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 1.32 2008/07/23 16:39:28 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/kernel.h>
56 #include <sys/malloc.h>
57 #include <sys/memrange.h>
60 #include <sys/random.h>
61 #include <sys/signalvar.h>
62 #include <sys/signal2.h>
64 #include <sys/vnode.h>
68 #include <vm/vm_extern.h>
71 static d_open_t mmopen;
72 static d_close_t mmclose;
73 static d_read_t mmread;
74 static d_write_t mmwrite;
75 static d_ioctl_t mmioctl;
76 static d_mmap_t memmmap;
77 static d_poll_t mmpoll;
80 static struct dev_ops mem_ops = {
81 { "mem", CDEV_MAJOR, D_MEM },
94 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
95 static int mem_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
96 static int random_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
98 struct mem_range_softc mem_range_softc;
102 mmopen(struct dev_open_args *ap)
104 cdev_t dev = ap->a_head.a_dev;
107 switch (minor(dev)) {
110 if (ap->a_oflags & FWRITE) {
111 if (securelevel > 0 || kernel_mem_readonly)
117 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
120 if (securelevel > 0 || kernel_mem_readonly) {
124 error = cpu_set_iopl();
134 mmclose(struct dev_close_args *ap)
136 cdev_t dev = ap->a_head.a_dev;
139 switch (minor(dev)) {
141 error = cpu_clr_iopl();
152 mmrw(cdev_t dev, struct uio *uio, int flags)
161 while (uio->uio_resid > 0 && error == 0) {
163 if (iov->iov_len == 0) {
166 if (uio->uio_iovcnt < 0)
170 switch (minor(dev)) {
173 * minor device 0 is physical memory, /dev/mem
177 pmap_kenter((vm_offset_t)ptvmmap, v);
178 o = (int)uio->uio_offset & PAGE_MASK;
179 c = (u_int)(PAGE_SIZE - ((uintptr_t)iov->iov_base & PAGE_MASK));
180 c = min(c, (u_int)(PAGE_SIZE - o));
181 c = min(c, (u_int)iov->iov_len);
182 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
183 pmap_kremove((vm_offset_t)ptvmmap);
188 * minor device 1 is kernel memory, /dev/kmem
190 vm_offset_t saddr, eaddr;
196 * Make sure that all of the pages are currently
197 * resident so that we don't create any zero-fill
200 saddr = trunc_page(uio->uio_offset);
201 eaddr = round_page(uio->uio_offset + c);
206 * Make sure the kernel addresses are mapped.
207 * platform_direct_mapped() can be used to bypass
208 * default mapping via the page table (virtual kernels
209 * contain a lot of out-of-band data).
212 if (uio->uio_rw != UIO_READ)
213 prot |= VM_PROT_WRITE;
214 error = kvm_access_check(saddr, eaddr, prot);
217 error = uiomove((caddr_t)(vm_offset_t)uio->uio_offset,
223 * minor device 2 is EOF/RATHOLE
225 if (uio->uio_rw == UIO_READ)
231 * minor device 3 (/dev/random) is source of filth
232 * on read, seeder on write
235 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
236 c = min(iov->iov_len, PAGE_SIZE);
237 if (uio->uio_rw == UIO_WRITE) {
238 error = uiomove(buf, (int)c, uio);
240 error = add_buffer_randomness(buf, c);
242 poolsize = read_random(buf, c);
246 if ((flags & IO_NDELAY) != 0)
247 return (EWOULDBLOCK);
250 c = min(c, poolsize);
251 error = uiomove(buf, (int)c, uio);
256 * minor device 4 (/dev/urandom) is source of muck
257 * on read, writes are disallowed.
259 c = min(iov->iov_len, PAGE_SIZE);
260 if (uio->uio_rw == UIO_WRITE) {
264 if (CURSIG(curthread->td_lwp) != 0) {
266 * Use tsleep() to get the error code right.
267 * It should return immediately.
269 error = tsleep(&rand_bolt, PCATCH, "urand", 1);
270 if (error != 0 && error != EWOULDBLOCK)
274 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
275 poolsize = read_random_unlimited(buf, c);
276 c = min(c, poolsize);
277 error = uiomove(buf, (int)c, uio);
281 * minor device 12 (/dev/zero) is source of nulls
282 * on read, write are disallowed.
284 if (uio->uio_rw == UIO_WRITE) {
289 zbuf = (caddr_t)kmalloc(PAGE_SIZE, M_TEMP,
292 c = min(iov->iov_len, PAGE_SIZE);
293 error = uiomove(zbuf, (int)c, uio);
300 iov->iov_base = (char *)iov->iov_base + c;
302 uio->uio_offset += c;
311 mmread(struct dev_read_args *ap)
313 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
317 mmwrite(struct dev_write_args *ap)
319 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
326 /*******************************************************\
327 * allow user processes to MMAP some memory sections *
328 * instead of going through read/write *
329 \*******************************************************/
332 memmmap(struct dev_mmap_args *ap)
334 cdev_t dev = ap->a_head.a_dev;
336 switch (minor(dev)) {
339 * minor device 0 is physical memory
341 #if defined(__i386__)
342 ap->a_result = i386_btop(ap->a_offset);
343 #elif defined(__amd64__)
344 ap->a_result = amd64_btop(ap->a_offset);
349 * minor device 1 is kernel memory
351 #if defined(__i386__)
352 ap->a_result = i386_btop(vtophys(ap->a_offset));
353 #elif defined(__amd64__)
354 ap->a_result = amd64_btop(vtophys(ap->a_offset));
364 mmioctl(struct dev_ioctl_args *ap)
366 cdev_t dev = ap->a_head.a_dev;
368 switch (minor(dev)) {
370 return mem_ioctl(dev, ap->a_cmd, ap->a_data,
371 ap->a_fflag, ap->a_cred);
374 return random_ioctl(dev, ap->a_cmd, ap->a_data,
375 ap->a_fflag, ap->a_cred);
381 * Operations for changing memory attributes.
383 * This is basically just an ioctl shim for mem_range_attr_get
384 * and mem_range_attr_set.
387 mem_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
390 struct mem_range_op *mo = (struct mem_range_op *)data;
391 struct mem_range_desc *md;
393 /* is this for us? */
394 if ((cmd != MEMRANGE_GET) &&
395 (cmd != MEMRANGE_SET))
398 /* any chance we can handle this? */
399 if (mem_range_softc.mr_op == NULL)
402 /* do we have any descriptors? */
403 if (mem_range_softc.mr_ndesc == 0)
408 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
410 md = (struct mem_range_desc *)
411 kmalloc(nd * sizeof(struct mem_range_desc),
412 M_MEMDESC, M_WAITOK);
413 error = mem_range_attr_get(md, &nd);
415 error = copyout(md, mo->mo_desc,
416 nd * sizeof(struct mem_range_desc));
417 kfree(md, M_MEMDESC);
419 nd = mem_range_softc.mr_ndesc;
425 md = (struct mem_range_desc *)kmalloc(sizeof(struct mem_range_desc),
426 M_MEMDESC, M_WAITOK);
427 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
428 /* clamp description string */
429 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
431 error = mem_range_attr_set(md, &mo->mo_arg[0]);
432 kfree(md, M_MEMDESC);
439 * Implementation-neutral, kernel-callable functions for manipulating
440 * memory range attributes.
443 mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
445 /* can we handle this? */
446 if (mem_range_softc.mr_op == NULL)
450 *arg = mem_range_softc.mr_ndesc;
452 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc));
458 mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
460 /* can we handle this? */
461 if (mem_range_softc.mr_op == NULL)
464 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
469 mem_range_AP_init(void)
471 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP)
472 return (mem_range_softc.mr_op->initAP(&mem_range_softc));
477 random_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
483 * Even inspecting the state is privileged, since it gives a hint
484 * about how easily the randomness might be guessed.
489 /* Really handled in upper layer */
493 intr = *(int16_t *)data;
494 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
496 if (intr < 0 || intr >= MAX_INTS)
498 register_randintr(intr);
501 intr = *(int16_t *)data;
502 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
504 if (intr < 0 || intr >= MAX_INTS)
506 unregister_randintr(intr);
512 intr = *(int16_t *)data;
513 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
515 if (intr < 0 || intr >= MAX_INTS)
517 intr = next_registered_randintr(intr);
518 if (intr == MAX_INTS)
520 *(u_int16_t *)data = intr;
530 mmpoll(struct dev_poll_args *ap)
532 cdev_t dev = ap->a_head.a_dev;
535 switch (minor(dev)) {
536 case 3: /* /dev/random */
537 revents = random_poll(dev, ap->a_events);
539 case 4: /* /dev/urandom */
541 revents = seltrue(dev, ap->a_events);
544 ap->a_events = revents;
549 iszerodev(cdev_t dev)
551 return ((major(dev) == mem_ops.head.maj)
552 && minor(dev) == 12);
556 mem_drvinit(void *unused)
559 /* Initialise memory range handling */
560 if (mem_range_softc.mr_op != NULL)
561 mem_range_softc.mr_op->init(&mem_range_softc);
563 dev_ops_add(&mem_ops, 0xf0, 0);
564 make_dev(&mem_ops, 0, UID_ROOT, GID_KMEM, 0640, "mem");
565 make_dev(&mem_ops, 1, UID_ROOT, GID_KMEM, 0640, "kmem");
566 make_dev(&mem_ops, 2, UID_ROOT, GID_WHEEL, 0666, "null");
567 make_dev(&mem_ops, 3, UID_ROOT, GID_WHEEL, 0644, "random");
568 make_dev(&mem_ops, 4, UID_ROOT, GID_WHEEL, 0644, "urandom");
569 make_dev(&mem_ops, 12, UID_ROOT, GID_WHEEL, 0666, "zero");
570 make_dev(&mem_ops, 14, UID_ROOT, GID_WHEEL, 0600, "io");
573 SYSINIT(memdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,mem_drvinit,NULL)