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/sx.h> 42 #include <sys/unistd.h> 43 44 #ifdef COMPAT_LINUX32 45 #include <machine/../linux32/linux.h> 46 #include <machine/../linux32/linux32_proto.h> 47 #else 48 #include <machine/../linux/linux.h> 49 #include <machine/../linux/linux_proto.h> 50 #endif 51 #include <compat/linux/linux_signal.h> 52 #include <compat/linux/linux_emul.h> 53 54 55 int 56 linux_fork(struct thread *td, struct linux_fork_args *args) 57 { 58 int error; 59 struct proc *p2; 60 struct thread *td2; 61 62 #ifdef DEBUG 63 if (ldebug(fork)) 64 printf(ARGS(fork, "")); 65 #endif 66 67 if ((error = fork1(td, RFFDG | RFPROC | RFSTOPPED, 0, &p2, NULL, 0)) 68 != 0) 69 return (error); 70 71 td->td_retval[0] = p2->p_pid; 72 td->td_retval[1] = 0; 73 74 error = linux_proc_init(td, td->td_retval[0], 0); 75 if (error) 76 return (error); 77 78 td2 = FIRST_THREAD_IN_PROC(p2); 79 80 /* 81 * Make this runnable after we are finished with it. 82 */ 83 thread_lock(td2); 84 TD_SET_CAN_RUN(td2); 85 sched_add(td2, SRQ_BORING); 86 thread_unlock(td2); 87 88 return (0); 89 } 90 91 int 92 linux_vfork(struct thread *td, struct linux_vfork_args *args) 93 { 94 int error; 95 struct proc *p2; 96 struct thread *td2; 97 98 #ifdef DEBUG 99 if (ldebug(vfork)) 100 printf(ARGS(vfork, "")); 101 #endif 102 103 /* Exclude RFPPWAIT */ 104 if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2, 105 NULL, 0)) != 0) 106 return (error); 107 108 td->td_retval[0] = p2->p_pid; 109 110 error = linux_proc_init(td, td->td_retval[0], 0); 111 if (error) 112 return (error); 113 114 PROC_LOCK(p2); 115 p2->p_flag |= P_PPWAIT; 116 PROC_UNLOCK(p2); 117 118 td2 = FIRST_THREAD_IN_PROC(p2); 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 /* wait for the children to exit, ie. emulate vfork */ 129 PROC_LOCK(p2); 130 while (p2->p_flag & P_PPWAIT) 131 cv_wait(&p2->p_pwait, &p2->p_mtx); 132 PROC_UNLOCK(p2); 133 134 return (0); 135 } 136 137 int 138 linux_clone(struct thread *td, struct linux_clone_args *args) 139 { 140 int error, ff = RFPROC | RFSTOPPED; 141 struct proc *p2; 142 struct thread *td2; 143 int exit_signal; 144 struct linux_emuldata *em; 145 146 #ifdef DEBUG 147 if (ldebug(clone)) { 148 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, " 149 "child tid: %p"), (unsigned)args->flags, 150 args->stack, args->parent_tidptr, args->child_tidptr); 151 } 152 #endif 153 154 exit_signal = args->flags & 0x000000ff; 155 if (LINUX_SIG_VALID(exit_signal)) { 156 if (exit_signal <= LINUX_SIGTBLSZ) 157 exit_signal = 158 linux_to_bsd_signal[_SIG_IDX(exit_signal)]; 159 } else if (exit_signal != 0) 160 return (EINVAL); 161 162 if (args->flags & LINUX_CLONE_VM) 163 ff |= RFMEM; 164 if (args->flags & LINUX_CLONE_SIGHAND) 165 ff |= RFSIGSHARE; 166 /* 167 * XXX: In Linux, sharing of fs info (chroot/cwd/umask) 168 * and open files is independant. In FreeBSD, its in one 169 * structure but in reality it does not cause any problems 170 * because both of these flags are usually set together. 171 */ 172 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS))) 173 ff |= RFFDG; 174 175 /* 176 * Attempt to detect when linux_clone(2) is used for creating 177 * kernel threads. Unfortunately despite the existence of the 178 * CLONE_THREAD flag, version of linuxthreads package used in 179 * most popular distros as of beginning of 2005 doesn't make 180 * any use of it. Therefore, this detection relies on 181 * empirical observation that linuxthreads sets certain 182 * combination of flags, so that we can make more or less 183 * precise detection and notify the FreeBSD kernel that several 184 * processes are in fact part of the same threading group, so 185 * that special treatment is necessary for signal delivery 186 * between those processes and fd locking. 187 */ 188 if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS) 189 ff |= RFTHREAD; 190 191 if (args->flags & LINUX_CLONE_PARENT_SETTID) 192 if (args->parent_tidptr == NULL) 193 return (EINVAL); 194 195 error = fork1(td, ff, 0, &p2, NULL, 0); 196 if (error) 197 return (error); 198 199 if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) { 200 sx_xlock(&proctree_lock); 201 PROC_LOCK(p2); 202 proc_reparent(p2, td->td_proc->p_pptr); 203 PROC_UNLOCK(p2); 204 sx_xunlock(&proctree_lock); 205 } 206 207 /* create the emuldata */ 208 error = linux_proc_init(td, p2->p_pid, args->flags); 209 /* reference it - no need to check this */ 210 em = em_find(p2, EMUL_DOLOCK); 211 KASSERT(em != NULL, ("clone: emuldata not found.")); 212 /* and adjust it */ 213 214 if (args->flags & LINUX_CLONE_THREAD) { 215 #ifdef notyet 216 PROC_LOCK(p2); 217 p2->p_pgrp = td->td_proc->p_pgrp; 218 PROC_UNLOCK(p2); 219 #endif 220 exit_signal = 0; 221 } 222 223 if (args->flags & LINUX_CLONE_CHILD_SETTID) 224 em->child_set_tid = args->child_tidptr; 225 else 226 em->child_set_tid = NULL; 227 228 if (args->flags & LINUX_CLONE_CHILD_CLEARTID) 229 em->child_clear_tid = args->child_tidptr; 230 else 231 em->child_clear_tid = NULL; 232 233 EMUL_UNLOCK(&emul_lock); 234 235 if (args->flags & LINUX_CLONE_PARENT_SETTID) { 236 error = copyout(&p2->p_pid, args->parent_tidptr, 237 sizeof(p2->p_pid)); 238 if (error) 239 printf(LMSG("copyout failed!")); 240 } 241 242 PROC_LOCK(p2); 243 p2->p_sigparent = exit_signal; 244 PROC_UNLOCK(p2); 245 td2 = FIRST_THREAD_IN_PROC(p2); 246 /* 247 * In a case of stack = NULL, we are supposed to COW calling process 248 * stack. This is what normal fork() does, so we just keep tf_rsp arg 249 * intact. 250 */ 251 if (args->stack) 252 linux_set_upcall_kse(td2, PTROUT(args->stack)); 253 254 if (args->flags & LINUX_CLONE_SETTLS) 255 linux_set_cloned_tls(td2, args->tls); 256 257 #ifdef DEBUG 258 if (ldebug(clone)) 259 printf(LMSG("clone: successful rfork to %d, " 260 "stack %p sig = %d"), (int)p2->p_pid, args->stack, 261 exit_signal); 262 #endif 263 if (args->flags & LINUX_CLONE_VFORK) { 264 PROC_LOCK(p2); 265 p2->p_flag |= P_PPWAIT; 266 PROC_UNLOCK(p2); 267 } 268 269 /* 270 * Make this runnable after we are finished with it. 271 */ 272 thread_lock(td2); 273 TD_SET_CAN_RUN(td2); 274 sched_add(td2, SRQ_BORING); 275 thread_unlock(td2); 276 277 td->td_retval[0] = p2->p_pid; 278 td->td_retval[1] = 0; 279 280 if (args->flags & LINUX_CLONE_VFORK) { 281 /* wait for the children to exit, ie. emulate vfork */ 282 PROC_LOCK(p2); 283 while (p2->p_flag & P_PPWAIT) 284 cv_wait(&p2->p_pwait, &p2->p_mtx); 285 PROC_UNLOCK(p2); 286 } 287 288 return (0); 289 } 290