/* * Copyright (c) 2000-2014 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /*- * Copyright (c) 1988 University of Utah. * Copyright (c) 1982, 1986, 1990, 1993 * 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 $Hdr: mem.c 1.13 89/10/08$ * @(#)mem.c 8.1 (Berkeley) 6/11/93 */ /* * Memory special file */ #include <sys/param.h> #include <sys/dir.h> #include <sys/proc.h> #include <sys/systm.h> #include <sys/conf.h> #include <sys/vm.h> #include <sys/uio_internal.h> #include <sys/malloc.h> #include <mach/vm_types.h> #include <mach/vm_param.h> #include <vm/vm_kern.h> /* for kernel_map */ #include <pexpert/pexpert.h> /* for PE_parse_boot_argn */ boolean_t iskmemdev(dev_t dev); #if CONFIG_DEV_KMEM boolean_t dev_kmem_enabled; boolean_t dev_kmem_mask_top_bit; void dev_kmem_init(void); #if defined(__x86_64__) extern addr64_t kvtophys(vm_offset_t va); #else #error need kvtophys prototype #endif extern boolean_t kernacc(off_t, size_t ); #endif static caddr_t devzerobuf; int mmread(dev_t dev, struct uio *uio); int mmwrite(dev_t dev, struct uio *uio); int mmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p); int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw); int mmread(dev_t dev, struct uio *uio) { return (mmrw(dev, uio, UIO_READ)); } int mmwrite(dev_t dev, struct uio *uio) { return (mmrw(dev, uio, UIO_WRITE)); } int mmioctl(dev_t dev, u_long cmd, __unused caddr_t data, __unused int flag, __unused struct proc *p) { int minnum = minor(dev); if (0 == minnum || 1 == minnum) { /* /dev/mem and /dev/kmem */ #if CONFIG_DEV_KMEM if (!dev_kmem_enabled) return (ENODEV); #else return (ENODEV); #endif } switch (cmd) { case FIONBIO: case FIOASYNC: /* OK to do nothing: we always return immediately */ break; default: return ENODEV; } return (0); } int mmrw(dev_t dev, struct uio *uio, enum uio_rw rw) { unsigned int c; int error = 0; while (uio_resid(uio) > 0) { uio_update(uio, 0); switch (minor(dev)) { /* minor device 0 is physical memory */ case 0: return (ENODEV); /* minor device 1 is kernel memory */ case 1: #if !CONFIG_DEV_KMEM return (ENODEV); #else /* CONFIG_DEV_KMEM */ if (!dev_kmem_enabled) return (ENODEV); vm_address_t kaddr = (vm_address_t)uio->uio_offset; if (dev_kmem_mask_top_bit) { /* * KVA addresses of the form 0xFFFFFF80AABBCCDD can't be * represented as a signed off_t correctly. In these cases, * 0x7FFFFF80AABBCCDD is passed in, and the top bit OR-ed * on. */ const vm_address_t top_bit = (~((vm_address_t)0)) ^ (~((vm_address_t)0) >> 1UL); if (kaddr & top_bit) { /* top bit should not be set already */ return (EFAULT); } kaddr |= top_bit; } c = uio_curriovlen(uio); /* Do some sanity checking */ if ((kaddr > (VM_MAX_KERNEL_ADDRESS - c)) || (kaddr <= VM_MIN_KERNEL_AND_KEXT_ADDRESS)) goto fault; if (!kernacc(kaddr, c)) goto fault; error = uiomove((const char *)(uintptr_t)kaddr, (int)c, uio); if (error) break; continue; /* Keep going until UIO is done */ #endif /* CONFIG_DEV_KMEM */ /* minor device 2 is EOF/RATHOLE */ case 2: if (rw == UIO_READ) return (0); c = uio_curriovlen(uio); error = 0; /* Always succeeds, always consumes all input */ break; case 3: if(devzerobuf == NULL) { MALLOC(devzerobuf, caddr_t,PAGE_SIZE, M_TEMP, M_WAITOK); bzero(devzerobuf, PAGE_SIZE); } if(uio->uio_rw == UIO_WRITE) { c = uio_curriovlen(uio); error = 0; /* Always succeeds, always consumes all input */ break; } c = min(uio_curriovlen(uio), PAGE_SIZE); error = uiomove(devzerobuf, (int)c, uio); if (error) break; continue; /* Keep going until UIO is done */ default: return (ENODEV); break; } if (error) break; uio_update(uio, c); } return (error); #if CONFIG_DEV_KMEM fault: return (EFAULT); #endif } #if CONFIG_DEV_KMEM void dev_kmem_init(void) { uint32_t kmem; if (PE_i_can_has_debugger(NULL) && PE_parse_boot_argn("kmem", &kmem, sizeof (kmem))) { if (kmem & 0x1) { dev_kmem_enabled = TRUE; } if (kmem & 0x2) { dev_kmem_mask_top_bit = TRUE; } } } boolean_t kernacc( off_t start, size_t len ) { off_t base; off_t end; base = trunc_page(start); end = start + len; while (base < end) { if(kvtophys((vm_offset_t)base) == 0ULL) return(FALSE); base += page_size; } return (TRUE); } #endif /* CONFIG_DEV_KMEM */ /* * Returns true if dev is /dev/mem or /dev/kmem. */ boolean_t iskmemdev(dev_t dev) { return (major(dev) == 3 && minor(dev) < 2); }