2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department, and code derived from software contributed to
9 * Berkeley by William Jolitz.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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 University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * from: Utah $Hdr: mem.c 1.13 89/10/08$
40 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
41 * $FreeBSD: src/sys/i386/i386/mem.c,v 1.79.2.9 2003/01/04 22:58:01 njl Exp $
42 * $DragonFly: src/sys/kern/kern_memio.c,v 1.27 2007/01/12 03:05:49 dillon Exp $
49 #include <sys/param.h>
50 #include <sys/systm.h>
53 #include <sys/fcntl.h>
54 #include <sys/filio.h>
55 #include <sys/ioccom.h>
56 #include <sys/kernel.h>
57 #include <sys/malloc.h>
58 #include <sys/memrange.h>
60 #include <sys/random.h>
61 #include <sys/signalvar.h>
63 #include <sys/vnode.h>
67 #include <vm/vm_extern.h>
70 static d_open_t mmopen;
71 static d_close_t mmclose;
72 static d_read_t mmread;
73 static d_write_t mmwrite;
74 static d_ioctl_t mmioctl;
75 static d_mmap_t memmmap;
76 static d_poll_t mmpoll;
79 static struct dev_ops mem_ops = {
80 { "mem", CDEV_MAJOR, D_MEM },
93 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
94 static int mem_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
95 static int random_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
97 struct mem_range_softc mem_range_softc;
101 mmopen(struct dev_open_args *ap)
103 cdev_t dev = ap->a_head.a_dev;
106 switch (minor(dev)) {
109 if ((ap->a_oflags & FWRITE) && securelevel > 0)
114 error = suser_cred(ap->a_cred, 0);
117 if (securelevel > 0) {
121 error = cpu_set_iopl();
131 mmclose(struct dev_close_args *ap)
133 cdev_t dev = ap->a_head.a_dev;
136 switch (minor(dev)) {
138 error = cpu_clr_iopl();
149 mmrw(cdev_t dev, struct uio *uio, int flags)
158 while (uio->uio_resid > 0 && error == 0) {
160 if (iov->iov_len == 0) {
163 if (uio->uio_iovcnt < 0)
167 switch (minor(dev)) {
170 * minor device 0 is physical memory, /dev/mem
174 pmap_kenter((vm_offset_t)ptvmmap, v);
175 o = (int)uio->uio_offset & PAGE_MASK;
176 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
177 c = min(c, (u_int)(PAGE_SIZE - o));
178 c = min(c, (u_int)iov->iov_len);
179 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
180 pmap_kremove((vm_offset_t)ptvmmap);
185 * minor device 1 is kernel memory, /dev/kmem
187 vm_offset_t saddr, eaddr;
193 * Make sure that all of the pages are currently
194 * resident so that we don't create any zero-fill
197 saddr = trunc_page(uio->uio_offset);
198 eaddr = round_page(uio->uio_offset + c);
203 * Make sure the kernel addresses are mapped.
204 * platform_direct_mapped() can be used to bypass
205 * default mapping via the page table (virtual kernels
206 * contain a lot of out-of-band data).
209 if (uio->uio_rw != UIO_READ)
210 prot |= VM_PROT_WRITE;
211 error = kvm_access_check(saddr, eaddr, prot);
214 error = uiomove((caddr_t)(vm_offset_t)uio->uio_offset,
220 * minor device 2 is EOF/RATHOLE
222 if (uio->uio_rw == UIO_READ)
228 * minor device 3 (/dev/random) is source of filth
229 * on read, seeder on write
232 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
233 c = min(iov->iov_len, PAGE_SIZE);
234 if (uio->uio_rw == UIO_WRITE) {
235 error = uiomove(buf, (int)c, uio);
237 error = add_buffer_randomness(buf, c);
239 poolsize = read_random(buf, c);
243 if ((flags & IO_NDELAY) != 0)
244 return (EWOULDBLOCK);
247 c = min(c, poolsize);
248 error = uiomove(buf, (int)c, uio);
253 * minor device 4 (/dev/urandom) is source of muck
254 * on read, writes are disallowed.
256 c = min(iov->iov_len, PAGE_SIZE);
257 if (uio->uio_rw == UIO_WRITE) {
261 if (CURSIG(curproc) != 0) {
263 * Use tsleep() to get the error code right.
264 * It should return immediately.
266 error = tsleep(&rand_bolt, PCATCH, "urand", 1);
267 if (error != 0 && error != EWOULDBLOCK)
271 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
272 poolsize = read_random_unlimited(buf, c);
273 c = min(c, poolsize);
274 error = uiomove(buf, (int)c, uio);
278 * minor device 12 (/dev/zero) is source of nulls
279 * on read, write are disallowed.
281 if (uio->uio_rw == UIO_WRITE) {
287 kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
288 bzero(zbuf, PAGE_SIZE);
290 c = min(iov->iov_len, PAGE_SIZE);
291 error = uiomove(zbuf, (int)c, uio);
300 uio->uio_offset += c;
309 mmread(struct dev_read_args *ap)
311 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
315 mmwrite(struct dev_write_args *ap)
317 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
324 /*******************************************************\
325 * allow user processes to MMAP some memory sections *
326 * instead of going through read/write *
327 \*******************************************************/
330 memmmap(struct dev_mmap_args *ap)
332 cdev_t dev = ap->a_head.a_dev;
334 switch (minor(dev)) {
337 * minor device 0 is physical memory
339 ap->a_result = i386_btop(ap->a_offset);
343 * minor device 1 is kernel memory
345 ap->a_result = i386_btop(vtophys(ap->a_offset));
354 mmioctl(struct dev_ioctl_args *ap)
356 cdev_t dev = ap->a_head.a_dev;
358 switch (minor(dev)) {
360 return mem_ioctl(dev, ap->a_cmd, ap->a_data,
361 ap->a_fflag, ap->a_cred);
364 return random_ioctl(dev, ap->a_cmd, ap->a_data,
365 ap->a_fflag, ap->a_cred);
371 * Operations for changing memory attributes.
373 * This is basically just an ioctl shim for mem_range_attr_get
374 * and mem_range_attr_set.
377 mem_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
380 struct mem_range_op *mo = (struct mem_range_op *)data;
381 struct mem_range_desc *md;
383 /* is this for us? */
384 if ((cmd != MEMRANGE_GET) &&
385 (cmd != MEMRANGE_SET))
388 /* any chance we can handle this? */
389 if (mem_range_softc.mr_op == NULL)
392 /* do we have any descriptors? */
393 if (mem_range_softc.mr_ndesc == 0)
398 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
400 md = (struct mem_range_desc *)
401 kmalloc(nd * sizeof(struct mem_range_desc),
402 M_MEMDESC, M_WAITOK);
403 error = mem_range_attr_get(md, &nd);
405 error = copyout(md, mo->mo_desc,
406 nd * sizeof(struct mem_range_desc));
407 kfree(md, M_MEMDESC);
409 nd = mem_range_softc.mr_ndesc;
415 md = (struct mem_range_desc *)kmalloc(sizeof(struct mem_range_desc),
416 M_MEMDESC, M_WAITOK);
417 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
418 /* clamp description string */
419 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
421 error = mem_range_attr_set(md, &mo->mo_arg[0]);
422 kfree(md, M_MEMDESC);
429 * Implementation-neutral, kernel-callable functions for manipulating
430 * memory range attributes.
433 mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
435 /* can we handle this? */
436 if (mem_range_softc.mr_op == NULL)
440 *arg = mem_range_softc.mr_ndesc;
442 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc));
448 mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
450 /* can we handle this? */
451 if (mem_range_softc.mr_op == NULL)
454 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
459 mem_range_AP_init(void)
461 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP)
462 return (mem_range_softc.mr_op->initAP(&mem_range_softc));
467 random_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
473 * Even inspecting the state is privileged, since it gives a hint
474 * about how easily the randomness might be guessed.
479 /* Really handled in upper layer */
483 intr = *(int16_t *)data;
484 if ((error = suser_cred(cred, 0)) != 0)
486 if (intr < 0 || intr >= MAX_INTS)
488 register_randintr(intr);
491 intr = *(int16_t *)data;
492 if ((error = suser_cred(cred, 0)) != 0)
494 if (intr < 0 || intr >= MAX_INTS)
496 unregister_randintr(intr);
502 intr = *(int16_t *)data;
503 if ((error = suser_cred(cred, 0)) != 0)
505 if (intr < 0 || intr >= MAX_INTS)
507 intr = next_registered_randintr(intr);
508 if (intr == MAX_INTS)
510 *(u_int16_t *)data = intr;
520 mmpoll(struct dev_poll_args *ap)
522 cdev_t dev = ap->a_head.a_dev;
525 switch (minor(dev)) {
526 case 3: /* /dev/random */
527 revents = random_poll(dev, ap->a_events);
529 case 4: /* /dev/urandom */
531 revents = seltrue(dev, ap->a_events);
534 ap->a_events = revents;
539 iszerodev(cdev_t dev)
541 return ((major(dev) == mem_ops.head.maj)
542 && minor(dev) == 12);
546 mem_drvinit(void *unused)
549 /* Initialise memory range handling */
550 if (mem_range_softc.mr_op != NULL)
551 mem_range_softc.mr_op->init(&mem_range_softc);
553 dev_ops_add(&mem_ops, 0xf0, 0);
554 make_dev(&mem_ops, 0, UID_ROOT, GID_KMEM, 0640, "mem");
555 make_dev(&mem_ops, 1, UID_ROOT, GID_KMEM, 0640, "kmem");
556 make_dev(&mem_ops, 2, UID_ROOT, GID_WHEEL, 0666, "null");
557 make_dev(&mem_ops, 3, UID_ROOT, GID_WHEEL, 0644, "random");
558 make_dev(&mem_ops, 4, UID_ROOT, GID_WHEEL, 0644, "urandom");
559 make_dev(&mem_ops, 12, UID_ROOT, GID_WHEEL, 0666, "zero");
560 make_dev(&mem_ops, 14, UID_ROOT, GID_WHEEL, 0600, "io");
563 SYSINIT(memdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,mem_drvinit,NULL)