sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 1 | |
| 2 | /*--------------------------------------------------------------------*/ |
| 3 | /*--- For when the client advises Valgrind about permissions. ---*/ |
| 4 | /*--- vg_clientperms.c ---*/ |
| 5 | /*--------------------------------------------------------------------*/ |
| 6 | |
| 7 | /* |
| 8 | This file is part of Valgrind, an x86 protected-mode emulator |
| 9 | designed for debugging and profiling binaries on x86-Unixes. |
| 10 | |
| 11 | Copyright (C) 2000-2002 Julian Seward |
| 12 | jseward@acm.org |
| 13 | Julian_Seward@muraroa.demon.co.uk |
| 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 | |
| 30 | The GNU General Public License is contained in the file LICENSE. |
| 31 | */ |
| 32 | |
| 33 | #include "vg_include.h" |
| 34 | #include "vg_constants.h" |
| 35 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 36 | #include "valgrind.h" /* for VG_USERREQ__* */ |
| 37 | |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 38 | |
| 39 | /*------------------------------------------------------------*/ |
| 40 | /*--- General client block management. ---*/ |
| 41 | /*------------------------------------------------------------*/ |
| 42 | |
| 43 | /* This is managed as an expanding array of client block descriptors. |
| 44 | Indices of live descriptors are issued to the client, so it can ask |
| 45 | to free them later. Therefore we cannot slide live entries down |
| 46 | over dead ones. Instead we must use free/inuse flags and scan for |
| 47 | an empty slot at allocation time. This in turn means allocation is |
| 48 | relatively expensive, so we hope this does not happen too often. |
| 49 | */ |
| 50 | |
| 51 | typedef |
| 52 | enum { CG_NotInUse, CG_NoAccess, CG_Writable, CG_Readable } |
| 53 | CGenBlockKind; |
| 54 | |
| 55 | typedef |
| 56 | struct { |
| 57 | Addr start; |
| 58 | UInt size; |
| 59 | ExeContext* where; |
| 60 | CGenBlockKind kind; |
| 61 | } |
| 62 | CGenBlock; |
| 63 | |
| 64 | /* This subsystem is self-initialising. */ |
| 65 | static UInt vg_cgb_size = 0; |
| 66 | static UInt vg_cgb_used = 0; |
| 67 | static CGenBlock* vg_cgbs = NULL; |
| 68 | |
| 69 | /* Stats for this subsystem. */ |
| 70 | static UInt vg_cgb_used_MAX = 0; /* Max in use. */ |
| 71 | static UInt vg_cgb_allocs = 0; /* Number of allocs. */ |
| 72 | static UInt vg_cgb_discards = 0; /* Number of discards. */ |
| 73 | static UInt vg_cgb_search = 0; /* Number of searches. */ |
| 74 | |
| 75 | |
| 76 | static |
| 77 | Int vg_alloc_client_block ( void ) |
| 78 | { |
| 79 | Int i, sz_new; |
| 80 | CGenBlock* cgbs_new; |
| 81 | |
| 82 | vg_cgb_allocs++; |
| 83 | |
| 84 | for (i = 0; i < vg_cgb_used; i++) { |
| 85 | vg_cgb_search++; |
| 86 | if (vg_cgbs[i].kind == CG_NotInUse) |
| 87 | return i; |
| 88 | } |
| 89 | |
| 90 | /* Not found. Try to allocate one at the end. */ |
| 91 | if (vg_cgb_used < vg_cgb_size) { |
| 92 | vg_cgb_used++; |
| 93 | return vg_cgb_used-1; |
| 94 | } |
| 95 | |
| 96 | /* Ok, we have to allocate a new one. */ |
| 97 | vg_assert(vg_cgb_used == vg_cgb_size); |
| 98 | sz_new = (vg_cgbs == NULL) ? 10 : (2 * vg_cgb_size); |
| 99 | |
| 100 | cgbs_new = VG_(malloc)( VG_AR_PRIVATE, sz_new * sizeof(CGenBlock) ); |
| 101 | for (i = 0; i < vg_cgb_used; i++) |
| 102 | cgbs_new[i] = vg_cgbs[i]; |
| 103 | |
| 104 | if (vg_cgbs != NULL) |
| 105 | VG_(free)( VG_AR_PRIVATE, vg_cgbs ); |
| 106 | vg_cgbs = cgbs_new; |
| 107 | |
| 108 | vg_cgb_size = sz_new; |
| 109 | vg_cgb_used++; |
| 110 | if (vg_cgb_used > vg_cgb_used_MAX) |
| 111 | vg_cgb_used_MAX = vg_cgb_used; |
| 112 | return vg_cgb_used-1; |
| 113 | } |
| 114 | |
| 115 | |
| 116 | /*------------------------------------------------------------*/ |
| 117 | /*--- Stack block management. ---*/ |
| 118 | /*------------------------------------------------------------*/ |
| 119 | |
| 120 | /* This is managed as an expanding array of CStackBlocks. They are |
| 121 | packed up against the left-hand end of the array, with no holes. |
| 122 | They are kept sorted by the start field, with the [0] having the |
| 123 | highest value. This means it's pretty cheap to put new blocks at |
| 124 | the end, corresponding to stack pushes, since the additions put |
| 125 | blocks on in what is presumably fairly close to strictly descending |
| 126 | order. If this assumption doesn't hold the performance |
| 127 | consequences will be horrible. |
| 128 | |
| 129 | When the client's %ESP jumps back upwards as the result of a RET |
| 130 | insn, we shrink the array backwards from the end, in a |
| 131 | guaranteed-cheap linear scan. |
| 132 | */ |
| 133 | |
| 134 | typedef |
| 135 | struct { |
| 136 | Addr start; |
| 137 | UInt size; |
| 138 | ExeContext* where; |
| 139 | } |
| 140 | CStackBlock; |
| 141 | |
| 142 | /* This subsystem is self-initialising. */ |
| 143 | static UInt vg_csb_size = 0; |
| 144 | static UInt vg_csb_used = 0; |
| 145 | static CStackBlock* vg_csbs = NULL; |
| 146 | |
| 147 | /* Stats for this subsystem. */ |
| 148 | static UInt vg_csb_used_MAX = 0; /* Max in use. */ |
| 149 | static UInt vg_csb_allocs = 0; /* Number of allocs. */ |
| 150 | static UInt vg_csb_discards = 0; /* Number of discards. */ |
| 151 | static UInt vg_csb_swaps = 0; /* Number of searches. */ |
| 152 | |
| 153 | static |
| 154 | void vg_add_client_stack_block ( Addr aa, UInt sz ) |
| 155 | { |
| 156 | UInt i, sz_new; |
| 157 | CStackBlock* csbs_new; |
| 158 | vg_csb_allocs++; |
| 159 | |
| 160 | /* Ensure there is space for a new block. */ |
| 161 | |
| 162 | if (vg_csb_used >= vg_csb_size) { |
| 163 | |
| 164 | /* No; we have to expand the array. */ |
| 165 | vg_assert(vg_csb_used == vg_csb_size); |
| 166 | |
| 167 | sz_new = (vg_csbs == NULL) ? 10 : (2 * vg_csb_size); |
| 168 | |
| 169 | csbs_new = VG_(malloc)( VG_AR_PRIVATE, sz_new * sizeof(CStackBlock) ); |
| 170 | for (i = 0; i < vg_csb_used; i++) |
| 171 | csbs_new[i] = vg_csbs[i]; |
| 172 | |
| 173 | if (vg_csbs != NULL) |
| 174 | VG_(free)( VG_AR_PRIVATE, vg_csbs ); |
| 175 | vg_csbs = csbs_new; |
| 176 | |
| 177 | vg_csb_size = sz_new; |
| 178 | } |
| 179 | |
| 180 | /* Ok, we can use [vg_csb_used]. */ |
| 181 | vg_csbs[vg_csb_used].start = aa; |
| 182 | vg_csbs[vg_csb_used].size = sz; |
| 183 | vg_csbs[vg_csb_used].where = VG_(get_ExeContext) ( False ); |
| 184 | vg_csb_used++; |
| 185 | |
| 186 | if (vg_csb_used > vg_csb_used_MAX) |
| 187 | vg_csb_used_MAX = vg_csb_used; |
| 188 | |
| 189 | vg_assert(vg_csb_used <= vg_csb_size); |
| 190 | |
| 191 | /* VG_(printf)("acsb %p %d\n", aa, sz); */ |
| 192 | VGM_(make_noaccess) ( aa, sz ); |
| 193 | |
| 194 | /* And make sure that they are in descending order of address. */ |
| 195 | i = vg_csb_used; |
| 196 | while (i > 0 && vg_csbs[i-1].start < vg_csbs[i].start) { |
| 197 | CStackBlock tmp = vg_csbs[i-1]; |
| 198 | vg_csbs[i-1] = vg_csbs[i]; |
| 199 | vg_csbs[i] = tmp; |
| 200 | vg_csb_swaps++; |
| 201 | } |
| 202 | |
| 203 | # if 1 |
| 204 | for (i = 1; i < vg_csb_used; i++) |
| 205 | vg_assert(vg_csbs[i-1].start >= vg_csbs[i].start); |
| 206 | # endif |
| 207 | } |
| 208 | |
| 209 | |
| 210 | /*------------------------------------------------------------*/ |
| 211 | /*--- Externally visible functions. ---*/ |
| 212 | /*------------------------------------------------------------*/ |
| 213 | |
| 214 | void VG_(show_client_block_stats) ( void ) |
| 215 | { |
| 216 | VG_(message)(Vg_DebugMsg, |
| 217 | "general CBs: %d allocs, %d discards, %d maxinuse, %d search", |
| 218 | vg_cgb_allocs, vg_cgb_discards, vg_cgb_used_MAX, vg_cgb_search |
| 219 | ); |
| 220 | VG_(message)(Vg_DebugMsg, |
| 221 | " stack CBs: %d allocs, %d discards, %d maxinuse, %d swap", |
| 222 | vg_csb_allocs, vg_csb_discards, vg_csb_used_MAX, vg_csb_swaps |
| 223 | ); |
| 224 | } |
| 225 | |
| 226 | |
| 227 | Bool VG_(client_perm_maybe_describe)( Addr a, AddrInfo* ai ) |
| 228 | { |
| 229 | Int i; |
| 230 | /* VG_(printf)("try to identify %d\n", a); */ |
| 231 | |
| 232 | /* First see if it's a stack block. We do two passes, one exact |
| 233 | and one with a bit of slop, so as to try and get the most |
| 234 | accurate fix. */ |
| 235 | for (i = 0; i < vg_csb_used; i++) { |
| 236 | if (vg_csbs[i].start <= a |
| 237 | && a < vg_csbs[i].start + vg_csbs[i].size) { |
| 238 | ai->akind = UserS; |
| 239 | ai->blksize = vg_csbs[i].size; |
| 240 | ai->rwoffset = (Int)(a) - (Int)(vg_csbs[i].start); |
| 241 | ai->lastchange = vg_csbs[i].where; |
| 242 | return True; |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | /* No exact match on the stack. Re-do the stack scan with a bit of |
| 247 | slop. */ |
| 248 | for (i = 0; i < vg_csb_used; i++) { |
| 249 | if (vg_csbs[i].start - 8 <= a |
| 250 | && a < vg_csbs[i].start + vg_csbs[i].size + 8) { |
| 251 | ai->akind = UserS; |
| 252 | ai->blksize = vg_csbs[i].size; |
| 253 | ai->rwoffset = (Int)(a) - (Int)(vg_csbs[i].start); |
| 254 | ai->lastchange = vg_csbs[i].where; |
| 255 | return True; |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | /* No match on the stack. Perhaps it's a general block ? */ |
| 260 | for (i = 0; i < vg_cgb_used; i++) { |
| 261 | if (vg_cgbs[i].kind == CG_NotInUse) |
| 262 | continue; |
| 263 | if (vg_cgbs[i].start - VG_AR_CLIENT_REDZONE_SZB <= a |
| 264 | && a < vg_cgbs[i].start + vg_cgbs[i].size + VG_AR_CLIENT_REDZONE_SZB) { |
| 265 | ai->akind = UserG; |
| 266 | ai->blksize = vg_cgbs[i].size; |
| 267 | ai->rwoffset = (Int)(a) - (Int)(vg_cgbs[i].start); |
| 268 | ai->lastchange = vg_cgbs[i].where; |
| 269 | return True; |
| 270 | } |
| 271 | } |
| 272 | return False; |
| 273 | } |
| 274 | |
| 275 | |
| 276 | void VG_(delete_client_stack_blocks_following_ESP_change) ( void ) |
| 277 | { |
| 278 | Addr newESP; |
| 279 | if (!VG_(clo_client_perms)) return; |
| 280 | newESP = VG_(baseBlock)[VGOFF_(m_esp)]; |
| 281 | while (vg_csb_used > 0 && |
| 282 | vg_csbs[vg_csb_used-1].start + vg_csbs[vg_csb_used-1].size <= newESP) { |
| 283 | vg_csb_used--; |
| 284 | vg_csb_discards++; |
| 285 | if (VG_(clo_verbosity) > 2) |
| 286 | VG_(printf)("discarding stack block %p for %d\n", |
| 287 | vg_csbs[vg_csb_used].start, vg_csbs[vg_csb_used].size); |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 292 | UInt VG_(handle_client_request) ( UInt* arg_block ) |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 293 | { |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 294 | Int i; |
| 295 | Bool ok; |
| 296 | Addr bad_addr; |
| 297 | UInt* arg = arg_block; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 298 | |
| 299 | if (VG_(clo_verbosity) > 2) |
| 300 | VG_(printf)("client request: code %d, addr %p, len %d\n", |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 301 | arg[0], arg[1], arg[2] ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 302 | |
| 303 | vg_assert(VG_(clo_client_perms)); |
| 304 | vg_assert(VG_(clo_instrument)); |
| 305 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 306 | switch (arg[0]) { |
| 307 | case VG_USERREQ__MAKE_NOACCESS: /* make no access */ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 308 | i = vg_alloc_client_block(); |
| 309 | /* VG_(printf)("allocated %d %p\n", i, vg_cgbs); */ |
| 310 | vg_cgbs[i].kind = CG_NoAccess; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 311 | vg_cgbs[i].start = arg[1]; |
| 312 | vg_cgbs[i].size = arg[2]; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 313 | vg_cgbs[i].where = VG_(get_ExeContext) ( False ); |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 314 | VGM_(make_noaccess) ( arg[1], arg[2] ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 315 | return i; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 316 | case VG_USERREQ__MAKE_WRITABLE: /* make writable */ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 317 | i = vg_alloc_client_block(); |
| 318 | vg_cgbs[i].kind = CG_Writable; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 319 | vg_cgbs[i].start = arg[1]; |
| 320 | vg_cgbs[i].size = arg[2]; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 321 | vg_cgbs[i].where = VG_(get_ExeContext) ( False ); |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 322 | VGM_(make_writable) ( arg[1], arg[2] ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 323 | return i; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 324 | case VG_USERREQ__MAKE_READABLE: /* make readable */ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 325 | i = vg_alloc_client_block(); |
| 326 | vg_cgbs[i].kind = CG_Readable; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 327 | vg_cgbs[i].start = arg[1]; |
| 328 | vg_cgbs[i].size = arg[2]; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 329 | vg_cgbs[i].where = VG_(get_ExeContext) ( False ); |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 330 | VGM_(make_readable) ( arg[1], arg[2] ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 331 | return i; |
| 332 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 333 | case VG_USERREQ__CHECK_WRITABLE: /* check writable */ |
| 334 | ok = VGM_(check_writable) ( arg[1], arg[2], &bad_addr ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 335 | if (!ok) |
| 336 | VG_(record_user_err) ( bad_addr, True ); |
| 337 | return ok ? (UInt)NULL : bad_addr; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 338 | case VG_USERREQ__CHECK_READABLE: /* check readable */ |
| 339 | ok = VGM_(check_readable) ( arg[1], arg[2], &bad_addr ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 340 | if (!ok) |
| 341 | VG_(record_user_err) ( bad_addr, False ); |
| 342 | return ok ? (UInt)NULL : bad_addr; |
| 343 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 344 | case VG_USERREQ__DISCARD: /* discard */ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 345 | if (vg_cgbs == NULL |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 346 | || arg[2] >= vg_cgb_used || vg_cgbs[arg[2]].kind == CG_NotInUse) |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 347 | return 1; |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 348 | vg_assert(arg[2] >= 0 && arg[2] < vg_cgb_used); |
| 349 | vg_cgbs[arg[2]].kind = CG_NotInUse; |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 350 | vg_cgb_discards++; |
| 351 | return 0; |
| 352 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 353 | case VG_USERREQ__MAKE_NOACCESS_STACK: /* make noaccess stack block */ |
| 354 | vg_add_client_stack_block ( arg[1], arg[2] ); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 355 | return 0; |
| 356 | |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 357 | case VG_USERREQ__RUNNING_ON_VALGRIND: |
| 358 | return 1; |
| 359 | |
| 360 | case VG_USERREQ__DO_LEAK_CHECK: |
| 361 | VG_(detect_memory_leaks)(); |
| 362 | return 0; /* return value is meaningless */ |
| 363 | |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 364 | default: |
| 365 | VG_(message)(Vg_UserMsg, |
sewardj | 2e93c50 | 2002-04-12 11:12:52 +0000 | [diff] [blame] | 366 | "Warning: unknown client request code %d", arg[0]); |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 367 | return 1; |
| 368 | } |
| 369 | } |
| 370 | |
| 371 | |
| 372 | /*--------------------------------------------------------------------*/ |
| 373 | /*--- end vg_clientperms.c ---*/ |
| 374 | /*--------------------------------------------------------------------*/ |