1 /* $NetBSD: linux_exec.c,v 1.104 2008/04/24 15:35:27 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 1994, 1995, 1998, 2000, 2007, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas, Frank van der Linden, Eric Haszlakiewicz and 9 * Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 __KERNEL_RCSID(0, "$NetBSD: linux_exec.c,v 1.104 2008/04/24 15:35:27 ad Exp $"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/malloc.h> 48 #include <sys/namei.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/exec.h> 52 #include <sys/exec_elf.h> 53 54 #include <sys/mman.h> 55 #include <sys/syscallargs.h> 56 57 #include <sys/ptrace.h> /* For proc_reparent() */ 58 59 #include <uvm/uvm_extern.h> 60 61 #include <sys/cpu.h> 62 #include <machine/reg.h> 63 64 #include <compat/linux/common/linux_types.h> 65 #include <compat/linux/common/linux_signal.h> 66 #include <compat/linux/common/linux_util.h> 67 #include <compat/linux/common/linux_sched.h> 68 #include <compat/linux/common/linux_machdep.h> 69 #include <compat/linux/common/linux_exec.h> 70 #include <compat/linux/common/linux_futex.h> 71 #include <compat/linux/common/linux_ipc.h> 72 #include <compat/linux/common/linux_sem.h> 73 74 #include <compat/linux/linux_syscallargs.h> 75 #include <compat/linux/linux_syscall.h> 76 #include <compat/linux/common/linux_misc.h> 77 #include <compat/linux/common/linux_errno.h> 78 #include <compat/linux/common/linux_emuldata.h> 79 80 extern struct sysent linux_sysent[]; 81 extern const char * const linux_syscallnames[]; 82 extern char linux_sigcode[], linux_esigcode[]; 83 84 static void linux_e_proc_exec(struct proc *, struct exec_package *); 85 static void linux_e_proc_fork(struct proc *, struct proc *, int); 86 static void linux_e_proc_exit(struct proc *); 87 static void linux_e_proc_init(struct proc *, struct proc *, int); 88 89 #ifdef LINUX_NPTL 90 void linux_userret(void); 91 #endif 92 93 /* 94 * Emulation switch. 95 */ 96 97 struct uvm_object *emul_linux_object; 98 99 const struct emul emul_linux = { 100 "linux", 101 "/emul/linux", 102 #ifndef __HAVE_MINIMAL_EMUL 103 0, 104 (const int *)native_to_linux_errno, 105 LINUX_SYS_syscall, 106 LINUX_SYS_NSYSENT, 107 #endif 108 linux_sysent, 109 linux_syscallnames, 110 linux_sendsig, 111 linux_trapsignal, 112 NULL, 113 linux_sigcode, 114 linux_esigcode, 115 &emul_linux_object, 116 linux_setregs, 117 linux_e_proc_exec, 118 linux_e_proc_fork, 119 linux_e_proc_exit, 120 NULL, 121 NULL, 122 #ifdef __HAVE_SYSCALL_INTERN 123 linux_syscall_intern, 124 #else 125 #error Implement __HAVE_SYSCALL_INTERN for this platform 126 #endif 127 NULL, 128 NULL, 129 130 uvm_default_mapaddr, 131 132 linux_usertrap, 133 0, 134 NULL, /* e_startlwp */ 135 }; 136 137 static void 138 linux_e_proc_init(p, parent, forkflags) 139 struct proc *p, *parent; 140 int forkflags; 141 { 142 struct linux_emuldata *e = p->p_emuldata; 143 struct linux_emuldata_shared *s; 144 struct linux_emuldata *ep = NULL; 145 146 if (!e) { 147 /* allocate new Linux emuldata */ 148 MALLOC(e, void *, sizeof(struct linux_emuldata), 149 M_EMULDATA, M_WAITOK); 150 } else { 151 mutex_enter(proc_lock); 152 e->s->refs--; 153 if (e->s->refs == 0) 154 FREE(e->s, M_EMULDATA); 155 mutex_exit(proc_lock); 156 } 157 158 memset(e, '\0', sizeof(struct linux_emuldata)); 159 160 e->proc = p; 161 162 if (parent) 163 ep = parent->p_emuldata; 164 165 if (forkflags & FORK_SHAREVM) { 166 mutex_enter(proc_lock); 167 #ifdef DIAGNOSTIC 168 if (ep == NULL) { 169 killproc(p, "FORK_SHAREVM while emuldata is NULL\n"); 170 mutex_exit(proc_lock); 171 FREE(e, M_EMULDATA); 172 return; 173 } 174 #endif 175 s = ep->s; 176 s->refs++; 177 } else { 178 struct vmspace *vm; 179 180 MALLOC(s, void *, sizeof(struct linux_emuldata_shared), 181 M_EMULDATA, M_WAITOK); 182 s->refs = 1; 183 184 /* 185 * Set the process idea of the break to the real value. 186 * For fork, we use parent's vmspace since our's 187 * is not setup at the time of this call and is going 188 * to be copy of parent's anyway. For exec, just 189 * use our own vmspace. 190 */ 191 vm = (parent) ? parent->p_vmspace : p->p_vmspace; 192 s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize); 193 194 /* 195 * Linux threads are emulated as NetBSD processes (not lwp) 196 * We use native PID for Linux TID. The Linux TID is the 197 * PID of the first process in the group. It is stored 198 * here 199 */ 200 s->group_pid = p->p_pid; 201 202 /* 203 * Initialize the list of threads in the group 204 */ 205 LIST_INIT(&s->threads); 206 207 s->xstat = 0; 208 s->flags = 0; 209 mutex_enter(proc_lock); 210 } 211 212 e->s = s; 213 214 /* 215 * Add this thread in the group thread list 216 */ 217 LIST_INSERT_HEAD(&s->threads, e, threads); 218 219 #ifdef LINUX_NPTL 220 if (ep != NULL) { 221 e->parent_tidptr = ep->parent_tidptr; 222 e->child_tidptr = ep->child_tidptr; 223 e->clone_flags = ep->clone_flags; 224 } 225 #endif /* LINUX_NPTL */ 226 227 mutex_exit(proc_lock); 228 p->p_emuldata = e; 229 } 230 231 /* 232 * Allocate new per-process structures. Called when executing Linux 233 * process. We can reuse the old emuldata - if it's not null, 234 * the executed process is of same emulation as original forked one. 235 */ 236 static void 237 linux_e_proc_exec(struct proc *p, struct exec_package *epp) 238 { 239 240 /* exec, use our vmspace */ 241 linux_e_proc_init(p, NULL, 0); 242 } 243 244 /* 245 * Emulation per-process exit hook. 246 */ 247 static void 248 linux_e_proc_exit(struct proc *p) 249 { 250 struct linux_emuldata *e = p->p_emuldata; 251 252 #ifdef LINUX_NPTL 253 linux_nptl_proc_exit(p); 254 #endif 255 256 /* Remove the thread for the group thread list */ 257 mutex_enter(proc_lock); 258 LIST_REMOVE(e, threads); 259 260 /* free Linux emuldata and set the pointer to null */ 261 e->s->refs--; 262 if (e->s->refs == 0) 263 FREE(e->s, M_EMULDATA); 264 p->p_emuldata = NULL; 265 mutex_exit(proc_lock); 266 FREE(e, M_EMULDATA); 267 } 268 269 /* 270 * Emulation fork hook. 271 */ 272 static void 273 linux_e_proc_fork(p, parent, forkflags) 274 struct proc *p, *parent; 275 int forkflags; 276 { 277 278 /* 279 * The new process might share some vmspace-related stuff 280 * with parent, depending on fork flags (CLONE_VM et.al). 281 * Force allocation of new base emuldata, and share the 282 * VM-related parts only if necessary. 283 */ 284 p->p_emuldata = NULL; 285 linux_e_proc_init(p, parent, forkflags); 286 287 #ifdef LINUX_NPTL 288 linux_nptl_proc_fork(p, parent, linux_userret); 289 #endif 290 291 return; 292 } 293 294 #ifdef LINUX_NPTL 295 void 296 linux_userret(void) 297 { 298 struct lwp *l = curlwp; 299 struct proc *p = l->l_proc; 300 struct linux_emuldata *led = p->p_emuldata; 301 int error; 302 303 /* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory */ 304 if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) { 305 if ((error = copyout(&l->l_proc->p_pid, 306 led->child_tidptr, sizeof(l->l_proc->p_pid))) != 0) 307 printf("linux_userret: LINUX_CLONE_CHILD_SETTID " 308 "failed (led->child_tidptr = %p, p->p_pid = %d)\n", 309 led->child_tidptr, p->p_pid); 310 } 311 312 /* LINUX_CLONE_SETTLS: allocate a new TLS */ 313 if (led->clone_flags & LINUX_CLONE_SETTLS) { 314 if (linux_set_newtls(l, linux_get_newtls(l)) != 0) 315 printf("linux_userret: linux_set_tls failed"); 316 } 317 318 return; 319 } 320 321 void 322 linux_nptl_proc_exit(struct proc *p) 323 { 324 struct linux_emuldata *e = p->p_emuldata; 325 326 mutex_enter(proc_lock); 327 328 /* 329 * Check if we are a thread group leader victim of another 330 * thread doing exit_group(). If we are, change the exit code. 331 */ 332 if ((e->s->group_pid == p->p_pid) && 333 (e->s->flags & LINUX_LES_INEXITGROUP)) { 334 p->p_xstat = e->s->xstat; 335 } 336 337 /* 338 * Members of the thread groups others than the leader should 339 * exit quietely: no zombie stage, no signal. We do that by 340 * reparenting to init. init will collect us and nobody will 341 * notice what happened. 342 */ 343 #ifdef DEBUG_LINUX 344 printf("%s:%d e->s->group_pid = %d, p->p_pid = %d, flags = 0x%x\n", 345 __func__, __LINE__, e->s->group_pid, p->p_pid, e->s->flags); 346 #endif 347 if ((e->s->group_pid != p->p_pid) && 348 (e->clone_flags & LINUX_CLONE_THREAD)) { 349 proc_reparent(p, initproc); 350 cv_broadcast(&initproc->p_waitcv); 351 } 352 353 mutex_exit(proc_lock); 354 355 /* Emulate LINUX_CLONE_CHILD_CLEARTID */ 356 if (e->clear_tid != NULL) { 357 int error; 358 int null = 0; 359 struct linux_sys_futex_args cup; 360 register_t retval; 361 362 error = copyout(&null, e->clear_tid, sizeof(null)); 363 #ifdef DEBUG_LINUX 364 if (error != 0) 365 printf("%s: cannot clear TID\n", __func__); 366 #endif 367 368 SCARG(&cup, uaddr) = e->clear_tid; 369 SCARG(&cup, op) = LINUX_FUTEX_WAKE; 370 SCARG(&cup, val) = 0x7fffffff; /* Awake everyone */ 371 SCARG(&cup, timeout) = NULL; 372 SCARG(&cup, uaddr2) = NULL; 373 SCARG(&cup, val3) = 0; 374 if ((error = linux_sys_futex(curlwp, &cup, &retval)) != 0) 375 printf("%s: linux_sys_futex failed\n", __func__); 376 } 377 378 return; 379 } 380 381 void 382 linux_nptl_proc_fork(p, parent, luserret) 383 struct proc *p; 384 struct proc *parent; 385 void (*luserret)(void); 386 { 387 struct linux_emuldata *e = p->p_emuldata; 388 389 /* LINUX_CLONE_CHILD_CLEARTID: clear TID in child's memory on exit() */ 390 if (e->clone_flags & LINUX_CLONE_CHILD_CLEARTID) 391 e->clear_tid = e->child_tidptr; 392 393 /* LINUX_CLONE_PARENT_SETTID: set child's TID in parent's memory */ 394 if (e->clone_flags & LINUX_CLONE_PARENT_SETTID) { 395 if (copyout_proc(parent, &p->p_pid, 396 e->parent_tidptr, sizeof(p->p_pid)) != 0) 397 printf("%s: LINUX_CLONE_PARENT_SETTID " 398 "failed (e->parent_tidptr = %p, " 399 "parent->p_pid = %d, p->p_pid = %d)\n", 400 __func__, e->parent_tidptr, 401 parent->p_pid, p->p_pid); 402 } 403 404 /* 405 * CLONE_CHILD_SETTID and LINUX_CLONE_SETTLS require child's VM 406 * setup to be completed, we postpone them until userret time. 407 */ 408 if (e->clone_flags & 409 (LINUX_CLONE_CHILD_CLEARTID | LINUX_CLONE_SETTLS)) 410 p->p_userret = luserret; 411 412 return; 413 } 414 415 void 416 linux_nptl_proc_init(struct proc *p, struct proc *parent) 417 { 418 struct linux_emuldata *e = p->p_emuldata; 419 struct linux_emuldata *ep; 420 421 if ((parent != NULL) && (parent->p_emuldata != NULL)) { 422 ep = parent->p_emuldata; 423 424 e->parent_tidptr = ep->parent_tidptr; 425 e->child_tidptr = ep->child_tidptr; 426 e->clone_flags = ep->clone_flags; 427 } 428 429 return; 430 } 431 #endif /* LINUX_NPTL */ 432