1 /* $NetBSD: linux_exec.c,v 1.113 2009/10/25 01:14:03 rmind 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 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: linux_exec.c,v 1.113 2009/10/25 01:14:03 rmind Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <sys/proc.h> 40 #include <sys/malloc.h> 41 #include <sys/namei.h> 42 #include <sys/vnode.h> 43 #include <sys/mount.h> 44 #include <sys/exec.h> 45 #include <sys/exec_elf.h> 46 47 #include <sys/mman.h> 48 #include <sys/syscallargs.h> 49 50 #include <sys/ptrace.h> /* For proc_reparent() */ 51 52 #include <uvm/uvm_extern.h> 53 54 #include <sys/cpu.h> 55 #include <machine/reg.h> 56 57 #include <compat/linux/common/linux_types.h> 58 #include <compat/linux/common/linux_signal.h> 59 #include <compat/linux/common/linux_util.h> 60 #include <compat/linux/common/linux_sched.h> 61 #include <compat/linux/common/linux_machdep.h> 62 #include <compat/linux/common/linux_exec.h> 63 #include <compat/linux/common/linux_futex.h> 64 #include <compat/linux/common/linux_ipc.h> 65 #include <compat/linux/common/linux_sem.h> 66 67 #include <compat/linux/linux_syscallargs.h> 68 #include <compat/linux/linux_syscall.h> 69 #include <compat/linux/common/linux_misc.h> 70 #include <compat/linux/common/linux_errno.h> 71 #include <compat/linux/common/linux_emuldata.h> 72 73 extern struct sysent linux_sysent[]; 74 extern const char * const linux_syscallnames[]; 75 extern char linux_sigcode[], linux_esigcode[]; 76 77 static void linux_e_proc_exec(struct proc *, struct exec_package *); 78 static void linux_e_proc_fork(struct proc *, struct proc *, int); 79 static void linux_e_proc_exit(struct proc *); 80 static void linux_e_proc_init(struct proc *, struct proc *, int); 81 82 #ifdef LINUX_NPTL 83 void linux_userret(void); 84 #endif 85 86 /* 87 * Emulation switch. 88 */ 89 90 struct uvm_object *emul_linux_object; 91 92 struct emul emul_linux = { 93 .e_name = "linux", 94 .e_path = "/emul/linux", 95 #ifndef __HAVE_MINIMAL_EMUL 96 .e_flags = 0, 97 .e_errno = (const int *)native_to_linux_errno, 98 .e_nosys = LINUX_SYS_syscall, 99 .e_nsysent = LINUX_SYS_NSYSENT, 100 #endif 101 .e_sysent = linux_sysent, 102 .e_syscallnames = linux_syscallnames, 103 .e_sendsig = linux_sendsig, 104 .e_trapsignal = linux_trapsignal, 105 .e_tracesig = NULL, 106 .e_sigcode = linux_sigcode, 107 .e_esigcode = linux_esigcode, 108 .e_sigobject = &emul_linux_object, 109 .e_setregs = linux_setregs, 110 .e_proc_exec = linux_e_proc_exec, 111 .e_proc_fork = linux_e_proc_fork, 112 .e_proc_exit = linux_e_proc_exit, 113 .e_lwp_fork = NULL, 114 .e_lwp_exit = NULL, 115 #ifdef __HAVE_SYSCALL_INTERN 116 .e_syscall_intern = linux_syscall_intern, 117 #else 118 #error Implement __HAVE_SYSCALL_INTERN for this platform 119 #endif 120 .e_sysctlovly = NULL, 121 .e_fault = NULL, 122 .e_vm_default_addr = uvm_default_mapaddr, 123 .e_usertrap = linux_usertrap, 124 .e_sa = NULL, 125 .e_ucsize = 0, 126 .e_startlwp = NULL 127 }; 128 129 static void 130 linux_e_proc_init(struct proc *p, struct proc *parent, int forkflags) 131 { 132 struct linux_emuldata *e = p->p_emuldata; 133 struct linux_emuldata_shared *s; 134 struct linux_emuldata *ep = NULL; 135 136 if (!e) { 137 /* allocate new Linux emuldata */ 138 e = malloc(sizeof(struct linux_emuldata), 139 M_EMULDATA, M_WAITOK); 140 } else { 141 mutex_enter(proc_lock); 142 e->s->refs--; 143 if (e->s->refs == 0) 144 free(e->s, M_EMULDATA); 145 mutex_exit(proc_lock); 146 } 147 148 memset(e, '\0', sizeof(struct linux_emuldata)); 149 150 e->proc = p; 151 e->robust_futexes = NULL; 152 153 if (parent) 154 ep = parent->p_emuldata; 155 156 if (forkflags & FORK_SHAREVM) { 157 mutex_enter(proc_lock); 158 #ifdef DIAGNOSTIC 159 if (ep == NULL) { 160 killproc(p, "FORK_SHAREVM while emuldata is NULL\n"); 161 mutex_exit(proc_lock); 162 free(e, M_EMULDATA); 163 return; 164 } 165 #endif 166 s = ep->s; 167 s->refs++; 168 } else { 169 struct vmspace *vm; 170 171 s = malloc(sizeof(struct linux_emuldata_shared), 172 M_EMULDATA, M_WAITOK); 173 s->refs = 1; 174 175 /* 176 * Set the process idea of the break to the real value. 177 * For fork, we use parent's vmspace since our's 178 * is not setup at the time of this call and is going 179 * to be copy of parent's anyway. For exec, just 180 * use our own vmspace. 181 */ 182 vm = (parent) ? parent->p_vmspace : p->p_vmspace; 183 s->p_break = (char *)vm->vm_daddr + ctob(vm->vm_dsize); 184 185 /* 186 * Linux threads are emulated as NetBSD processes (not lwp) 187 * We use native PID for Linux TID. The Linux TID is the 188 * PID of the first process in the group. It is stored 189 * here 190 */ 191 s->group_pid = p->p_pid; 192 193 /* 194 * Initialize the list of threads in the group 195 */ 196 LIST_INIT(&s->threads); 197 198 s->xstat = 0; 199 s->flags = 0; 200 mutex_enter(proc_lock); 201 } 202 203 e->s = s; 204 205 /* 206 * Add this thread in the group thread list 207 */ 208 LIST_INSERT_HEAD(&s->threads, e, threads); 209 210 #ifdef LINUX_NPTL 211 if (ep != NULL) { 212 e->parent_tidptr = ep->parent_tidptr; 213 e->child_tidptr = ep->child_tidptr; 214 e->clone_flags = ep->clone_flags; 215 } 216 #endif /* LINUX_NPTL */ 217 218 mutex_exit(proc_lock); 219 p->p_emuldata = e; 220 } 221 222 /* 223 * Allocate new per-process structures. Called when executing Linux 224 * process. We can reuse the old emuldata - if it's not null, 225 * the executed process is of same emulation as original forked one. 226 */ 227 static void 228 linux_e_proc_exec(struct proc *p, struct exec_package *epp) 229 { 230 231 /* exec, use our vmspace */ 232 linux_e_proc_init(p, NULL, 0); 233 } 234 235 /* 236 * Emulation per-process exit hook. 237 */ 238 static void 239 linux_e_proc_exit(struct proc *p) 240 { 241 struct linux_emuldata *e = p->p_emuldata; 242 243 #ifdef LINUX_NPTL 244 linux_nptl_proc_exit(p); 245 release_futexes(p); 246 #endif 247 248 /* Remove the thread for the group thread list */ 249 mutex_enter(proc_lock); 250 LIST_REMOVE(e, threads); 251 252 /* free Linux emuldata and set the pointer to null */ 253 e->s->refs--; 254 if (e->s->refs == 0) 255 free(e->s, M_EMULDATA); 256 p->p_emuldata = NULL; 257 mutex_exit(proc_lock); 258 free(e, M_EMULDATA); 259 } 260 261 /* 262 * Emulation fork hook. 263 */ 264 static void 265 linux_e_proc_fork(struct proc *p, struct proc *parent, int forkflags) 266 { 267 268 /* 269 * The new process might share some vmspace-related stuff 270 * with parent, depending on fork flags (CLONE_VM et.al). 271 * Force allocation of new base emuldata, and share the 272 * VM-related parts only if necessary. 273 */ 274 p->p_emuldata = NULL; 275 linux_e_proc_init(p, parent, forkflags); 276 277 #ifdef LINUX_NPTL 278 linux_nptl_proc_fork(p, parent, linux_userret); 279 #endif 280 281 return; 282 } 283 284 #ifdef LINUX_NPTL 285 void 286 linux_userret(void) 287 { 288 struct lwp *l = curlwp; 289 struct proc *p = l->l_proc; 290 struct linux_emuldata *led = p->p_emuldata; 291 int error; 292 293 /* LINUX_CLONE_CHILD_SETTID: copy child's TID to child's memory */ 294 if (led->clone_flags & LINUX_CLONE_CHILD_SETTID) { 295 if ((error = copyout(&l->l_proc->p_pid, 296 led->child_tidptr, sizeof(l->l_proc->p_pid))) != 0) 297 printf("linux_userret: LINUX_CLONE_CHILD_SETTID " 298 "failed (led->child_tidptr = %p, p->p_pid = %d)\n", 299 led->child_tidptr, p->p_pid); 300 } 301 302 /* LINUX_CLONE_SETTLS: allocate a new TLS */ 303 if (led->clone_flags & LINUX_CLONE_SETTLS) { 304 if (linux_set_newtls(l, linux_get_newtls(l)) != 0) 305 printf("linux_userret: linux_set_tls failed"); 306 } 307 308 return; 309 } 310 311 void 312 linux_nptl_proc_exit(struct proc *p) 313 { 314 struct linux_emuldata *e = p->p_emuldata; 315 316 mutex_enter(proc_lock); 317 318 /* 319 * Check if we are a thread group leader victim of another 320 * thread doing exit_group(). If we are, change the exit code. 321 */ 322 if ((e->s->group_pid == p->p_pid) && 323 (e->s->flags & LINUX_LES_INEXITGROUP)) { 324 p->p_xstat = e->s->xstat; 325 } 326 327 /* 328 * Members of the thread groups others than the leader should 329 * exit quietely: no zombie stage, no signal. We do that by 330 * reparenting to init. init will collect us and nobody will 331 * notice what happened. 332 */ 333 #ifdef DEBUG_LINUX 334 printf("%s:%d e->s->group_pid = %d, p->p_pid = %d, flags = 0x%x\n", 335 __func__, __LINE__, e->s->group_pid, p->p_pid, e->s->flags); 336 #endif 337 if ((e->s->group_pid != p->p_pid) && 338 (e->clone_flags & LINUX_CLONE_THREAD)) { 339 proc_reparent(p, initproc); 340 cv_broadcast(&initproc->p_waitcv); 341 } 342 343 mutex_exit(proc_lock); 344 345 /* Emulate LINUX_CLONE_CHILD_CLEARTID */ 346 if (e->clear_tid != NULL) { 347 int error; 348 int null = 0; 349 struct linux_sys_futex_args cup; 350 register_t retval; 351 352 error = copyout(&null, e->clear_tid, sizeof(null)); 353 #ifdef DEBUG_LINUX 354 if (error != 0) 355 printf("%s: cannot clear TID\n", __func__); 356 #endif 357 358 SCARG(&cup, uaddr) = e->clear_tid; 359 SCARG(&cup, op) = LINUX_FUTEX_WAKE; 360 SCARG(&cup, val) = 0x7fffffff; /* Awake everyone */ 361 SCARG(&cup, timeout) = NULL; 362 SCARG(&cup, uaddr2) = NULL; 363 SCARG(&cup, val3) = 0; 364 if ((error = linux_sys_futex(curlwp, &cup, &retval)) != 0) 365 printf("%s: linux_sys_futex failed\n", __func__); 366 } 367 368 return; 369 } 370 371 void 372 linux_nptl_proc_fork(struct proc *p, struct proc *parent, void (*luserret)(void)) 373 { 374 struct linux_emuldata *e = p->p_emuldata; 375 376 /* LINUX_CLONE_CHILD_CLEARTID: clear TID in child's memory on exit() */ 377 if (e->clone_flags & LINUX_CLONE_CHILD_CLEARTID) 378 e->clear_tid = e->child_tidptr; 379 380 /* LINUX_CLONE_PARENT_SETTID: set child's TID in parent's memory */ 381 if (e->clone_flags & LINUX_CLONE_PARENT_SETTID) { 382 if (copyout_proc(parent, &p->p_pid, 383 e->parent_tidptr, sizeof(p->p_pid)) != 0) 384 printf("%s: LINUX_CLONE_PARENT_SETTID " 385 "failed (e->parent_tidptr = %p, " 386 "parent->p_pid = %d, p->p_pid = %d)\n", 387 __func__, e->parent_tidptr, 388 parent->p_pid, p->p_pid); 389 } 390 391 /* 392 * CLONE_CHILD_SETTID and LINUX_CLONE_SETTLS require child's VM 393 * setup to be completed, we postpone them until userret time. 394 */ 395 if (e->clone_flags & 396 (LINUX_CLONE_CHILD_CLEARTID | LINUX_CLONE_SETTLS)) 397 p->p_userret = luserret; 398 399 return; 400 } 401 402 void 403 linux_nptl_proc_init(struct proc *p, struct proc *parent) 404 { 405 struct linux_emuldata *e = p->p_emuldata; 406 struct linux_emuldata *ep; 407 408 if ((parent != NULL) && (parent->p_emuldata != NULL)) { 409 ep = parent->p_emuldata; 410 411 e->parent_tidptr = ep->parent_tidptr; 412 e->child_tidptr = ep->child_tidptr; 413 e->clone_flags = ep->clone_flags; 414 } 415 416 return; 417 } 418 #endif /* LINUX_NPTL */ 419