linux_fork.c revision 297305
1/*- 2 * Copyright (c) 2004 Tim J. Robbins 3 * Copyright (c) 2002 Doug Rabson 4 * Copyright (c) 2000 Marcel Moolenaar 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT 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 OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <sys/cdefs.h> 30__FBSDID("$FreeBSD: stable/10/sys/compat/linux/linux_fork.c 297305 2016-03-27 06:55:49Z dchagin $"); 31 32#include "opt_compat.h" 33#include "opt_kdtrace.h" 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/imgact.h> 38#include <sys/ktr.h> 39#include <sys/lock.h> 40#include <sys/mutex.h> 41#include <sys/proc.h> 42#include <sys/racct.h> 43#include <sys/sched.h> 44#include <sys/syscallsubr.h> 45#include <sys/sx.h> 46#include <sys/unistd.h> 47#include <sys/wait.h> 48 49#include <vm/vm.h> 50#include <vm/pmap.h> 51#include <vm/vm_map.h> 52 53#ifdef COMPAT_LINUX32 54#include <machine/../linux32/linux.h> 55#include <machine/../linux32/linux32_proto.h> 56#else 57#include <machine/../linux/linux.h> 58#include <machine/../linux/linux_proto.h> 59#endif 60#include <compat/linux/linux_emul.h> 61#include <compat/linux/linux_futex.h> 62#include <compat/linux/linux_misc.h> 63#include <compat/linux/linux_util.h> 64 65int 66linux_fork(struct thread *td, struct linux_fork_args *args) 67{ 68 int error; 69 struct proc *p2; 70 struct thread *td2; 71 72#ifdef DEBUG 73 if (ldebug(fork)) 74 printf(ARGS(fork, "")); 75#endif 76 77 if ((error = fork1(td, RFFDG | RFPROC | RFSTOPPED, 0, &p2, NULL, 0)) 78 != 0) 79 return (error); 80 81 td2 = FIRST_THREAD_IN_PROC(p2); 82 83 linux_proc_init(td, td2, 0); 84 85 td->td_retval[0] = p2->p_pid; 86 87 /* 88 * Make this runnable after we are finished with it. 89 */ 90 thread_lock(td2); 91 TD_SET_CAN_RUN(td2); 92 sched_add(td2, SRQ_BORING); 93 thread_unlock(td2); 94 95 return (0); 96} 97 98int 99linux_vfork(struct thread *td, struct linux_vfork_args *args) 100{ 101 int error; 102 struct proc *p2; 103 struct thread *td2; 104 105#ifdef DEBUG 106 if (ldebug(vfork)) 107 printf(ARGS(vfork, "")); 108#endif 109 110 if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFPPWAIT | RFSTOPPED, 111 0, &p2, NULL, 0)) != 0) 112 return (error); 113 114 td2 = FIRST_THREAD_IN_PROC(p2); 115 116 linux_proc_init(td, td2, 0); 117 118 td->td_retval[0] = p2->p_pid; 119 120 /* 121 * Make this runnable after we are finished with it. 122 */ 123 thread_lock(td2); 124 TD_SET_CAN_RUN(td2); 125 sched_add(td2, SRQ_BORING); 126 thread_unlock(td2); 127 128 return (0); 129} 130 131static int 132linux_clone_proc(struct thread *td, struct linux_clone_args *args) 133{ 134 int error, ff = RFPROC | RFSTOPPED; 135 struct proc *p2; 136 struct thread *td2; 137 int exit_signal; 138 struct linux_emuldata *em; 139 140#ifdef DEBUG 141 if (ldebug(clone)) { 142 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, " 143 "child tid: %p"), (unsigned)args->flags, 144 args->stack, args->parent_tidptr, args->child_tidptr); 145 } 146#endif 147 148 exit_signal = args->flags & 0x000000ff; 149 if (LINUX_SIG_VALID(exit_signal)) { 150 exit_signal = linux_to_bsd_signal(exit_signal); 151 } else if (exit_signal != 0) 152 return (EINVAL); 153 154 if (args->flags & LINUX_CLONE_VM) 155 ff |= RFMEM; 156 if (args->flags & LINUX_CLONE_SIGHAND) 157 ff |= RFSIGSHARE; 158 /* 159 * XXX: In Linux, sharing of fs info (chroot/cwd/umask) 160 * and open files is independant. In FreeBSD, its in one 161 * structure but in reality it does not cause any problems 162 * because both of these flags are usually set together. 163 */ 164 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS))) 165 ff |= RFFDG; 166 167 if (args->flags & LINUX_CLONE_PARENT_SETTID) 168 if (args->parent_tidptr == NULL) 169 return (EINVAL); 170 171 if (args->flags & LINUX_CLONE_VFORK) 172 ff |= RFPPWAIT; 173 174 error = fork1(td, ff, 0, &p2, NULL, 0); 175 if (error) 176 return (error); 177 178 td2 = FIRST_THREAD_IN_PROC(p2); 179 180 /* create the emuldata */ 181 linux_proc_init(td, td2, args->flags); 182 183 em = em_find(td2); 184 KASSERT(em != NULL, ("clone_proc: emuldata not found.\n")); 185 186 if (args->flags & LINUX_CLONE_CHILD_SETTID) 187 em->child_set_tid = args->child_tidptr; 188 else 189 em->child_set_tid = NULL; 190 191 if (args->flags & LINUX_CLONE_CHILD_CLEARTID) 192 em->child_clear_tid = args->child_tidptr; 193 else 194 em->child_clear_tid = NULL; 195 196 if (args->flags & LINUX_CLONE_PARENT_SETTID) { 197 error = copyout(&p2->p_pid, args->parent_tidptr, 198 sizeof(p2->p_pid)); 199 if (error) 200 printf(LMSG("copyout failed!")); 201 } 202 203 PROC_LOCK(p2); 204 p2->p_sigparent = exit_signal; 205 PROC_UNLOCK(p2); 206 /* 207 * In a case of stack = NULL, we are supposed to COW calling process 208 * stack. This is what normal fork() does, so we just keep tf_rsp arg 209 * intact. 210 */ 211 linux_set_upcall_kse(td2, PTROUT(args->stack)); 212 213 if (args->flags & LINUX_CLONE_SETTLS) 214 linux_set_cloned_tls(td2, args->tls); 215 216 /* 217 * If CLONE_PARENT is set, then the parent of the new process will be 218 * the same as that of the calling process. 219 */ 220 if (args->flags & LINUX_CLONE_PARENT) { 221 sx_xlock(&proctree_lock); 222 PROC_LOCK(p2); 223 proc_reparent(p2, td->td_proc->p_pptr); 224 PROC_UNLOCK(p2); 225 sx_xunlock(&proctree_lock); 226 } 227 228#ifdef DEBUG 229 if (ldebug(clone)) 230 printf(LMSG("clone: successful rfork to %d, " 231 "stack %p sig = %d"), (int)p2->p_pid, args->stack, 232 exit_signal); 233#endif 234 235 /* 236 * Make this runnable after we are finished with it. 237 */ 238 thread_lock(td2); 239 TD_SET_CAN_RUN(td2); 240 sched_add(td2, SRQ_BORING); 241 thread_unlock(td2); 242 243 td->td_retval[0] = p2->p_pid; 244 245 return (0); 246} 247 248static int 249linux_clone_thread(struct thread *td, struct linux_clone_args *args) 250{ 251 struct linux_emuldata *em; 252 struct thread *newtd; 253 struct proc *p; 254 int error; 255 256#ifdef DEBUG 257 if (ldebug(clone)) { 258 printf(ARGS(clone, "thread: flags %x, stack %p, parent tid: %p, " 259 "child tid: %p"), (unsigned)args->flags, 260 args->stack, args->parent_tidptr, args->child_tidptr); 261 } 262#endif 263 264 LINUX_CTR4(clone_thread, "thread(%d) flags %x ptid %p ctid %p", 265 td->td_tid, (unsigned)args->flags, 266 args->parent_tidptr, args->child_tidptr); 267 268 if (args->flags & LINUX_CLONE_PARENT_SETTID) 269 if (args->parent_tidptr == NULL) 270 return (EINVAL); 271 272 /* Threads should be created with own stack */ 273 if (args->stack == NULL) 274 return (EINVAL); 275 276 p = td->td_proc; 277 278#ifdef RACCT 279 if (racct_enable) { 280 PROC_LOCK(p); 281 error = racct_add(p, RACCT_NTHR, 1); 282 PROC_UNLOCK(p); 283 if (error != 0) 284 return (EPROCLIM); 285 } 286#endif 287 288 /* Initialize our td */ 289 error = kern_thr_alloc(p, 0, &newtd); 290 if (error) 291 goto fail; 292 293 cpu_set_upcall(newtd, td); 294 295 bzero(&newtd->td_startzero, 296 __rangeof(struct thread, td_startzero, td_endzero)); 297 bcopy(&td->td_startcopy, &newtd->td_startcopy, 298 __rangeof(struct thread, td_startcopy, td_endcopy)); 299 300 newtd->td_proc = p; 301 newtd->td_ucred = crhold(td->td_ucred); 302 303 /* create the emuldata */ 304 linux_proc_init(td, newtd, args->flags); 305 306 em = em_find(newtd); 307 KASSERT(em != NULL, ("clone_thread: emuldata not found.\n")); 308 309 if (args->flags & LINUX_CLONE_SETTLS) 310 linux_set_cloned_tls(newtd, args->tls); 311 312 if (args->flags & LINUX_CLONE_CHILD_SETTID) 313 em->child_set_tid = args->child_tidptr; 314 else 315 em->child_set_tid = NULL; 316 317 if (args->flags & LINUX_CLONE_CHILD_CLEARTID) 318 em->child_clear_tid = args->child_tidptr; 319 else 320 em->child_clear_tid = NULL; 321 322 cpu_thread_clean(newtd); 323 324 linux_set_upcall_kse(newtd, PTROUT(args->stack)); 325 326 PROC_LOCK(p); 327 p->p_flag |= P_HADTHREADS; 328 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name)); 329 330 if (args->flags & LINUX_CLONE_PARENT) 331 thread_link(newtd, p->p_pptr); 332 else 333 thread_link(newtd, p); 334 335 thread_lock(td); 336 /* let the scheduler know about these things. */ 337 sched_fork_thread(td, newtd); 338 thread_unlock(td); 339 if (P_SHOULDSTOP(p)) 340 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 341 PROC_UNLOCK(p); 342 343 tidhash_add(newtd); 344 345#ifdef DEBUG 346 if (ldebug(clone)) 347 printf(ARGS(clone, "successful clone to %d, stack %p"), 348 (int)newtd->td_tid, args->stack); 349#endif 350 351 LINUX_CTR2(clone_thread, "thread(%d) successful clone to %d", 352 td->td_tid, newtd->td_tid); 353 354 if (args->flags & LINUX_CLONE_PARENT_SETTID) { 355 error = copyout(&newtd->td_tid, args->parent_tidptr, 356 sizeof(newtd->td_tid)); 357 if (error) 358 printf(LMSG("clone_thread: copyout failed!")); 359 } 360 361 /* 362 * Make this runnable after we are finished with it. 363 */ 364 thread_lock(newtd); 365 TD_SET_CAN_RUN(newtd); 366 sched_add(newtd, SRQ_BORING); 367 thread_unlock(newtd); 368 369 td->td_retval[0] = newtd->td_tid; 370 371 return (0); 372 373fail: 374#ifdef RACCT 375 if (racct_enable) { 376 PROC_LOCK(p); 377 racct_sub(p, RACCT_NTHR, 1); 378 PROC_UNLOCK(p); 379 } 380#endif 381 return (error); 382} 383 384int 385linux_clone(struct thread *td, struct linux_clone_args *args) 386{ 387 388 if (args->flags & LINUX_CLONE_THREAD) 389 return (linux_clone_thread(td, args)); 390 else 391 return (linux_clone_proc(td, args)); 392} 393 394int 395linux_exit(struct thread *td, struct linux_exit_args *args) 396{ 397 struct linux_emuldata *em; 398 399 em = em_find(td); 400 KASSERT(em != NULL, ("exit: emuldata not found.\n")); 401 402 LINUX_CTR2(exit, "thread(%d) (%d)", em->em_tid, args->rval); 403 404 linux_thread_detach(td); 405 406 /* 407 * XXX. When the last two threads of a process 408 * exit via pthread_exit() try thr_exit() first. 409 */ 410 kern_thr_exit(td); 411 exit1(td, W_EXITCODE(args->rval, 0)); 412 /* NOTREACHED */ 413} 414 415int 416linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args) 417{ 418 struct linux_emuldata *em; 419 420 em = em_find(td); 421 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n")); 422 423 em->child_clear_tid = args->tidptr; 424 425 td->td_retval[0] = em->em_tid; 426 427 LINUX_CTR3(set_tid_address, "tidptr(%d) %p, returns %d", 428 em->em_tid, args->tidptr, td->td_retval[0]); 429 430 return (0); 431} 432 433void 434linux_thread_detach(struct thread *td) 435{ 436 struct linux_sys_futex_args cup; 437 struct linux_emuldata *em; 438 int *child_clear_tid; 439 int error; 440 441 em = em_find(td); 442 KASSERT(em != NULL, ("thread_detach: emuldata not found.\n")); 443 444 LINUX_CTR1(thread_detach, "thread(%d)", em->em_tid); 445 446 release_futexes(td, em); 447 448 child_clear_tid = em->child_clear_tid; 449 450 if (child_clear_tid != NULL) { 451 452 LINUX_CTR2(thread_detach, "thread(%d) %p", 453 em->em_tid, child_clear_tid); 454 455 error = suword32(child_clear_tid, 0); 456 if (error != 0) 457 return; 458 459 cup.uaddr = child_clear_tid; 460 cup.op = LINUX_FUTEX_WAKE; 461 cup.val = 1; /* wake one */ 462 cup.timeout = NULL; 463 cup.uaddr2 = NULL; 464 cup.val3 = 0; 465 error = linux_sys_futex(td, &cup); 466 /* 467 * this cannot happen at the moment and if this happens it 468 * probably means there is a user space bug 469 */ 470 if (error != 0) 471 linux_msg(td, "futex stuff in thread_detach failed."); 472 } 473} 474