1 /* 2 * Copyright (c) 1993 The Regents of the University of California. 3 * Copyright (c) 1993 Jan-Simon Pendry 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Jan-Simon Pendry. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * From: 38 * Id: procfs_mem.c,v 4.1 1993/12/17 10:47:45 jsp Rel 39 * 40 * $Id: procfs_mem.c,v 1.3 1994/03/17 04:10:32 briggs 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 pfs_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 error = vm_map_find(kernel_map, object, off, &kva, 163 PAGE_SIZE, 1); 164 165 if (!error) { 166 /* 167 * Neither vm_map_lookup() nor vm_map_find() appear 168 * to add a reference count to the object, so we do 169 * that here and now. 170 */ 171 vm_object_reference(object); 172 173 /* 174 * Mark the page we just found as pageable. 175 */ 176 error = vm_map_pageable(kernel_map, kva, 177 kva + PAGE_SIZE, 0); 178 179 /* 180 * Now do the i/o move. 181 */ 182 if (!error) 183 error = uiomove(kva + page_offset, len, uio); 184 185 vm_map_remove(kernel_map, kva, kva + PAGE_SIZE); 186 } 187 if (fix_prot) 188 vm_map_protect(map, pageno, pageno + PAGE_SIZE, 189 VM_PROT_READ|VM_PROT_EXECUTE, 0); 190 } while (error == 0 && uio->uio_resid > 0); 191 192 return (error); 193 } 194 195 /* 196 * Copy data in and out of the target process. 197 * We do this by mapping the process's page into 198 * the kernel and then doing a uiomove direct 199 * from the kernel address space. 200 */ 201 pfs_domem(curp, p, pfs, uio) 202 struct proc *curp; 203 struct proc *p; 204 struct pfsnode *pfs; 205 struct uio *uio; 206 { 207 int error; 208 209 if (uio->uio_resid == 0) 210 return (0); 211 212 error = pfs_rwmem(p, uio); 213 214 return (error); 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 return (p->p_textvp); 233 } 234 235 236 #ifdef probably_never 237 /* 238 * Given process (p), find the vnode from which 239 * it's text segment is being mapped. 240 * 241 * (This is here, rather than in procfs_subr in order 242 * to keep all the VM related code in one place.) 243 */ 244 struct vnode * 245 procfs_findtextvp(p) 246 struct proc *p; 247 { 248 int error; 249 vm_object_t object; 250 vm_offset_t pageno; /* page number */ 251 252 /* find a vnode pager for the user address space */ 253 254 for (pageno = VM_MIN_ADDRESS; 255 pageno < VM_MAXUSER_ADDRESS; 256 pageno += PAGE_SIZE) { 257 vm_map_t map; 258 vm_map_entry_t out_entry; 259 vm_prot_t out_prot; 260 boolean_t wired, single_use; 261 vm_offset_t off; 262 263 map = &p->p_vmspace->vm_map; 264 error = vm_map_lookup(&map, pageno, 265 VM_PROT_READ, 266 &out_entry, &object, &off, &out_prot, 267 &wired, &single_use); 268 269 if (!error) { 270 vm_pager_t pager; 271 272 printf("procfs: found object\n"); 273 vm_map_lookup_done(map, out_entry); 274 printf("procfs: object = %x\n", object); 275 276 /* 277 * At this point, assuming no errors, object 278 * is the VM object mapping UVA (pageno). 279 * Ensure it has a vnode pager, then grab 280 * the vnode from that pager's handle. 281 */ 282 283 pager = object->pager; 284 printf("procfs: pager = %x\n", pager); 285 if (pager) 286 printf("procfs: found pager, type = %d\n", pager->pg_type); 287 if (pager && pager->pg_type == PG_VNODE) { 288 struct vnode *vp; 289 290 vp = (struct vnode *) pager->pg_handle; 291 printf("procfs: vp = 0x%x\n", vp); 292 return (vp); 293 } 294 } 295 } 296 297 printf("procfs: not found\n"); 298 return (0); 299 } 300 #endif /* notyet */ 301