given that we don't really implement mmap, munmap is really easy 190 return 0; 191} 192 193 194const char *hostname = "m5.eecs.umich.edu"; 195 196SyscallReturn 197gethostnameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 198{ 199 int name_len = tc->getSyscallArg(1); 200 BufferArg name(tc->getSyscallArg(0), name_len); 201 202 strncpy((char *)name.bufferPtr(), hostname, name_len); 203 204 name.copyOut(tc->getMemPort()); 205 206 return 0; 207} 208 209SyscallReturn 210unlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 211{ 212 string path; 213 214 if (!tc->getMemPort()->tryReadString(path, tc->getSyscallArg(0))) 215 return (TheISA::IntReg)-EFAULT; 216 217 // Adjust path for current working directory 218 path = p->fullPath(path); 219 220 int result = unlink(path.c_str()); 221 return (result == -1) ? -errno : result; 222} 223 224SyscallReturn 225renameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 226{ 227 string old_name; 228 229 if (!tc->getMemPort()->tryReadString(old_name, tc->getSyscallArg(0))) 230 return -EFAULT; 231 232 string new_name; 233 234 if (!tc->getMemPort()->tryReadString(new_name, tc->getSyscallArg(1))) 235 return -EFAULT; 236 237 // Adjust path for current working directory 238 old_name = p->fullPath(old_name); 239 new_name = p->fullPath(new_name); 240 241 int64_t result = rename(old_name.c_str(), new_name.c_str()); 242 return (result == -1) ? -errno : result; 243} 244 245SyscallReturn 246truncateFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 247{ 248 string path; 249 250 if (!tc->getMemPort()->tryReadString(path, tc->getSyscallArg(0))) 251 return -EFAULT; 252 253 off_t length = tc->getSyscallArg(1); 254 255 // Adjust path for current working directory 256 path = p->fullPath(path); 257 258 int result = truncate(path.c_str(), length); 259 return (result == -1) ? -errno : result; 260} 261 262SyscallReturn 263ftruncateFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 264{ 265 int fd = process->sim_fd(tc->getSyscallArg(0)); 266 267 if (fd < 0) 268 return -EBADF; 269 270 off_t length = tc->getSyscallArg(1); 271 272 int result = ftruncate(fd, length); 273 return (result == -1) ? -errno : result; 274} 275 276SyscallReturn 277chownFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 278{ 279 string path; 280 281 if (!tc->getMemPort()->tryReadString(path, tc->getSyscallArg(0))) 282 return -EFAULT; 283 284 /* XXX endianess */ 285 uint32_t owner = tc->getSyscallArg(1); 286 uid_t hostOwner = owner; 287 uint32_t group = tc->getSyscallArg(2); 288 gid_t hostGroup = group; 289 290 // Adjust path for current working directory 291 path = p->fullPath(path); 292 293 int result = chown(path.c_str(), hostOwner, hostGroup); 294 return (result == -1) ? -errno : result; 295} 296 297SyscallReturn 298fchownFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 299{ 300 int fd = process->sim_fd(tc->getSyscallArg(0)); 301 302 if (fd < 0) 303 return -EBADF; 304 305 /* XXX endianess */ 306 uint32_t owner = tc->getSyscallArg(1); 307 uid_t hostOwner = owner; 308 uint32_t group = tc->getSyscallArg(2); 309 gid_t hostGroup = group; 310 311 int result = fchown(fd, hostOwner, hostGroup); 312 return (result == -1) ? -errno : result; 313} 314 315 316SyscallReturn 317dupFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 318{ 319 int fd = process->sim_fd(tc->getSyscallArg(0)); 320 321 if (fd < 0) 322 return -EBADF; 323 324 int result = dup(fd); 325 return (result == -1) ? -errno : process->alloc_fd(result); 326} 327 328 329SyscallReturn 330fcntlFunc(SyscallDesc *desc, int num, LiveProcess *process, 331 ThreadContext *tc) 332{ 333 int fd = tc->getSyscallArg(0); 334 335 if (fd < 0 || process->sim_fd(fd) < 0) 336 return -EBADF; 337 338 int cmd = tc->getSyscallArg(1); 339 switch (cmd) { 340 case 0: // F_DUPFD 341 // if we really wanted to support this, we'd need to do it 342 // in the target fd space. 343 warn("fcntl(%d, F_DUPFD) not supported, error returned\n", fd); 344 return -EMFILE; 345 346 case 1: // F_GETFD (get close-on-exec flag) 347 case 2: // F_SETFD (set close-on-exec flag) 348 return 0; 349 350 case 3: // F_GETFL (get file flags) 351 case 4: // F_SETFL (set file flags) 352 // not sure if this is totally valid, but we'll pass it through 353 // to the underlying OS 354 warn("fcntl(%d, %d) passed through to host\n", fd, cmd); 355 return fcntl(process->sim_fd(fd), cmd); 356 // return 0; 357 358 case 7: // F_GETLK (get lock) 359 case 8: // F_SETLK (set lock) 360 case 9: // F_SETLKW (set lock and wait) 361 // don't mess with file locking... just act like it's OK 362 warn("File lock call (fcntl(%d, %d)) ignored.\n", fd, cmd); 363 return 0; 364 365 default: 366 warn("Unknown fcntl command %d\n", cmd); 367 return 0; 368 } 369} 370 371SyscallReturn 372fcntl64Func(SyscallDesc *desc, int num, LiveProcess *process, 373 ThreadContext *tc) 374{ 375 int fd = tc->getSyscallArg(0); 376 377 if (fd < 0 || process->sim_fd(fd) < 0) 378 return -EBADF; 379 380 int cmd = tc->getSyscallArg(1); 381 switch (cmd) { 382 case 33: //F_GETLK64 383 warn("fcntl64(%d, F_GETLK64) not supported, error returned\n", fd); 384 return -EMFILE; 385 386 case 34: // F_SETLK64 387 case 35: // F_SETLKW64 388 warn("fcntl64(%d, F_SETLK(W)64) not supported, error returned\n", fd); 389 return -EMFILE; 390 391 default: 392 // not sure if this is totally valid, but we'll pass it through 393 // to the underlying OS 394 warn("fcntl64(%d, %d) passed through to host\n", fd, cmd); 395 return fcntl(process->sim_fd(fd), cmd); 396 // return 0; 397 } 398} 399 400SyscallReturn 401pipePseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 402 ThreadContext *tc) 403{ 404 int fds[2], sim_fds[2]; 405 int pipe_retval = pipe(fds); 406 407 if (pipe_retval < 0) { 408 // error 409 return pipe_retval; 410 } 411 412 sim_fds[0] = process->alloc_fd(fds[0]); 413 sim_fds[1] = process->alloc_fd(fds[1]); 414 415 // Alpha Linux convention for pipe() is that fd[0] is returned as 416 // the return value of the function, and fd[1] is returned in r20. 417 tc->setIntReg(SyscallPseudoReturnReg, sim_fds[1]); 418 return sim_fds[0]; 419} 420 421 422SyscallReturn 423getpidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 424 ThreadContext *tc) 425{ 426 // Make up a PID. There's no interprocess communication in 427 // fake_syscall mode, so there's no way for a process to know it's 428 // not getting a unique value. 429 430 tc->setIntReg(SyscallPseudoReturnReg, process->ppid()); 431 return process->pid(); 432} 433 434 435SyscallReturn 436getuidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 437 ThreadContext *tc) 438{ 439 // Make up a UID and EUID... it shouldn't matter, and we want the 440 // simulation to be deterministic. 441 442 // EUID goes in r20. 443 tc->setIntReg(SyscallPseudoReturnReg, process->euid()); //EUID 444 return process->uid(); // UID 445} 446 447 448SyscallReturn 449getgidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 450 ThreadContext *tc) 451{ 452 // Get current group ID. EGID goes in r20. 453 tc->setIntReg(SyscallPseudoReturnReg, process->egid()); //EGID 454 return process->gid(); 455} 456 457 458SyscallReturn 459setuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 460 ThreadContext *tc) 461{ 462 // can't fathom why a benchmark would call this. 463 warn("Ignoring call to setuid(%d)\n", tc->getSyscallArg(0)); 464 return 0; 465} 466 467SyscallReturn 468getpidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 469 ThreadContext *tc) 470{ 471 // Make up a PID. There's no interprocess communication in 472 // fake_syscall mode, so there's no way for a process to know it's 473 // not getting a unique value. 474 475 tc->setIntReg(SyscallPseudoReturnReg, process->ppid()); //PID 476 return process->pid(); 477} 478 479SyscallReturn 480getppidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 481 ThreadContext *tc) 482{ 483 return process->ppid(); 484} 485 486SyscallReturn 487getuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 488 ThreadContext *tc) 489{ 490 return process->uid(); // UID 491} 492 493SyscallReturn 494geteuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 495 ThreadContext *tc) 496{ 497 return process->euid(); // UID 498} 499 500SyscallReturn 501getgidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 502 ThreadContext *tc) 503{ 504 return process->gid(); 505} 506 507SyscallReturn 508getegidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 509 ThreadContext *tc) 510{ 511 return process->egid(); 512} 513 514 515