1 /* $NetBSD: linux_exec.c,v 1.97 2007/10/19 18:52:10 njoly Exp $ */ 2 3 /*- 4 * Copyright (c) 1994, 1995, 1998, 2000, 2007 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 1.97 2007/10/19 18:52:10 njoly 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 __P((struct proc *, struct exec_package *)); 85 static void linux_e_proc_fork __P((struct proc *, struct proc *, int)); 86 static void linux_e_proc_exit __P((struct proc *)); 87 static void linux_e_proc_init __P((struct proc *, struct proc *, int)); 88 89 #ifdef LINUX_NPTL 90 void linux_userret(void); 91 #endif 92 93 /* 94 * Execve(2). Just check the alternate emulation path, and pass it on 95 * to the NetBSD execve(). 96 */ 97 int 98 linux_sys_execve(l, v, retval) 99 struct lwp *l; 100 void *v; 101 register_t *retval; 102 { 103 struct linux_sys_execve_args /* { 104 syscallarg(const char *) path; 105 syscallarg(char **) argv; 106 syscallarg(char **) envp; 107 } */ *uap = v; 108 struct sys_execve_args ap; 109 110 SCARG(&ap, path) = SCARG(uap, path); 111 SCARG(&ap, argp) = SCARG(uap, argp); 112 SCARG(&ap, envp) = SCARG(uap, envp); 113 114 return sys_execve(l, &ap, retval); 115 } 116 117 /* 118 * Emulation switch. 119 */ 120 121 struct uvm_object *emul_linux_object; 122 123 const struct emul emul_linux = { 124 "linux", 125 "/emul/linux", 126 #ifndef __HAVE_MINIMAL_EMUL 127 0, 128 (const int *)native_to_linux_errno, 129 LINUX_SYS_syscall, 130 LINUX_SYS_NSYSENT, 131 #endif 132 linux_sysent, 133 linux_syscallnames, 134 linux_sendsig, 135 linux_trapsignal, 136 NULL, 137 linux_sigcode, 138 linux_esigcode, 139 &emul_linux_object, 140 linux_setregs, 141 linux_e_proc_exec, 142 linux_e_proc_fork, 143 linux_e_proc_exit, 144 NULL, 145 NULL, 146 #ifdef __HAVE_SYSCALL_INTERN 147 linux_syscall_intern, 148 #else 149 #error Implement __HAVE_SYSCALL_INTERN for this platform 150 #endif 151 NULL, 152 NULL, 153 154 uvm_default_mapaddr, 155 156 linux_usertrap, 157 0, 158 NULL, /* e_startlwp */ 159 }; 160 161 static void 162 linux_e_proc_init(p, parent, forkflags) 163 struct proc *p, *parent; 164 int forkflags; 165 { 166 struct linux_emuldata *e = p->p_emuldata; 167 struct linux_emuldata_shared *s; 168 struct linux_emuldata *ep = NULL; 169 170 if (!e) { 171 /* allocate new Linux emuldata */ 172 MALLOC(e, void *, sizeof(struct linux_emuldata), 173 M_EMULDATA, M_WAITOK); 174 } else { 175 e->s->refs--; 176 if (e->s->refs == 0) 177 FREE(e->s, M_EMULDATA); 178 } 179 180 memset(e, '\0', sizeof(struct linux_emuldata)); 181 182 e->proc = p; 183 184 if (parent) 185 ep = parent->p_emuldata; 186 187 if (forkflags & FORK_SHAREVM) { 188 #ifdef DIAGNOSTIC 189 if (ep == NULL) { 190 killproc(p, "FORK_SHAREVM while emuldata is NULL\n"); 191 FREE(e, M_EMULDATA); 192 return; 193 } 194 #endif 195 s = ep->s; 196 s->refs++; 197 } else { 198 struct vmspace *vm; 199 200 MALLOC(s, void *, sizeof(struct linux_emuldata_shared), 201 M_EMULDATA, M_WAITOK); 202 s->refs = 1; 203 204 /* 205 * Set the process idea of the break to the real value. 206 * For fork, we use parent's vmspace since our's 207 * is not setup at the time of this call and is going 208 * to be copy of parent's anyway. For exec, just 209 * use our own vmspace. 210 */ 211 vm = (parent) ? parent->p_vmspace : p->p_vmspace; 212 s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize); 213 214 /* 215 * Linux threads are emulated as NetBSD processes (not lwp) 216 * We use native PID for Linux TID. The Linux TID is the 217 * PID of the first process in the group. It is stored 218 * here 219 */ 220 s->group_pid = p->p_pid; 221 222 /* 223 * Initialize the list of threads in the group 224 */ 225 LIST_INIT(&s->threads); 226 227 s->xstat = 0; 228 s->flags = 0; 229 } 230 231 e->s = s; 232 233 /* 234 * Add this thread in the group thread list 235 */ 236 LIST_INSERT_HEAD(&s->threads, e, threads); 237 238 #ifdef LINUX_NPTL 239 if (ep != NULL) { 240 e->parent_tidptr = ep->parent_tidptr; 241 e->child_tidptr = ep->child_tidptr; 242 e->clone_flags = ep->clone_flags; 243 } 244 #endif /* LINUX_NPTL */ 245 246 p->p_emuldata = e; 247 } 248 249 /* 250 * Allocate new per-process structures. Called when executing Linux 251 * process. We can reuse the old emuldata - if it's not null, 252 * the executed process is of same emulation as original forked one. 253 */ 254 static void 255 linux_e_proc_exec(struct proc *p, struct exec_package *epp) 256 { 257 /* exec, use our vmspace */ 258 linux_e_proc_init(p, NULL, 0); 259 } 260 261 /* 262 * Emulation per-process exit hook. 263 */ 264 static void 265 linux_e_proc_exit(p) 266 struct proc *p; 267 { 268 struct linux_emuldata *e = p->p_emuldata; 269 270 #ifdef LINUX_NPTL 271 linux_nptl_proc_exit(p); 272 #endif 273 /* Remove the thread for the group thread list */ 274 LIST_REMOVE(e, threads); 275 276 /* free Linux emuldata and set the pointer to null */ 277 e->s->refs--; 278 if (e->s->refs == 0) 279 FREE(e->s, M_EMULDATA); 280 FREE(e, M_EMULDATA); 281 p->p_emuldata = NULL; 282 } 283 284 /* 285 * Emulation fork hook. 286 */ 287 static void 288 linux_e_proc_fork(p, parent, forkflags) 289 struct proc *p, *parent; 290 int forkflags; 291 { 292 /* 293 * The new process might share some vmspace-related stuff 294 * with parent, depending on fork flags (CLONE_VM et.al). 295 * Force allocation of new base emuldata, and share the 296 * VM-related parts only if necessary. 297 */ 298 p->p_emuldata = NULL; 299 linux_e_proc_init(p, parent, forkflags); 300 301 #ifdef LINUX_NPTL 302 linux_nptl_proc_fork(p, parent, linux_userret); 303 #endif 304 305 return; 306 } 307 308 #ifdef LINUX_NPTL 309 void 310 linux_userret(void) 311 { 312 struct lwp *l = curlwp; 313 struct proc *p = l->l_proc; 314 struct linux_emuldata *led = p->p_emuldata; 315 int error; 316 317 /* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory */ 318 if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) { 319 if ((error = copyout(&l->l_proc->p_pid, 320 led->child_tidptr, sizeof(l->l_proc->p_pid))) != 0) 321 printf("linux_userret: LINUX_CLONE_CHILD_SETTID " 322 "failed (led->child_tidptr = %p, p->p_pid = %d)\n", 323 led->child_tidptr, p->p_pid); 324 } 325 326 /* LINUX_CLONE_SETTLS: allocate a new TLS */ 327 if (led->clone_flags & LINUX_CLONE_SETTLS) { 328 if (linux_set_newtls(l, linux_get_newtls(l)) != 0) 329 printf("linux_userret: linux_set_tls failed"); 330 } 331 332 return; 333 } 334 335 void 336 linux_nptl_proc_exit(p) 337 struct proc *p; 338 { 339 struct linux_emuldata *e = p->p_emuldata; 340 341 mutex_enter(&proclist_lock); 342 343 /* 344 * Check if we are a thread group leader victim of another 345 * thread doing exit_group(). If we are, change the exit code. 346 */ 347 if ((e->s->group_pid == p->p_pid) && 348 (e->s->flags & LINUX_LES_INEXITGROUP)) { 349 p->p_xstat = e->s->xstat; 350 } 351 352 /* 353 * Members of the thread groups others than the leader should 354 * exit quietely: no zombie stage, no signal. We do that by 355 * reparenting to init. init will collect us and nobody will 356 * notice what happened. 357 */ 358 #ifdef DEBUG_LINUX 359 printf("%s:%d e->s->group_pid = %d, p->p_pid = %d, flags = 0x%x\n", 360 __func__, __LINE__, e->s->group_pid, p->p_pid, e->s->flags); 361 #endif 362 if (e->s->group_pid != p->p_pid) { 363 proc_reparent(p, initproc); 364 cv_broadcast(&initproc->p_waitcv); 365 } 366 367 mutex_exit(&proclist_lock); 368 369 /* Emulate LINUX_CLONE_CHILD_CLEARTID */ 370 if (e->clear_tid != NULL) { 371 int error; 372 int null = 0; 373 struct linux_sys_futex_args cup; 374 register_t retval; 375 376 error = copyout(&null, e->clear_tid, sizeof(null)); 377 #ifdef DEBUG_LINUX 378 if (error != 0) 379 printf("%s: cannot clear TID\n", __func__); 380 #endif 381 382 SCARG(&cup, uaddr) = e->clear_tid; 383 SCARG(&cup, op) = LINUX_FUTEX_WAKE; 384 SCARG(&cup, val) = 0x7fffffff; /* Awake everyone */ 385 SCARG(&cup, timeout) = NULL; 386 SCARG(&cup, uaddr2) = NULL; 387 SCARG(&cup, val3) = 0; 388 if ((error = linux_sys_futex(curlwp, &cup, &retval)) != 0) 389 printf("%s: linux_sys_futex failed\n", __func__); 390 } 391 392 return; 393 } 394 395 void 396 linux_nptl_proc_fork(p, parent, luserret) 397 struct proc *p; 398 struct proc *parent; 399 void (*luserret)(void); 400 { 401 #ifdef LINUX_NPTL 402 struct linux_emuldata *e; 403 #endif 404 405 e = p->p_emuldata; 406 407 /* LINUX_CLONE_CHILD_CLEARTID: clear TID in child's memory on exit() */ 408 if (e->clone_flags & LINUX_CLONE_CHILD_CLEARTID) 409 e->clear_tid = e->child_tidptr; 410 411 /* LINUX_CLONE_PARENT_SETTID: set child's TID in parent's memory */ 412 if (e->clone_flags & LINUX_CLONE_PARENT_SETTID) { 413 if (copyout_proc(parent, &p->p_pid, 414 e->parent_tidptr, sizeof(p->p_pid)) != 0) 415 printf("%s: LINUX_CLONE_PARENT_SETTID " 416 "failed (e->parent_tidptr = %p, " 417 "parent->p_pid = %d, p->p_pid = %d)\n", 418 __func__, e->parent_tidptr, 419 parent->p_pid, p->p_pid); 420 } 421 422 /* 423 * CLONE_CHILD_SETTID and LINUX_CLONE_SETTLS require child's VM 424 * setup to be completed, we postpone them until userret time. 425 */ 426 if (e->clone_flags & 427 (LINUX_CLONE_CHILD_CLEARTID | LINUX_CLONE_SETTLS)) 428 p->p_userret = luserret; 429 430 return; 431 } 432 433 void 434 linux_nptl_proc_init(p, parent) 435 struct proc *p; 436 struct proc *parent; 437 { 438 struct linux_emuldata *e = p->p_emuldata; 439 struct linux_emuldata *ep; 440 441 if ((parent != NULL) && (parent->p_emuldata != NULL)) { 442 ep = parent->p_emuldata; 443 444 e->parent_tidptr = ep->parent_tidptr; 445 e->child_tidptr = ep->child_tidptr; 446 e->clone_flags = ep->clone_flags; 447 } 448 449 return; 450 } 451 452 453 #endif /* LINUX_NPTL */ 454