1 /* 2 * Copyright (c) 1993 Jan-Simon Pendry 3 * Copyright (c) 1993 Sean Eric Fagan 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Jan-Simon Pendry and Sean Eric Fagan. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)procfs_mem.c 8.4 (Berkeley) 1/21/94 39 * 40 * $Id: procfs_mem.c,v 1.9 1995/07/13 08:47:48 davidg Exp $ 41 */ 42 43 /* 44 * This is a lightly hacked and merged version 45 * of sef's pread/pwrite functions 46 */ 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/time.h> 51 #include <sys/kernel.h> 52 #include <sys/proc.h> 53 #include <sys/vnode.h> 54 #include <miscfs/procfs/procfs.h> 55 #include <vm/vm.h> 56 #include <vm/vm_kern.h> 57 #include <vm/vm_page.h> 58 59 static int 60 procfs_rwmem(p, uio) 61 struct proc *p; 62 struct uio *uio; 63 { 64 int error; 65 int writing; 66 67 writing = uio->uio_rw == UIO_WRITE; 68 69 /* 70 * Only map in one page at a time. We don't have to, but it 71 * makes things easier. This way is trivial - right? 72 */ 73 do { 74 vm_map_t map, tmap; 75 vm_object_t object; 76 vm_offset_t kva = 0; 77 vm_offset_t uva; 78 int page_offset; /* offset into page */ 79 vm_offset_t pageno; /* page number */ 80 vm_map_entry_t out_entry; 81 vm_prot_t out_prot; 82 vm_page_t m; 83 boolean_t wired, single_use; 84 vm_offset_t off; 85 u_int len; 86 int fix_prot; 87 88 uva = (vm_offset_t) uio->uio_offset; 89 if (uva >= VM_MAXUSER_ADDRESS) { 90 if (writing || (uva >= (VM_MAXUSER_ADDRESS + UPAGES * PAGE_SIZE))) { 91 error = 0; 92 break; 93 } 94 } 95 96 /* 97 * Get the page number of this segment. 98 */ 99 pageno = trunc_page(uva); 100 page_offset = uva - pageno; 101 102 /* 103 * How many bytes to copy 104 */ 105 len = min(PAGE_SIZE - page_offset, uio->uio_resid); 106 107 /* 108 * The map we want... 109 */ 110 map = &p->p_vmspace->vm_map; 111 112 /* 113 * Check the permissions for the area we're interested 114 * in. 115 */ 116 fix_prot = 0; 117 if (writing) 118 fix_prot = !vm_map_check_protection(map, pageno, 119 pageno + PAGE_SIZE, VM_PROT_WRITE); 120 121 if (fix_prot) { 122 /* 123 * If the page is not writable, we make it so. 124 * XXX It is possible that a page may *not* be 125 * read/executable, if a process changes that! 126 * We will assume, for now, that a page is either 127 * VM_PROT_ALL, or VM_PROT_READ|VM_PROT_EXECUTE. 128 */ 129 error = vm_map_protect(map, pageno, 130 pageno + PAGE_SIZE, VM_PROT_ALL, 0); 131 if (error) 132 break; 133 } 134 135 /* 136 * Now we need to get the page. out_entry, out_prot, wired, 137 * and single_use aren't used. One would think the vm code 138 * would be a *bit* nicer... We use tmap because 139 * vm_map_lookup() can change the map argument. 140 */ 141 tmap = map; 142 error = vm_map_lookup(&tmap, pageno, 143 writing ? VM_PROT_WRITE : VM_PROT_READ, 144 &out_entry, &object, &off, &out_prot, 145 &wired, &single_use); 146 /* 147 * We're done with tmap now. 148 */ 149 if (!error) 150 vm_map_lookup_done(tmap, out_entry); 151 152 /* 153 * Fault the page in... 154 */ 155 if (!error && writing && object->backing_object) { 156 m = vm_page_lookup(object, off); 157 if (m == 0) 158 error = vm_fault(map, pageno, 159 VM_PROT_WRITE, FALSE); 160 } 161 162 /* Find space in kernel_map for the page we're interested in */ 163 if (!error) 164 error = vm_map_find(kernel_map, object, off, &kva, 165 PAGE_SIZE, 1); 166 167 if (!error) { 168 /* 169 * Neither vm_map_lookup() nor vm_map_find() appear 170 * to add a reference count to the object, so we do 171 * that here and now. 172 */ 173 vm_object_reference(object); 174 175 /* 176 * Mark the page we just found as pageable. 177 */ 178 error = vm_map_pageable(kernel_map, kva, 179 kva + PAGE_SIZE, 0); 180 181 /* 182 * Now do the i/o move. 183 */ 184 if (!error) 185 error = uiomove((caddr_t)(kva + page_offset), 186 len, uio); 187 188 vm_map_remove(kernel_map, kva, kva + PAGE_SIZE); 189 } 190 if (fix_prot) 191 vm_map_protect(map, pageno, pageno + PAGE_SIZE, 192 VM_PROT_READ|VM_PROT_EXECUTE, 0); 193 } while (error == 0 && uio->uio_resid > 0); 194 195 return (error); 196 } 197 198 /* 199 * Copy data in and out of the target process. 200 * We do this by mapping the process's page into 201 * the kernel and then doing a uiomove direct 202 * from the kernel address space. 203 */ 204 int 205 procfs_domem(curp, p, pfs, uio) 206 struct proc *curp; 207 struct proc *p; 208 struct pfsnode *pfs; 209 struct uio *uio; 210 { 211 int error; 212 213 if (uio->uio_resid == 0) 214 return (0); 215 216 error = procfs_rwmem(p, uio); 217 218 return (error); 219 } 220 221 /* 222 * Given process (p), find the vnode from which 223 * it's text segment is being executed. 224 * 225 * It would be nice to grab this information from 226 * the VM system, however, there is no sure-fire 227 * way of doing that. Instead, fork(), exec() and 228 * wait() all maintain the p_textvp field in the 229 * process proc structure which contains a held 230 * reference to the exec'ed vnode. 231 */ 232 struct vnode * 233 procfs_findtextvp(p) 234 struct proc *p; 235 { 236 return (p->p_textvp); 237 } 238