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("$FreeBSD$"); 31 32 #include "opt_compat.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/imgact.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/proc.h> 40 #include <sys/sched.h> 41 #include <sys/sdt.h> 42 #include <sys/sx.h> 43 #include <sys/unistd.h> 44 45 #ifdef COMPAT_LINUX32 46 #include <machine/../linux32/linux.h> 47 #include <machine/../linux32/linux32_proto.h> 48 #else 49 #include <machine/../linux/linux.h> 50 #include <machine/../linux/linux_proto.h> 51 #endif 52 #include <compat/linux/linux_dtrace.h> 53 #include <compat/linux/linux_signal.h> 54 #include <compat/linux/linux_emul.h> 55 #include <compat/linux/linux_misc.h> 56 57 /* DTrace init */ 58 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE); 59 60 /* Linuxulator-global DTrace probes */ 61 LIN_SDT_PROBE_DECLARE(locks, emul_lock, locked); 62 LIN_SDT_PROBE_DECLARE(locks, emul_lock, unlock); 63 64 65 int 66 linux_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 td->td_retval[0] = p2->p_pid; 82 td->td_retval[1] = 0; 83 84 error = linux_proc_init(td, td->td_retval[0], 0); 85 if (error) 86 return (error); 87 88 td2 = FIRST_THREAD_IN_PROC(p2); 89 90 /* 91 * Make this runnable after we are finished with it. 92 */ 93 thread_lock(td2); 94 TD_SET_CAN_RUN(td2); 95 sched_add(td2, SRQ_BORING); 96 thread_unlock(td2); 97 98 return (0); 99 } 100 101 int 102 linux_vfork(struct thread *td, struct linux_vfork_args *args) 103 { 104 int error; 105 struct proc *p2; 106 struct thread *td2; 107 108 #ifdef DEBUG 109 if (ldebug(vfork)) 110 printf(ARGS(vfork, "")); 111 #endif 112 113 /* Exclude RFPPWAIT */ 114 if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2, 115 NULL, 0)) != 0) 116 return (error); 117 118 td->td_retval[0] = p2->p_pid; 119 120 error = linux_proc_init(td, td->td_retval[0], 0); 121 if (error) 122 return (error); 123 124 PROC_LOCK(p2); 125 p2->p_flag |= P_PPWAIT; 126 PROC_UNLOCK(p2); 127 128 td2 = FIRST_THREAD_IN_PROC(p2); 129 130 /* 131 * Make this runnable after we are finished with it. 132 */ 133 thread_lock(td2); 134 TD_SET_CAN_RUN(td2); 135 sched_add(td2, SRQ_BORING); 136 thread_unlock(td2); 137 138 /* wait for the children to exit, ie. emulate vfork */ 139 PROC_LOCK(p2); 140 while (p2->p_flag & P_PPWAIT) 141 cv_wait(&p2->p_pwait, &p2->p_mtx); 142 PROC_UNLOCK(p2); 143 144 return (0); 145 } 146 147 int 148 linux_clone(struct thread *td, struct linux_clone_args *args) 149 { 150 int error, ff = RFPROC | RFSTOPPED; 151 struct proc *p2; 152 struct thread *td2; 153 int exit_signal; 154 struct linux_emuldata *em; 155 156 #ifdef DEBUG 157 if (ldebug(clone)) { 158 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, " 159 "child tid: %p"), (unsigned)args->flags, 160 args->stack, args->parent_tidptr, args->child_tidptr); 161 } 162 #endif 163 164 exit_signal = args->flags & 0x000000ff; 165 if (LINUX_SIG_VALID(exit_signal)) { 166 if (exit_signal <= LINUX_SIGTBLSZ) 167 exit_signal = 168 linux_to_bsd_signal[_SIG_IDX(exit_signal)]; 169 } else if (exit_signal != 0) 170 return (EINVAL); 171 172 if (args->flags & LINUX_CLONE_VM) 173 ff |= RFMEM; 174 if (args->flags & LINUX_CLONE_SIGHAND) 175 ff |= RFSIGSHARE; 176 /* 177 * XXX: In Linux, sharing of fs info (chroot/cwd/umask) 178 * and open files is independant. In FreeBSD, its in one 179 * structure but in reality it does not cause any problems 180 * because both of these flags are usually set together. 181 */ 182 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS))) 183 ff |= RFFDG; 184 185 /* 186 * Attempt to detect when linux_clone(2) is used for creating 187 * kernel threads. Unfortunately despite the existence of the 188 * CLONE_THREAD flag, version of linuxthreads package used in 189 * most popular distros as of beginning of 2005 doesn't make 190 * any use of it. Therefore, this detection relies on 191 * empirical observation that linuxthreads sets certain 192 * combination of flags, so that we can make more or less 193 * precise detection and notify the FreeBSD kernel that several 194 * processes are in fact part of the same threading group, so 195 * that special treatment is necessary for signal delivery 196 * between those processes and fd locking. 197 */ 198 if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS) 199 ff |= RFTHREAD; 200 201 if (args->flags & LINUX_CLONE_PARENT_SETTID) 202 if (args->parent_tidptr == NULL) 203 return (EINVAL); 204 205 error = fork1(td, ff, 0, &p2, NULL, 0); 206 if (error) 207 return (error); 208 209 if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) { 210 sx_xlock(&proctree_lock); 211 PROC_LOCK(p2); 212 proc_reparent(p2, td->td_proc->p_pptr); 213 PROC_UNLOCK(p2); 214 sx_xunlock(&proctree_lock); 215 } 216 217 /* create the emuldata */ 218 error = linux_proc_init(td, p2->p_pid, args->flags); 219 /* reference it - no need to check this */ 220 em = em_find(p2, EMUL_DOLOCK); 221 KASSERT(em != NULL, ("clone: emuldata not found.")); 222 /* and adjust it */ 223 224 if (args->flags & LINUX_CLONE_THREAD) { 225 #ifdef notyet 226 PROC_LOCK(p2); 227 p2->p_pgrp = td->td_proc->p_pgrp; 228 PROC_UNLOCK(p2); 229 #endif 230 exit_signal = 0; 231 } 232 233 if (args->flags & LINUX_CLONE_CHILD_SETTID) 234 em->child_set_tid = args->child_tidptr; 235 else 236 em->child_set_tid = NULL; 237 238 if (args->flags & LINUX_CLONE_CHILD_CLEARTID) 239 em->child_clear_tid = args->child_tidptr; 240 else 241 em->child_clear_tid = NULL; 242 243 EMUL_UNLOCK(&emul_lock); 244 245 if (args->flags & LINUX_CLONE_PARENT_SETTID) { 246 error = copyout(&p2->p_pid, args->parent_tidptr, 247 sizeof(p2->p_pid)); 248 if (error) 249 printf(LMSG("copyout failed!")); 250 } 251 252 PROC_LOCK(p2); 253 p2->p_sigparent = exit_signal; 254 PROC_UNLOCK(p2); 255 td2 = FIRST_THREAD_IN_PROC(p2); 256 /* 257 * In a case of stack = NULL, we are supposed to COW calling process 258 * stack. This is what normal fork() does, so we just keep tf_rsp arg 259 * intact. 260 */ 261 if (args->stack) 262 linux_set_upcall_kse(td2, PTROUT(args->stack)); 263 264 if (args->flags & LINUX_CLONE_SETTLS) 265 linux_set_cloned_tls(td2, args->tls); 266 267 #ifdef DEBUG 268 if (ldebug(clone)) 269 printf(LMSG("clone: successful rfork to %d, " 270 "stack %p sig = %d"), (int)p2->p_pid, args->stack, 271 exit_signal); 272 #endif 273 if (args->flags & LINUX_CLONE_VFORK) { 274 PROC_LOCK(p2); 275 p2->p_flag |= P_PPWAIT; 276 PROC_UNLOCK(p2); 277 } 278 279 /* 280 * Make this runnable after we are finished with it. 281 */ 282 thread_lock(td2); 283 TD_SET_CAN_RUN(td2); 284 sched_add(td2, SRQ_BORING); 285 thread_unlock(td2); 286 287 td->td_retval[0] = p2->p_pid; 288 td->td_retval[1] = 0; 289 290 if (args->flags & LINUX_CLONE_VFORK) { 291 /* wait for the children to exit, ie. emulate vfork */ 292 PROC_LOCK(p2); 293 while (p2->p_flag & P_PPWAIT) 294 cv_wait(&p2->p_pwait, &p2->p_mtx); 295 PROC_UNLOCK(p2); 296 } 297 298 return (0); 299 } 300