1 2 /*--------------------------------------------------------------------*/ 3 /*--- Function replacement and wrapping. m_redir.c ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2000-2011 Julian Seward 11 jseward (at) acm.org 12 Copyright (C) 2003-2011 Jeremy Fitzhardinge 13 jeremy (at) goop.org 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 COPYING. 31 */ 32 33 #include "pub_core_basics.h" 34 #include "pub_core_debuglog.h" 35 #include "pub_core_debuginfo.h" 36 #include "pub_core_libcbase.h" 37 #include "pub_core_libcassert.h" 38 #include "pub_core_libcprint.h" 39 #include "pub_core_seqmatch.h" 40 #include "pub_core_mallocfree.h" 41 #include "pub_core_options.h" 42 #include "pub_core_oset.h" 43 #include "pub_core_redir.h" 44 #include "pub_core_trampoline.h" 45 #include "pub_core_transtab.h" 46 #include "pub_core_tooliface.h" // VG_(needs).malloc_replacement 47 #include "pub_core_machine.h" // VG_(fnptr_to_fnentry) 48 #include "pub_core_aspacemgr.h" // VG_(am_find_nsegment) 49 #include "pub_core_xarray.h" 50 #include "pub_core_clientstate.h" // VG_(client___libc_freeres_wrapper) 51 #include "pub_core_demangle.h" // VG_(maybe_Z_demangle) 52 53 #include "config.h" /* GLIBC_2_* */ 54 55 56 /* This module is a critical part of the redirection/intercept system. 57 It keeps track of the current intercept state, cleans up the 58 translation caches when that state changes, and finally, answers 59 queries about the whether an address is currently redirected or 60 not. It doesn't do any of the control-flow trickery needed to put 61 the redirections into practice. That is the job of m_translate, 62 which calls here to find out which translations need to be 63 redirected. 64 65 The interface is simple. VG_(redir_initialise) initialises and 66 loads some hardwired redirects which never disappear; this is 67 platform-specific. 68 69 The module is notified of redirection state changes by m_debuginfo. 70 That calls VG_(redir_notify_new_DebugInfo) when a new DebugInfo 71 (shared object symbol table, basically) appears. Appearance of new 72 symbols can cause new (active) redirections to appear for two 73 reasons: the symbols in the new table may match existing 74 redirection specifications (see comments below), and because the 75 symbols in the new table may themselves supply new redirect 76 specifications which match existing symbols (or ones in the new 77 table). 78 79 Redirect specifications are really symbols with "funny" prefixes 80 (_vgrNNNNZU_ and _vgrNNNNZZ_). These names tell m_redir that the 81 associated code should replace the standard entry point for some 82 set of functions. The set of functions is specified by a (soname 83 pattern, function name pattern) pair which is encoded in the symbol 84 name following the prefix. The names use a Z-encoding scheme so 85 that they may contain punctuation characters and wildcards (*). 86 The encoding scheme is described in pub_tool_redir.h and is decoded 87 by VG_(maybe_Z_demangle). The NNNN are behavioural equivalence 88 class tags, and are used to by code in this module to resolve 89 situations where one address appears to be redirected to more than 90 one replacement/wrapper. This is also described in 91 pub_tool_redir.h. 92 93 When a shared object is unloaded, this module learns of it via a 94 call to VG_(redir_notify_delete_DebugInfo). It then removes from 95 its tables all active redirections in any way associated with that 96 object, and tidies up the translation caches accordingly. 97 98 That takes care of tracking the redirection state. When a 99 translation is actually to be made, m_translate calls to 100 VG_(redir_do_lookup) in this module to find out if the 101 translation's address should be redirected. 102 */ 103 104 /*------------------------------------------------------------*/ 105 /*--- Semantics ---*/ 106 /*------------------------------------------------------------*/ 107 108 /* The redirector holds two pieces of state: 109 110 Specs - a set of (soname pattern, fnname pattern) -> redir addr 111 Active - a set of orig addr -> (bool, redir addr) 112 113 Active is the currently active set of bindings that the translator 114 consults. Specs is the current set of specifications as harvested 115 from reading symbol tables of the currently loaded objects. 116 117 Active is a pure function of Specs and the current symbol table 118 state (maintained by m_debuginfo). Call the latter SyminfoState. 119 120 Therefore whenever either Specs or SyminfoState changes, Active 121 must be recomputed. [Inefficient if done naively, but this is a 122 spec]. 123 124 Active is computed as follows: 125 126 Active = empty 127 for spec in Specs { 128 sopatt = spec.soname pattern 129 fnpatt = spec.fnname pattern 130 redir = spec.redir addr 131 for so matching sopatt in SyminfoState { 132 for fn matching fnpatt in fnnames_of(so) { 133 &fn -> redir is added to Active 134 } 135 } 136 } 137 138 [as an implementation detail, when a binding (orig -> redir) is 139 deleted from Active as a result of recomputing it, then all 140 translations intersecting redir must be deleted. However, this is 141 not part of the spec]. 142 143 [Active also depends on where the aspacemgr has decided to put all 144 the pieces of code -- that affects the "orig addr" and "redir addr" 145 values.] 146 147 --------------------- 148 149 That completes the spec, apart from one difficult issue: duplicates. 150 151 Clearly we must impose the requirement that domain(Active) contains 152 no duplicates. The difficulty is how to constrain Specs enough to 153 avoid getting into that situation. It's easy to write specs which 154 could cause conflicting bindings in Active, eg: 155 156 (libpthread.so, pthread_mutex_lock) -> a1 157 (libpthread.so, pthread_*) -> a2 158 159 for a1 != a2. Or even hairier: 160 161 (libpthread.so, pthread_mutex_*) -> a1 162 (libpthread.so, pthread_*_lock) -> a2 163 164 I can't think of any sane way of detecting when an addition to 165 Specs would generate conflicts. However, considering we don't 166 actually want to have a system that allows this, I propose this: 167 all changes to Specs are acceptable. But, when recomputing Active 168 following the change, if the same orig is bound to more than one 169 redir, then the first binding for orig is retained, and all the 170 rest ignored. 171 172 =========================================================== 173 =========================================================== 174 Incremental implementation: 175 176 When a new DebugInfo appears: 177 - it may be the source of new specs 178 - it may be the source of new matches for existing specs 179 Therefore: 180 181 - (new Specs x existing DebugInfos): scan all symbols in the new 182 DebugInfo to find new specs. Each of these needs to be compared 183 against all symbols in all the existing DebugInfos to generate 184 new actives. 185 186 - (existing Specs x new DebugInfo): scan all symbols in the 187 DebugInfo, trying to match them to any existing specs, also 188 generating new actives. 189 190 - (new Specs x new DebugInfo): scan all symbols in the new 191 DebugInfo, trying to match them against the new specs, to 192 generate new actives. 193 194 - Finally, add new new specs to the current set of specs. 195 196 When adding a new active (s,d) to the Actives: 197 lookup s in Actives 198 if already bound to d, ignore 199 if already bound to something other than d, complain loudly and ignore 200 else add (s,d) to Actives 201 and discard (s,1) and (d,1) (maybe overly conservative) 202 203 When a DebugInfo disappears: 204 - delete all specs acquired from the seginfo 205 - delete all actives derived from the just-deleted specs 206 - if each active (s,d) deleted, discard (s,1) and (d,1) 207 */ 208 209 210 /*------------------------------------------------------------*/ 211 /*--- REDIRECTION SPECIFICATIONS ---*/ 212 /*------------------------------------------------------------*/ 213 214 /* A specification of a redirection we want to do. Note that because 215 both the "from" soname and function name may contain wildcards, the 216 spec can match an arbitrary number of times. 217 218 16 Nov 2007: Comments re .mandatory field: The initial motivation 219 for this is making Memcheck work sanely on glibc-2.6.X ppc32-linux. 220 We really need to intercept 'strlen' in ld.so right from startup. 221 If ld.so does not have a visible 'strlen' symbol, Memcheck 222 generates an impossible number of errors resulting from highly 223 tuned strlen implementation in ld.so, and is completely unusable 224 -- the resulting undefinedness eventually seeps everywhere. */ 225 typedef 226 struct _Spec { 227 struct _Spec* next; /* linked list */ 228 /* FIXED PARTS -- set when created and not changed */ 229 HChar* from_sopatt; /* from soname pattern */ 230 HChar* from_fnpatt; /* from fnname pattern */ 231 Addr to_addr; /* where redirecting to */ 232 Bool isWrap; /* wrap or replacement? */ 233 Int becTag; /* 0 through 9999. Behavioural equivalance class tag. 234 If two wrappers have the same (non-zero) tag, they 235 are promising that they behave identically. */ 236 Int becPrio; /* 0 through 9. Behavioural equivalence class prio. 237 Used to choose between competing wrappers with 238 the same (non-zero) tag. */ 239 const HChar** mandatory; /* non-NULL ==> abort V and print the 240 strings if from_sopatt is loaded but 241 from_fnpatt cannot be found */ 242 /* VARIABLE PARTS -- used transiently whilst processing redirections */ 243 Bool mark; /* set if spec requires further processing */ 244 Bool done; /* set if spec was successfully matched */ 245 } 246 Spec; 247 248 /* Top-level data structure. It contains a pointer to a DebugInfo and 249 also a list of the specs harvested from that DebugInfo. Note that 250 seginfo is allowed to be NULL, meaning that the specs are 251 pre-loaded ones at startup and are not associated with any 252 particular seginfo. */ 253 typedef 254 struct _TopSpec { 255 struct _TopSpec* next; /* linked list */ 256 DebugInfo* seginfo; /* symbols etc */ 257 Spec* specs; /* specs pulled out of seginfo */ 258 Bool mark; /* transient temporary used during deletion */ 259 } 260 TopSpec; 261 262 /* This is the top level list of redirections. m_debuginfo maintains 263 a list of DebugInfos, and the idea here is to maintain a list with 264 the same number of elements (in fact, with one more element, so as 265 to record abovementioned preloaded specifications.) */ 266 static TopSpec* topSpecs = NULL; 267 268 269 /*------------------------------------------------------------*/ 270 /*--- CURRENTLY ACTIVE REDIRECTIONS ---*/ 271 /*------------------------------------------------------------*/ 272 273 /* Represents a currently active binding. If either parent_spec or 274 parent_sym is NULL, then this binding was hardwired at startup and 275 should not be deleted. Same is true if either parent's seginfo 276 field is NULL. */ 277 typedef 278 struct { 279 Addr from_addr; /* old addr -- MUST BE THE FIRST WORD! */ 280 Addr to_addr; /* where redirecting to */ 281 TopSpec* parent_spec; /* the TopSpec which supplied the Spec */ 282 TopSpec* parent_sym; /* the TopSpec which supplied the symbol */ 283 Int becTag; /* behavioural eclass tag for ::to_addr */ 284 Int becPrio; /* and its priority */ 285 Bool isWrap; /* wrap or replacement? */ 286 Bool isIFunc; /* indirect function? */ 287 } 288 Active; 289 290 /* The active set is a fast lookup table */ 291 static OSet* activeSet = NULL; 292 293 /* Wrapper routine for indirect functions */ 294 static Addr iFuncWrapper; 295 296 /*------------------------------------------------------------*/ 297 /*--- FWDses ---*/ 298 /*------------------------------------------------------------*/ 299 300 static void maybe_add_active ( Active /*by value; callee copies*/ ); 301 302 static void* dinfo_zalloc(HChar* ec, SizeT); 303 static void dinfo_free(void*); 304 static HChar* dinfo_strdup(HChar* ec, HChar*); 305 static Bool is_plausible_guest_addr(Addr); 306 307 static void show_redir_state ( HChar* who ); 308 static void show_active ( HChar* left, Active* act ); 309 310 static void handle_maybe_load_notifier( const UChar* soname, 311 HChar* symbol, Addr addr ); 312 313 static void handle_require_text_symbols ( DebugInfo* ); 314 315 /*------------------------------------------------------------*/ 316 /*--- NOTIFICATIONS ---*/ 317 /*------------------------------------------------------------*/ 318 319 static 320 void generate_and_add_actives ( 321 /* spec list and the owning TopSpec */ 322 Spec* specs, 323 TopSpec* parent_spec, 324 /* debuginfo and the owning TopSpec */ 325 DebugInfo* di, 326 TopSpec* parent_sym 327 ); 328 329 330 /* Copy all the names from a given symbol into an AR_DINFO allocated, 331 NULL terminated array, for easy iteration. Caller must pass also 332 the address of a 2-entry array which can be used in the common case 333 to avoid dynamic allocation. */ 334 static UChar** alloc_symname_array ( UChar* pri_name, UChar** sec_names, 335 UChar** twoslots ) 336 { 337 /* Special-case the common case: only one name. We expect the 338 caller to supply a stack-allocated 2-entry array for this. */ 339 if (sec_names == NULL) { 340 twoslots[0] = pri_name; 341 twoslots[1] = NULL; 342 return twoslots; 343 } 344 /* Else must use dynamic allocation. Figure out size .. */ 345 Word n_req = 1; 346 UChar** pp = sec_names; 347 while (*pp) { n_req++; pp++; } 348 /* .. allocate and copy in. */ 349 UChar** arr = dinfo_zalloc( "redir.asa.1", (n_req+1) * sizeof(UChar*) ); 350 Word i = 0; 351 arr[i++] = pri_name; 352 pp = sec_names; 353 while (*pp) { arr[i++] = *pp; pp++; } 354 tl_assert(i == n_req); 355 tl_assert(arr[n_req] == NULL); 356 return arr; 357 } 358 359 360 /* Free the array allocated by alloc_symname_array, if any. */ 361 static void free_symname_array ( UChar** names, UChar** twoslots ) 362 { 363 if (names != twoslots) 364 dinfo_free(names); 365 } 366 367 368 /* Notify m_redir of the arrival of a new DebugInfo. This is fairly 369 complex, but the net effect is to (1) add a new entry to the 370 topspecs list, and (2) figure out what new binding are now active, 371 and, as a result, add them to the actives mapping. */ 372 373 #define N_DEMANGLED 256 374 375 void VG_(redir_notify_new_DebugInfo)( DebugInfo* newdi ) 376 { 377 Bool ok, isWrap; 378 Int i, nsyms, becTag, becPrio; 379 Spec* specList; 380 Spec* spec; 381 TopSpec* ts; 382 TopSpec* newts; 383 UChar* sym_name_pri; 384 UChar** sym_names_sec; 385 Addr sym_addr, sym_toc; 386 HChar demangled_sopatt[N_DEMANGLED]; 387 HChar demangled_fnpatt[N_DEMANGLED]; 388 Bool check_ppcTOCs = False; 389 Bool isText; 390 const UChar* newdi_soname; 391 392 # if defined(VG_PLAT_USES_PPCTOC) 393 check_ppcTOCs = True; 394 # endif 395 396 vg_assert(newdi); 397 newdi_soname = VG_(DebugInfo_get_soname)(newdi); 398 vg_assert(newdi_soname != NULL); 399 400 /* stay sane: we don't already have this. */ 401 for (ts = topSpecs; ts; ts = ts->next) 402 vg_assert(ts->seginfo != newdi); 403 404 /* scan this DebugInfo's symbol table, pulling out and demangling 405 any specs found */ 406 407 specList = NULL; /* the spec list we're building up */ 408 409 nsyms = VG_(DebugInfo_syms_howmany)( newdi ); 410 for (i = 0; i < nsyms; i++) { 411 VG_(DebugInfo_syms_getidx)( newdi, i, &sym_addr, &sym_toc, 412 NULL, &sym_name_pri, &sym_names_sec, 413 &isText, NULL ); 414 /* Set up to conveniently iterate over all names for this symbol. */ 415 UChar* twoslots[2]; 416 UChar** names_init = alloc_symname_array(sym_name_pri, sym_names_sec, 417 &twoslots[0]); 418 UChar** names; 419 for (names = names_init; *names; names++) { 420 ok = VG_(maybe_Z_demangle)( *names, 421 demangled_sopatt, N_DEMANGLED, 422 demangled_fnpatt, N_DEMANGLED, 423 &isWrap, &becTag, &becPrio ); 424 /* ignore data symbols */ 425 if (!isText) 426 continue; 427 if (!ok) { 428 /* It's not a full-scale redirect, but perhaps it is a load-notify 429 fn? Let the load-notify department see it. */ 430 handle_maybe_load_notifier( newdi_soname, *names, sym_addr ); 431 continue; 432 } 433 if (check_ppcTOCs && sym_toc == 0) { 434 /* This platform uses toc pointers, but none could be found 435 for this symbol, so we can't safely redirect/wrap to it. 436 Just skip it; we'll make a second pass over the symbols in 437 the following loop, and complain at that point. */ 438 continue; 439 } 440 spec = dinfo_zalloc("redir.rnnD.1", sizeof(Spec)); 441 vg_assert(spec); 442 spec->from_sopatt = dinfo_strdup("redir.rnnD.2", demangled_sopatt); 443 spec->from_fnpatt = dinfo_strdup("redir.rnnD.3", demangled_fnpatt); 444 vg_assert(spec->from_sopatt); 445 vg_assert(spec->from_fnpatt); 446 spec->to_addr = sym_addr; 447 spec->isWrap = isWrap; 448 spec->becTag = becTag; 449 spec->becPrio = becPrio; 450 /* check we're not adding manifestly stupid destinations */ 451 vg_assert(is_plausible_guest_addr(sym_addr)); 452 spec->next = specList; 453 spec->mark = False; /* not significant */ 454 spec->done = False; /* not significant */ 455 specList = spec; 456 } 457 free_symname_array(names_init, &twoslots[0]); 458 } 459 460 if (check_ppcTOCs) { 461 for (i = 0; i < nsyms; i++) { 462 VG_(DebugInfo_syms_getidx)( newdi, i, &sym_addr, &sym_toc, 463 NULL, &sym_name_pri, &sym_names_sec, 464 &isText, NULL ); 465 UChar* twoslots[2]; 466 UChar** names_init = alloc_symname_array(sym_name_pri, sym_names_sec, 467 &twoslots[0]); 468 UChar** names; 469 for (names = names_init; *names; names++) { 470 ok = isText 471 && VG_(maybe_Z_demangle)( 472 *names, demangled_sopatt, N_DEMANGLED, 473 demangled_fnpatt, N_DEMANGLED, &isWrap, NULL, NULL ); 474 if (!ok) 475 /* not a redirect. Ignore. */ 476 continue; 477 if (sym_toc != 0) 478 /* has a valid toc pointer. Ignore. */ 479 continue; 480 481 for (spec = specList; spec; spec = spec->next) 482 if (0 == VG_(strcmp)(spec->from_sopatt, demangled_sopatt) 483 && 0 == VG_(strcmp)(spec->from_fnpatt, demangled_fnpatt)) 484 break; 485 if (spec) 486 /* a redirect to some other copy of that symbol, which 487 does have a TOC value, already exists */ 488 continue; 489 490 /* Complain */ 491 VG_(message)(Vg_DebugMsg, 492 "WARNING: no TOC ptr for redir/wrap to %s %s\n", 493 demangled_sopatt, demangled_fnpatt); 494 } 495 free_symname_array(names_init, &twoslots[0]); 496 } 497 } 498 499 /* Ok. Now specList holds the list of specs from the DebugInfo. 500 Build a new TopSpec, but don't add it to topSpecs yet. */ 501 newts = dinfo_zalloc("redir.rnnD.4", sizeof(TopSpec)); 502 vg_assert(newts); 503 newts->next = NULL; /* not significant */ 504 newts->seginfo = newdi; 505 newts->specs = specList; 506 newts->mark = False; /* not significant */ 507 508 /* We now need to augment the active set with the following partial 509 cross product: 510 511 (1) actives formed by matching the new specs in specList against 512 all symbols currently listed in topSpecs 513 514 (2) actives formed by matching the new symbols in newdi against 515 all specs currently listed in topSpecs 516 517 (3) actives formed by matching the new symbols in newdi against 518 the new specs in specList 519 520 This is necessary in order to maintain the invariant that 521 Actives contains all bindings generated by matching ALL specs in 522 topSpecs against ALL symbols in topSpecs (that is, a cross 523 product of ALL known specs against ALL known symbols). 524 */ 525 /* Case (1) */ 526 for (ts = topSpecs; ts; ts = ts->next) { 527 if (ts->seginfo) 528 generate_and_add_actives( specList, newts, 529 ts->seginfo, ts ); 530 } 531 532 /* Case (2) */ 533 for (ts = topSpecs; ts; ts = ts->next) { 534 generate_and_add_actives( ts->specs, ts, 535 newdi, newts ); 536 } 537 538 /* Case (3) */ 539 generate_and_add_actives( specList, newts, 540 newdi, newts ); 541 542 /* Finally, add the new TopSpec. */ 543 newts->next = topSpecs; 544 topSpecs = newts; 545 546 if (VG_(clo_trace_redir)) 547 show_redir_state("after VG_(redir_notify_new_DebugInfo)"); 548 549 /* Really finally (quite unrelated to all the above) check the 550 names in the module against any --require-text-symbol= 551 specifications we might have. */ 552 handle_require_text_symbols(newdi); 553 } 554 555 #undef N_DEMANGLED 556 557 /* Add a new target for an indirect function. Adds a new redirection 558 for the indirection function with address old_from that redirects 559 the ordinary function with address new_from to the target address 560 of the original redirection. */ 561 562 void VG_(redir_add_ifunc_target)( Addr old_from, Addr new_from ) 563 { 564 Active *old, new; 565 566 old = VG_(OSetGen_Lookup)(activeSet, &old_from); 567 vg_assert(old); 568 vg_assert(old->isIFunc); 569 570 new = *old; 571 new.from_addr = new_from; 572 new.isIFunc = False; 573 maybe_add_active (new); 574 575 if (VG_(clo_trace_redir)) { 576 VG_(message)( Vg_DebugMsg, 577 "Adding redirect for indirect function " 578 "0x%llx from 0x%llx -> 0x%llx\n", 579 (ULong)old_from, (ULong)new_from, (ULong)new.to_addr ); 580 } 581 } 582 583 /* Do one element of the basic cross product: add to the active set, 584 all matches resulting from comparing all the given specs against 585 all the symbols in the given seginfo. If a conflicting binding 586 would thereby arise, don't add it, but do complain. */ 587 588 static 589 void generate_and_add_actives ( 590 /* spec list and the owning TopSpec */ 591 Spec* specs, 592 TopSpec* parent_spec, 593 /* seginfo and the owning TopSpec */ 594 DebugInfo* di, 595 TopSpec* parent_sym 596 ) 597 { 598 Spec* sp; 599 Bool anyMark, isText, isIFunc; 600 Active act; 601 Int nsyms, i; 602 Addr sym_addr; 603 UChar* sym_name_pri; 604 UChar** sym_names_sec; 605 606 /* First figure out which of the specs match the seginfo's soname. 607 Also clear the 'done' bits, so that after the main loop below 608 tell which of the Specs really did get done. */ 609 anyMark = False; 610 for (sp = specs; sp; sp = sp->next) { 611 sp->done = False; 612 sp->mark = VG_(string_match)( sp->from_sopatt, 613 VG_(DebugInfo_get_soname)(di) ); 614 anyMark = anyMark || sp->mark; 615 } 616 617 /* shortcut: if none of the sonames match, there will be no bindings. */ 618 if (!anyMark) 619 return; 620 621 /* Iterate outermost over the symbols in the seginfo, in the hope 622 of trashing the caches less. */ 623 nsyms = VG_(DebugInfo_syms_howmany)( di ); 624 for (i = 0; i < nsyms; i++) { 625 VG_(DebugInfo_syms_getidx)( di, i, &sym_addr, NULL, 626 NULL, &sym_name_pri, &sym_names_sec, 627 &isText, &isIFunc ); 628 UChar* twoslots[2]; 629 UChar** names_init = alloc_symname_array(sym_name_pri, sym_names_sec, 630 &twoslots[0]); 631 UChar** names; 632 for (names = names_init; *names; names++) { 633 634 /* ignore data symbols */ 635 if (!isText) 636 continue; 637 638 for (sp = specs; sp; sp = sp->next) { 639 if (!sp->mark) 640 continue; /* soname doesn't match */ 641 if (VG_(string_match)( sp->from_fnpatt, *names )) { 642 /* got a new binding. Add to collection. */ 643 act.from_addr = sym_addr; 644 act.to_addr = sp->to_addr; 645 act.parent_spec = parent_spec; 646 act.parent_sym = parent_sym; 647 act.becTag = sp->becTag; 648 act.becPrio = sp->becPrio; 649 act.isWrap = sp->isWrap; 650 act.isIFunc = isIFunc; 651 sp->done = True; 652 maybe_add_active( act ); 653 } 654 } /* for (sp = specs; sp; sp = sp->next) */ 655 656 } /* iterating over names[] */ 657 free_symname_array(names_init, &twoslots[0]); 658 } /* for (i = 0; i < nsyms; i++) */ 659 660 /* Now, finally, look for Specs which were marked to be done, but 661 didn't get matched. If any such are mandatory we must abort the 662 system at this point. */ 663 for (sp = specs; sp; sp = sp->next) { 664 if (!sp->mark) 665 continue; 666 if (sp->mark && (!sp->done) && sp->mandatory) 667 break; 668 } 669 if (sp) { 670 const HChar** strp; 671 HChar* v = "valgrind: "; 672 vg_assert(sp->mark); 673 vg_assert(!sp->done); 674 vg_assert(sp->mandatory); 675 VG_(printf)("\n"); 676 VG_(printf)( 677 "%sFatal error at startup: a function redirection\n", v); 678 VG_(printf)( 679 "%swhich is mandatory for this platform-tool combination\n", v); 680 VG_(printf)( 681 "%scannot be set up. Details of the redirection are:\n", v); 682 VG_(printf)( 683 "%s\n", v); 684 VG_(printf)( 685 "%sA must-be-redirected function\n", v); 686 VG_(printf)( 687 "%swhose name matches the pattern: %s\n", v, sp->from_fnpatt); 688 VG_(printf)( 689 "%sin an object with soname matching: %s\n", v, sp->from_sopatt); 690 VG_(printf)( 691 "%swas not found whilst processing\n", v); 692 VG_(printf)( 693 "%ssymbols from the object with soname: %s\n", 694 v, VG_(DebugInfo_get_soname)(di)); 695 VG_(printf)( 696 "%s\n", v); 697 698 for (strp = sp->mandatory; *strp; strp++) 699 VG_(printf)( 700 "%s%s\n", v, *strp); 701 702 VG_(printf)( 703 "%s\n", v); 704 VG_(printf)( 705 "%sCannot continue -- exiting now. Sorry.\n", v); 706 VG_(printf)("\n"); 707 VG_(exit)(1); 708 } 709 } 710 711 712 /* Add an act (passed by value; is copied here) and deal with 713 conflicting bindings. */ 714 static void maybe_add_active ( Active act ) 715 { 716 HChar* what = NULL; 717 Active* old = NULL; 718 Bool add_act = False; 719 720 /* Complain and ignore manifestly bogus 'from' addresses. 721 722 Kludge: because this can get called befor the trampoline area (a 723 bunch of magic 'to' addresses) has its ownership changed from V 724 to C, we can't check the 'to' address similarly. Sigh. 725 726 amd64-linux hack: the vsysinfo pages appear to have no 727 permissions 728 ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0 729 so skip the check for them. */ 730 if (!is_plausible_guest_addr(act.from_addr) 731 # if defined(VGP_amd64_linux) 732 && act.from_addr != 0xFFFFFFFFFF600000ULL 733 && act.from_addr != 0xFFFFFFFFFF600400ULL 734 # endif 735 ) { 736 what = "redirection from-address is in non-executable area"; 737 goto bad; 738 } 739 740 old = VG_(OSetGen_Lookup)( activeSet, &act.from_addr ); 741 if (old) { 742 /* Dodgy. Conflicting binding. */ 743 vg_assert(old->from_addr == act.from_addr); 744 if (old->to_addr != act.to_addr) { 745 /* We've got a conflicting binding -- that is, from_addr is 746 specified to redirect to two different destinations, 747 old->to_addr and act.to_addr. If we can prove that they 748 are behaviourally equivalent then that's no problem. So 749 we can look at the behavioural eclass tags for both 750 functions to see if that's so. If they are equal, and 751 nonzero, then that's fine. But if not, we can't show they 752 are equivalent, so we have to complain, and ignore the new 753 binding. */ 754 vg_assert(old->becTag >= 0 && old->becTag <= 9999); 755 vg_assert(old->becPrio >= 0 && old->becPrio <= 9); 756 vg_assert(act.becTag >= 0 && act.becTag <= 9999); 757 vg_assert(act.becPrio >= 0 && act.becPrio <= 9); 758 if (old->becTag == 0) 759 vg_assert(old->becPrio == 0); 760 if (act.becTag == 0) 761 vg_assert(act.becPrio == 0); 762 763 if (old->becTag == 0 || act.becTag == 0 || old->becTag != act.becTag) { 764 /* We can't show that they are equivalent. Complain and 765 ignore. */ 766 what = "new redirection conflicts with existing -- ignoring it"; 767 goto bad; 768 } 769 /* They have the same eclass tag. Use the priorities to 770 resolve the ambiguity. */ 771 if (act.becPrio <= old->becPrio) { 772 /* The new one doesn't have a higher priority, so just 773 ignore it. */ 774 if (VG_(clo_verbosity) > 2) { 775 VG_(message)(Vg_UserMsg, "Ignoring %s redirection:\n", 776 act.becPrio < old->becPrio ? "lower priority" 777 : "duplicate"); 778 show_active( " old: ", old); 779 show_active( " new: ", &act); 780 } 781 } else { 782 /* The tricky case. The new one has a higher priority, so 783 we need to get the old one out of the OSet and install 784 this one in its place. */ 785 if (VG_(clo_verbosity) > 1) { 786 VG_(message)(Vg_UserMsg, 787 "Preferring higher priority redirection:\n"); 788 show_active( " old: ", old); 789 show_active( " new: ", &act); 790 } 791 add_act = True; 792 void* oldNd = VG_(OSetGen_Remove)( activeSet, &act.from_addr ); 793 vg_assert(oldNd == old); 794 VG_(OSetGen_FreeNode)( activeSet, old ); 795 old = NULL; 796 } 797 } else { 798 /* This appears to be a duplicate of an existing binding. 799 Safe(ish) -- ignore. */ 800 /* XXXXXXXXXXX COMPLAIN if new and old parents differ */ 801 } 802 803 } else { 804 /* There's no previous binding for this from_addr, so we must 805 add 'act' to the active set. */ 806 add_act = True; 807 } 808 809 /* So, finally, actually add it. */ 810 if (add_act) { 811 Active* a = VG_(OSetGen_AllocNode)(activeSet, sizeof(Active)); 812 vg_assert(a); 813 *a = act; 814 VG_(OSetGen_Insert)(activeSet, a); 815 /* Now that a new from->to redirection is in force, we need to 816 get rid of any translations intersecting 'from' in order that 817 they get redirected to 'to'. So discard them. Just for 818 paranoia (but, I believe, unnecessarily), discard 'to' as 819 well. */ 820 VG_(discard_translations)( (Addr64)act.from_addr, 1, 821 "redir_new_DebugInfo(from_addr)"); 822 VG_(discard_translations)( (Addr64)act.to_addr, 1, 823 "redir_new_DebugInfo(to_addr)"); 824 if (VG_(clo_verbosity) > 2) { 825 VG_(message)(Vg_UserMsg, "Adding active redirection:\n"); 826 show_active( " new: ", &act); 827 } 828 } 829 return; 830 831 bad: 832 vg_assert(what); 833 vg_assert(!add_act); 834 if (VG_(clo_verbosity) > 1) { 835 VG_(message)(Vg_UserMsg, "WARNING: %s\n", what); 836 if (old) { 837 show_active( " old: ", old); 838 } 839 show_active( " new: ", &act); 840 } 841 } 842 843 844 /* Notify m_redir of the deletion of a DebugInfo. This is relatively 845 simple -- just get rid of all actives derived from it, and free up 846 the associated list elements. */ 847 848 void VG_(redir_notify_delete_DebugInfo)( DebugInfo* delsi ) 849 { 850 TopSpec* ts; 851 TopSpec* tsPrev; 852 Spec* sp; 853 Spec* sp_next; 854 OSet* tmpSet; 855 Active* act; 856 Bool delMe; 857 Addr addr; 858 859 vg_assert(delsi); 860 861 /* Search for it, and make tsPrev point to the previous entry, if 862 any. */ 863 tsPrev = NULL; 864 ts = topSpecs; 865 while (True) { 866 if (ts == NULL) break; 867 if (ts->seginfo == delsi) break; 868 tsPrev = ts; 869 ts = ts->next; 870 } 871 872 vg_assert(ts); /* else we don't have the deleted DebugInfo */ 873 vg_assert(ts->seginfo == delsi); 874 875 /* Traverse the actives, copying the addresses of those we intend 876 to delete into tmpSet. */ 877 tmpSet = VG_(OSetWord_Create)(dinfo_zalloc, "redir.rndD.1", dinfo_free); 878 879 ts->mark = True; 880 881 VG_(OSetGen_ResetIter)( activeSet ); 882 while ( (act = VG_(OSetGen_Next)(activeSet)) ) { 883 delMe = act->parent_spec != NULL 884 && act->parent_sym != NULL 885 && act->parent_spec->seginfo != NULL 886 && act->parent_sym->seginfo != NULL 887 && (act->parent_spec->mark || act->parent_sym->mark); 888 889 /* While we're at it, a bit of paranoia: delete any actives 890 which don't have both feet in valid client executable areas. 891 But don't delete hardwired-at-startup ones; these are denoted 892 by having parent_spec or parent_sym being NULL. */ 893 if ( (!delMe) 894 && act->parent_spec != NULL 895 && act->parent_sym != NULL ) { 896 if (!is_plausible_guest_addr(act->from_addr)) 897 delMe = True; 898 if (!is_plausible_guest_addr(act->to_addr)) 899 delMe = True; 900 } 901 902 if (delMe) { 903 VG_(OSetWord_Insert)( tmpSet, act->from_addr ); 904 /* While we have our hands on both the 'from' and 'to' 905 of this Active, do paranoid stuff with tt/tc. */ 906 VG_(discard_translations)( (Addr64)act->from_addr, 1, 907 "redir_del_DebugInfo(from_addr)"); 908 VG_(discard_translations)( (Addr64)act->to_addr, 1, 909 "redir_del_DebugInfo(to_addr)"); 910 } 911 } 912 913 /* Now traverse tmpSet, deleting corresponding elements in activeSet. */ 914 VG_(OSetWord_ResetIter)( tmpSet ); 915 while ( VG_(OSetWord_Next)(tmpSet, &addr) ) { 916 act = VG_(OSetGen_Remove)( activeSet, &addr ); 917 vg_assert(act); 918 VG_(OSetGen_FreeNode)( activeSet, act ); 919 } 920 921 VG_(OSetWord_Destroy)( tmpSet ); 922 923 /* The Actives set is now cleaned up. Free up this TopSpec and 924 everything hanging off it. */ 925 for (sp = ts->specs; sp; sp = sp_next) { 926 if (sp->from_sopatt) dinfo_free(sp->from_sopatt); 927 if (sp->from_fnpatt) dinfo_free(sp->from_fnpatt); 928 sp_next = sp->next; 929 dinfo_free(sp); 930 } 931 932 if (tsPrev == NULL) { 933 /* first in list */ 934 topSpecs = ts->next; 935 } else { 936 tsPrev->next = ts->next; 937 } 938 dinfo_free(ts); 939 940 if (VG_(clo_trace_redir)) 941 show_redir_state("after VG_(redir_notify_delete_DebugInfo)"); 942 } 943 944 945 /*------------------------------------------------------------*/ 946 /*--- QUERIES (really the whole point of this module) ---*/ 947 /*------------------------------------------------------------*/ 948 949 /* This is the crucial redirection function. It answers the question: 950 should this code address be redirected somewhere else? It's used 951 just before translating a basic block. */ 952 Addr VG_(redir_do_lookup) ( Addr orig, Bool* isWrap ) 953 { 954 Active* r = VG_(OSetGen_Lookup)(activeSet, &orig); 955 if (r == NULL) 956 return orig; 957 958 vg_assert(r->to_addr != 0); 959 if (isWrap) 960 *isWrap = r->isWrap || r->isIFunc; 961 if (r->isIFunc) { 962 vg_assert(iFuncWrapper); 963 return iFuncWrapper; 964 } 965 return r->to_addr; 966 } 967 968 969 /*------------------------------------------------------------*/ 970 /*--- INITIALISATION ---*/ 971 /*------------------------------------------------------------*/ 972 973 /* Add a never-delete-me Active. */ 974 975 __attribute__((unused)) /* only used on amd64 */ 976 static void add_hardwired_active ( Addr from, Addr to ) 977 { 978 Active act; 979 act.from_addr = from; 980 act.to_addr = to; 981 act.parent_spec = NULL; 982 act.parent_sym = NULL; 983 act.becTag = 0; /* "not equivalent to any other fn" */ 984 act.becPrio = 0; /* mandatory when becTag == 0 */ 985 act.isWrap = False; 986 act.isIFunc = False; 987 maybe_add_active( act ); 988 } 989 990 991 /* Add a never-delete-me Spec. This is a bit of a kludge. On the 992 assumption that this is called only at startup, only handle the 993 case where topSpecs is completely empty, or if it isn't, it has 994 just one entry and that is the one with NULL seginfo -- that is the 995 entry that holds these initial specs. */ 996 997 __attribute__((unused)) /* not used on all platforms */ 998 static void add_hardwired_spec ( HChar* sopatt, HChar* fnpatt, 999 Addr to_addr, 1000 const HChar** mandatory ) 1001 { 1002 Spec* spec = dinfo_zalloc("redir.ahs.1", sizeof(Spec)); 1003 vg_assert(spec); 1004 1005 if (topSpecs == NULL) { 1006 topSpecs = dinfo_zalloc("redir.ahs.2", sizeof(TopSpec)); 1007 vg_assert(topSpecs); 1008 /* symtab_zalloc sets all fields to zero */ 1009 } 1010 1011 vg_assert(topSpecs != NULL); 1012 vg_assert(topSpecs->next == NULL); 1013 vg_assert(topSpecs->seginfo == NULL); 1014 /* FIXED PARTS */ 1015 spec->from_sopatt = sopatt; 1016 spec->from_fnpatt = fnpatt; 1017 spec->to_addr = to_addr; 1018 spec->isWrap = False; 1019 spec->mandatory = mandatory; 1020 /* VARIABLE PARTS */ 1021 spec->mark = False; /* not significant */ 1022 spec->done = False; /* not significant */ 1023 1024 spec->next = topSpecs->specs; 1025 topSpecs->specs = spec; 1026 } 1027 1028 1029 __attribute__((unused)) /* not used on all platforms */ 1030 static const HChar* complain_about_stripped_glibc_ldso[] 1031 = { "Possible fixes: (1, short term): install glibc's debuginfo", 1032 "package on this machine. (2, longer term): ask the packagers", 1033 "for your Linux distribution to please in future ship a non-", 1034 "stripped ld.so (or whatever the dynamic linker .so is called)", 1035 "that exports the above-named function using the standard", 1036 "calling conventions for this platform. The package you need", 1037 "to install for fix (1) is called", 1038 "", 1039 " On Debian, Ubuntu: libc6-dbg", 1040 " On SuSE, openSuSE, Fedora, RHEL: glibc-debuginfo", 1041 NULL 1042 }; 1043 1044 1045 /* Initialise the redir system, and create the initial Spec list and 1046 for amd64-linux a couple of permanent active mappings. The initial 1047 Specs are not converted into Actives yet, on the (checked) 1048 assumption that no DebugInfos have so far been created, and so when 1049 they are created, that will happen. */ 1050 1051 void VG_(redir_initialise) ( void ) 1052 { 1053 // Assert that there are no DebugInfos so far 1054 vg_assert( VG_(next_DebugInfo)(NULL) == NULL ); 1055 1056 // Initialise active mapping. 1057 activeSet = VG_(OSetGen_Create)(offsetof(Active, from_addr), 1058 NULL, // Use fast comparison 1059 dinfo_zalloc, 1060 "redir.ri.1", 1061 dinfo_free); 1062 1063 // The rest of this function just adds initial Specs. 1064 1065 # if defined(VGP_x86_linux) 1066 /* If we're using memcheck, use this intercept right from the 1067 start, otherwise ld.so (glibc-2.3.5) makes a lot of noise. */ 1068 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1069 const HChar** mandatory; 1070 # if defined(GLIBC_2_2) || defined(GLIBC_2_3) || defined(GLIBC_2_4) \ 1071 || defined(GLIBC_2_5) || defined(GLIBC_2_6) || defined(GLIBC_2_7) \ 1072 || defined(GLIBC_2_8) || defined(GLIBC_2_9) \ 1073 || defined(GLIBC_2_10) || defined(GLIBC_2_11) 1074 mandatory = NULL; 1075 # else 1076 /* for glibc-2.12 and later, this is mandatory - can't sanely 1077 continue without it */ 1078 mandatory = complain_about_stripped_glibc_ldso; 1079 # endif 1080 add_hardwired_spec( 1081 "ld-linux.so.2", "index", 1082 (Addr)&VG_(x86_linux_REDIR_FOR_index), mandatory); 1083 add_hardwired_spec( 1084 "ld-linux.so.2", "strlen", 1085 (Addr)&VG_(x86_linux_REDIR_FOR_strlen), mandatory); 1086 } 1087 1088 # elif defined(VGP_amd64_linux) 1089 /* Redirect vsyscalls to local versions */ 1090 add_hardwired_active( 1091 0xFFFFFFFFFF600000ULL, 1092 (Addr)&VG_(amd64_linux_REDIR_FOR_vgettimeofday) 1093 ); 1094 add_hardwired_active( 1095 0xFFFFFFFFFF600400ULL, 1096 (Addr)&VG_(amd64_linux_REDIR_FOR_vtime) 1097 ); 1098 1099 /* If we're using memcheck, use these intercepts right from 1100 the start, otherwise ld.so makes a lot of noise. */ 1101 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1102 1103 add_hardwired_spec( 1104 "ld-linux-x86-64.so.2", "strlen", 1105 (Addr)&VG_(amd64_linux_REDIR_FOR_strlen), 1106 # if defined(GLIBC_2_2) || defined(GLIBC_2_3) || defined(GLIBC_2_4) \ 1107 || defined(GLIBC_2_5) || defined(GLIBC_2_6) || defined(GLIBC_2_7) \ 1108 || defined(GLIBC_2_8) || defined(GLIBC_2_9) 1109 NULL 1110 # else 1111 /* for glibc-2.10 and later, this is mandatory - can't sanely 1112 continue without it */ 1113 complain_about_stripped_glibc_ldso 1114 # endif 1115 ); 1116 } 1117 1118 # elif defined(VGP_ppc32_linux) 1119 /* If we're using memcheck, use these intercepts right from 1120 the start, otherwise ld.so makes a lot of noise. */ 1121 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1122 1123 /* this is mandatory - can't sanely continue without it */ 1124 add_hardwired_spec( 1125 "ld.so.1", "strlen", 1126 (Addr)&VG_(ppc32_linux_REDIR_FOR_strlen), 1127 complain_about_stripped_glibc_ldso 1128 ); 1129 add_hardwired_spec( 1130 "ld.so.1", "strcmp", 1131 (Addr)&VG_(ppc32_linux_REDIR_FOR_strcmp), 1132 NULL /* not mandatory - so why bother at all? */ 1133 /* glibc-2.6.1 (openSUSE 10.3, ppc32) seems fine without it */ 1134 ); 1135 add_hardwired_spec( 1136 "ld.so.1", "index", 1137 (Addr)&VG_(ppc32_linux_REDIR_FOR_strchr), 1138 NULL /* not mandatory - so why bother at all? */ 1139 /* glibc-2.6.1 (openSUSE 10.3, ppc32) seems fine without it */ 1140 ); 1141 } 1142 1143 # elif defined(VGP_ppc64_linux) 1144 /* If we're using memcheck, use these intercepts right from 1145 the start, otherwise ld.so makes a lot of noise. */ 1146 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1147 1148 /* this is mandatory - can't sanely continue without it */ 1149 add_hardwired_spec( 1150 "ld64.so.1", "strlen", 1151 (Addr)VG_(fnptr_to_fnentry)( &VG_(ppc64_linux_REDIR_FOR_strlen) ), 1152 complain_about_stripped_glibc_ldso 1153 ); 1154 1155 add_hardwired_spec( 1156 "ld64.so.1", "index", 1157 (Addr)VG_(fnptr_to_fnentry)( &VG_(ppc64_linux_REDIR_FOR_strchr) ), 1158 NULL /* not mandatory - so why bother at all? */ 1159 /* glibc-2.5 (FC6, ppc64) seems fine without it */ 1160 ); 1161 } 1162 1163 # elif defined(VGP_arm_linux) 1164 /* If we're using memcheck, use these intercepts right from 1165 the start, otherwise ld.so makes a lot of noise. */ 1166 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1167 add_hardwired_spec( 1168 "ld-linux.so.3", "strlen", 1169 (Addr)&VG_(arm_linux_REDIR_FOR_strlen), 1170 complain_about_stripped_glibc_ldso 1171 ); 1172 //add_hardwired_spec( 1173 // "ld-linux.so.3", "index", 1174 // (Addr)&VG_(arm_linux_REDIR_FOR_index), 1175 // NULL 1176 //); 1177 add_hardwired_spec( 1178 "ld-linux.so.3", "memcpy", 1179 (Addr)&VG_(arm_linux_REDIR_FOR_memcpy), 1180 complain_about_stripped_glibc_ldso 1181 ); 1182 } 1183 /* nothing so far */ 1184 1185 # elif defined(VGP_x86_darwin) 1186 /* If we're using memcheck, use these intercepts right from 1187 the start, otherwise dyld makes a lot of noise. */ 1188 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1189 add_hardwired_spec("dyld", "strcmp", 1190 (Addr)&VG_(x86_darwin_REDIR_FOR_strcmp), NULL); 1191 add_hardwired_spec("dyld", "strlen", 1192 (Addr)&VG_(x86_darwin_REDIR_FOR_strlen), NULL); 1193 add_hardwired_spec("dyld", "strcat", 1194 (Addr)&VG_(x86_darwin_REDIR_FOR_strcat), NULL); 1195 add_hardwired_spec("dyld", "strcpy", 1196 (Addr)&VG_(x86_darwin_REDIR_FOR_strcpy), NULL); 1197 add_hardwired_spec("dyld", "strlcat", 1198 (Addr)&VG_(x86_darwin_REDIR_FOR_strlcat), NULL); 1199 } 1200 1201 # elif defined(VGP_amd64_darwin) 1202 /* If we're using memcheck, use these intercepts right from 1203 the start, otherwise dyld makes a lot of noise. */ 1204 if (0==VG_(strcmp)("Memcheck", VG_(details).name)) { 1205 add_hardwired_spec("dyld", "strcmp", 1206 (Addr)&VG_(amd64_darwin_REDIR_FOR_strcmp), NULL); 1207 add_hardwired_spec("dyld", "strlen", 1208 (Addr)&VG_(amd64_darwin_REDIR_FOR_strlen), NULL); 1209 add_hardwired_spec("dyld", "strcat", 1210 (Addr)&VG_(amd64_darwin_REDIR_FOR_strcat), NULL); 1211 add_hardwired_spec("dyld", "strcpy", 1212 (Addr)&VG_(amd64_darwin_REDIR_FOR_strcpy), NULL); 1213 add_hardwired_spec("dyld", "strlcat", 1214 (Addr)&VG_(amd64_darwin_REDIR_FOR_strlcat), NULL); 1215 // DDD: #warning fixme rdar://6166275 1216 add_hardwired_spec("dyld", "arc4random", 1217 (Addr)&VG_(amd64_darwin_REDIR_FOR_arc4random), NULL); 1218 } 1219 1220 # elif defined(VGP_s390x_linux) 1221 /* nothing so far */ 1222 1223 # else 1224 # error Unknown platform 1225 # endif 1226 1227 if (VG_(clo_trace_redir)) 1228 show_redir_state("after VG_(redir_initialise)"); 1229 } 1230 1231 1232 /*------------------------------------------------------------*/ 1233 /*--- MISC HELPERS ---*/ 1234 /*------------------------------------------------------------*/ 1235 1236 static void* dinfo_zalloc(HChar* ec, SizeT n) { 1237 void* p; 1238 vg_assert(n > 0); 1239 p = VG_(arena_malloc)(VG_AR_DINFO, ec, n); 1240 tl_assert(p); 1241 VG_(memset)(p, 0, n); 1242 return p; 1243 } 1244 1245 static void dinfo_free(void* p) { 1246 tl_assert(p); 1247 return VG_(arena_free)(VG_AR_DINFO, p); 1248 } 1249 1250 static HChar* dinfo_strdup(HChar* ec, HChar* str) 1251 { 1252 return VG_(arena_strdup)(VG_AR_DINFO, ec, str); 1253 } 1254 1255 /* Really this should be merged with translations_allowable_from_seg 1256 in m_translate. */ 1257 static Bool is_plausible_guest_addr(Addr a) 1258 { 1259 NSegment const* seg = VG_(am_find_nsegment)(a); 1260 return seg != NULL 1261 && (seg->kind == SkAnonC || seg->kind == SkFileC) 1262 && (seg->hasX || seg->hasR); /* crude x86-specific hack */ 1263 } 1264 1265 1266 /*------------------------------------------------------------*/ 1267 /*--- NOTIFY-ON-LOAD FUNCTIONS ---*/ 1268 /*------------------------------------------------------------*/ 1269 1270 static 1271 void handle_maybe_load_notifier( const UChar* soname, 1272 HChar* symbol, Addr addr ) 1273 { 1274 # if defined(VGP_x86_linux) 1275 /* x86-linux only: if we see _dl_sysinfo_int80, note its address. 1276 See comment on declaration of VG_(client__dl_sysinfo_int80) for 1277 the reason. As far as I can tell, the relevant symbol is always 1278 in object with soname "ld-linux.so.2". */ 1279 if (symbol && symbol[0] == '_' 1280 && 0 == VG_(strcmp)(symbol, "_dl_sysinfo_int80") 1281 && 0 == VG_(strcmp)(soname, "ld-linux.so.2")) { 1282 if (VG_(client__dl_sysinfo_int80) == 0) 1283 VG_(client__dl_sysinfo_int80) = addr; 1284 } 1285 # endif 1286 1287 /* Normal load-notifier handling after here. First, ignore all 1288 symbols lacking the right prefix. */ 1289 vg_assert(symbol); // assert rather than segfault if it is NULL 1290 if (0 != VG_(strncmp)(symbol, VG_NOTIFY_ON_LOAD_PREFIX, 1291 VG_NOTIFY_ON_LOAD_PREFIX_LEN)) 1292 /* Doesn't have the right prefix */ 1293 return; 1294 1295 if (VG_(strcmp)(symbol, VG_STRINGIFY(VG_NOTIFY_ON_LOAD(freeres))) == 0) 1296 VG_(client___libc_freeres_wrapper) = addr; 1297 else 1298 if (VG_(strcmp)(symbol, VG_STRINGIFY(VG_NOTIFY_ON_LOAD(ifunc_wrapper))) == 0) 1299 iFuncWrapper = addr; 1300 else 1301 vg_assert2(0, "unrecognised load notification function: %s", symbol); 1302 } 1303 1304 1305 /*------------------------------------------------------------*/ 1306 /*--- REQUIRE-TEXT-SYMBOL HANDLING ---*/ 1307 /*------------------------------------------------------------*/ 1308 1309 /* In short: check that the currently-being-loaded object has text 1310 symbols that satisfy any --require-text-symbol= specifications that 1311 apply to it, and abort the run with an error message if not. 1312 */ 1313 static void handle_require_text_symbols ( DebugInfo* di ) 1314 { 1315 /* First thing to do is figure out which, if any, 1316 --require-text-symbol specification strings apply to this 1317 object. Most likely none do, since it is not expected to 1318 frequently be used. Work through the list of specs and 1319 accumulate in fnpatts[] the fn patterns that pertain to this 1320 object. */ 1321 HChar* fnpatts[VG_CLO_MAX_REQ_TSYMS]; 1322 Int fnpatts_used = 0; 1323 Int i, j; 1324 const HChar* di_soname = VG_(DebugInfo_get_soname)(di); 1325 vg_assert(di_soname); // must be present 1326 1327 VG_(memset)(&fnpatts, 0, sizeof(fnpatts)); 1328 1329 vg_assert(VG_(clo_n_req_tsyms) >= 0); 1330 vg_assert(VG_(clo_n_req_tsyms) <= VG_CLO_MAX_REQ_TSYMS); 1331 for (i = 0; i < VG_(clo_n_req_tsyms); i++) { 1332 HChar* spec = VG_(clo_req_tsyms)[i]; 1333 vg_assert(spec && VG_(strlen)(spec) >= 4); 1334 // clone the spec, so we can stick a zero at the end of the sopatt 1335 spec = VG_(strdup)("m_redir.hrts.1", spec); 1336 HChar sep = spec[0]; 1337 HChar* sopatt = &spec[1]; 1338 HChar* fnpatt = VG_(strchr)(sopatt, sep); 1339 // the initial check at clo processing in time in m_main 1340 // should ensure this. 1341 vg_assert(fnpatt && *fnpatt == sep); 1342 *fnpatt = 0; 1343 fnpatt++; 1344 if (VG_(string_match)(sopatt, di_soname)) 1345 fnpatts[fnpatts_used++] 1346 = VG_(strdup)("m_redir.hrts.2", fnpatt); 1347 VG_(free)(spec); 1348 } 1349 1350 if (fnpatts_used == 0) 1351 return; /* no applicable spec strings */ 1352 1353 /* So finally, fnpatts[0 .. fnpatts_used - 1] contains the set of 1354 (patterns for) text symbol names that must be found in this 1355 object, in order to continue. That is, we must find at least 1356 one text symbol name that matches each pattern, else we must 1357 abort the run. */ 1358 1359 if (0) VG_(printf)("for %s\n", di_soname); 1360 for (i = 0; i < fnpatts_used; i++) 1361 if (0) VG_(printf)(" fnpatt: %s\n", fnpatts[i]); 1362 1363 /* For each spec, look through the syms to find one that matches. 1364 This isn't terribly efficient but it happens rarely, so no big 1365 deal. */ 1366 for (i = 0; i < fnpatts_used; i++) { 1367 Bool found = False; 1368 HChar* fnpatt = fnpatts[i]; 1369 Int nsyms = VG_(DebugInfo_syms_howmany)(di); 1370 for (j = 0; j < nsyms; j++) { 1371 Bool isText = False; 1372 UChar* sym_name_pri = NULL; 1373 UChar** sym_names_sec = NULL; 1374 VG_(DebugInfo_syms_getidx)( di, j, NULL, NULL, 1375 NULL, &sym_name_pri, &sym_names_sec, 1376 &isText, NULL ); 1377 UChar* twoslots[2]; 1378 UChar** names_init = alloc_symname_array(sym_name_pri, sym_names_sec, 1379 &twoslots[0]); 1380 UChar** names; 1381 for (names = names_init; *names; names++) { 1382 /* ignore data symbols */ 1383 if (0) VG_(printf)("QQQ %s\n", *names); 1384 vg_assert(sym_name_pri); 1385 if (!isText) 1386 continue; 1387 if (VG_(string_match)(fnpatt, *names)) { 1388 found = True; 1389 break; 1390 } 1391 } 1392 free_symname_array(names_init, &twoslots[0]); 1393 if (found) 1394 break; 1395 } 1396 1397 if (!found) { 1398 HChar* v = "valgrind: "; 1399 VG_(printf)("\n"); 1400 VG_(printf)( 1401 "%sFatal error at when loading library with soname\n", v); 1402 VG_(printf)( 1403 "%s %s\n", v, di_soname); 1404 VG_(printf)( 1405 "%sCannot find any text symbol with a name " 1406 "that matches the pattern\n", v); 1407 VG_(printf)("%s %s\n", v, fnpatt); 1408 VG_(printf)("%sas required by a --require-text-symbol= " 1409 "specification.\n", v); 1410 VG_(printf)("\n"); 1411 VG_(printf)( 1412 "%sCannot continue -- exiting now.\n", v); 1413 VG_(printf)("\n"); 1414 VG_(exit)(1); 1415 } 1416 } 1417 1418 /* All required specs were found. Just free memory and return. */ 1419 for (i = 0; i < fnpatts_used; i++) 1420 VG_(free)(fnpatts[i]); 1421 } 1422 1423 1424 /*------------------------------------------------------------*/ 1425 /*--- SANITY/DEBUG ---*/ 1426 /*------------------------------------------------------------*/ 1427 1428 static void show_spec ( HChar* left, Spec* spec ) 1429 { 1430 VG_(message)( Vg_DebugMsg, 1431 "%s%25s %30s %s-> (%04d.%d) 0x%08llx\n", 1432 left, 1433 spec->from_sopatt, spec->from_fnpatt, 1434 spec->isWrap ? "W" : "R", 1435 spec->becTag, spec->becPrio, 1436 (ULong)spec->to_addr ); 1437 } 1438 1439 static void show_active ( HChar* left, Active* act ) 1440 { 1441 Bool ok; 1442 HChar name1[64] = ""; 1443 HChar name2[64] = ""; 1444 name1[0] = name2[0] = 0; 1445 ok = VG_(get_fnname_w_offset)(act->from_addr, name1, 64); 1446 if (!ok) VG_(strcpy)(name1, "???"); 1447 ok = VG_(get_fnname_w_offset)(act->to_addr, name2, 64); 1448 if (!ok) VG_(strcpy)(name2, "???"); 1449 1450 VG_(message)(Vg_DebugMsg, "%s0x%08llx (%20s) %s-> (%04d.%d) 0x%08llx %s\n", 1451 left, 1452 (ULong)act->from_addr, name1, 1453 act->isWrap ? "W" : "R", 1454 act->becTag, act->becPrio, 1455 (ULong)act->to_addr, name2 ); 1456 } 1457 1458 static void show_redir_state ( HChar* who ) 1459 { 1460 TopSpec* ts; 1461 Spec* sp; 1462 Active* act; 1463 VG_(message)(Vg_DebugMsg, "<<\n"); 1464 VG_(message)(Vg_DebugMsg, " ------ REDIR STATE %s ------\n", who); 1465 for (ts = topSpecs; ts; ts = ts->next) { 1466 VG_(message)(Vg_DebugMsg, 1467 " TOPSPECS of soname %s\n", 1468 ts->seginfo 1469 ? (HChar*)VG_(DebugInfo_get_soname)(ts->seginfo) 1470 : "(hardwired)" ); 1471 for (sp = ts->specs; sp; sp = sp->next) 1472 show_spec(" ", sp); 1473 } 1474 VG_(message)(Vg_DebugMsg, " ------ ACTIVE ------\n"); 1475 VG_(OSetGen_ResetIter)( activeSet ); 1476 while ( (act = VG_(OSetGen_Next)(activeSet)) ) { 1477 show_active(" ", act); 1478 } 1479 1480 VG_(message)(Vg_DebugMsg, ">>\n"); 1481 } 1482 1483 /*--------------------------------------------------------------------*/ 1484 /*--- end ---*/ 1485 /*--------------------------------------------------------------------*/ 1486
