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 #include "opt_kdtrace.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/imgact.h> 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/proc.h> 41 #include <sys/sched.h> 42 #include <sys/sdt.h> 43 #include <sys/sx.h> 44 #include <sys/unistd.h> 45 46 #ifdef COMPAT_LINUX32 47 #include <machine/../linux32/linux.h> 48 #include <machine/../linux32/linux32_proto.h> 49 #else 50 #include <machine/../linux/linux.h> 51 #include <machine/../linux/linux_proto.h> 52 #endif 53 #include <compat/linux/linux_dtrace.h> 54 #include <compat/linux/linux_signal.h> 55 #include <compat/linux/linux_emul.h> 56 #include <compat/linux/linux_misc.h> 57 58 /* DTrace init */ 59 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE); 60 61 /* Linuxulator-global DTrace probes */ 62 LIN_SDT_PROBE_DECLARE(locks, emul_lock, locked); 63 LIN_SDT_PROBE_DECLARE(locks, emul_lock, unlock); 64 65 66 int 67 linux_fork(struct thread *td, struct linux_fork_args *args) 68 { 69 int error; 70 struct proc *p2; 71 struct thread *td2; 72 73 #ifdef DEBUG 74 if (ldebug(fork)) 75 printf(ARGS(fork, "")); 76 #endif 77 78 if ((error = fork1(td, RFFDG | RFPROC | RFSTOPPED, 0, &p2, NULL, 0)) 79 != 0) 80 return (error); 81 82 td->td_retval[0] = p2->p_pid; 83 td->td_retval[1] = 0; 84 85 error = linux_proc_init(td, td->td_retval[0], 0); 86 if (error) 87 return (error); 88 89 td2 = FIRST_THREAD_IN_PROC(p2); 90 91 /* 92 * Make this runnable after we are finished with it. 93 */ 94 thread_lock(td2); 95 TD_SET_CAN_RUN(td2); 96 sched_add(td2, SRQ_BORING); 97 thread_unlock(td2); 98 99 return (0); 100 } 101 102 int 103 linux_vfork(struct thread *td, struct linux_vfork_args *args) 104 { 105 int error; 106 struct proc *p2; 107 struct thread *td2; 108 109 #ifdef DEBUG 110 if (ldebug(vfork)) 111 printf(ARGS(vfork, "")); 112 #endif 113 114 /* Exclude RFPPWAIT */ 115 if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2, 116 NULL, 0)) != 0) 117 return (error); 118 119 td->td_retval[0] = p2->p_pid; 120 121 error = linux_proc_init(td, td->td_retval[0], 0); 122 if (error) 123 return (error); 124 125 PROC_LOCK(p2); 126 p2->p_flag |= P_PPWAIT; 127 PROC_UNLOCK(p2); 128 129 td2 = FIRST_THREAD_IN_PROC(p2); 130 131 /* 132 * Make this runnable after we are finished with it. 133 */ 134 thread_lock(td2); 135 TD_SET_CAN_RUN(td2); 136 sched_add(td2, SRQ_BORING); 137 thread_unlock(td2); 138 139 /* wait for the children to exit, ie. emulate vfork */ 140 PROC_LOCK(p2); 141 while (p2->p_flag & P_PPWAIT) 142 cv_wait(&p2->p_pwait, &p2->p_mtx); 143 PROC_UNLOCK(p2); 144 145 return (0); 146 } 147 148 int 149 linux_clone(struct thread *td, struct linux_clone_args *args) 150 { 151 int error, ff = RFPROC | RFSTOPPED; 152 struct proc *p2; 153 struct thread *td2; 154 int exit_signal; 155 struct linux_emuldata *em; 156 157 #ifdef DEBUG 158 if (ldebug(clone)) { 159 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, " 160 "child tid: %p"), (unsigned)args->flags, 161 args->stack, args->parent_tidptr, args->child_tidptr); 162 } 163 #endif 164 165 exit_signal = args->flags & 0x000000ff; 166 if (LINUX_SIG_VALID(exit_signal)) { 167 if (exit_signal <= LINUX_SIGTBLSZ) 168 exit_signal = 169 linux_to_bsd_signal[_SIG_IDX(exit_signal)]; 170 } else if (exit_signal != 0) 171 return (EINVAL); 172 173 if (args->flags & LINUX_CLONE_VM) 174 ff |= RFMEM; 175 if (args->flags & LINUX_CLONE_SIGHAND) 176 ff |= RFSIGSHARE; 177 /* 178 * XXX: In Linux, sharing of fs info (chroot/cwd/umask) 179 * and open files is independant. In FreeBSD, its in one 180 * structure but in reality it does not cause any problems 181 * because both of these flags are usually set together. 182 */ 183 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS))) 184 ff |= RFFDG; 185 186 /* 187 * Attempt to detect when linux_clone(2) is used for creating 188 * kernel threads. Unfortunately despite the existence of the 189 * CLONE_THREAD flag, version of linuxthreads package used in 190 * most popular distros as of beginning of 2005 doesn't make 191 * any use of it. Therefore, this detection relies on 192 * empirical observation that linuxthreads sets certain 193 * combination of flags, so that we can make more or less 194 * precise detection and notify the FreeBSD kernel that several 195 * processes are in fact part of the same threading group, so 196 * that special treatment is necessary for signal delivery 197 * between those processes and fd locking. 198 */ 199 if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS) 200 ff |= RFTHREAD; 201 202 if (args->flags & LINUX_CLONE_PARENT_SETTID) 203 if (args->parent_tidptr == NULL) 204 return (EINVAL); 205 206 error = fork1(td, ff, 0, &p2, NULL, 0); 207 if (error) 208 return (error); 209 210 if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) { 211 sx_xlock(&proctree_lock); 212 PROC_LOCK(p2); 213 proc_reparent(p2, td->td_proc->p_pptr); 214 PROC_UNLOCK(p2); 215 sx_xunlock(&proctree_lock); 216 } 217 218 /* create the emuldata */ 219 error = linux_proc_init(td, p2->p_pid, args->flags); 220 /* reference it - no need to check this */ 221 em = em_find(p2, EMUL_DOLOCK); 222 KASSERT(em != NULL, ("clone: emuldata not found.")); 223 /* and adjust it */ 224 225 if (args->flags & LINUX_CLONE_THREAD) { 226 #ifdef notyet 227 PROC_LOCK(p2); 228 p2->p_pgrp = td->td_proc->p_pgrp; 229 PROC_UNLOCK(p2); 230 #endif 231 exit_signal = 0; 232 } 233 234 if (args->flags & LINUX_CLONE_CHILD_SETTID) 235 em->child_set_tid = args->child_tidptr; 236 else 237 em->child_set_tid = NULL; 238 239 if (args->flags & LINUX_CLONE_CHILD_CLEARTID) 240 em->child_clear_tid = args->child_tidptr; 241 else 242 em->child_clear_tid = NULL; 243 244 EMUL_UNLOCK(&emul_lock); 245 246 if (args->flags & LINUX_CLONE_PARENT_SETTID) { 247 error = copyout(&p2->p_pid, args->parent_tidptr, 248 sizeof(p2->p_pid)); 249 if (error) 250 printf(LMSG("copyout failed!")); 251 } 252 253 PROC_LOCK(p2); 254 p2->p_sigparent = exit_signal; 255 PROC_UNLOCK(p2); 256 td2 = FIRST_THREAD_IN_PROC(p2); 257 /* 258 * In a case of stack = NULL, we are supposed to COW calling process 259 * stack. This is what normal fork() does, so we just keep tf_rsp arg 260 * intact. 261 */ 262 if (args->stack) 263 linux_set_upcall_kse(td2, PTROUT(args->stack)); 264 265 if (args->flags & LINUX_CLONE_SETTLS) 266 linux_set_cloned_tls(td2, args->tls); 267 268 #ifdef DEBUG 269 if (ldebug(clone)) 270 printf(LMSG("clone: successful rfork to %d, " 271 "stack %p sig = %d"), (int)p2->p_pid, args->stack, 272 exit_signal); 273 #endif 274 if (args->flags & LINUX_CLONE_VFORK) { 275 PROC_LOCK(p2); 276 p2->p_flag |= P_PPWAIT; 277 PROC_UNLOCK(p2); 278 } 279 280 /* 281 * Make this runnable after we are finished with it. 282 */ 283 thread_lock(td2); 284 TD_SET_CAN_RUN(td2); 285 sched_add(td2, SRQ_BORING); 286 thread_unlock(td2); 287 288 td->td_retval[0] = p2->p_pid; 289 td->td_retval[1] = 0; 290 291 if (args->flags & LINUX_CLONE_VFORK) { 292 /* wait for the children to exit, ie. emulate vfork */ 293 PROC_LOCK(p2); 294 while (p2->p_flag & P_PPWAIT) 295 cv_wait(&p2->p_pwait, &p2->p_mtx); 296 PROC_UNLOCK(p2); 297 } 298 299 return (0); 300 } 301