lwproc.c revision 1.25
1 /* $NetBSD: lwproc.c,v 1.25 2013/12/09 16:21:15 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2010, 2011 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: lwproc.c,v 1.25 2013/12/09 16:21:15 pooka Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/atomic.h> 33 #include <sys/filedesc.h> 34 #include <sys/kauth.h> 35 #include <sys/kmem.h> 36 #include <sys/lwp.h> 37 #include <sys/ktrace.h> 38 #include <sys/pool.h> 39 #include <sys/proc.h> 40 #include <sys/queue.h> 41 #include <sys/resourcevar.h> 42 #include <sys/uidinfo.h> 43 44 #include <rump/rumpuser.h> 45 46 #include "rump_private.h" 47 48 struct emul *emul_default = &emul_netbsd; 49 50 static void 51 lwproc_proc_free(struct proc *p) 52 { 53 kauth_cred_t cred; 54 55 KASSERT(p->p_stat == SDYING || p->p_stat == SDEAD); 56 57 #ifdef KTRACE 58 if (p->p_tracep) { 59 mutex_enter(&ktrace_lock); 60 ktrderef(p); 61 mutex_exit(&ktrace_lock); 62 } 63 #endif 64 65 mutex_enter(proc_lock); 66 67 KASSERT(p->p_nlwps == 0); 68 KASSERT(LIST_EMPTY(&p->p_lwps)); 69 70 LIST_REMOVE(p, p_list); 71 LIST_REMOVE(p, p_sibling); 72 proc_free_pid(p->p_pid); /* decrements nprocs */ 73 proc_leavepgrp(p); /* releases proc_lock */ 74 75 cred = p->p_cred; 76 chgproccnt(kauth_cred_getuid(cred), -1); 77 if (rump_proc_vfs_release) 78 rump_proc_vfs_release(p); 79 80 lim_free(p->p_limit); 81 pstatsfree(p->p_stats); 82 kauth_cred_free(p->p_cred); 83 proc_finispecific(p); 84 85 mutex_obj_free(p->p_lock); 86 mutex_destroy(&p->p_stmutex); 87 mutex_destroy(&p->p_auxlock); 88 rw_destroy(&p->p_reflock); 89 cv_destroy(&p->p_waitcv); 90 cv_destroy(&p->p_lwpcv); 91 92 /* non-kernel vmspaces are not shared */ 93 if (!RUMP_LOCALPROC_P(p)) { 94 KASSERT(p->p_vmspace->vm_refcnt == 1); 95 kmem_free(p->p_vmspace, sizeof(*p->p_vmspace)); 96 } 97 98 proc_free_mem(p); 99 } 100 101 /* 102 * Allocate a new process. Mostly mimic fork by 103 * copying the properties of the parent. However, there are some 104 * differences. 105 * 106 * Switch to the new lwp and return a pointer to it. 107 */ 108 static struct proc * 109 lwproc_newproc(struct proc *parent, int flags) 110 { 111 uid_t uid = kauth_cred_getuid(parent->p_cred); 112 struct proc *p; 113 114 /* maxproc not enforced */ 115 atomic_inc_uint(&nprocs); 116 117 /* allocate process */ 118 p = proc_alloc(); 119 memset(&p->p_startzero, 0, 120 offsetof(struct proc, p_endzero) 121 - offsetof(struct proc, p_startzero)); 122 memcpy(&p->p_startcopy, &parent->p_startcopy, 123 offsetof(struct proc, p_endcopy) 124 - offsetof(struct proc, p_startcopy)); 125 126 /* some other garbage we need to zero */ 127 p->p_sigacts = NULL; 128 p->p_aio = NULL; 129 p->p_dtrace = NULL; 130 p->p_mqueue_cnt = p->p_exitsig = 0; 131 p->p_flag = p->p_sflag = p->p_slflag = p->p_lflag = p->p_stflag = 0; 132 p->p_trace_enabled = 0; 133 p->p_xstat = p->p_acflag = 0; 134 p->p_stackbase = 0; 135 136 p->p_stats = pstatscopy(parent->p_stats); 137 138 p->p_vmspace = vmspace_kernel(); 139 p->p_emul = emul_default; 140 if (*parent->p_comm) 141 strcpy(p->p_comm, parent->p_comm); 142 else 143 strcpy(p->p_comm, "rumproc"); 144 145 if ((flags & RUMP_RFCFDG) == 0) 146 KASSERT(parent == curproc); 147 if (flags & RUMP_RFFDG) 148 p->p_fd = fd_copy(); 149 else if (flags & RUMP_RFCFDG) 150 p->p_fd = fd_init(NULL); 151 else 152 fd_share(p); 153 154 lim_addref(parent->p_limit); 155 p->p_limit = parent->p_limit; 156 157 LIST_INIT(&p->p_lwps); 158 LIST_INIT(&p->p_children); 159 160 p->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 161 mutex_init(&p->p_stmutex, MUTEX_DEFAULT, IPL_HIGH); 162 mutex_init(&p->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 163 rw_init(&p->p_reflock); 164 cv_init(&p->p_waitcv, "pwait"); 165 cv_init(&p->p_lwpcv, "plwp"); 166 167 p->p_pptr = parent; 168 p->p_ppid = parent->p_pid; 169 p->p_stat = SACTIVE; 170 171 kauth_proc_fork(parent, p); 172 173 /* initialize cwd in rump kernels with vfs */ 174 if (rump_proc_vfs_init) 175 rump_proc_vfs_init(p); 176 177 chgproccnt(uid, 1); /* not enforced */ 178 179 /* publish proc various proc lists */ 180 mutex_enter(proc_lock); 181 LIST_INSERT_HEAD(&allproc, p, p_list); 182 LIST_INSERT_HEAD(&parent->p_children, p, p_sibling); 183 LIST_INSERT_AFTER(parent, p, p_pglist); 184 mutex_exit(proc_lock); 185 186 return p; 187 } 188 189 static void 190 lwproc_freelwp(struct lwp *l) 191 { 192 struct proc *p; 193 194 p = l->l_proc; 195 mutex_enter(p->p_lock); 196 197 KASSERT(l->l_flag & LW_WEXIT); 198 KASSERT(l->l_refcnt == 0); 199 200 /* ok, zero references, continue with nuke */ 201 LIST_REMOVE(l, l_sibling); 202 KASSERT(p->p_nlwps >= 1); 203 if (--p->p_nlwps == 0) { 204 KASSERT(p != &proc0); 205 p->p_stat = SDEAD; 206 } 207 cv_broadcast(&p->p_lwpcv); /* nobody sleeps on this in a rump kernel? */ 208 kauth_cred_free(l->l_cred); 209 mutex_exit(p->p_lock); 210 211 mutex_enter(proc_lock); 212 LIST_REMOVE(l, l_list); 213 mutex_exit(proc_lock); 214 215 if (l->l_name) 216 kmem_free(l->l_name, MAXCOMLEN); 217 lwp_finispecific(l); 218 219 rumpuser_curlwpop(RUMPUSER_LWP_DESTROY, l); 220 membar_exit(); 221 kmem_free(l, sizeof(*l)); 222 223 if (p->p_stat == SDEAD) 224 lwproc_proc_free(p); 225 } 226 227 extern kmutex_t unruntime_lock; 228 229 /* 230 * called with p_lock held, releases lock before return 231 */ 232 static void 233 lwproc_makelwp(struct proc *p, struct lwp *l, bool doswitch, bool procmake) 234 { 235 236 p->p_nlwps++; 237 l->l_refcnt = 1; 238 l->l_proc = p; 239 240 l->l_lid = p->p_nlwpid++; 241 LIST_INSERT_HEAD(&p->p_lwps, l, l_sibling); 242 243 l->l_fd = p->p_fd; 244 l->l_cpu = rump_cpu; 245 l->l_target_cpu = rump_cpu; /* Initial target CPU always the same */ 246 l->l_stat = LSRUN; 247 l->l_mutex = &unruntime_lock; 248 TAILQ_INIT(&l->l_ld_locks); 249 mutex_exit(p->p_lock); 250 251 lwp_update_creds(l); 252 lwp_initspecific(l); 253 254 membar_enter(); 255 rumpuser_curlwpop(RUMPUSER_LWP_CREATE, l); 256 if (doswitch) { 257 rump_lwproc_switch(l); 258 } 259 260 /* filedesc already has refcount 1 when process is created */ 261 if (!procmake) { 262 fd_hold(l); 263 } 264 265 mutex_enter(proc_lock); 266 LIST_INSERT_HEAD(&alllwp, l, l_list); 267 mutex_exit(proc_lock); 268 } 269 270 struct lwp * 271 rump__lwproc_alloclwp(struct proc *p) 272 { 273 struct lwp *l; 274 bool newproc = false; 275 276 if (p == NULL) { 277 p = lwproc_newproc(&proc0, 0); 278 newproc = true; 279 } 280 281 l = kmem_zalloc(sizeof(*l), KM_SLEEP); 282 283 mutex_enter(p->p_lock); 284 KASSERT((p->p_sflag & PS_RUMP_LWPEXIT) == 0); 285 lwproc_makelwp(p, l, false, newproc); 286 287 return l; 288 } 289 290 int 291 rump_lwproc_newlwp(pid_t pid) 292 { 293 struct proc *p; 294 struct lwp *l; 295 296 l = kmem_zalloc(sizeof(*l), KM_SLEEP); 297 mutex_enter(proc_lock); 298 p = proc_find_raw(pid); 299 if (p == NULL) { 300 mutex_exit(proc_lock); 301 kmem_free(l, sizeof(*l)); 302 return ESRCH; 303 } 304 mutex_enter(p->p_lock); 305 if (p->p_sflag & PS_RUMP_LWPEXIT) { 306 mutex_exit(proc_lock); 307 mutex_exit(p->p_lock); 308 kmem_free(l, sizeof(*l)); 309 return EBUSY; 310 } 311 mutex_exit(proc_lock); 312 lwproc_makelwp(p, l, true, false); 313 314 return 0; 315 } 316 317 int 318 rump_lwproc_rfork(int flags) 319 { 320 struct proc *p; 321 struct lwp *l; 322 323 if (flags & ~(RUMP_RFFDG|RUMP_RFCFDG) || 324 (~flags & (RUMP_RFFDG|RUMP_RFCFDG)) == 0) 325 return EINVAL; 326 327 p = lwproc_newproc(curproc, flags); 328 l = kmem_zalloc(sizeof(*l), KM_SLEEP); 329 mutex_enter(p->p_lock); 330 KASSERT((p->p_sflag & PS_RUMP_LWPEXIT) == 0); 331 lwproc_makelwp(p, l, true, true); 332 333 return 0; 334 } 335 336 /* 337 * Switch to a new process/thread. Release previous one if 338 * deemed to be exiting. This is considered a slow path for 339 * rump kernel entry. 340 */ 341 void 342 rump_lwproc_switch(struct lwp *newlwp) 343 { 344 struct lwp *l = curlwp; 345 346 KASSERT(!(l->l_flag & LW_WEXIT) || newlwp); 347 348 if (__predict_false(newlwp && (newlwp->l_pflag & LP_RUNNING))) 349 panic("lwp %p (%d:%d) already running", 350 newlwp, newlwp->l_proc->p_pid, newlwp->l_lid); 351 352 if (newlwp == NULL) { 353 l->l_pflag &= ~LP_RUNNING; 354 l->l_flag |= LW_RUMP_CLEAR; 355 return; 356 } 357 358 /* fd_free() must be called from curlwp context. talk about ugh */ 359 if (l->l_flag & LW_WEXIT) { 360 fd_free(); 361 } 362 363 KERNEL_UNLOCK_ALL(NULL, &l->l_biglocks); 364 rumpuser_curlwpop(RUMPUSER_LWP_CLEAR, l); 365 366 newlwp->l_cpu = newlwp->l_target_cpu = l->l_cpu; 367 newlwp->l_mutex = l->l_mutex; 368 newlwp->l_pflag |= LP_RUNNING; 369 370 rumpuser_curlwpop(RUMPUSER_LWP_SET, newlwp); 371 curcpu()->ci_curlwp = newlwp; 372 KERNEL_LOCK(newlwp->l_biglocks, NULL); 373 374 /* 375 * Check if the thread should get a signal. This is 376 * mostly to satisfy the "record" rump sigmodel. 377 */ 378 mutex_enter(newlwp->l_proc->p_lock); 379 if (sigispending(newlwp, 0)) { 380 newlwp->l_flag |= LW_PENDSIG; 381 } 382 mutex_exit(newlwp->l_proc->p_lock); 383 384 l->l_mutex = &unruntime_lock; 385 l->l_pflag &= ~LP_RUNNING; 386 l->l_flag &= ~LW_PENDSIG; 387 l->l_stat = LSRUN; 388 389 if (l->l_flag & LW_WEXIT) { 390 lwproc_freelwp(l); 391 } 392 } 393 394 /* 395 * Mark the current thread to be released upon return from 396 * kernel. 397 */ 398 void 399 rump_lwproc_releaselwp(void) 400 { 401 struct lwp *l = curlwp; 402 403 if (l->l_refcnt == 0 || l->l_flag & LW_WEXIT) 404 panic("releasing non-pertinent lwp"); 405 406 rump__lwproc_lwprele(); 407 KASSERT(l->l_refcnt == 0 && (l->l_flag & LW_WEXIT)); 408 } 409 410 /* 411 * In-kernel routines used to add and remove references for the 412 * current thread. The main purpose is to make it possible for 413 * implicit threads to persist over scheduling operations in 414 * rump kernel drivers. Note that we don't need p_lock in a 415 * rump kernel, since we do refcounting only for curlwp. 416 */ 417 void 418 rump__lwproc_lwphold(void) 419 { 420 struct lwp *l = curlwp; 421 422 l->l_refcnt++; 423 l->l_flag &= ~LW_WEXIT; 424 } 425 426 void 427 rump__lwproc_lwprele(void) 428 { 429 struct lwp *l = curlwp; 430 431 l->l_refcnt--; 432 if (l->l_refcnt == 0) 433 l->l_flag |= LW_WEXIT; 434 } 435 436 struct lwp * 437 rump_lwproc_curlwp(void) 438 { 439 struct lwp *l = curlwp; 440 441 if (l->l_flag & LW_WEXIT) 442 return NULL; 443 return l; 444 } 445 446 /* this interface is under construction (like the proverbial 90's web page) */ 447 int rump_i_know_what_i_am_doing_with_sysents = 0; 448 void 449 rump_lwproc_sysent_usenative() 450 { 451 452 if (!rump_i_know_what_i_am_doing_with_sysents) 453 panic("don't use rump_lwproc_sysent_usenative()"); 454 curproc->p_emul = &emul_netbsd; 455 } 456
Indexes created Mon Sep 29 21:09:56 GMT 2025