1 /* $NetBSD: procfs_mem.c,v 1.7 1995/01/05 07:10:54 chopps Exp $ */ 2 3 /* 4 * Copyright (c) 1993 Jan-Simon Pendry 5 * Copyright (c) 1993 Sean Eric Fagan 6 * Copyright (c) 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Jan-Simon Pendry and Sean Eric Fagan. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)procfs_mem.c 8.5 (Berkeley) 6/15/94 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; 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 error = 0; 91 break; 92 } 93 94 /* 95 * Get the page number of this segment. 96 */ 97 pageno = trunc_page(uva); 98 page_offset = uva - pageno; 99 100 /* 101 * How many bytes to copy 102 */ 103 len = min(PAGE_SIZE - page_offset, uio->uio_resid); 104 105 /* 106 * The map we want... 107 */ 108 map = &p->p_vmspace->vm_map; 109 110 /* 111 * Check the permissions for the area we're interested 112 * in. 113 */ 114 fix_prot = 0; 115 if (writing) 116 fix_prot = !vm_map_check_protection(map, pageno, 117 pageno + PAGE_SIZE, VM_PROT_WRITE); 118 119 if (fix_prot) { 120 /* 121 * If the page is not writable, we make it so. 122 * XXX It is possible that a page may *not* be 123 * read/executable, if a process changes that! 124 * We will assume, for now, that a page is either 125 * VM_PROT_ALL, or VM_PROT_READ|VM_PROT_EXECUTE. 126 */ 127 error = vm_map_protect(map, pageno, 128 pageno + PAGE_SIZE, VM_PROT_ALL, 0); 129 if (error) 130 break; 131 } 132 133 /* 134 * Now we need to get the page. out_entry, out_prot, wired, 135 * and single_use aren't used. One would think the vm code 136 * would be a *bit* nicer... We use tmap because 137 * vm_map_lookup() can change the map argument. 138 */ 139 tmap = map; 140 error = vm_map_lookup(&tmap, pageno, 141 writing ? VM_PROT_WRITE : VM_PROT_READ, 142 &out_entry, &object, &off, &out_prot, 143 &wired, &single_use); 144 /* 145 * We're done with tmap now. 146 */ 147 if (!error) 148 vm_map_lookup_done(tmap, out_entry); 149 150 /* 151 * Fault the page in... 152 */ 153 if (!error && writing && object->shadow) { 154 m = vm_page_lookup(object, off); 155 if (m == 0 || (m->flags & PG_COPYONWRITE)) 156 error = vm_fault(map, pageno, 157 VM_PROT_WRITE, FALSE); 158 } 159 160 /* Find space in kernel_map for the page we're interested in */ 161 if (!error) { 162 kva = VM_MIN_KERNEL_ADDRESS; 163 error = vm_map_find(kernel_map, object, off, &kva, 164 PAGE_SIZE, 1); 165 } 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(kva + page_offset, len, uio); 186 187 vm_map_remove(kernel_map, kva, kva + PAGE_SIZE); 188 } 189 if (fix_prot) 190 vm_map_protect(map, pageno, pageno + PAGE_SIZE, 191 VM_PROT_READ|VM_PROT_EXECUTE, 0); 192 } while (error == 0 && uio->uio_resid > 0); 193 194 return (error); 195 } 196 197 /* 198 * Copy data in and out of the target process. 199 * We do this by mapping the process's page into 200 * the kernel and then doing a uiomove direct 201 * from the kernel address space. 202 */ 203 int 204 procfs_domem(curp, p, pfs, uio) 205 struct proc *curp; 206 struct proc *p; 207 struct pfsnode *pfs; 208 struct uio *uio; 209 { 210 211 if (uio->uio_resid == 0) 212 return (0); 213 214 return (procfs_rwmem(p, uio)); 215 } 216 217 /* 218 * Given process (p), find the vnode from which 219 * it's text segment is being executed. 220 * 221 * It would be nice to grab this information from 222 * the VM system, however, there is no sure-fire 223 * way of doing that. Instead, fork(), exec() and 224 * wait() all maintain the p_textvp field in the 225 * process proc structure which contains a held 226 * reference to the exec'ed vnode. 227 */ 228 struct vnode * 229 procfs_findtextvp(p) 230 struct proc *p; 231 { 232 233 return (p->p_textvp); 234 } 235 236 237 #ifdef probably_never 238 /* 239 * Given process (p), find the vnode from which 240 * it's text segment is being mapped. 241 * 242 * (This is here, rather than in procfs_subr in order 243 * to keep all the VM related code in one place.) 244 */ 245 struct vnode * 246 procfs_findtextvp(p) 247 struct proc *p; 248 { 249 int error; 250 vm_object_t object; 251 vm_offset_t pageno; /* page number */ 252 253 /* find a vnode pager for the user address space */ 254 255 for (pageno = VM_MIN_ADDRESS; 256 pageno < VM_MAXUSER_ADDRESS; 257 pageno += PAGE_SIZE) { 258 vm_map_t map; 259 vm_map_entry_t out_entry; 260 vm_prot_t out_prot; 261 boolean_t wired, single_use; 262 vm_offset_t off; 263 264 map = &p->p_vmspace->vm_map; 265 error = vm_map_lookup(&map, pageno, 266 VM_PROT_READ, 267 &out_entry, &object, &off, &out_prot, 268 &wired, &single_use); 269 270 if (!error) { 271 vm_pager_t pager; 272 273 printf("procfs: found vm object\n"); 274 vm_map_lookup_done(map, out_entry); 275 printf("procfs: vm object = %x\n", object); 276 277 /* 278 * At this point, assuming no errors, object 279 * is the VM object mapping UVA (pageno). 280 * Ensure it has a vnode pager, then grab 281 * the vnode from that pager's handle. 282 */ 283 284 pager = object->pager; 285 printf("procfs: pager = %x\n", pager); 286 if (pager) 287 printf("procfs: found pager, type = %d\n", pager->pg_type); 288 if (pager && pager->pg_type == PG_VNODE) { 289 struct vnode *vp; 290 291 vp = (struct vnode *) pager->pg_handle; 292 printf("procfs: vp = 0x%x\n", vp); 293 return (vp); 294 } 295 } 296 } 297 298 printf("procfs: text object not found\n"); 299 return (0); 300 } 301 #endif /* probably_never */ 302