1 /* $NetBSD: linux_exec.c,v 1.100 2007/12/08 18:36:06 dsl 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 1.100 2007/12/08 18:36:06 dsl 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 e->s->refs--; 152 if (e->s->refs == 0) 153 FREE(e->s, M_EMULDATA); 154 } 155 156 memset(e, '\0', sizeof(struct linux_emuldata)); 157 158 e->proc = p; 159 160 if (parent) 161 ep = parent->p_emuldata; 162 163 if (forkflags & FORK_SHAREVM) { 164 #ifdef DIAGNOSTIC 165 if (ep == NULL) { 166 killproc(p, "FORK_SHAREVM while emuldata is NULL\n"); 167 FREE(e, M_EMULDATA); 168 return; 169 } 170 #endif 171 s = ep->s; 172 s->refs++; 173 } else { 174 struct vmspace *vm; 175 176 MALLOC(s, void *, sizeof(struct linux_emuldata_shared), 177 M_EMULDATA, M_WAITOK); 178 s->refs = 1; 179 180 /* 181 * Set the process idea of the break to the real value. 182 * For fork, we use parent's vmspace since our's 183 * is not setup at the time of this call and is going 184 * to be copy of parent's anyway. For exec, just 185 * use our own vmspace. 186 */ 187 vm = (parent) ? parent->p_vmspace : p->p_vmspace; 188 s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize); 189 190 /* 191 * Linux threads are emulated as NetBSD processes (not lwp) 192 * We use native PID for Linux TID. The Linux TID is the 193 * PID of the first process in the group. It is stored 194 * here 195 */ 196 s->group_pid = p->p_pid; 197 198 /* 199 * Initialize the list of threads in the group 200 */ 201 LIST_INIT(&s->threads); 202 203 s->xstat = 0; 204 s->flags = 0; 205 } 206 207 e->s = s; 208 209 /* 210 * Add this thread in the group thread list 211 */ 212 LIST_INSERT_HEAD(&s->threads, e, threads); 213 214 #ifdef LINUX_NPTL 215 if (ep != NULL) { 216 e->parent_tidptr = ep->parent_tidptr; 217 e->child_tidptr = ep->child_tidptr; 218 e->clone_flags = ep->clone_flags; 219 } 220 #endif /* LINUX_NPTL */ 221 222 p->p_emuldata = e; 223 } 224 225 /* 226 * Allocate new per-process structures. Called when executing Linux 227 * process. We can reuse the old emuldata - if it's not null, 228 * the executed process is of same emulation as original forked one. 229 */ 230 static void 231 linux_e_proc_exec(struct proc *p, struct exec_package *epp) 232 { 233 /* exec, use our vmspace */ 234 linux_e_proc_init(p, NULL, 0); 235 } 236 237 /* 238 * Emulation per-process exit hook. 239 */ 240 static void 241 linux_e_proc_exit(struct proc *p) 242 { 243 struct linux_emuldata *e = p->p_emuldata; 244 245 #ifdef LINUX_NPTL 246 linux_nptl_proc_exit(p); 247 #endif 248 /* Remove the thread for the group thread list */ 249 LIST_REMOVE(e, threads); 250 251 /* free Linux emuldata and set the pointer to null */ 252 e->s->refs--; 253 if (e->s->refs == 0) 254 FREE(e->s, M_EMULDATA); 255 FREE(e, M_EMULDATA); 256 p->p_emuldata = NULL; 257 } 258 259 /* 260 * Emulation fork hook. 261 */ 262 static void 263 linux_e_proc_fork(p, parent, forkflags) 264 struct proc *p, *parent; 265 int forkflags; 266 { 267 /* 268 * The new process might share some vmspace-related stuff 269 * with parent, depending on fork flags (CLONE_VM et.al). 270 * Force allocation of new base emuldata, and share the 271 * VM-related parts only if necessary. 272 */ 273 p->p_emuldata = NULL; 274 linux_e_proc_init(p, parent, forkflags); 275 276 #ifdef LINUX_NPTL 277 linux_nptl_proc_fork(p, parent, linux_userret); 278 #endif 279 280 return; 281 } 282 283 #ifdef LINUX_NPTL 284 void 285 linux_userret(void) 286 { 287 struct lwp *l = curlwp; 288 struct proc *p = l->l_proc; 289 struct linux_emuldata *led = p->p_emuldata; 290 int error; 291 292 /* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory */ 293 if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) { 294 if ((error = copyout(&l->l_proc->p_pid, 295 led->child_tidptr, sizeof(l->l_proc->p_pid))) != 0) 296 printf("linux_userret: LINUX_CLONE_CHILD_SETTID " 297 "failed (led->child_tidptr = %p, p->p_pid = %d)\n", 298 led->child_tidptr, p->p_pid); 299 } 300 301 /* LINUX_CLONE_SETTLS: allocate a new TLS */ 302 if (led->clone_flags & LINUX_CLONE_SETTLS) { 303 if (linux_set_newtls(l, linux_get_newtls(l)) != 0) 304 printf("linux_userret: linux_set_tls failed"); 305 } 306 307 return; 308 } 309 310 void 311 linux_nptl_proc_exit(struct proc *p) 312 { 313 struct linux_emuldata *e = p->p_emuldata; 314 315 mutex_enter(&proclist_lock); 316 317 /* 318 * Check if we are a thread group leader victim of another 319 * thread doing exit_group(). If we are, change the exit code. 320 */ 321 if ((e->s->group_pid == p->p_pid) && 322 (e->s->flags & LINUX_LES_INEXITGROUP)) { 323 p->p_xstat = e->s->xstat; 324 } 325 326 /* 327 * Members of the thread groups others than the leader should 328 * exit quietely: no zombie stage, no signal. We do that by 329 * reparenting to init. init will collect us and nobody will 330 * notice what happened. 331 */ 332 #ifdef DEBUG_LINUX 333 printf("%s:%d e->s->group_pid = %d, p->p_pid = %d, flags = 0x%x\n", 334 __func__, __LINE__, e->s->group_pid, p->p_pid, e->s->flags); 335 #endif 336 if (e->s->group_pid != p->p_pid) { 337 proc_reparent(p, initproc); 338 cv_broadcast(&initproc->p_waitcv); 339 } 340 341 mutex_exit(&proclist_lock); 342 343 /* Emulate LINUX_CLONE_CHILD_CLEARTID */ 344 if (e->clear_tid != NULL) { 345 int error; 346 int null = 0; 347 struct linux_sys_futex_args cup; 348 register_t retval; 349 350 error = copyout(&null, e->clear_tid, sizeof(null)); 351 #ifdef DEBUG_LINUX 352 if (error != 0) 353 printf("%s: cannot clear TID\n", __func__); 354 #endif 355 356 SCARG(&cup, uaddr) = e->clear_tid; 357 SCARG(&cup, op) = LINUX_FUTEX_WAKE; 358 SCARG(&cup, val) = 0x7fffffff; /* Awake everyone */ 359 SCARG(&cup, timeout) = NULL; 360 SCARG(&cup, uaddr2) = NULL; 361 SCARG(&cup, val3) = 0; 362 if ((error = linux_sys_futex(curlwp, &cup, &retval)) != 0) 363 printf("%s: linux_sys_futex failed\n", __func__); 364 } 365 366 return; 367 } 368 369 void 370 linux_nptl_proc_fork(p, parent, luserret) 371 struct proc *p; 372 struct proc *parent; 373 void (*luserret)(void); 374 { 375 #ifdef LINUX_NPTL 376 struct linux_emuldata *e; 377 #endif 378 379 e = p->p_emuldata; 380 381 /* LINUX_CLONE_CHILD_CLEARTID: clear TID in child's memory on exit() */ 382 if (e->clone_flags & LINUX_CLONE_CHILD_CLEARTID) 383 e->clear_tid = e->child_tidptr; 384 385 /* LINUX_CLONE_PARENT_SETTID: set child's TID in parent's memory */ 386 if (e->clone_flags & LINUX_CLONE_PARENT_SETTID) { 387 if (copyout_proc(parent, &p->p_pid, 388 e->parent_tidptr, sizeof(p->p_pid)) != 0) 389 printf("%s: LINUX_CLONE_PARENT_SETTID " 390 "failed (e->parent_tidptr = %p, " 391 "parent->p_pid = %d, p->p_pid = %d)\n", 392 __func__, e->parent_tidptr, 393 parent->p_pid, p->p_pid); 394 } 395 396 /* 397 * CLONE_CHILD_SETTID and LINUX_CLONE_SETTLS require child's VM 398 * setup to be completed, we postpone them until userret time. 399 */ 400 if (e->clone_flags & 401 (LINUX_CLONE_CHILD_CLEARTID | LINUX_CLONE_SETTLS)) 402 p->p_userret = luserret; 403 404 return; 405 } 406 407 void 408 linux_nptl_proc_init(struct proc *p, struct proc *parent) 409 { 410 struct linux_emuldata *e = p->p_emuldata; 411 struct linux_emuldata *ep; 412 413 if ((parent != NULL) && (parent->p_emuldata != NULL)) { 414 ep = parent->p_emuldata; 415 416 e->parent_tidptr = ep->parent_tidptr; 417 e->child_tidptr = ep->child_tidptr; 418 e->clone_flags = ep->clone_flags; 419 } 420 421 return; 422 } 423 424 425 #endif /* LINUX_NPTL */ 426