bsd/kern/bsd_stubs.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #include <sys/time.h>
  29 #include <kern/task.h>
  30 #include <kern/thread.h>
  31 #include <mach/mach_types.h>
  32 #include <mach/vm_prot.h>
  33 #include <vm/vm_kern.h>
  34 #include <sys/stat.h>
  35 #include <vm/vm_map.h>
  36 #include <sys/systm.h>
  37 #include <kern/assert.h>
  38 #include <sys/conf.h>
  39 #include <sys/proc_internal.h>
  40 #include <sys/buf.h> /* for SET */
  41 #include <sys/kernel.h>
  42 #include <sys/user.h>
  43 #include <sys/sysent.h>
  44 #include <sys/sysproto.h>
  45
  46 /* XXX these should be in a common header somwhere, but aren't */
  47 extern int chrtoblk_set(int, int);
  48 extern vm_offset_t kmem_mb_alloc(vm_map_t, int, int, kern_return_t *);
  49
  50 /* XXX most of these just exist to export; there's no good header for them*/
  51 void pcb_synch(void);
  52
  53 TAILQ_HEAD(, devsw_lock) devsw_locks;
  54 lck_mtx_t devsw_lock_list_mtx;
  55 lck_grp_t * devsw_lock_grp;
  56
  57 /* Just to satisfy pstat command */
  58 int dmmin, dmmax, dmtext;
  59
  60 vm_offset_t
  61 kmem_mb_alloc(vm_map_t mbmap, int size, int physContig, kern_return_t *err)
  62 {
  63         vm_offset_t addr = 0;
  64         kern_return_t kr = KERN_SUCCESS;
  65
  66         if (!physContig) {
  67                 kr = kernel_memory_allocate(mbmap, &addr, size, 0, KMA_KOBJECT | KMA_LOMEM, VM_KERN_MEMORY_MBUF);
  68         } else {
  69                 kr = kmem_alloc_contig(mbmap, &addr, size, PAGE_MASK, 0xfffff, 0, KMA_KOBJECT | KMA_LOMEM, VM_KERN_MEMORY_MBUF);
  70         }
  71
  72         if (kr != KERN_SUCCESS) {
  73                 addr = 0;
  74         }
  75         if (err) {
  76                 *err = kr;
  77         }
  78
  79         return addr;
  80 }
  81
  82 /*
  83  * XXX this function only exists to be exported and do nothing.
  84  */
  85 void
  86 pcb_synch(void)
  87 {
  88 }
  89
  90 struct proc *
  91 current_proc(void)
  92 {
  93         /* Never returns a NULL */
  94         struct uthread * ut;
  95         struct proc * p;
  96         thread_t thread = current_thread();
  97
  98         ut = (struct uthread *)get_bsdthread_info(thread);
  99         if (ut && (ut->uu_flag & UT_VFORK) && ut->uu_proc) {
 100                 p = ut->uu_proc;
 101                 if ((p->p_lflag & P_LINVFORK) == 0) {
 102                         panic("returning child proc not under vfork");
 103                 }
 104                 if (p->p_vforkact != (void *)thread) {
 105                         panic("returning child proc which is not cur_act");
 106                 }
 107                 return p;
 108         }
 109
 110         p = (struct proc *)get_bsdtask_info(current_task());
 111
 112         if (p == NULL) {
 113                 return kernproc;
 114         }
 115
 116         return p;
 117 }
 118
 119 /* Device switch add delete routines */
 120
 121 struct bdevsw nobdev = NO_BDEVICE;
 122 struct cdevsw nocdev = NO_CDEVICE;
 123 /*
 124  *      if index is -1, return a free slot if avaliable
 125  *        else see whether the index is free
 126  *      return the major number that is free else -1
 127  *
 128  *      if index is negative, we start
 129  *      looking for a free slot at the absolute value of index,
 130  *      instead of starting at 0
 131  */
 132 int
 133 bdevsw_isfree(int index)
 134 {
 135         struct bdevsw * devsw;
 136
 137         if (index < 0) {
 138                 if (index == -1) {
 139                         index = 1; /* start at 1 to avoid collision with volfs (Radar 2842228) */
 140                 } else {
 141                         index = -index; /* start at least this far up in the table */
 142                 }
 143                 devsw = &bdevsw[index];
 144                 for (; index < nblkdev; index++, devsw++) {
 145                         if (memcmp((char *)devsw, (char *)&nobdev, sizeof(struct bdevsw)) == 0) {
 146                                 break;
 147                         }
 148                 }
 149         }
 150
 151         if (index < 0 || index >= nblkdev) {
 152                 return -1;
 153         }
 154
 155         devsw = &bdevsw[index];
 156         if ((memcmp((char *)devsw, (char *)&nobdev, sizeof(struct bdevsw)) != 0)) {
 157                 return -1;
 158         }
 159         return index;
 160 }
 161
 162 /*
 163  *      if index is -1, find a free slot to add
 164  *        else see whether the slot is free
 165  *      return the major number that is used else -1
 166  *
 167  *      if index is negative, we start
 168  *      looking for a free slot at the absolute value of index,
 169  *      instead of starting at 0
 170  */
 171 int
 172 bdevsw_add(int index, struct bdevsw * bsw)
 173 {
 174         lck_mtx_lock_spin(&devsw_lock_list_mtx);
 175         index = bdevsw_isfree(index);
 176         if (index < 0) {
 177                 index = -1;
 178         } else {
 179                 bdevsw[index] = *bsw;
 180         }
 181         lck_mtx_unlock(&devsw_lock_list_mtx);
 182         return index;
 183 }
 184 /*
 185  *      if the slot has the same bsw, then remove
 186  *      else -1
 187  */
 188 int
 189 bdevsw_remove(int index, struct bdevsw * bsw)
 190 {
 191         struct bdevsw * devsw;
 192
 193         if (index < 0 || index >= nblkdev) {
 194                 return -1;
 195         }
 196
 197         devsw = &bdevsw[index];
 198         lck_mtx_lock_spin(&devsw_lock_list_mtx);
 199         if ((memcmp((char *)devsw, (char *)bsw, sizeof(struct bdevsw)) != 0)) {
 200                 index = -1;
 201         } else {
 202                 bdevsw[index] = nobdev;
 203         }
 204         lck_mtx_unlock(&devsw_lock_list_mtx);
 205         return index;
 206 }
 207
 208 /*
 209  *      if index is -1, return a free slot if avaliable
 210  *        else see whether the index is free
 211  *      return the major number that is free else -1
 212  *
 213  *      if index is negative, we start
 214  *      looking for a free slot at the absolute value of index,
 215  *      instead of starting at 0
 216  */
 217 int
 218 cdevsw_isfree(int index)
 219 {
 220         struct cdevsw * devsw;
 221
 222         if (index < 0) {
 223                 if (index == -1) {
 224                         index = 0;
 225                 } else {
 226                         index = -index; /* start at least this far up in the table */
 227                 }
 228                 devsw = &cdevsw[index];
 229                 for (; index < nchrdev; index++, devsw++) {
 230                         if (memcmp((char *)devsw, (char *)&nocdev, sizeof(struct cdevsw)) == 0) {
 231                                 break;
 232                         }
 233                 }
 234         }
 235
 236         if (index < 0 || index >= nchrdev) {
 237                 return -1;
 238         }
 239
 240         devsw = &cdevsw[index];
 241         if ((memcmp((char *)devsw, (char *)&nocdev, sizeof(struct cdevsw)) != 0)) {
 242                 return -1;
 243         }
 244         return index;
 245 }
 246
 247 /*
 248  *      if index is -1, find a free slot to add
 249  *        else see whether the slot is free
 250  *      return the major number that is used else -1
 251  *
 252  *      if index is negative, we start
 253  *      looking for a free slot at the absolute value of index,
 254  *      instead of starting at 0
 255  *
 256  * NOTE:        In practice, -1 is unusable, since there are kernel internal
 257  *              devices that call this function with absolute index values,
 258  *              which will stomp on free-slot based assignments that happen
 259  *              before them.  -24 is currently a safe starting point.
 260  */
 261 int
 262 cdevsw_add(int index, struct cdevsw * csw)
 263 {
 264         lck_mtx_lock_spin(&devsw_lock_list_mtx);
 265         index = cdevsw_isfree(index);
 266         if (index < 0) {
 267                 index = -1;
 268         } else {
 269                 cdevsw[index] = *csw;
 270         }
 271         lck_mtx_unlock(&devsw_lock_list_mtx);
 272         return index;
 273 }
 274 /*
 275  *      if the slot has the same csw, then remove
 276  *      else -1
 277  */
 278 int
 279 cdevsw_remove(int index, struct cdevsw * csw)
 280 {
 281         struct cdevsw * devsw;
 282
 283         if (index < 0 || index >= nchrdev) {
 284                 return -1;
 285         }
 286
 287         devsw = &cdevsw[index];
 288         lck_mtx_lock_spin(&devsw_lock_list_mtx);
 289         if ((memcmp((char *)devsw, (char *)csw, sizeof(struct cdevsw)) != 0)) {
 290                 index = -1;
 291         } else {
 292                 cdevsw[index] = nocdev;
 293                 cdevsw_flags[index] = 0;
 294         }
 295         lck_mtx_unlock(&devsw_lock_list_mtx);
 296         return index;
 297 }
 298
 299 static int
 300 cdev_set_bdev(int cdev, int bdev)
 301 {
 302         return chrtoblk_set(cdev, bdev);
 303 }
 304
 305 int
 306 cdevsw_add_with_bdev(int index, struct cdevsw * csw, int bdev)
 307 {
 308         index = cdevsw_add(index, csw);
 309         if (index < 0) {
 310                 return index;
 311         }
 312         if (cdev_set_bdev(index, bdev) < 0) {
 313                 cdevsw_remove(index, csw);
 314                 return -1;
 315         }
 316         return index;
 317 }
 318
 319 int
 320 cdevsw_setkqueueok(int maj, struct cdevsw * csw, int extra_flags)
 321 {
 322         struct cdevsw * devsw;
 323         uint64_t flags = CDEVSW_SELECT_KQUEUE;
 324
 325         if (maj < 0 || maj >= nchrdev) {
 326                 return -1;
 327         }
 328
 329         devsw = &cdevsw[maj];
 330         if ((memcmp((char *)devsw, (char *)csw, sizeof(struct cdevsw)) != 0)) {
 331                 return -1;
 332         }
 333
 334         flags |= extra_flags;
 335
 336         cdevsw_flags[maj] = flags;
 337         return 0;
 338 }
 339
 340 #include <pexpert/pexpert.h> /* for PE_parse_boot_arg */
 341
 342 /*
 343  * Copy the "hostname" variable into a caller-provided buffer
 344  * Returns: 0 for success, ENAMETOOLONG for insufficient buffer space.
 345  * On success, "len" will be set to the number of characters preceding
 346  * the NULL character in the hostname.
 347  */
 348 int
 349 bsd_hostname(char * buf, int bufsize, int * len)
 350 {
 351         /*
 352          * "hostname" is null-terminated, and "hostnamelen" is equivalent to strlen(hostname).
 353          */
 354         if (hostnamelen < bufsize) {
 355                 strlcpy(buf, hostname, bufsize);
 356                 *len = hostnamelen;
 357                 return 0;
 358         } else {
 359                 return ENAMETOOLONG;
 360         }
 361 }
 362
 363 void
 364 devsw_lock(dev_t dev, int mode)
 365 {
 366         devsw_lock_t newlock, tmplock;
 367         int res;
 368
 369         assert(0 <= major(dev) && major(dev) < nchrdev);
 370         assert(mode == S_IFCHR || mode == S_IFBLK);
 371
 372         MALLOC(newlock, devsw_lock_t, sizeof(struct devsw_lock), M_TEMP, M_WAITOK | M_ZERO);
 373         newlock->dl_dev = dev;
 374         newlock->dl_thread = current_thread();
 375         newlock->dl_mode = mode;
 376
 377         lck_mtx_lock_spin(&devsw_lock_list_mtx);
 378 retry:
 379         TAILQ_FOREACH(tmplock, &devsw_locks, dl_list)
 380         {
 381                 if (tmplock->dl_dev == dev && tmplock->dl_mode == mode) {
 382                         res = msleep(tmplock, &devsw_lock_list_mtx, PVFS, "devsw_lock", NULL);
 383                         assert(res == 0);
 384                         goto retry;
 385                 }
 386         }
 387
 388         TAILQ_INSERT_TAIL(&devsw_locks, newlock, dl_list);
 389         lck_mtx_unlock(&devsw_lock_list_mtx);
 390 }
 391 void
 392 devsw_unlock(dev_t dev, int mode)
 393 {
 394         devsw_lock_t tmplock;
 395
 396         assert(0 <= major(dev) && major(dev) < nchrdev);
 397
 398         lck_mtx_lock_spin(&devsw_lock_list_mtx);
 399
 400         TAILQ_FOREACH(tmplock, &devsw_locks, dl_list)
 401         {
 402                 if (tmplock->dl_dev == dev && tmplock->dl_mode == mode) {
 403                         break;
 404                 }
 405         }
 406
 407         if (tmplock == NULL) {
 408                 panic("Trying to unlock, and couldn't find lock.");
 409         }
 410
 411         if (tmplock->dl_thread != current_thread()) {
 412                 panic("Trying to unlock, but I don't hold the lock.");
 413         }
 414
 415         wakeup(tmplock);
 416         TAILQ_REMOVE(&devsw_locks, tmplock, dl_list);
 417
 418         lck_mtx_unlock(&devsw_lock_list_mtx);
 419
 420         FREE(tmplock, M_TEMP);
 421 }
 422
 423 void
 424 devsw_init()
 425 {
 426         devsw_lock_grp = lck_grp_alloc_init("devsw", NULL);
 427         assert(devsw_lock_grp != NULL);
 428
 429         lck_mtx_init(&devsw_lock_list_mtx, devsw_lock_grp, NULL);
 430         TAILQ_INIT(&devsw_locks);
 431 }