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. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * from: Utah $Hdr: mem.c 1.13 89/10/08$
36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
37 * $FreeBSD: src/sys/i386/i386/mem.c,v 1.79.2.9 2003/01/04 22:58:01 njl Exp $
44 #include <sys/param.h>
45 #include <sys/systm.h>
48 #include <sys/fcntl.h>
49 #include <sys/filio.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/memrange.h>
55 #include <sys/random.h>
56 #include <sys/signalvar.h>
58 #include <sys/vnode.h>
59 #include <sys/sysctl.h>
61 #include <sys/signal2.h>
62 #include <sys/mplock2.h>
66 #include <vm/vm_extern.h>
69 static d_open_t mmopen;
70 static d_close_t mmclose;
71 static d_read_t mmread;
72 static d_write_t mmwrite;
73 static d_ioctl_t mmioctl;
74 static d_mmap_t memmmap;
75 static d_kqfilter_t mmkqfilter;
78 static struct dev_ops mem_ops = {
79 { "mem", 0, D_MPSAFE },
85 .d_kqfilter = mmkqfilter,
91 static cdev_t zerodev = NULL;
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;
99 static int seedenable;
100 SYSCTL_INT(_kern, OID_AUTO, seedenable, CTLFLAG_RW, &seedenable, 0, "");
103 mmopen(struct dev_open_args *ap)
105 cdev_t dev = ap->a_head.a_dev;
108 switch (minor(dev)) {
111 if (ap->a_oflags & FWRITE) {
112 if (securelevel > 0 || kernel_mem_readonly)
118 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
121 if (securelevel > 0 || kernel_mem_readonly) {
125 error = cpu_set_iopl();
135 mmclose(struct dev_close_args *ap)
137 cdev_t dev = ap->a_head.a_dev;
140 switch (minor(dev)) {
142 error = cpu_clr_iopl();
153 mmrw(cdev_t dev, struct uio *uio, int flags)
163 while (uio->uio_resid > 0 && error == 0) {
165 if (iov->iov_len == 0) {
168 if (uio->uio_iovcnt < 0)
172 switch (minor(dev)) {
175 * minor device 0 is physical memory, /dev/mem
178 v &= ~(long)PAGE_MASK;
179 pmap_kenter((vm_offset_t)ptvmmap, v);
180 o = (int)uio->uio_offset & PAGE_MASK;
181 c = (u_int)(PAGE_SIZE - ((uintptr_t)iov->iov_base & PAGE_MASK));
182 c = min(c, (u_int)(PAGE_SIZE - o));
183 c = min(c, (u_int)iov->iov_len);
184 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
185 pmap_kremove((vm_offset_t)ptvmmap);
190 * minor device 1 is kernel memory, /dev/kmem
192 vm_offset_t saddr, eaddr;
198 * Make sure that all of the pages are currently
199 * resident so that we don't create any zero-fill
202 saddr = trunc_page(uio->uio_offset);
203 eaddr = round_page(uio->uio_offset + c);
208 * Make sure the kernel addresses are mapped.
209 * platform_direct_mapped() can be used to bypass
210 * default mapping via the page table (virtual kernels
211 * contain a lot of out-of-band data).
214 if (uio->uio_rw != UIO_READ)
215 prot |= VM_PROT_WRITE;
216 error = kvm_access_check(saddr, eaddr, prot);
219 error = uiomove((caddr_t)(vm_offset_t)uio->uio_offset,
225 * minor device 2 (/dev/null) is EOF/RATHOLE
227 if (uio->uio_rw == UIO_READ)
233 * minor device 3 (/dev/random) is source of filth
234 * on read, seeder on write
237 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
238 c = min(iov->iov_len, PAGE_SIZE);
239 if (uio->uio_rw == UIO_WRITE) {
240 error = uiomove(buf, (int)c, uio);
244 error = add_buffer_randomness_src(buf, c, RAND_SRC_SEEDING);
245 } else if (error == 0) {
249 poolsize = read_random(buf, c);
253 if ((flags & IO_NDELAY) != 0)
254 return (EWOULDBLOCK);
257 c = min(c, poolsize);
258 error = uiomove(buf, (int)c, uio);
263 * minor device 4 (/dev/urandom) is source of muck
264 * on read, writes are disallowed.
266 c = min(iov->iov_len, PAGE_SIZE);
267 if (uio->uio_rw == UIO_WRITE) {
271 if (CURSIG(curthread->td_lwp) != 0) {
273 * Use tsleep() to get the error code right.
274 * It should return immediately.
276 error = tsleep(&rand_bolt, PCATCH, "urand", 1);
277 if (error != 0 && error != EWOULDBLOCK)
281 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
282 poolsize = read_random_unlimited(buf, c);
283 c = min(c, poolsize);
284 error = uiomove(buf, (int)c, uio);
288 * minor device 12 (/dev/zero) is source of nulls
289 * on read, write are disallowed.
291 if (uio->uio_rw == UIO_WRITE) {
296 zbuf = (caddr_t)kmalloc(PAGE_SIZE, M_TEMP,
299 c = min(iov->iov_len, PAGE_SIZE);
300 error = uiomove(zbuf, (int)c, uio);
307 iov->iov_base = (char *)iov->iov_base + c;
309 uio->uio_offset += c;
318 mmread(struct dev_read_args *ap)
320 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
324 mmwrite(struct dev_write_args *ap)
326 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
333 /*******************************************************\
334 * allow user processes to MMAP some memory sections *
335 * instead of going through read/write *
336 \*******************************************************/
339 memmmap(struct dev_mmap_args *ap)
341 cdev_t dev = ap->a_head.a_dev;
343 switch (minor(dev)) {
346 * minor device 0 is physical memory
348 #if defined(__i386__)
349 ap->a_result = i386_btop(ap->a_offset);
350 #elif defined(__x86_64__)
351 ap->a_result = x86_64_btop(ap->a_offset);
356 * minor device 1 is kernel memory
358 #if defined(__i386__)
359 ap->a_result = i386_btop(vtophys(ap->a_offset));
360 #elif defined(__x86_64__)
361 ap->a_result = x86_64_btop(vtophys(ap->a_offset));
371 mmioctl(struct dev_ioctl_args *ap)
373 cdev_t dev = ap->a_head.a_dev;
378 switch (minor(dev)) {
380 error = mem_ioctl(dev, ap->a_cmd, ap->a_data,
381 ap->a_fflag, ap->a_cred);
385 error = random_ioctl(dev, ap->a_cmd, ap->a_data,
386 ap->a_fflag, ap->a_cred);
398 * Operations for changing memory attributes.
400 * This is basically just an ioctl shim for mem_range_attr_get
401 * and mem_range_attr_set.
404 mem_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
407 struct mem_range_op *mo = (struct mem_range_op *)data;
408 struct mem_range_desc *md;
410 /* is this for us? */
411 if ((cmd != MEMRANGE_GET) &&
412 (cmd != MEMRANGE_SET))
415 /* any chance we can handle this? */
416 if (mem_range_softc.mr_op == NULL)
419 /* do we have any descriptors? */
420 if (mem_range_softc.mr_ndesc == 0)
425 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
427 md = (struct mem_range_desc *)
428 kmalloc(nd * sizeof(struct mem_range_desc),
429 M_MEMDESC, M_WAITOK);
430 error = mem_range_attr_get(md, &nd);
432 error = copyout(md, mo->mo_desc,
433 nd * sizeof(struct mem_range_desc));
434 kfree(md, M_MEMDESC);
436 nd = mem_range_softc.mr_ndesc;
442 md = (struct mem_range_desc *)kmalloc(sizeof(struct mem_range_desc),
443 M_MEMDESC, M_WAITOK);
444 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
445 /* clamp description string */
446 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
448 error = mem_range_attr_set(md, &mo->mo_arg[0]);
449 kfree(md, M_MEMDESC);
456 * Implementation-neutral, kernel-callable functions for manipulating
457 * memory range attributes.
460 mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
462 /* can we handle this? */
463 if (mem_range_softc.mr_op == NULL)
467 *arg = mem_range_softc.mr_ndesc;
469 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc));
475 mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
477 /* can we handle this? */
478 if (mem_range_softc.mr_op == NULL)
481 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
485 mem_range_AP_init(void)
487 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP)
488 mem_range_softc.mr_op->initAP(&mem_range_softc);
492 random_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
498 * Even inspecting the state is privileged, since it gives a hint
499 * about how easily the randomness might be guessed.
504 /* Really handled in upper layer */
508 intr = *(int16_t *)data;
509 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
511 if (intr < 0 || intr >= MAX_INTS)
513 register_randintr(intr);
516 intr = *(int16_t *)data;
517 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
519 if (intr < 0 || intr >= MAX_INTS)
521 unregister_randintr(intr);
527 intr = *(int16_t *)data;
528 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
530 if (intr < 0 || intr >= MAX_INTS)
532 intr = next_registered_randintr(intr);
533 if (intr == MAX_INTS)
535 *(u_int16_t *)data = intr;
545 mm_filter_read(struct knote *kn, long hint)
551 mm_filter_write(struct knote *kn, long hint)
557 dummy_filter_detach(struct knote *kn) {}
559 /* Implemented in kern_nrandom.c */
560 static struct filterops random_read_filtops =
561 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, random_filter_read };
563 static struct filterops mm_read_filtops =
564 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, mm_filter_read };
566 static struct filterops mm_write_filtops =
567 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, mm_filter_write };
570 mmkqfilter(struct dev_kqfilter_args *ap)
572 struct knote *kn = ap->a_kn;
573 cdev_t dev = ap->a_head.a_dev;
576 switch (kn->kn_filter) {
578 switch (minor(dev)) {
580 kn->kn_fop = &random_read_filtops;
583 kn->kn_fop = &mm_read_filtops;
588 kn->kn_fop = &mm_write_filtops;
591 ap->a_result = EOPNOTSUPP;
599 iszerodev(cdev_t dev)
601 return (zerodev == dev);
605 mem_drvinit(void *unused)
608 /* Initialise memory range handling */
609 if (mem_range_softc.mr_op != NULL)
610 mem_range_softc.mr_op->init(&mem_range_softc);
612 make_dev(&mem_ops, 0, UID_ROOT, GID_KMEM, 0640, "mem");
613 make_dev(&mem_ops, 1, UID_ROOT, GID_KMEM, 0640, "kmem");
614 make_dev(&mem_ops, 2, UID_ROOT, GID_WHEEL, 0666, "null");
615 make_dev(&mem_ops, 3, UID_ROOT, GID_WHEEL, 0644, "random");
616 make_dev(&mem_ops, 4, UID_ROOT, GID_WHEEL, 0644, "urandom");
617 zerodev = make_dev(&mem_ops, 12, UID_ROOT, GID_WHEEL, 0666, "zero");
618 make_dev(&mem_ops, 14, UID_ROOT, GID_WHEEL, 0600, "io");
621 SYSINIT(memdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,mem_drvinit,NULL)