sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 1 | |
| 2 | /*--------------------------------------------------------------------*/ |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 3 | /*--- Memory-related stuff: segment initialisation and tracking, ---*/ |
| 4 | /*--- stack operations ---*/ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 5 | /*--- vg_memory.c ---*/ |
| 6 | /*--------------------------------------------------------------------*/ |
| 7 | |
| 8 | /* |
njn | c953984 | 2002-10-02 13:26:35 +0000 | [diff] [blame] | 9 | This file is part of Valgrind, an extensible x86 protected-mode |
| 10 | emulator for monitoring program execution on x86-Unixes. |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 11 | |
njn | 0e1b514 | 2003-04-15 14:58:06 +0000 | [diff] [blame] | 12 | Copyright (C) 2000-2003 Julian Seward |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 13 | jseward@acm.org |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 14 | |
| 15 | This program is free software; you can redistribute it and/or |
| 16 | modify it under the terms of the GNU General Public License as |
| 17 | published by the Free Software Foundation; either version 2 of the |
| 18 | License, or (at your option) any later version. |
| 19 | |
| 20 | This program is distributed in the hope that it will be useful, but |
| 21 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 23 | General Public License for more details. |
| 24 | |
| 25 | You should have received a copy of the GNU General Public License |
| 26 | along with this program; if not, write to the Free Software |
| 27 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 28 | 02111-1307, USA. |
| 29 | |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 30 | The GNU General Public License is contained in the file COPYING. |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 31 | */ |
| 32 | |
| 33 | #include "vg_include.h" |
| 34 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 35 | #include <stddef.h> |
| 36 | |
sewardj | a449568 | 2002-10-21 07:29:59 +0000 | [diff] [blame] | 37 | /* Define to debug the memory-leak-detector. */ |
| 38 | /* #define VG_DEBUG_LEAKCHECK */ |
| 39 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 40 | static const Bool mem_debug = False; |
| 41 | |
| 42 | static Int addrcmp(const void *ap, const void *bp) |
| 43 | { |
| 44 | Addr a = *(Addr *)ap; |
| 45 | Addr b = *(Addr *)bp; |
| 46 | Int ret; |
| 47 | |
| 48 | if (a == b) |
| 49 | ret = 0; |
| 50 | else |
| 51 | ret = (a < b) ? -1 : 1; |
| 52 | |
| 53 | return ret; |
| 54 | } |
| 55 | |
| 56 | static Char *straddr(void *p) |
| 57 | { |
| 58 | static Char buf[16]; |
| 59 | |
| 60 | VG_(sprintf)(buf, "%p", *(Addr *)p); |
| 61 | |
| 62 | return buf; |
| 63 | } |
| 64 | |
| 65 | static SkipList sk_segments = SKIPLIST_INIT(Segment, addr, addrcmp, straddr, VG_AR_CORE); |
| 66 | |
| 67 | /*--------------------------------------------------------------*/ |
| 68 | /*--- Maintain an ordered list of all the client's mappings ---*/ |
| 69 | /*--------------------------------------------------------------*/ |
| 70 | |
| 71 | Bool VG_(seg_contains)(const Segment *s, Addr p, UInt len) |
| 72 | { |
| 73 | Addr se = s->addr+s->len; |
| 74 | Addr pe = p+len; |
| 75 | |
| 76 | vg_assert(pe >= p); |
| 77 | |
| 78 | return (p >= s->addr && pe <= se); |
| 79 | } |
| 80 | |
| 81 | Bool VG_(seg_overlaps)(const Segment *s, Addr p, UInt len) |
| 82 | { |
| 83 | Addr se = s->addr+s->len; |
| 84 | Addr pe = p+len; |
| 85 | |
| 86 | vg_assert(pe >= p); |
| 87 | |
| 88 | return (p < se && pe > s->addr); |
| 89 | } |
| 90 | |
| 91 | /* Prepare a Segment structure for recycling by freeing everything |
| 92 | hanging off it. */ |
| 93 | static void recycleseg(Segment *s) |
| 94 | { |
| 95 | if (s->flags & SF_CODE) |
| 96 | VG_(invalidate_translations)(s->addr, s->len, False); |
| 97 | |
| 98 | if (s->filename != NULL) |
| 99 | VG_(arena_free)(VG_AR_CORE, (Char *)s->filename); |
| 100 | |
| 101 | /* keep the SegInfo, if any - it probably still applies */ |
| 102 | } |
| 103 | |
| 104 | /* When freeing a Segment, also clean up every one else's ideas of |
| 105 | what was going on in that range of memory */ |
| 106 | static void freeseg(Segment *s) |
| 107 | { |
| 108 | recycleseg(s); |
| 109 | if (s->symtab != NULL) { |
| 110 | VG_(symtab_decref)(s->symtab, s->addr, s->len); |
| 111 | s->symtab = NULL; |
| 112 | } |
| 113 | |
| 114 | VG_(SkipNode_Free)(&sk_segments, s); |
| 115 | } |
| 116 | |
| 117 | /* Split a segment at address a */ |
| 118 | static Segment *split_segment(Addr a) |
| 119 | { |
| 120 | Segment *s = VG_(SkipList_Find)(&sk_segments, &a); |
| 121 | Segment *ns; |
| 122 | Int delta; |
| 123 | |
| 124 | vg_assert((a & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 125 | |
| 126 | /* missed */ |
| 127 | if (s == NULL) |
| 128 | return NULL; |
| 129 | |
| 130 | /* a at or beyond endpoint */ |
| 131 | if (s->addr == a || a >= (s->addr+s->len)) |
| 132 | return NULL; |
| 133 | |
| 134 | vg_assert(a > s->addr && a < (s->addr+s->len)); |
| 135 | |
| 136 | ns = VG_(SkipNode_Alloc)(&sk_segments); |
| 137 | |
| 138 | *ns = *s; |
| 139 | |
| 140 | delta = a - s->addr; |
| 141 | ns->addr += delta; |
| 142 | ns->offset += delta; |
| 143 | ns->len -= delta; |
| 144 | |
| 145 | if (ns->symtab != NULL) |
| 146 | VG_(symtab_incref)(ns->symtab); |
| 147 | |
| 148 | VG_(SkipList_Insert)(&sk_segments, ns); |
| 149 | |
| 150 | return ns; |
| 151 | } |
| 152 | |
| 153 | /* This unmaps all the segments in the range [addr, addr+len); any |
| 154 | partial mappings at the ends are truncated. */ |
| 155 | void VG_(unmap_range)(Addr addr, UInt len) |
| 156 | { |
| 157 | Segment *s; |
| 158 | Segment *next; |
| 159 | static const Bool debug = False || mem_debug; |
| 160 | |
| 161 | if (len == 0) |
| 162 | return; |
| 163 | |
| 164 | if (debug) |
| 165 | VG_(printf)("unmap_range(%p, %d)\n", addr, len); |
| 166 | |
| 167 | len = PGROUNDUP(addr+len)-PGROUNDDN(addr); |
| 168 | addr = PGROUNDDN(addr); |
| 169 | |
| 170 | /* Everything must be page-aligned */ |
| 171 | vg_assert((addr & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 172 | vg_assert((len & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 173 | |
| 174 | for(s = VG_(SkipList_Find)(&sk_segments, &addr); |
| 175 | s != NULL && s->addr < (addr+len); |
| 176 | s = next) { |
| 177 | |
| 178 | /* fetch next now in case we end up deleting this segment */ |
| 179 | next = VG_(SkipNode_Next)(&sk_segments, s); |
| 180 | |
| 181 | if (debug) |
| 182 | VG_(printf)("unmap: addr=%p s=%p ->addr=%p len=%d end=%p\n", |
| 183 | addr, s, s->addr, s->len, s->addr+s->len); |
| 184 | |
| 185 | if (!VG_(seg_overlaps)(s, addr, len)) |
| 186 | continue; |
| 187 | |
| 188 | /* 4 cases: */ |
| 189 | if (addr > s->addr && addr < (s->addr + s->len)) { |
| 190 | /* this segment's tail is truncated by [addr, addr+len) |
| 191 | -> truncate tail |
| 192 | */ |
| 193 | s->len = addr - s->addr; |
| 194 | |
| 195 | if (debug) |
| 196 | VG_(printf)(" case 1: s->len=%d\n", s->len); |
| 197 | } else if (addr <= s->addr && (addr+len) >= (s->addr + s->len)) { |
| 198 | /* this segment is completely contained within [addr, addr+len) |
| 199 | -> delete segment |
| 200 | */ |
| 201 | Segment *rs = VG_(SkipList_Remove)(&sk_segments, &s->addr); |
| 202 | vg_assert(rs == s); |
| 203 | freeseg(s); |
| 204 | |
| 205 | if (debug) |
| 206 | VG_(printf)(" case 2: s==%p deleted\n", s); |
| 207 | } else if ((addr+len) > s->addr && (addr+len) < (s->addr+s->len)) { |
| 208 | /* this segment's head is truncated by [addr, addr+len) |
| 209 | -> truncate head |
| 210 | */ |
| 211 | Int delta = (addr+len) - s->addr; |
| 212 | |
| 213 | s->addr += delta; |
| 214 | s->offset += delta; |
| 215 | s->len -= delta; |
| 216 | |
| 217 | if (debug) |
| 218 | VG_(printf)(" case 3: s->addr=%p s->len=%d delta=%d\n", s->addr, s->len, delta); |
| 219 | } else if (addr > s->addr && (addr+len) < (s->addr + s->len)) { |
| 220 | /* [addr, addr+len) is contained within a single segment |
| 221 | -> split segment into 3, delete middle portion |
| 222 | */ |
| 223 | Segment *middle, *rs; |
| 224 | |
| 225 | middle = split_segment(addr); |
| 226 | split_segment(addr+len); |
| 227 | |
| 228 | vg_assert(middle->addr == addr); |
| 229 | rs = VG_(SkipList_Remove)(&sk_segments, &addr); |
| 230 | vg_assert(rs == middle); |
| 231 | |
| 232 | freeseg(rs); |
| 233 | |
| 234 | if (debug) |
| 235 | VG_(printf)(" case 4: subrange %p-%p deleted\n", |
| 236 | addr, addr+len); |
| 237 | } |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | /* If possible, merge segment with its neighbours - some segments, |
| 242 | including s, may be destroyed in the process */ |
| 243 | static inline Bool neighbours(Segment *s1, Segment *s2) |
| 244 | { |
| 245 | if (s1->addr+s1->len != s2->addr) |
| 246 | return False; |
| 247 | |
| 248 | if (s1->flags != s2->flags) |
| 249 | return False; |
| 250 | |
| 251 | if (s1->prot != s2->prot) |
| 252 | return False; |
| 253 | |
| 254 | if (s1->symtab != s2->symtab) |
| 255 | return False; |
| 256 | |
| 257 | if (s1->flags & SF_FILE){ |
| 258 | if ((s1->offset + s1->len) != s2->offset) |
| 259 | return False; |
| 260 | if (s1->dev != s2->dev) |
| 261 | return False; |
| 262 | if (s1->ino != s2->ino) |
| 263 | return False; |
| 264 | } |
| 265 | |
| 266 | return True; |
| 267 | } |
| 268 | |
| 269 | /* Merge segments in the address range if they're adjacent and |
| 270 | compatible */ |
| 271 | static void merge_segments(Addr a, UInt len) |
| 272 | { |
| 273 | Segment *s; |
| 274 | Segment *next; |
| 275 | |
| 276 | vg_assert((a & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 277 | vg_assert((len & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 278 | |
| 279 | a -= VKI_BYTES_PER_PAGE; |
| 280 | len += VKI_BYTES_PER_PAGE; |
| 281 | |
| 282 | for(s = VG_(SkipList_Find)(&sk_segments, &a); |
| 283 | s != NULL && s->addr < (a+len);) { |
| 284 | next = VG_(SkipNode_Next)(&sk_segments, s); |
| 285 | |
| 286 | if (next && neighbours(s, next)) { |
| 287 | Segment *rs; |
| 288 | |
| 289 | if (0) |
| 290 | VG_(printf)("merge %p-%p with %p-%p\n", |
| 291 | s->addr, s->addr+s->len, |
| 292 | next->addr, next->addr+next->len); |
| 293 | s->len += next->len; |
| 294 | s = VG_(SkipNode_Next)(&sk_segments, next); |
| 295 | |
| 296 | rs = VG_(SkipList_Remove)(&sk_segments, &next->addr); |
| 297 | vg_assert(next == rs); |
| 298 | freeseg(next); |
| 299 | } else |
| 300 | s = next; |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | void VG_(map_file_segment)(Addr addr, UInt len, UInt prot, UInt flags, |
| 305 | UInt dev, UInt ino, ULong off, const Char *filename) |
| 306 | { |
| 307 | Segment *s; |
| 308 | static const Bool debug = False || mem_debug; |
| 309 | Bool recycled; |
| 310 | |
| 311 | if (debug) |
| 312 | VG_(printf)("map_file_segment(%p, %d, %x, %x, %4x, %d, %ld, %s)\n", |
| 313 | addr, len, prot, flags, dev, ino, off, filename); |
| 314 | |
| 315 | /* Everything must be page-aligned */ |
| 316 | vg_assert((addr & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 317 | len = PGROUNDUP(len); |
| 318 | |
| 319 | /* First look to see what already exists around here */ |
| 320 | s = VG_(SkipList_Find)(&sk_segments, &addr); |
| 321 | |
| 322 | if (s != NULL && s->addr == addr && s->len == len) { |
| 323 | /* This probably means we're just updating the flags */ |
| 324 | recycled = True; |
| 325 | recycleseg(s); |
| 326 | |
| 327 | /* If we had a symtab, but the new mapping is incompatible, then |
| 328 | free up the old symtab in preparation for a new one. */ |
| 329 | if (s->symtab != NULL && |
| 330 | (!(s->flags & SF_FILE) || |
| 331 | !(flags & SF_FILE) || |
| 332 | s->dev != dev || |
| 333 | s->ino != ino || |
| 334 | s->offset != off)) { |
| 335 | VG_(symtab_decref)(s->symtab, s->addr, s->len); |
| 336 | s->symtab = NULL; |
| 337 | } |
| 338 | } else { |
| 339 | recycled = False; |
| 340 | VG_(unmap_range)(addr, len); |
| 341 | |
| 342 | s = VG_(SkipNode_Alloc)(&sk_segments); |
| 343 | |
| 344 | s->addr = addr; |
| 345 | s->len = len; |
| 346 | s->symtab = NULL; |
| 347 | } |
| 348 | |
| 349 | s->flags = flags; |
| 350 | s->prot = prot; |
| 351 | s->dev = dev; |
| 352 | s->ino = ino; |
| 353 | s->offset = off; |
| 354 | |
| 355 | if (filename != NULL) |
| 356 | s->filename = VG_(arena_strdup)(VG_AR_CORE, filename); |
| 357 | else |
| 358 | s->filename = NULL; |
| 359 | |
| 360 | if (debug) { |
| 361 | Segment *ts; |
| 362 | for(ts = VG_(SkipNode_First)(&sk_segments); |
| 363 | ts != NULL; |
| 364 | ts = VG_(SkipNode_Next)(&sk_segments, ts)) |
| 365 | VG_(printf)("list: %8p->%8p ->%d (0x%x) prot=%x flags=%x\n", |
| 366 | ts, ts->addr, ts->len, ts->len, ts->prot, ts->flags); |
| 367 | |
| 368 | VG_(printf)("inserting s=%p addr=%p len=%d\n", |
| 369 | s, s->addr, s->len); |
| 370 | } |
| 371 | |
| 372 | if (!recycled) |
| 373 | VG_(SkipList_Insert)(&sk_segments, s); |
| 374 | |
| 375 | /* If this mapping is of the beginning of a file, isn't part of |
| 376 | Valgrind, is at least readable and seems to contain an object |
| 377 | file, then try reading symbols from it. */ |
| 378 | if ((flags & (SF_MMAP|SF_NOSYMS)) == SF_MMAP && |
| 379 | s->symtab == NULL) { |
| 380 | if (off == 0 && |
| 381 | filename != NULL && |
| 382 | (prot & (VKI_PROT_READ|VKI_PROT_EXEC)) == (VKI_PROT_READ|VKI_PROT_EXEC) && |
| 383 | len >= VKI_BYTES_PER_PAGE && |
| 384 | s->symtab == NULL && |
| 385 | VG_(is_object_file)((void *)addr)) { |
| 386 | |
| 387 | s->symtab = VG_(read_seg_symbols)(s); |
| 388 | |
| 389 | if (s->symtab != NULL) |
| 390 | s->flags |= SF_DYNLIB; |
| 391 | } else if (flags & SF_MMAP) { |
| 392 | const SegInfo *info; |
| 393 | |
| 394 | /* Otherwise see if an existing symtab applies to this Segment */ |
| 395 | for(info = VG_(next_seginfo)(NULL); |
| 396 | info != NULL; |
| 397 | info = VG_(next_seginfo)(info)) { |
| 398 | if (VG_(seg_overlaps)(s, VG_(seg_start)(info), VG_(seg_size)(info))) { |
| 399 | s->symtab = (SegInfo *)info; |
| 400 | VG_(symtab_incref)((SegInfo *)info); |
| 401 | } |
| 402 | } |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | /* clean up */ |
| 407 | merge_segments(addr, len); |
| 408 | } |
| 409 | |
| 410 | void VG_(map_fd_segment)(Addr addr, UInt len, UInt prot, UInt flags, |
| 411 | Int fd, ULong off, const Char *filename) |
| 412 | { |
| 413 | struct vki_stat st; |
| 414 | Char *name = NULL; |
| 415 | |
| 416 | st.st_dev = 0; |
| 417 | st.st_ino = 0; |
| 418 | |
| 419 | if (fd != -1 && (flags & SF_FILE)) { |
| 420 | vg_assert((off & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 421 | |
| 422 | if (VG_(fstat)(fd, &st) < 0) |
| 423 | flags &= ~SF_FILE; |
| 424 | } |
| 425 | |
| 426 | if ((flags & SF_FILE) && filename == NULL && fd != -1) |
| 427 | name = VG_(resolve_filename)(fd); |
| 428 | |
| 429 | if (filename == NULL) |
| 430 | filename = name; |
| 431 | |
| 432 | VG_(map_file_segment)(addr, len, prot, flags, st.st_dev, st.st_ino, off, filename); |
| 433 | |
| 434 | if (name) |
| 435 | VG_(arena_free)(VG_AR_CORE, name); |
| 436 | } |
| 437 | |
| 438 | void VG_(map_segment)(Addr addr, UInt len, UInt prot, UInt flags) |
| 439 | { |
| 440 | flags &= ~SF_FILE; |
| 441 | |
| 442 | VG_(map_file_segment)(addr, len, prot, flags, 0, 0, 0, 0); |
| 443 | } |
| 444 | |
| 445 | /* set new protection flags on an address range */ |
| 446 | void VG_(mprotect_range)(Addr a, UInt len, UInt prot) |
| 447 | { |
| 448 | Segment *s, *next; |
| 449 | static const Bool debug = False || mem_debug; |
| 450 | |
| 451 | if (debug) |
| 452 | VG_(printf)("mprotect_range(%p, %d, %x)\n", a, len, prot); |
| 453 | |
| 454 | /* Everything must be page-aligned */ |
| 455 | vg_assert((a & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 456 | vg_assert((len & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 457 | |
| 458 | split_segment(a); |
| 459 | split_segment(a+len); |
| 460 | |
| 461 | for(s = VG_(SkipList_Find)(&sk_segments, &a); |
| 462 | s != NULL && s->addr < a+len; |
| 463 | s = next) |
| 464 | { |
| 465 | next = VG_(SkipNode_Next)(&sk_segments, s); |
| 466 | if (s->addr < a) |
| 467 | continue; |
| 468 | |
| 469 | s->prot = prot; |
| 470 | } |
| 471 | |
| 472 | merge_segments(a, len); |
| 473 | } |
| 474 | |
| 475 | Addr VG_(find_map_space)(Addr addr, UInt len, Bool for_client) |
| 476 | { |
| 477 | Segment *s; |
| 478 | Addr ret; |
| 479 | static const Bool debug = False || mem_debug; |
| 480 | Addr limit = (for_client ? VG_(client_end) : VG_(valgrind_mmap_end)); |
| 481 | |
| 482 | if (addr == 0) |
| 483 | addr = for_client ? VG_(client_mapbase) : VG_(valgrind_base); |
| 484 | else { |
| 485 | /* leave space for redzone and still try to get the exact |
| 486 | address asked for */ |
| 487 | addr -= VKI_BYTES_PER_PAGE; |
| 488 | } |
| 489 | ret = addr; |
| 490 | |
| 491 | /* Everything must be page-aligned */ |
| 492 | vg_assert((addr & (VKI_BYTES_PER_PAGE-1)) == 0); |
| 493 | len = PGROUNDUP(len); |
| 494 | |
| 495 | len += VKI_BYTES_PER_PAGE * 2; /* leave redzone gaps before and after mapping */ |
| 496 | |
| 497 | if (debug) |
| 498 | VG_(printf)("find_map_space: ret starts as %p-%p client=%d\n", |
| 499 | ret, ret+len, for_client); |
| 500 | |
| 501 | for(s = VG_(SkipList_Find)(&sk_segments, &ret); |
| 502 | s != NULL && s->addr < (ret+len); |
| 503 | s = VG_(SkipNode_Next)(&sk_segments, s)) |
| 504 | { |
| 505 | if (debug) |
| 506 | VG_(printf)("s->addr=%p len=%d (%p) ret=%p\n", |
| 507 | s->addr, s->len, s->addr+s->len, ret); |
| 508 | |
| 509 | if (s->addr < (ret + len) && (s->addr + s->len) > ret) |
| 510 | ret = s->addr+s->len; |
| 511 | } |
| 512 | |
| 513 | if (debug) { |
| 514 | if (s) |
| 515 | VG_(printf)(" s->addr=%p ->len=%d\n", s->addr, s->len); |
| 516 | else |
| 517 | VG_(printf)(" s == NULL\n"); |
| 518 | } |
| 519 | |
| 520 | if ((limit - len) < ret) |
| 521 | ret = 0; /* no space */ |
| 522 | else |
| 523 | ret += VKI_BYTES_PER_PAGE; /* skip leading redzone */ |
| 524 | |
| 525 | if (debug) |
| 526 | VG_(printf)("find_map_space(%p, %d, %d) -> %p\n", |
| 527 | addr, len, for_client, ret); |
| 528 | |
| 529 | return ret; |
| 530 | } |
| 531 | |
| 532 | Segment *VG_(find_segment)(Addr a) |
| 533 | { |
| 534 | return VG_(SkipList_Find)(&sk_segments, &a); |
| 535 | } |
| 536 | |
| 537 | Segment *VG_(next_segment)(Segment *s) |
| 538 | { |
| 539 | return VG_(SkipNode_Next)(&sk_segments, s); |
| 540 | } |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 541 | |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 542 | /*--------------------------------------------------------------*/ |
| 543 | /*--- Initialise program data/text etc on program startup. ---*/ |
| 544 | /*--------------------------------------------------------------*/ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 545 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 546 | static |
| 547 | void build_valgrind_map_callback ( Addr start, UInt size, |
| 548 | Char rr, Char ww, Char xx, UInt dev, UInt ino, |
| 549 | ULong foffset, const UChar* filename ) |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 550 | { |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 551 | UInt prot = 0; |
| 552 | UInt flags; |
| 553 | Bool is_stack_segment; |
| 554 | Bool verbose = False || mem_debug; /* set to True for debugging */ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 555 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 556 | is_stack_segment = (start == VG_(clstk_base) && (start+size) == VG_(clstk_end)); |
| 557 | |
| 558 | prot = 0; |
| 559 | flags = SF_MMAP|SF_NOSYMS; |
| 560 | |
| 561 | if (start >= VG_(valgrind_base) && (start+size) <= VG_(valgrind_end)) |
| 562 | flags |= SF_VALGRIND; |
| 563 | |
| 564 | /* Only record valgrind mappings for now, without loading any |
| 565 | symbols. This is so we know where the free space is before we |
| 566 | start allocating more memory (note: heap is OK, it's just mmap |
| 567 | which is the problem here). */ |
| 568 | if (flags & SF_VALGRIND) { |
| 569 | if (verbose) |
| 570 | VG_(printf)("adding segment %08p-%08p prot=%x flags=%4x filename=%s\n", |
| 571 | start, start+size, prot, flags, filename); |
| 572 | |
| 573 | VG_(map_file_segment)(start, size, prot, flags, dev, ino, foffset, filename); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 574 | } |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 575 | } |
| 576 | |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 577 | static |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 578 | void build_segment_map_callback ( Addr start, UInt size, |
| 579 | Char rr, Char ww, Char xx, UInt dev, UInt ino, |
| 580 | ULong foffset, const UChar* filename ) |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 581 | { |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 582 | UInt prot = 0; |
| 583 | UInt flags; |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 584 | Bool is_stack_segment; |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 585 | Bool verbose = False || mem_debug; /* set to True for debugging */ |
| 586 | Addr r_esp; |
| 587 | |
| 588 | is_stack_segment = (start == VG_(clstk_base) && (start+size) == VG_(clstk_end)); |
| 589 | |
| 590 | if (rr == 'r') |
| 591 | prot |= VKI_PROT_READ; |
| 592 | if (ww == 'w') |
| 593 | prot |= VKI_PROT_WRITE; |
| 594 | if (xx == 'x') |
| 595 | prot |= VKI_PROT_EXEC; |
| 596 | |
| 597 | |
| 598 | if (is_stack_segment) |
| 599 | flags = SF_STACK | SF_GROWDOWN; |
| 600 | else |
| 601 | flags = SF_EXEC|SF_MMAP; |
| 602 | |
| 603 | if (filename != NULL) |
| 604 | flags |= SF_FILE; |
| 605 | |
| 606 | if (start >= VG_(valgrind_base) && (start+size) <= VG_(valgrind_end)) |
| 607 | flags |= SF_VALGRIND; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 608 | |
sewardj | ecf8e10 | 2003-07-12 12:11:39 +0000 | [diff] [blame] | 609 | if (verbose) |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 610 | VG_(printf)("adding segment %08p-%08p prot=%x flags=%4x filename=%s\n", |
| 611 | start, start+size, prot, flags, filename); |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 612 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 613 | VG_(map_file_segment)(start, size, prot, flags, dev, ino, foffset, filename); |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 614 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 615 | if (VG_(is_client_addr)(start) && VG_(is_client_addr)(start+size-1)) |
| 616 | VG_TRACK( new_mem_startup, start, size, rr=='r', ww=='w', xx=='x' ); |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 617 | |
| 618 | /* If this is the stack segment mark all below %esp as noaccess. */ |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 619 | r_esp = VG_(m_state_static)[40/4]; |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 620 | if (is_stack_segment) { |
| 621 | if (0) |
| 622 | VG_(message)(Vg_DebugMsg, "invalidating stack area: %x .. %x", |
| 623 | start,r_esp); |
| 624 | VG_TRACK( die_mem_stack, start, r_esp-start ); |
| 625 | } |
| 626 | } |
| 627 | |
| 628 | |
njn | 3e88418 | 2003-04-15 13:03:23 +0000 | [diff] [blame] | 629 | /* 1. Records startup segments from /proc/pid/maps. Takes special note |
| 630 | of the executable ones, because if they're munmap()ed we need to |
| 631 | discard translations. Also checks there's no exe segment overlaps. |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 632 | |
njn | 3e88418 | 2003-04-15 13:03:23 +0000 | [diff] [blame] | 633 | Note that `read_from_file' is false; we read /proc/self/maps into a |
| 634 | buffer at the start of VG_(main) so that any superblocks mmap'd by |
| 635 | calls to VG_(malloc)() by SK_({pre,post}_clo_init) aren't erroneously |
| 636 | thought of as being owned by the client. |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 637 | */ |
| 638 | void VG_(init_memory) ( void ) |
| 639 | { |
njn | 3e88418 | 2003-04-15 13:03:23 +0000 | [diff] [blame] | 640 | /* 1 */ |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 641 | /* reserve Valgrind's kickstart, heap and stack */ |
| 642 | VG_(map_segment)(VG_(valgrind_mmap_end), VG_(valgrind_end)-VG_(valgrind_mmap_end), |
| 643 | VKI_PROT_NONE, SF_VALGRIND|SF_FIXED); |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 644 | |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 645 | /* work out what's mapped where, and read interesting symtabs */ |
| 646 | VG_(parse_procselfmaps) ( build_valgrind_map_callback ); /* just Valgrind mappings */ |
| 647 | VG_(parse_procselfmaps) ( build_segment_map_callback ); /* everything */ |
sewardj | d5815ec | 2003-04-06 12:23:27 +0000 | [diff] [blame] | 648 | |
| 649 | /* kludge: some newer kernels place a "sysinfo" page up high, with |
| 650 | vsyscalls in it, and possibly some other stuff in the future. */ |
| 651 | if (VG_(sysinfo_page_exists)) { |
njn | fa1016e | 2003-09-25 17:54:11 +0000 | [diff] [blame] | 652 | // 2003-Sep-25, njn: Jeremy thinks the sysinfo page probably doesn't |
| 653 | // have any symbols that need to be loaded. So just treat it like |
| 654 | // a non-executable page. |
| 655 | //VG_(new_exeseg_mmap)( VG_(sysinfo_page_addr), 4096 ); |
sewardj | d5815ec | 2003-04-06 12:23:27 +0000 | [diff] [blame] | 656 | VG_TRACK( new_mem_startup, VG_(sysinfo_page_addr), 4096, |
| 657 | True, True, True ); |
| 658 | } |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 659 | } |
| 660 | |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 661 | /*------------------------------------------------------------*/ |
| 662 | /*--- Tracking permissions around %esp changes. ---*/ |
| 663 | /*------------------------------------------------------------*/ |
| 664 | |
| 665 | /* |
| 666 | The stack |
| 667 | ~~~~~~~~~ |
| 668 | The stack's segment seems to be dynamically extended downwards |
| 669 | by the kernel as the stack pointer moves down. Initially, a |
| 670 | 1-page (4k) stack is allocated. When %esp moves below that for |
| 671 | the first time, presumably a page fault occurs. The kernel |
| 672 | detects that the faulting address is in the range from %esp upwards |
| 673 | to the current valid stack. It then extends the stack segment |
| 674 | downwards for enough to cover the faulting address, and resumes |
| 675 | the process (invisibly). The process is unaware of any of this. |
| 676 | |
| 677 | That means that Valgrind can't spot when the stack segment is |
| 678 | being extended. Fortunately, we want to precisely and continuously |
| 679 | update stack permissions around %esp, so we need to spot all |
| 680 | writes to %esp anyway. |
| 681 | |
| 682 | The deal is: when %esp is assigned a lower value, the stack is |
| 683 | being extended. Create a secondary maps to fill in any holes |
| 684 | between the old stack ptr and this one, if necessary. Then |
| 685 | mark all bytes in the area just "uncovered" by this %esp change |
| 686 | as write-only. |
| 687 | |
| 688 | When %esp goes back up, mark the area receded over as unreadable |
| 689 | and unwritable. |
| 690 | |
| 691 | Just to record the %esp boundary conditions somewhere convenient: |
| 692 | %esp always points to the lowest live byte in the stack. All |
| 693 | addresses below %esp are not live; those at and above it are. |
| 694 | */ |
| 695 | |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 696 | /* Kludgey ... how much does %esp have to change before we reckon that |
| 697 | the application is switching stacks ? */ |
njn | 9b007f6 | 2003-04-07 14:40:25 +0000 | [diff] [blame] | 698 | #define VG_PLAUSIBLE_STACK_SIZE 8000000 |
| 699 | #define VG_HUGE_DELTA (VG_PLAUSIBLE_STACK_SIZE / 4) |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 700 | |
njn | 9b007f6 | 2003-04-07 14:40:25 +0000 | [diff] [blame] | 701 | /* This function gets called if new_mem_stack and/or die_mem_stack are |
| 702 | tracked by the skin, and one of the specialised cases (eg. new_mem_stack_4) |
| 703 | isn't used in preference */ |
| 704 | __attribute__((regparm(1))) |
| 705 | void VG_(unknown_esp_update)(Addr new_ESP) |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 706 | { |
njn | 9b007f6 | 2003-04-07 14:40:25 +0000 | [diff] [blame] | 707 | Addr old_ESP = VG_(get_archreg)(R_ESP); |
| 708 | Int delta = (Int)new_ESP - (Int)old_ESP; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 709 | |
njn | 9b007f6 | 2003-04-07 14:40:25 +0000 | [diff] [blame] | 710 | if (delta < -(VG_HUGE_DELTA) || VG_HUGE_DELTA < delta) { |
| 711 | /* %esp has changed by more than HUGE_DELTA. We take this to mean |
| 712 | that the application is switching to a new stack, for whatever |
| 713 | reason. |
| 714 | |
| 715 | JRS 20021001: following discussions with John Regehr, if a stack |
| 716 | switch happens, it seems best not to mess at all with memory |
| 717 | permissions. Seems to work well with Netscape 4.X. Really the |
| 718 | only remaining difficulty is knowing exactly when a stack switch is |
| 719 | happening. */ |
| 720 | if (VG_(clo_verbosity) > 1) |
| 721 | VG_(message)(Vg_UserMsg, "Warning: client switching stacks? " |
| 722 | "%%esp: %p --> %p", old_ESP, new_ESP); |
| 723 | } else if (delta < 0) { |
| 724 | VG_TRACK( new_mem_stack, new_ESP, -delta ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 725 | |
njn | 9b007f6 | 2003-04-07 14:40:25 +0000 | [diff] [blame] | 726 | } else if (delta > 0) { |
| 727 | VG_TRACK( die_mem_stack, old_ESP, delta ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 728 | } |
| 729 | } |
| 730 | |
jsgf | 855d93d | 2003-10-13 22:26:55 +0000 | [diff] [blame] | 731 | static jmp_buf segv_jmpbuf; |
| 732 | |
| 733 | static void segv_handler(Int seg) |
| 734 | { |
| 735 | __builtin_longjmp(segv_jmpbuf, 1); |
| 736 | VG_(core_panic)("longjmp failed"); |
| 737 | } |
| 738 | |
| 739 | /* |
| 740 | Test if a piece of memory is addressable by setting up a temporary |
| 741 | SIGSEGV handler, then try to touch the memory. No signal = good, |
| 742 | signal = bad. |
| 743 | */ |
| 744 | Bool VG_(is_addressable)(Addr p, Int size) |
| 745 | { |
| 746 | volatile Char * volatile cp = (volatile Char *)p; |
| 747 | volatile Bool ret; |
| 748 | vki_ksigaction sa, origsa; |
| 749 | vki_ksigset_t mask; |
| 750 | |
| 751 | vg_assert(size > 0); |
| 752 | |
| 753 | sa.ksa_handler = segv_handler; |
| 754 | sa.ksa_flags = 0; |
| 755 | VG_(ksigfillset)(&sa.ksa_mask); |
| 756 | VG_(ksigaction)(VKI_SIGSEGV, &sa, &origsa); |
| 757 | VG_(ksigprocmask)(VKI_SIG_SETMASK, NULL, &mask); |
| 758 | |
| 759 | if (__builtin_setjmp(&segv_jmpbuf) == 0) { |
| 760 | while(size--) |
| 761 | *cp++; |
| 762 | ret = True; |
| 763 | } else |
| 764 | ret = False; |
| 765 | |
| 766 | VG_(ksigaction)(VKI_SIGSEGV, &origsa, NULL); |
| 767 | VG_(ksigprocmask)(VKI_SIG_SETMASK, &mask, NULL); |
| 768 | |
| 769 | return ret; |
| 770 | } |
| 771 | |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 772 | /*--------------------------------------------------------------------*/ |
fitzhardinge | 98abfc7 | 2003-12-16 02:05:15 +0000 | [diff] [blame^] | 773 | /*--- manage allocation of memory on behalf of the client ---*/ |
| 774 | /*--------------------------------------------------------------------*/ |
| 775 | |
| 776 | Addr VG_(client_alloc)(Addr addr, UInt len, UInt prot, UInt flags) |
| 777 | { |
| 778 | len = PGROUNDUP(len); |
| 779 | |
| 780 | if (!(flags & SF_FIXED)) |
| 781 | addr = VG_(find_map_space)(addr, len, True); |
| 782 | |
| 783 | flags |= SF_CORE; |
| 784 | |
| 785 | if (VG_(mmap)((void *)addr, len, prot, |
| 786 | VKI_MAP_FIXED | VKI_MAP_PRIVATE | VKI_MAP_ANONYMOUS | VKI_MAP_CLIENT, |
| 787 | -1, 0) == (void *)addr) { |
| 788 | VG_(map_segment)(addr, len, prot, flags); |
| 789 | return addr; |
| 790 | } |
| 791 | |
| 792 | return 0; |
| 793 | } |
| 794 | |
| 795 | void VG_(client_free)(Addr addr) |
| 796 | { |
| 797 | Segment *s = VG_(find_segment)(addr); |
| 798 | |
| 799 | if (s == NULL || s->addr != addr || !(s->flags & SF_CORE)) { |
| 800 | VG_(message)(Vg_DebugMsg, "VG_(client_free)(%p) - no CORE memory found there", addr); |
| 801 | return; |
| 802 | } |
| 803 | |
| 804 | VG_(munmap)((void *)s->addr, s->len); |
| 805 | } |
| 806 | |
| 807 | Bool VG_(is_client_addr)(Addr a) |
| 808 | { |
| 809 | return a >= VG_(client_base) && a < VG_(client_end); |
| 810 | } |
| 811 | |
| 812 | Bool VG_(is_shadow_addr)(Addr a) |
| 813 | { |
| 814 | return a >= VG_(shadow_base) && a < VG_(shadow_end); |
| 815 | } |
| 816 | |
| 817 | Bool VG_(is_valgrind_addr)(Addr a) |
| 818 | { |
| 819 | return a >= VG_(valgrind_base) && a < VG_(valgrind_end); |
| 820 | } |
| 821 | |
| 822 | Addr VG_(get_client_base)(void) |
| 823 | { |
| 824 | return VG_(client_base); |
| 825 | } |
| 826 | |
| 827 | Addr VG_(get_client_end)(void) |
| 828 | { |
| 829 | return VG_(client_end); |
| 830 | } |
| 831 | |
| 832 | Addr VG_(get_client_size)(void) |
| 833 | { |
| 834 | return VG_(client_end)-VG_(client_base); |
| 835 | } |
| 836 | |
| 837 | Addr VG_(get_shadow_base)(void) |
| 838 | { |
| 839 | return VG_(shadow_base); |
| 840 | } |
| 841 | |
| 842 | Addr VG_(get_shadow_end)(void) |
| 843 | { |
| 844 | return VG_(shadow_end); |
| 845 | } |
| 846 | |
| 847 | Addr VG_(get_shadow_size)(void) |
| 848 | { |
| 849 | return VG_(shadow_end)-VG_(shadow_base); |
| 850 | } |
| 851 | |
| 852 | |
| 853 | void VG_(init_shadow_range)(Addr p, UInt sz, Bool call_init) |
| 854 | { |
| 855 | if (0) |
| 856 | VG_(printf)("init_shadow_range(%p, %d)\n", p, sz); |
| 857 | |
| 858 | vg_assert(VG_(needs).shadow_memory); |
| 859 | vg_assert(VG_(defined_init_shadow_page)()); |
| 860 | |
| 861 | sz = PGROUNDUP(p+sz) - PGROUNDDN(p); |
| 862 | p = PGROUNDDN(p); |
| 863 | |
| 864 | VG_(mprotect)((void *)p, sz, VKI_PROT_READ|VKI_PROT_WRITE); |
| 865 | |
| 866 | if (call_init) |
| 867 | while(sz) { |
| 868 | /* ask the skin to initialize each page */ |
| 869 | VG_TRACK( init_shadow_page, PGROUNDDN(p) ); |
| 870 | |
| 871 | p += VKI_BYTES_PER_PAGE; |
| 872 | sz -= VKI_BYTES_PER_PAGE; |
| 873 | } |
| 874 | } |
| 875 | |
| 876 | void *VG_(shadow_alloc)(UInt size) |
| 877 | { |
| 878 | static Addr shadow_alloc = 0; |
| 879 | void *ret; |
| 880 | |
| 881 | vg_assert(VG_(needs).shadow_memory); |
| 882 | vg_assert(!VG_(defined_init_shadow_page)()); |
| 883 | |
| 884 | size = PGROUNDUP(size); |
| 885 | |
| 886 | if (shadow_alloc == 0) |
| 887 | shadow_alloc = VG_(shadow_base); |
| 888 | |
| 889 | if (shadow_alloc >= VG_(shadow_end)) |
| 890 | return 0; |
| 891 | |
| 892 | ret = (void *)shadow_alloc; |
| 893 | VG_(mprotect)(ret, size, VKI_PROT_READ|VKI_PROT_WRITE); |
| 894 | |
| 895 | shadow_alloc += size; |
| 896 | |
| 897 | return ret; |
| 898 | } |
| 899 | |
| 900 | /*--------------------------------------------------------------------*/ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 901 | /*--- end vg_memory.c ---*/ |
| 902 | /*--------------------------------------------------------------------*/ |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 903 | |