1 /* $NetBSD: lwproc.c,v 1.13 2011/01/28 18:48:21 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 1.13 2011/01/28 18:48:21 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/pool.h> 38 #include <sys/proc.h> 39 #include <sys/queue.h> 40 #include <sys/resourcevar.h> 41 #include <sys/uidinfo.h> 42 43 #include <rump/rumpuser.h> 44 45 #include "rump_private.h" 46 47 static void 48 lwproc_proc_free(struct proc *p) 49 { 50 kauth_cred_t cred; 51 52 mutex_enter(proc_lock); 53 54 KASSERT(p->p_nlwps == 0); 55 KASSERT(LIST_EMPTY(&p->p_lwps)); 56 KASSERT(p->p_stat == SACTIVE || p->p_stat == SDYING || 57 p->p_stat == SDEAD); 58 59 LIST_REMOVE(p, p_list); 60 LIST_REMOVE(p, p_sibling); 61 proc_free_pid(p->p_pid); /* decrements nprocs */ 62 proc_leavepgrp(p); /* releases proc_lock */ 63 64 cred = p->p_cred; 65 chgproccnt(kauth_cred_getuid(cred), -1); 66 if (rump_proc_vfs_release) 67 rump_proc_vfs_release(p); 68 69 limfree(p->p_limit); 70 pstatsfree(p->p_stats); 71 kauth_cred_free(p->p_cred); 72 proc_finispecific(p); 73 74 mutex_obj_free(p->p_lock); 75 mutex_destroy(&p->p_stmutex); 76 mutex_destroy(&p->p_auxlock); 77 rw_destroy(&p->p_reflock); 78 cv_destroy(&p->p_waitcv); 79 cv_destroy(&p->p_lwpcv); 80 81 /* non-kernel vmspaces are not shared */ 82 if (!RUMP_LOCALPROC_P(p)) { 83 KASSERT(p->p_vmspace->vm_refcnt == 1); 84 kmem_free(p->p_vmspace, sizeof(*p->p_vmspace)); 85 } 86 87 proc_free_mem(p); 88 } 89 90 /* 91 * Allocate a new process. Mostly mimic fork by 92 * copying the properties of the parent. However, there are some 93 * differences. For example, we never share the fd table. 94 * 95 * Switch to the new lwp and return a pointer to it. 96 */ 97 static struct proc * 98 lwproc_newproc(struct proc *parent, int flags) 99 { 100 uid_t uid = kauth_cred_getuid(parent->p_cred); 101 struct proc *p; 102 103 /* maxproc not enforced */ 104 atomic_inc_uint(&nprocs); 105 106 /* allocate process */ 107 p = proc_alloc(); 108 memset(&p->p_startzero, 0, 109 offsetof(struct proc, p_endzero) 110 - offsetof(struct proc, p_startzero)); 111 memcpy(&p->p_startcopy, &parent->p_startcopy, 112 offsetof(struct proc, p_endcopy) 113 - offsetof(struct proc, p_startcopy)); 114 115 p->p_stats = pstatscopy(parent->p_stats); 116 117 p->p_vmspace = vmspace_kernel(); 118 p->p_emul = &emul_netbsd; 119 strcpy(p->p_comm, "rumproc"); 120 121 if ((flags & RUMP_RFCFDG) == 0) 122 KASSERT(parent == curproc); 123 if (flags & RUMP_RFFDG) 124 p->p_fd = fd_copy(); 125 else if (flags & RUMP_RFCFDG) 126 p->p_fd = fd_init(NULL); 127 else 128 fd_share(p); 129 130 lim_addref(parent->p_limit); 131 p->p_limit = parent->p_limit; 132 133 LIST_INIT(&p->p_lwps); 134 LIST_INIT(&p->p_children); 135 136 p->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE); 137 mutex_init(&p->p_stmutex, MUTEX_DEFAULT, IPL_NONE); 138 mutex_init(&p->p_auxlock, MUTEX_DEFAULT, IPL_NONE); 139 rw_init(&p->p_reflock); 140 cv_init(&p->p_waitcv, "pwait"); 141 cv_init(&p->p_lwpcv, "plwp"); 142 143 p->p_pptr = parent; 144 p->p_ppid = parent->p_pid; 145 p->p_stat = SACTIVE; 146 147 kauth_proc_fork(parent, p); 148 149 /* initialize cwd in rump kernels with vfs */ 150 if (rump_proc_vfs_init) 151 rump_proc_vfs_init(p); 152 153 chgproccnt(uid, 1); /* not enforced */ 154 155 /* publish proc various proc lists */ 156 mutex_enter(proc_lock); 157 LIST_INSERT_HEAD(&allproc, p, p_list); 158 LIST_INSERT_HEAD(&parent->p_children, p, p_sibling); 159 LIST_INSERT_AFTER(parent, p, p_pglist); 160 mutex_exit(proc_lock); 161 162 return p; 163 } 164 165 static void 166 lwproc_freelwp(struct lwp *l) 167 { 168 struct proc *p; 169 bool freeproc; 170 171 p = l->l_proc; 172 mutex_enter(p->p_lock); 173 174 /* XXX: l_refcnt */ 175 KASSERT(l->l_flag & LW_WEXIT); 176 KASSERT(l->l_refcnt == 0); 177 178 /* ok, zero references, continue with nuke */ 179 LIST_REMOVE(l, l_sibling); 180 KASSERT(p->p_nlwps >= 1); 181 if (--p->p_nlwps == 0) { 182 KASSERT(p != &proc0); 183 p->p_stat = SDEAD; 184 } 185 freeproc = p->p_nlwps == 0; 186 cv_broadcast(&p->p_lwpcv); /* nobody sleeps on this in rump? */ 187 kauth_cred_free(l->l_cred); 188 mutex_exit(p->p_lock); 189 190 mutex_enter(proc_lock); 191 LIST_REMOVE(l, l_list); 192 mutex_exit(proc_lock); 193 194 if (l->l_name) 195 kmem_free(l->l_name, MAXCOMLEN); 196 lwp_finispecific(l); 197 198 kmem_free(l, sizeof(*l)); 199 200 if (p->p_stat == SDEAD) 201 lwproc_proc_free(p); 202 } 203 204 extern kmutex_t unruntime_lock; 205 206 /* 207 * called with p_lock held, releases lock before return 208 */ 209 static void 210 lwproc_makelwp(struct proc *p, struct lwp *l, bool doswitch, bool procmake) 211 { 212 213 p->p_nlwps++; 214 l->l_refcnt = 1; 215 l->l_proc = p; 216 217 l->l_lid = p->p_nlwpid++; 218 LIST_INSERT_HEAD(&p->p_lwps, l, l_sibling); 219 mutex_exit(p->p_lock); 220 221 lwp_update_creds(l); 222 223 l->l_fd = p->p_fd; 224 l->l_cpu = rump_cpu; 225 l->l_target_cpu = rump_cpu; /* Initial target CPU always the same */ 226 l->l_stat = LSRUN; 227 l->l_mutex = &unruntime_lock; 228 TAILQ_INIT(&l->l_ld_locks); 229 230 lwp_initspecific(l); 231 232 if (doswitch) { 233 rump_lwproc_switch(l); 234 } 235 236 /* filedesc already has refcount 1 when process is created */ 237 if (!procmake) { 238 fd_hold(l); 239 } 240 241 mutex_enter(proc_lock); 242 LIST_INSERT_HEAD(&alllwp, l, l_list); 243 mutex_exit(proc_lock); 244 } 245 246 struct lwp * 247 rump__lwproc_alloclwp(struct proc *p) 248 { 249 struct lwp *l; 250 bool newproc = false; 251 252 if (p == NULL) { 253 p = lwproc_newproc(&proc0, 0); 254 newproc = true; 255 } 256 257 l = kmem_zalloc(sizeof(*l), KM_SLEEP); 258 259 mutex_enter(p->p_lock); 260 lwproc_makelwp(p, l, false, newproc); 261 262 return l; 263 } 264 265 int 266 rump_lwproc_newlwp(pid_t pid) 267 { 268 struct proc *p; 269 struct lwp *l; 270 271 l = kmem_zalloc(sizeof(*l), KM_SLEEP); 272 mutex_enter(proc_lock); 273 p = proc_find_raw(pid); 274 if (p == NULL) { 275 mutex_exit(proc_lock); 276 kmem_free(l, sizeof(*l)); 277 return ESRCH; 278 } 279 mutex_enter(p->p_lock); 280 mutex_exit(proc_lock); 281 lwproc_makelwp(p, l, true, false); 282 283 return 0; 284 } 285 286 int 287 rump_lwproc_rfork(int flags) 288 { 289 struct proc *p; 290 struct lwp *l; 291 292 if (flags & ~(RUMP_RFFDG|RUMP_RFCFDG) || 293 (~flags & (RUMP_RFFDG|RUMP_RFCFDG)) == 0) 294 return EINVAL; 295 296 p = lwproc_newproc(curproc, flags); 297 l = kmem_zalloc(sizeof(*l), KM_SLEEP); 298 mutex_enter(p->p_lock); 299 lwproc_makelwp(p, l, true, true); 300 301 return 0; 302 } 303 304 /* 305 * Switch to a new process/thread. Release previous one if 306 * deemed to be exiting. This is considered a slow path for 307 * rump kernel entry. 308 */ 309 void 310 rump_lwproc_switch(struct lwp *newlwp) 311 { 312 struct lwp *l = curlwp; 313 314 KASSERT(!(l->l_flag & LW_WEXIT) || newlwp); 315 316 if (__predict_false(newlwp && (newlwp->l_pflag & LP_RUNNING))) 317 panic("lwp %p (%d:%d) already running", 318 newlwp, newlwp->l_proc->p_pid, newlwp->l_lid); 319 320 if (newlwp == NULL) { 321 l->l_pflag &= ~LP_RUNNING; 322 l->l_flag |= LW_RUMP_CLEAR; 323 return; 324 } 325 326 /* fd_free() must be called from curlwp context. talk about ugh */ 327 if (l->l_flag & LW_WEXIT) { 328 fd_free(); 329 } 330 331 rumpuser_set_curlwp(NULL); 332 333 newlwp->l_cpu = newlwp->l_target_cpu = l->l_cpu; 334 newlwp->l_mutex = l->l_mutex; 335 newlwp->l_pflag |= LP_RUNNING; 336 337 rumpuser_set_curlwp(newlwp); 338 339 /* 340 * Check if the thread should get a signal. This is 341 * mostly to satisfy the "record" rump sigmodel. 342 */ 343 mutex_enter(newlwp->l_proc->p_lock); 344 if (sigispending(newlwp, 0)) { 345 newlwp->l_flag |= LW_PENDSIG; 346 } 347 mutex_exit(newlwp->l_proc->p_lock); 348 349 l->l_mutex = &unruntime_lock; 350 l->l_pflag &= ~LP_RUNNING; 351 l->l_flag &= ~LW_PENDSIG; 352 l->l_stat = LSRUN; 353 354 if (l->l_flag & LW_WEXIT) { 355 lwproc_freelwp(l); 356 } 357 } 358 359 void 360 rump_lwproc_releaselwp(void) 361 { 362 struct proc *p; 363 struct lwp *l = curlwp; 364 365 if (l->l_refcnt == 0 && l->l_flag & LW_WEXIT) 366 panic("releasing non-pertinent lwp"); 367 368 p = l->l_proc; 369 mutex_enter(p->p_lock); 370 KASSERT(l->l_refcnt != 0); 371 l->l_refcnt--; 372 mutex_exit(p->p_lock); 373 l->l_flag |= LW_WEXIT; /* will be released when unscheduled */ 374 } 375 376 struct lwp * 377 rump_lwproc_curlwp(void) 378 { 379 struct lwp *l = curlwp; 380 381 if (l->l_flag & LW_WEXIT) 382 return NULL; 383 return l; 384 } 385