syscall_emul.cc revision 4118:ddd23e5282d7
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 187_llseekFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 188{ 189 int fd = p->sim_fd(tc->getSyscallArg(0)); 190 uint64_t offset_high = tc->getSyscallArg(1); 191 uint32_t offset_low = tc->getSyscallArg(2); 192 Addr result_ptr = tc->getSyscallArg(3); 193 int whence = tc->getSyscallArg(4); 194 195 uint64_t offset = (offset_high << 32) | offset_low; 196 197 uint64_t result = lseek(fd, offset, whence); 198 result = TheISA::htog(result); 199 200 if (result == (off_t)-1) { 201 //The seek failed. 202 return -errno; 203 } else { 204 //The seek succeeded. 205 //Copy "result" to "result_ptr" 206 //XXX We'll assume that the size of loff_t is 64 bits on the 207 //target platform 208 BufferArg result_buf(result_ptr, sizeof(result)); 209 memcpy(result_buf.bufferPtr(), &result, sizeof(result)); 210 result_buf.copyOut(tc->getMemPort()); 211 return 0; 212 } 213 214 215 return (result == (off_t)-1) ? -errno : result; 216} 217 218 219SyscallReturn 220munmapFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 221{ 222 // given that we don't really implement mmap, munmap is really easy 223 return 0; 224} 225 226 227const char *hostname = "m5.eecs.umich.edu"; 228 229SyscallReturn 230gethostnameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 231{ 232 int name_len = tc->getSyscallArg(1); 233 BufferArg name(tc->getSyscallArg(0), name_len); 234 235 strncpy((char *)name.bufferPtr(), hostname, name_len); 236 237 name.copyOut(tc->getMemPort()); 238 239 return 0; 240} 241 242SyscallReturn 243unlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 244{ 245 string path; 246 247 if (!tc->getMemPort()->tryReadString(path, tc->getSyscallArg(0))) 248 return (TheISA::IntReg)-EFAULT; 249 250 // Adjust path for current working directory 251 path = p->fullPath(path); 252 253 int result = unlink(path.c_str()); 254 return (result == -1) ? -errno : result; 255} 256 257SyscallReturn 258renameFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 259{ 260 string old_name; 261 262 if (!tc->getMemPort()->tryReadString(old_name, tc->getSyscallArg(0))) 263 return -EFAULT; 264 265 string new_name; 266 267 if (!tc->getMemPort()->tryReadString(new_name, tc->getSyscallArg(1))) 268 return -EFAULT; 269 270 // Adjust path for current working directory 271 old_name = p->fullPath(old_name); 272 new_name = p->fullPath(new_name); 273 274 int64_t result = rename(old_name.c_str(), new_name.c_str()); 275 return (result == -1) ? -errno : result; 276} 277 278SyscallReturn 279truncateFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 280{ 281 string path; 282 283 if (!tc->getMemPort()->tryReadString(path, tc->getSyscallArg(0))) 284 return -EFAULT; 285 286 off_t length = tc->getSyscallArg(1); 287 288 // Adjust path for current working directory 289 path = p->fullPath(path); 290 291 int result = truncate(path.c_str(), length); 292 return (result == -1) ? -errno : result; 293} 294 295SyscallReturn 296ftruncateFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 297{ 298 int fd = process->sim_fd(tc->getSyscallArg(0)); 299 300 if (fd < 0) 301 return -EBADF; 302 303 off_t length = tc->getSyscallArg(1); 304 305 int result = ftruncate(fd, length); 306 return (result == -1) ? -errno : result; 307} 308 309SyscallReturn 310chownFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) 311{ 312 string path; 313 314 if (!tc->getMemPort()->tryReadString(path, tc->getSyscallArg(0))) 315 return -EFAULT; 316 317 /* XXX endianess */ 318 uint32_t owner = tc->getSyscallArg(1); 319 uid_t hostOwner = owner; 320 uint32_t group = tc->getSyscallArg(2); 321 gid_t hostGroup = group; 322 323 // Adjust path for current working directory 324 path = p->fullPath(path); 325 326 int result = chown(path.c_str(), hostOwner, hostGroup); 327 return (result == -1) ? -errno : result; 328} 329 330SyscallReturn 331fchownFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 332{ 333 int fd = process->sim_fd(tc->getSyscallArg(0)); 334 335 if (fd < 0) 336 return -EBADF; 337 338 /* XXX endianess */ 339 uint32_t owner = tc->getSyscallArg(1); 340 uid_t hostOwner = owner; 341 uint32_t group = tc->getSyscallArg(2); 342 gid_t hostGroup = group; 343 344 int result = fchown(fd, hostOwner, hostGroup); 345 return (result == -1) ? -errno : result; 346} 347 348 349SyscallReturn 350dupFunc(SyscallDesc *desc, int num, LiveProcess *process, ThreadContext *tc) 351{ 352 int fd = process->sim_fd(tc->getSyscallArg(0)); 353 354 if (fd < 0) 355 return -EBADF; 356 357 int result = dup(fd); 358 return (result == -1) ? -errno : process->alloc_fd(result); 359} 360 361 362SyscallReturn 363fcntlFunc(SyscallDesc *desc, int num, LiveProcess *process, 364 ThreadContext *tc) 365{ 366 int fd = tc->getSyscallArg(0); 367 368 if (fd < 0 || process->sim_fd(fd) < 0) 369 return -EBADF; 370 371 int cmd = tc->getSyscallArg(1); 372 switch (cmd) { 373 case 0: // F_DUPFD 374 // if we really wanted to support this, we'd need to do it 375 // in the target fd space. 376 warn("fcntl(%d, F_DUPFD) not supported, error returned\n", fd); 377 return -EMFILE; 378 379 case 1: // F_GETFD (get close-on-exec flag) 380 case 2: // F_SETFD (set close-on-exec flag) 381 return 0; 382 383 case 3: // F_GETFL (get file flags) 384 case 4: // F_SETFL (set file flags) 385 // not sure if this is totally valid, but we'll pass it through 386 // to the underlying OS 387 warn("fcntl(%d, %d) passed through to host\n", fd, cmd); 388 return fcntl(process->sim_fd(fd), cmd); 389 // return 0; 390 391 case 7: // F_GETLK (get lock) 392 case 8: // F_SETLK (set lock) 393 case 9: // F_SETLKW (set lock and wait) 394 // don't mess with file locking... just act like it's OK 395 warn("File lock call (fcntl(%d, %d)) ignored.\n", fd, cmd); 396 return 0; 397 398 default: 399 warn("Unknown fcntl command %d\n", cmd); 400 return 0; 401 } 402} 403 404SyscallReturn 405fcntl64Func(SyscallDesc *desc, int num, LiveProcess *process, 406 ThreadContext *tc) 407{ 408 int fd = tc->getSyscallArg(0); 409 410 if (fd < 0 || process->sim_fd(fd) < 0) 411 return -EBADF; 412 413 int cmd = tc->getSyscallArg(1); 414 switch (cmd) { 415 case 33: //F_GETLK64 416 warn("fcntl64(%d, F_GETLK64) not supported, error returned\n", fd); 417 return -EMFILE; 418 419 case 34: // F_SETLK64 420 case 35: // F_SETLKW64 421 warn("fcntl64(%d, F_SETLK(W)64) not supported, error returned\n", fd); 422 return -EMFILE; 423 424 default: 425 // not sure if this is totally valid, but we'll pass it through 426 // to the underlying OS 427 warn("fcntl64(%d, %d) passed through to host\n", fd, cmd); 428 return fcntl(process->sim_fd(fd), cmd); 429 // return 0; 430 } 431} 432 433SyscallReturn 434pipePseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 435 ThreadContext *tc) 436{ 437 int fds[2], sim_fds[2]; 438 int pipe_retval = pipe(fds); 439 440 if (pipe_retval < 0) { 441 // error 442 return pipe_retval; 443 } 444 445 sim_fds[0] = process->alloc_fd(fds[0]); 446 sim_fds[1] = process->alloc_fd(fds[1]); 447 448 // Alpha Linux convention for pipe() is that fd[0] is returned as 449 // the return value of the function, and fd[1] is returned in r20. 450 tc->setIntReg(SyscallPseudoReturnReg, sim_fds[1]); 451 return sim_fds[0]; 452} 453 454 455SyscallReturn 456getpidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 457 ThreadContext *tc) 458{ 459 // Make up a PID. There's no interprocess communication in 460 // fake_syscall mode, so there's no way for a process to know it's 461 // not getting a unique value. 462 463 tc->setIntReg(SyscallPseudoReturnReg, process->ppid()); 464 return process->pid(); 465} 466 467 468SyscallReturn 469getuidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 470 ThreadContext *tc) 471{ 472 // Make up a UID and EUID... it shouldn't matter, and we want the 473 // simulation to be deterministic. 474 475 // EUID goes in r20. 476 tc->setIntReg(SyscallPseudoReturnReg, process->euid()); //EUID 477 return process->uid(); // UID 478} 479 480 481SyscallReturn 482getgidPseudoFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 483 ThreadContext *tc) 484{ 485 // Get current group ID. EGID goes in r20. 486 tc->setIntReg(SyscallPseudoReturnReg, process->egid()); //EGID 487 return process->gid(); 488} 489 490 491SyscallReturn 492setuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 493 ThreadContext *tc) 494{ 495 // can't fathom why a benchmark would call this. 496 warn("Ignoring call to setuid(%d)\n", tc->getSyscallArg(0)); 497 return 0; 498} 499 500SyscallReturn 501getpidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 502 ThreadContext *tc) 503{ 504 // Make up a PID. There's no interprocess communication in 505 // fake_syscall mode, so there's no way for a process to know it's 506 // not getting a unique value. 507 508 tc->setIntReg(SyscallPseudoReturnReg, process->ppid()); //PID 509 return process->pid(); 510} 511 512SyscallReturn 513getppidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 514 ThreadContext *tc) 515{ 516 return process->ppid(); 517} 518 519SyscallReturn 520getuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 521 ThreadContext *tc) 522{ 523 return process->uid(); // UID 524} 525 526SyscallReturn 527geteuidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 528 ThreadContext *tc) 529{ 530 return process->euid(); // UID 531} 532 533SyscallReturn 534getgidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 535 ThreadContext *tc) 536{ 537 return process->gid(); 538} 539 540SyscallReturn 541getegidFunc(SyscallDesc *desc, int callnum, LiveProcess *process, 542 ThreadContext *tc) 543{ 544 return process->egid(); 545} 546 547 548