ths | 831b782 | 2007-01-18 20:06:33 +0000 | [diff] [blame] | 1 | /* |
| 2 | * mmap support for qemu |
| 3 | * |
| 4 | * Copyright (c) 2003 Fabrice Bellard |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
Blue Swirl | 8167ee8 | 2009-07-16 20:47:01 +0000 | [diff] [blame] | 17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
ths | 831b782 | 2007-01-18 20:06:33 +0000 | [diff] [blame] | 18 | */ |
| 19 | #include <stdlib.h> |
| 20 | #include <stdio.h> |
| 21 | #include <stdarg.h> |
| 22 | #include <string.h> |
| 23 | #include <unistd.h> |
| 24 | #include <errno.h> |
| 25 | #include <sys/mman.h> |
| 26 | |
| 27 | #include "qemu.h" |
| 28 | |
| 29 | //#define DEBUG_MMAP |
| 30 | |
| 31 | /* NOTE: all the constants are the HOST ones */ |
| 32 | int target_mprotect(unsigned long start, unsigned long len, int prot) |
| 33 | { |
| 34 | unsigned long end, host_start, host_end, addr; |
| 35 | int prot1, ret; |
| 36 | |
| 37 | #ifdef DEBUG_MMAP |
| 38 | printf("mprotect: start=0x%lx len=0x%lx prot=%c%c%c\n", start, len, |
| 39 | prot & PROT_READ ? 'r' : '-', |
| 40 | prot & PROT_WRITE ? 'w' : '-', |
| 41 | prot & PROT_EXEC ? 'x' : '-'); |
| 42 | #endif |
| 43 | |
| 44 | if ((start & ~TARGET_PAGE_MASK) != 0) |
| 45 | return -EINVAL; |
| 46 | len = TARGET_PAGE_ALIGN(len); |
| 47 | end = start + len; |
| 48 | if (end < start) |
| 49 | return -EINVAL; |
| 50 | if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) |
| 51 | return -EINVAL; |
| 52 | if (len == 0) |
| 53 | return 0; |
| 54 | |
| 55 | host_start = start & qemu_host_page_mask; |
| 56 | host_end = HOST_PAGE_ALIGN(end); |
| 57 | if (start > host_start) { |
| 58 | /* handle host page containing start */ |
| 59 | prot1 = prot; |
| 60 | for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { |
| 61 | prot1 |= page_get_flags(addr); |
| 62 | } |
| 63 | if (host_end == host_start + qemu_host_page_size) { |
| 64 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| 65 | prot1 |= page_get_flags(addr); |
| 66 | } |
| 67 | end = host_end; |
| 68 | } |
| 69 | ret = mprotect((void *)host_start, qemu_host_page_size, prot1 & PAGE_BITS); |
| 70 | if (ret != 0) |
| 71 | return ret; |
| 72 | host_start += qemu_host_page_size; |
| 73 | } |
| 74 | if (end < host_end) { |
| 75 | prot1 = prot; |
| 76 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| 77 | prot1 |= page_get_flags(addr); |
| 78 | } |
| 79 | ret = mprotect((void *)(host_end - qemu_host_page_size), qemu_host_page_size, |
| 80 | prot1 & PAGE_BITS); |
| 81 | if (ret != 0) |
| 82 | return ret; |
| 83 | host_end -= qemu_host_page_size; |
| 84 | } |
| 85 | |
| 86 | /* handle the pages in the middle */ |
| 87 | if (host_start < host_end) { |
| 88 | ret = mprotect((void *)host_start, host_end - host_start, prot); |
| 89 | if (ret != 0) |
| 90 | return ret; |
| 91 | } |
| 92 | page_set_flags(start, start + len, prot | PAGE_VALID); |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | /* map an incomplete host page */ |
| 97 | int mmap_frag(unsigned long host_start, |
| 98 | unsigned long start, unsigned long end, |
| 99 | int prot, int flags, int fd, unsigned long offset) |
| 100 | { |
| 101 | unsigned long host_end, ret, addr; |
| 102 | int prot1, prot_new; |
| 103 | |
| 104 | host_end = host_start + qemu_host_page_size; |
| 105 | |
| 106 | /* get the protection of the target pages outside the mapping */ |
| 107 | prot1 = 0; |
| 108 | for(addr = host_start; addr < host_end; addr++) { |
| 109 | if (addr < start || addr >= end) |
| 110 | prot1 |= page_get_flags(addr); |
| 111 | } |
| 112 | |
| 113 | if (prot1 == 0) { |
| 114 | /* no page was there, so we allocate one */ |
| 115 | ret = (long)mmap((void *)host_start, qemu_host_page_size, prot, |
| 116 | flags | MAP_ANONYMOUS, -1, 0); |
| 117 | if (ret == -1) |
| 118 | return ret; |
| 119 | } |
| 120 | prot1 &= PAGE_BITS; |
| 121 | |
| 122 | prot_new = prot | prot1; |
| 123 | if (!(flags & MAP_ANONYMOUS)) { |
| 124 | /* msync() won't work here, so we return an error if write is |
| 125 | possible while it is a shared mapping */ |
| 126 | #ifndef __APPLE__ |
| 127 | if ((flags & MAP_TYPE) == MAP_SHARED && |
| 128 | #else |
| 129 | if ((flags & MAP_SHARED) && |
| 130 | #endif |
| 131 | (prot & PROT_WRITE)) |
| 132 | return -EINVAL; |
| 133 | |
| 134 | /* adjust protection to be able to read */ |
| 135 | if (!(prot1 & PROT_WRITE)) |
| 136 | mprotect((void *)host_start, qemu_host_page_size, prot1 | PROT_WRITE); |
| 137 | |
| 138 | /* read the corresponding file data */ |
| 139 | pread(fd, (void *)start, end - start, offset); |
| 140 | |
| 141 | /* put final protection */ |
| 142 | if (prot_new != (prot1 | PROT_WRITE)) |
| 143 | mprotect((void *)host_start, qemu_host_page_size, prot_new); |
| 144 | } else { |
| 145 | /* just update the protection */ |
| 146 | if (prot_new != prot1) { |
| 147 | mprotect((void *)host_start, qemu_host_page_size, prot_new); |
| 148 | } |
| 149 | } |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | /* NOTE: all the constants are the HOST ones */ |
| 154 | long target_mmap(unsigned long start, unsigned long len, int prot, |
| 155 | int flags, int fd, unsigned long offset) |
| 156 | { |
| 157 | unsigned long ret, end, host_start, host_end, retaddr, host_offset, host_len; |
| 158 | #if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) |
| 159 | static unsigned long last_start = 0x40000000; |
| 160 | #endif |
| 161 | |
| 162 | #ifdef DEBUG_MMAP |
| 163 | { |
| 164 | printf("mmap: start=0x%lx len=0x%lx prot=%c%c%c flags=", |
| 165 | start, len, |
| 166 | prot & PROT_READ ? 'r' : '-', |
| 167 | prot & PROT_WRITE ? 'w' : '-', |
| 168 | prot & PROT_EXEC ? 'x' : '-'); |
| 169 | if (flags & MAP_FIXED) |
| 170 | printf("MAP_FIXED "); |
| 171 | if (flags & MAP_ANONYMOUS) |
| 172 | printf("MAP_ANON "); |
| 173 | #ifndef MAP_TYPE |
| 174 | # define MAP_TYPE 0x3 |
| 175 | #endif |
| 176 | switch(flags & MAP_TYPE) { |
| 177 | case MAP_PRIVATE: |
| 178 | printf("MAP_PRIVATE "); |
| 179 | break; |
| 180 | case MAP_SHARED: |
| 181 | printf("MAP_SHARED "); |
| 182 | break; |
| 183 | default: |
| 184 | printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE); |
| 185 | break; |
| 186 | } |
| 187 | printf("fd=%d offset=%lx\n", fd, offset); |
| 188 | } |
| 189 | #endif |
| 190 | |
| 191 | if (offset & ~TARGET_PAGE_MASK) |
| 192 | return -EINVAL; |
| 193 | |
| 194 | len = TARGET_PAGE_ALIGN(len); |
| 195 | if (len == 0) |
| 196 | return start; |
| 197 | host_start = start & qemu_host_page_mask; |
| 198 | |
| 199 | if (!(flags & MAP_FIXED)) { |
| 200 | #if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) |
ths | e91c8a7 | 2007-06-03 13:35:16 +0000 | [diff] [blame] | 201 | /* tell the kernel to search at the same place as i386 */ |
ths | 831b782 | 2007-01-18 20:06:33 +0000 | [diff] [blame] | 202 | if (host_start == 0) { |
| 203 | host_start = last_start; |
| 204 | last_start += HOST_PAGE_ALIGN(len); |
| 205 | } |
| 206 | #endif |
| 207 | if (qemu_host_page_size != qemu_real_host_page_size) { |
| 208 | /* NOTE: this code is only for debugging with '-p' option */ |
| 209 | /* reserve a memory area */ |
| 210 | host_len = HOST_PAGE_ALIGN(len) + qemu_host_page_size - TARGET_PAGE_SIZE; |
| 211 | host_start = (long)mmap((void *)host_start, host_len, PROT_NONE, |
| 212 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| 213 | if (host_start == -1) |
| 214 | return host_start; |
| 215 | host_end = host_start + host_len; |
| 216 | start = HOST_PAGE_ALIGN(host_start); |
| 217 | end = start + HOST_PAGE_ALIGN(len); |
| 218 | if (start > host_start) |
| 219 | munmap((void *)host_start, start - host_start); |
| 220 | if (end < host_end) |
| 221 | munmap((void *)end, host_end - end); |
| 222 | /* use it as a fixed mapping */ |
| 223 | flags |= MAP_FIXED; |
| 224 | } else { |
| 225 | /* if not fixed, no need to do anything */ |
| 226 | host_offset = offset & qemu_host_page_mask; |
| 227 | host_len = len + offset - host_offset; |
| 228 | start = (long)mmap((void *)host_start, host_len, |
| 229 | prot, flags, fd, host_offset); |
| 230 | if (start == -1) |
| 231 | return start; |
| 232 | /* update start so that it points to the file position at 'offset' */ |
| 233 | if (!(flags & MAP_ANONYMOUS)) |
| 234 | start += offset - host_offset; |
| 235 | goto the_end1; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | if (start & ~TARGET_PAGE_MASK) |
| 240 | return -EINVAL; |
| 241 | end = start + len; |
| 242 | host_end = HOST_PAGE_ALIGN(end); |
| 243 | |
| 244 | /* worst case: we cannot map the file because the offset is not |
| 245 | aligned, so we read it */ |
| 246 | if (!(flags & MAP_ANONYMOUS) && |
| 247 | (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { |
| 248 | /* msync() won't work here, so we return an error if write is |
| 249 | possible while it is a shared mapping */ |
| 250 | #ifndef __APPLE__ |
| 251 | if ((flags & MAP_TYPE) == MAP_SHARED && |
| 252 | #else |
| 253 | if ((flags & MAP_SHARED) && |
| 254 | #endif |
| 255 | (prot & PROT_WRITE)) |
| 256 | return -EINVAL; |
| 257 | retaddr = target_mmap(start, len, prot | PROT_WRITE, |
| 258 | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, |
| 259 | -1, 0); |
| 260 | if (retaddr == -1) |
| 261 | return retaddr; |
| 262 | pread(fd, (void *)start, len, offset); |
| 263 | if (!(prot & PROT_WRITE)) { |
| 264 | ret = target_mprotect(start, len, prot); |
| 265 | if (ret != 0) |
| 266 | return ret; |
| 267 | } |
| 268 | goto the_end; |
| 269 | } |
| 270 | |
| 271 | /* handle the start of the mapping */ |
| 272 | if (start > host_start) { |
| 273 | if (host_end == host_start + qemu_host_page_size) { |
| 274 | /* one single host page */ |
| 275 | ret = mmap_frag(host_start, start, end, |
| 276 | prot, flags, fd, offset); |
| 277 | if (ret == -1) |
| 278 | return ret; |
| 279 | goto the_end1; |
| 280 | } |
| 281 | ret = mmap_frag(host_start, start, host_start + qemu_host_page_size, |
| 282 | prot, flags, fd, offset); |
| 283 | if (ret == -1) |
| 284 | return ret; |
| 285 | host_start += qemu_host_page_size; |
| 286 | } |
| 287 | /* handle the end of the mapping */ |
| 288 | if (end < host_end) { |
| 289 | ret = mmap_frag(host_end - qemu_host_page_size, |
| 290 | host_end - qemu_host_page_size, host_end, |
| 291 | prot, flags, fd, |
| 292 | offset + host_end - qemu_host_page_size - start); |
| 293 | if (ret == -1) |
| 294 | return ret; |
| 295 | host_end -= qemu_host_page_size; |
| 296 | } |
| 297 | |
| 298 | /* map the middle (easier) */ |
| 299 | if (host_start < host_end) { |
| 300 | unsigned long offset1; |
| 301 | if (flags & MAP_ANONYMOUS) |
| 302 | offset1 = 0; |
| 303 | else |
| 304 | offset1 = offset + host_start - start; |
| 305 | ret = (long)mmap((void *)host_start, host_end - host_start, |
| 306 | prot, flags, fd, offset1); |
| 307 | if (ret == -1) |
| 308 | return ret; |
| 309 | } |
| 310 | the_end1: |
| 311 | page_set_flags(start, start + len, prot | PAGE_VALID); |
| 312 | the_end: |
| 313 | #ifdef DEBUG_MMAP |
| 314 | printf("target_mmap: ret=0x%lx\n", (long)start); |
| 315 | page_dump(stdout); |
| 316 | printf("\n"); |
| 317 | #endif |
| 318 | return start; |
| 319 | } |
| 320 | |
| 321 | int target_munmap(unsigned long start, unsigned long len) |
| 322 | { |
| 323 | unsigned long end, host_start, host_end, addr; |
| 324 | int prot, ret; |
| 325 | |
| 326 | #ifdef DEBUG_MMAP |
| 327 | printf("munmap: start=0x%lx len=0x%lx\n", start, len); |
| 328 | #endif |
| 329 | if (start & ~TARGET_PAGE_MASK) |
| 330 | return -EINVAL; |
| 331 | len = TARGET_PAGE_ALIGN(len); |
| 332 | if (len == 0) |
| 333 | return -EINVAL; |
| 334 | end = start + len; |
| 335 | host_start = start & qemu_host_page_mask; |
| 336 | host_end = HOST_PAGE_ALIGN(end); |
| 337 | |
| 338 | if (start > host_start) { |
| 339 | /* handle host page containing start */ |
| 340 | prot = 0; |
| 341 | for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { |
| 342 | prot |= page_get_flags(addr); |
| 343 | } |
| 344 | if (host_end == host_start + qemu_host_page_size) { |
| 345 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| 346 | prot |= page_get_flags(addr); |
| 347 | } |
| 348 | end = host_end; |
| 349 | } |
| 350 | if (prot != 0) |
| 351 | host_start += qemu_host_page_size; |
| 352 | } |
| 353 | if (end < host_end) { |
| 354 | prot = 0; |
| 355 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
| 356 | prot |= page_get_flags(addr); |
| 357 | } |
| 358 | if (prot != 0) |
| 359 | host_end -= qemu_host_page_size; |
| 360 | } |
| 361 | |
| 362 | /* unmap what we can */ |
| 363 | if (host_start < host_end) { |
| 364 | ret = munmap((void *)host_start, host_end - host_start); |
| 365 | if (ret != 0) |
| 366 | return ret; |
| 367 | } |
| 368 | |
| 369 | page_set_flags(start, start + len, 0); |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | /* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED |
| 374 | blocks which have been allocated starting on a host page */ |
| 375 | long target_mremap(unsigned long old_addr, unsigned long old_size, |
| 376 | unsigned long new_size, unsigned long flags, |
| 377 | unsigned long new_addr) |
| 378 | { |
| 379 | #ifndef __APPLE__ |
| 380 | /* XXX: use 5 args syscall */ |
| 381 | new_addr = (long)mremap((void *)old_addr, old_size, new_size, flags); |
| 382 | if (new_addr == -1) |
| 383 | return new_addr; |
| 384 | prot = page_get_flags(old_addr); |
| 385 | page_set_flags(old_addr, old_addr + old_size, 0); |
| 386 | page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); |
| 387 | return new_addr; |
| 388 | #else |
| 389 | qerror("target_mremap: unsupported\n"); |
| 390 | #endif |
| 391 | |
| 392 | } |
| 393 | |
| 394 | int target_msync(unsigned long start, unsigned long len, int flags) |
| 395 | { |
| 396 | unsigned long end; |
| 397 | |
| 398 | if (start & ~TARGET_PAGE_MASK) |
| 399 | return -EINVAL; |
| 400 | len = TARGET_PAGE_ALIGN(len); |
| 401 | end = start + len; |
| 402 | if (end < start) |
| 403 | return -EINVAL; |
| 404 | if (end == start) |
| 405 | return 0; |
| 406 | |
| 407 | start &= qemu_host_page_mask; |
| 408 | return msync((void *)start, end - start, flags); |
| 409 | } |