/*- * Copyright (c) 1988 University of Utah. * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department, and code derived from software contributed to * Berkeley by William Jolitz. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: Utah $Hdr: mem.c 1.13 89/10/08$ * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 * $FreeBSD: src/sys/i386/i386/mem.c,v 1.79.2.9 2003/01/04 22:58:01 njl Exp $ * $DragonFly: src/sys/kern/kern_memio.c,v 1.12 2005/11/02 22:59:43 dillon Exp $ */ /* * Memory special file */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static d_open_t mmopen; static d_close_t mmclose; static d_read_t mmrw; static d_ioctl_t mmioctl; static d_mmap_t memmmap; static d_poll_t mmpoll; #define CDEV_MAJOR 2 static struct cdevsw mem_cdevsw = { /* name */ "mem", /* maj */ CDEV_MAJOR, /* flags */ D_MEM, /* port */ NULL, /* clone */ NULL, /* open */ mmopen, /* close */ mmclose, /* read */ mmrw, /* write */ mmrw, /* ioctl */ mmioctl, /* poll */ mmpoll, /* mmap */ memmmap, /* strategy */ nostrategy, /* dump */ nodump, /* psize */ nopsize }; static int rand_bolt; static caddr_t zbuf; MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); static int mem_ioctl (dev_t, u_long, caddr_t, int, struct thread *); static int random_ioctl (dev_t, u_long, caddr_t, int, struct thread *); struct mem_range_softc mem_range_softc; static int mmclose(dev_t dev, int flags, int fmt, struct thread *td) { struct proc *p = td->td_proc; switch (minor(dev)) { case 14: p->p_md.md_regs->tf_eflags &= ~PSL_IOPL; break; default: break; } return (0); } static int mmopen(dev_t dev, int flags, int fmt, struct thread *td) { int error; struct proc *p = td->td_proc; switch (minor(dev)) { case 0: case 1: if ((flags & FWRITE) && securelevel > 0) return (EPERM); break; case 14: error = suser(td); if (error != 0) return (error); if (securelevel > 0) return (EPERM); p->p_md.md_regs->tf_eflags |= PSL_IOPL; break; default: break; } return (0); } static int mmrw(dev, uio, flags) dev_t dev; struct uio *uio; int flags; { int o; u_int c, v; u_int poolsize; struct iovec *iov; int error = 0; caddr_t buf = NULL; while (uio->uio_resid > 0 && error == 0) { iov = uio->uio_iov; if (iov->iov_len == 0) { uio->uio_iov++; uio->uio_iovcnt--; if (uio->uio_iovcnt < 0) panic("mmrw"); continue; } switch (minor(dev)) { /* minor device 0 is physical memory */ case 0: v = uio->uio_offset; v &= ~PAGE_MASK; pmap_kenter((vm_offset_t)ptvmmap, v); o = (int)uio->uio_offset & PAGE_MASK; c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK)); c = min(c, (u_int)(PAGE_SIZE - o)); c = min(c, (u_int)iov->iov_len); error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); pmap_kremove((vm_offset_t)ptvmmap); continue; /* minor device 1 is kernel memory */ case 1: { vm_offset_t addr, eaddr; c = iov->iov_len; /* * Make sure that all of the pages are currently resident so * that we don't create any zero-fill pages. */ addr = trunc_page(uio->uio_offset); eaddr = round_page(uio->uio_offset + c); if (addr < (vm_offset_t)VADDR(PTDPTDI, 0)) return EFAULT; if (eaddr >= (vm_offset_t)VADDR(APTDPTDI, 0)) return EFAULT; for (; addr < eaddr; addr += PAGE_SIZE) if (pmap_extract(kernel_pmap, addr) == 0) return EFAULT; if (!kernacc((caddr_t)(int)uio->uio_offset, c, uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE)) return (EFAULT); error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio); continue; } /* minor device 2 is EOF/RATHOLE */ case 2: if (uio->uio_rw == UIO_READ) return (0); c = iov->iov_len; break; /* minor device 3 (/dev/random) is source of filth on read, rathole on write */ case 3: if (uio->uio_rw == UIO_WRITE) { c = iov->iov_len; break; } if (buf == NULL) buf = (caddr_t) malloc(PAGE_SIZE, M_TEMP, M_WAITOK); c = min(iov->iov_len, PAGE_SIZE); poolsize = read_random(buf, c); if (poolsize == 0) { if (buf) free(buf, M_TEMP); if ((flags & IO_NDELAY) != 0) return (EWOULDBLOCK); return (0); } c = min(c, poolsize); error = uiomove(buf, (int)c, uio); continue; /* minor device 4 (/dev/urandom) is source of muck on read, rathole on write */ case 4: if (uio->uio_rw == UIO_WRITE) { c = iov->iov_len; break; } if (CURSIG(curproc) != 0) { /* * Use tsleep() to get the error code right. * It should return immediately. */ error = tsleep(&rand_bolt, PCATCH, "urand", 1); if (error != 0 && error != EWOULDBLOCK) continue; } if (buf == NULL) buf = (caddr_t) malloc(PAGE_SIZE, M_TEMP, M_WAITOK); c = min(iov->iov_len, PAGE_SIZE); poolsize = read_random_unlimited(buf, c); c = min(c, poolsize); error = uiomove(buf, (int)c, uio); continue; /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */ case 12: if (uio->uio_rw == UIO_WRITE) { c = iov->iov_len; break; } if (zbuf == NULL) { zbuf = (caddr_t) malloc(PAGE_SIZE, M_TEMP, M_WAITOK); bzero(zbuf, PAGE_SIZE); } c = min(iov->iov_len, PAGE_SIZE); error = uiomove(zbuf, (int)c, uio); continue; default: return (ENODEV); } if (error) break; iov->iov_base += c; iov->iov_len -= c; uio->uio_offset += c; uio->uio_resid -= c; } if (buf) free(buf, M_TEMP); return (error); } /*******************************************************\ * allow user processes to MMAP some memory sections * * instead of going through read/write * \*******************************************************/ static int memmmap(dev_t dev, vm_offset_t offset, int nprot) { switch (minor(dev)) { /* minor device 0 is physical memory */ case 0: return i386_btop(offset); /* minor device 1 is kernel memory */ case 1: return i386_btop(vtophys(offset)); default: return -1; } } static int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) { switch (minor(dev)) { case 0: return mem_ioctl(dev, cmd, data, flags, td); case 3: case 4: return random_ioctl(dev, cmd, data, flags, td); } return (ENODEV); } /* * Operations for changing memory attributes. * * This is basically just an ioctl shim for mem_range_attr_get * and mem_range_attr_set. */ static int mem_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) { int nd, error = 0; struct mem_range_op *mo = (struct mem_range_op *)data; struct mem_range_desc *md; /* is this for us? */ if ((cmd != MEMRANGE_GET) && (cmd != MEMRANGE_SET)) return (ENOTTY); /* any chance we can handle this? */ if (mem_range_softc.mr_op == NULL) return (EOPNOTSUPP); /* do we have any descriptors? */ if (mem_range_softc.mr_ndesc == 0) return (ENXIO); switch (cmd) { case MEMRANGE_GET: nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); if (nd > 0) { md = (struct mem_range_desc *) malloc(nd * sizeof(struct mem_range_desc), M_MEMDESC, M_WAITOK); error = mem_range_attr_get(md, &nd); if (!error) error = copyout(md, mo->mo_desc, nd * sizeof(struct mem_range_desc)); free(md, M_MEMDESC); } else { nd = mem_range_softc.mr_ndesc; } mo->mo_arg[0] = nd; break; case MEMRANGE_SET: md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), M_MEMDESC, M_WAITOK); error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); /* clamp description string */ md->mr_owner[sizeof(md->mr_owner) - 1] = 0; if (error == 0) error = mem_range_attr_set(md, &mo->mo_arg[0]); free(md, M_MEMDESC); break; } return (error); } /* * Implementation-neutral, kernel-callable functions for manipulating * memory range attributes. */ int mem_range_attr_get(mrd, arg) struct mem_range_desc *mrd; int *arg; { /* can we handle this? */ if (mem_range_softc.mr_op == NULL) return (EOPNOTSUPP); if (*arg == 0) { *arg = mem_range_softc.mr_ndesc; } else { bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc)); } return (0); } int mem_range_attr_set(mrd, arg) struct mem_range_desc *mrd; int *arg; { /* can we handle this? */ if (mem_range_softc.mr_op == NULL) return (EOPNOTSUPP); return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); } #ifdef SMP void mem_range_AP_init(void) { if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) return (mem_range_softc.mr_op->initAP(&mem_range_softc)); } #endif static int random_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) { int error; int intr; /* * Even inspecting the state is privileged, since it gives a hint * about how easily the randomness might be guessed. */ error = 0; switch (cmd) { /* Really handled in upper layer */ case FIOASYNC: case FIONBIO: break; case MEM_SETIRQ: intr = *(int16_t *)data; if ((error = suser(td)) != 0) break; if (intr < 0 || intr >= MAX_INTS) return (EINVAL); register_randintr(intr); break; case MEM_CLEARIRQ: intr = *(int16_t *)data; if ((error = suser(td)) != 0) break; if (intr < 0 || intr >= MAX_INTS) return (EINVAL); unregister_randintr(intr); break; case MEM_RETURNIRQ: error = ENOTSUP; break; case MEM_FINDIRQ: intr = *(int16_t *)data; if ((error = suser(td)) != 0) break; if (intr < 0 || intr >= MAX_INTS) return (EINVAL); intr = next_registered_randintr(intr); if (intr == MAX_INTS) return (ENOENT); *(u_int16_t *)data = intr; break; default: error = ENOTSUP; break; } return (error); } int mmpoll(dev_t dev, int events, struct thread *td) { switch (minor(dev)) { case 3: /* /dev/random */ return random_poll(dev, events, td); case 4: /* /dev/urandom */ default: return seltrue(dev, events, td); } } int iszerodev(dev) dev_t dev; { return ((major(dev) == mem_cdevsw.d_maj) && minor(dev) == 12); } static void mem_drvinit(void *unused) { /* Initialise memory range handling */ if (mem_range_softc.mr_op != NULL) mem_range_softc.mr_op->init(&mem_range_softc); cdevsw_add(&mem_cdevsw, 0xf0, 0); make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 0640, "mem"); make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 0640, "kmem"); make_dev(&mem_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "null"); make_dev(&mem_cdevsw, 3, UID_ROOT, GID_WHEEL, 0644, "random"); make_dev(&mem_cdevsw, 4, UID_ROOT, GID_WHEEL, 0644, "urandom"); make_dev(&mem_cdevsw, 12, UID_ROOT, GID_WHEEL, 0666, "zero"); make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 0600, "io"); } SYSINIT(memdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,mem_drvinit,NULL)