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1 
2 /*--------------------------------------------------------------------*/
3 /*--- Management, printing, etc, of errors and suppressions.       ---*/
4 /*---                                                  mc_errors.c ---*/
5 /*--------------------------------------------------------------------*/
6 
7 /*
8    This file is part of MemCheck, a heavyweight Valgrind tool for
9    detecting memory errors.
10 
11    Copyright (C) 2000-2015 Julian Seward
12       jseward@acm.org
13 
14    This program is free software; you can redistribute it and/or
15    modify it under the terms of the GNU General Public License as
16    published by the Free Software Foundation; either version 2 of the
17    License, or (at your option) any later version.
18 
19    This program is distributed in the hope that it will be useful, but
20    WITHOUT ANY WARRANTY; without even the implied warranty of
21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22    General Public License for more details.
23 
24    You should have received a copy of the GNU General Public License
25    along with this program; if not, write to the Free Software
26    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
27    02111-1307, USA.
28 
29    The GNU General Public License is contained in the file COPYING.
30 */
31 
32 #include "pub_tool_basics.h"
33 #include "pub_tool_gdbserver.h"
34 #include "pub_tool_poolalloc.h"     // For mc_include.h
35 #include "pub_tool_hashtable.h"     // For mc_include.h
36 #include "pub_tool_libcbase.h"
37 #include "pub_tool_libcassert.h"
38 #include "pub_tool_libcprint.h"
39 #include "pub_tool_machine.h"
40 #include "pub_tool_mallocfree.h"
41 #include "pub_tool_options.h"
42 #include "pub_tool_replacemalloc.h"
43 #include "pub_tool_tooliface.h"
44 #include "pub_tool_threadstate.h"
45 #include "pub_tool_debuginfo.h"     // VG_(get_dataname_and_offset)
46 #include "pub_tool_xarray.h"
47 #include "pub_tool_aspacemgr.h"
48 #include "pub_tool_addrinfo.h"
49 
50 #include "mc_include.h"
51 
52 
53 /*------------------------------------------------------------*/
54 /*--- Error types                                          ---*/
55 /*------------------------------------------------------------*/
56 
57 /* See comment in mc_include.h */
58 Bool MC_(any_value_errors) = False;
59 
60 
61 /* ------------------ Errors ----------------------- */
62 
63 /* What kind of error it is. */
64 typedef
65    enum {
66       Err_Value,
67       Err_Cond,
68       Err_CoreMem,
69       Err_Addr,
70       Err_Jump,
71       Err_RegParam,
72       Err_MemParam,
73       Err_User,
74       Err_Free,
75       Err_FreeMismatch,
76       Err_Overlap,
77       Err_Leak,
78       Err_IllegalMempool,
79       Err_FishyValue,
80    }
81    MC_ErrorTag;
82 
83 
84 typedef struct _MC_Error MC_Error;
85 
86 struct _MC_Error {
87    // Nb: we don't need the tag here, as it's stored in the Error type! Yuk.
88    //MC_ErrorTag tag;
89 
90    union {
91       // Use of an undefined value:
92       // - as a pointer in a load or store
93       // - as a jump target
94       struct {
95          SizeT szB;   // size of value in bytes
96          // Origin info
97          UInt        otag;      // origin tag
98          ExeContext* origin_ec; // filled in later
99       } Value;
100 
101       // Use of an undefined value in a conditional branch or move.
102       struct {
103          // Origin info
104          UInt        otag;      // origin tag
105          ExeContext* origin_ec; // filled in later
106       } Cond;
107 
108       // Addressability error in core (signal-handling) operation.
109       // It would be good to get rid of this error kind, merge it with
110       // another one somehow.
111       struct {
112       } CoreMem;
113 
114       // Use of an unaddressable memory location in a load or store.
115       struct {
116          Bool     isWrite;    // read or write?
117          SizeT    szB;        // not used for exec (jump) errors
118          Bool     maybe_gcc;  // True if just below %esp -- could be a gcc bug
119          AddrInfo ai;
120       } Addr;
121 
122       // Jump to an unaddressable memory location.
123       struct {
124          AddrInfo ai;
125       } Jump;
126 
127       // System call register input contains undefined bytes.
128       struct {
129          // Origin info
130          UInt        otag;      // origin tag
131          ExeContext* origin_ec; // filled in later
132       } RegParam;
133 
134       // System call memory input contains undefined/unaddressable bytes
135       struct {
136          Bool     isAddrErr;  // Addressability or definedness error?
137          AddrInfo ai;
138          // Origin info
139          UInt        otag;      // origin tag
140          ExeContext* origin_ec; // filled in later
141       } MemParam;
142 
143       // Problem found from a client request like CHECK_MEM_IS_ADDRESSABLE.
144       struct {
145          Bool     isAddrErr;  // Addressability or definedness error?
146          AddrInfo ai;
147          // Origin info
148          UInt        otag;      // origin tag
149          ExeContext* origin_ec; // filled in later
150       } User;
151 
152       // Program tried to free() something that's not a heap block (this
153       // covers double-frees). */
154       struct {
155          AddrInfo ai;
156       } Free;
157 
158       // Program allocates heap block with one function
159       // (malloc/new/new[]/custom) and deallocates with not the matching one.
160       struct {
161          AddrInfo ai;
162       } FreeMismatch;
163 
164       // Call to strcpy, memcpy, etc, with overlapping blocks.
165       struct {
166          Addr  src;   // Source block
167          Addr  dst;   // Destination block
168          SizeT szB;   // Size in bytes;  0 if unused.
169       } Overlap;
170 
171       // A memory leak.
172       struct {
173          UInt        n_this_record;
174          UInt        n_total_records;
175          LossRecord* lr;
176       } Leak;
177 
178       // A memory pool error.
179       struct {
180          AddrInfo ai;
181       } IllegalMempool;
182 
183       // A fishy function argument value
184       // An argument value is considered fishy if the corresponding
185       // parameter has SizeT type and the value when interpreted as a
186       // signed number is negative.
187      struct {
188          const HChar *function_name;
189          const HChar *argument_name;
190          SizeT value;
191       } FishyValue;
192    } Err;
193 };
194 
195 
196 /*------------------------------------------------------------*/
197 /*--- Printing errors                                      ---*/
198 /*------------------------------------------------------------*/
199 
200 /* This is the "this error is due to be printed shortly; so have a
201    look at it any print any preamble you want" function.  Which, in
202    Memcheck, we don't use.  Hence a no-op.
203 */
MC_(before_pp_Error)204 void MC_(before_pp_Error) ( const Error* err ) {
205 }
206 
207 /* Do a printf-style operation on either the XML or normal output
208    channel, depending on the setting of VG_(clo_xml).
209 */
emit_WRK(const HChar * format,va_list vargs)210 static void emit_WRK ( const HChar* format, va_list vargs )
211 {
212    if (VG_(clo_xml)) {
213       VG_(vprintf_xml)(format, vargs);
214    } else {
215       VG_(vmessage)(Vg_UserMsg, format, vargs);
216    }
217 }
218 static void emit ( const HChar* format, ... ) PRINTF_CHECK(1, 2);
emit(const HChar * format,...)219 static void emit ( const HChar* format, ... )
220 {
221    va_list vargs;
222    va_start(vargs, format);
223    emit_WRK(format, vargs);
224    va_end(vargs);
225 }
226 
227 
str_leak_lossmode(Reachedness lossmode)228 static const HChar* str_leak_lossmode ( Reachedness lossmode )
229 {
230    const HChar *loss = "?";
231    switch (lossmode) {
232       case Unreached:    loss = "definitely lost"; break;
233       case IndirectLeak: loss = "indirectly lost"; break;
234       case Possible:     loss = "possibly lost"; break;
235       case Reachable:    loss = "still reachable"; break;
236    }
237    return loss;
238 }
239 
xml_leak_kind(Reachedness lossmode)240 static const HChar* xml_leak_kind ( Reachedness lossmode )
241 {
242    const HChar *loss = "?";
243    switch (lossmode) {
244       case Unreached:    loss = "Leak_DefinitelyLost"; break;
245       case IndirectLeak: loss = "Leak_IndirectlyLost"; break;
246       case Possible:     loss = "Leak_PossiblyLost"; break;
247       case Reachable:    loss = "Leak_StillReachable"; break;
248    }
249    return loss;
250 }
251 
252 const HChar* MC_(parse_leak_kinds_tokens) =
253    "reachable,possible,indirect,definite";
254 
MC_(all_Reachedness)255 UInt MC_(all_Reachedness)(void)
256 {
257    static UInt all;
258 
259    if (all == 0) {
260       // Compute a set with all values by doing a parsing of the "all" keyword.
261       Bool parseok = VG_(parse_enum_set)(MC_(parse_leak_kinds_tokens),
262                                          True,/*allow_all*/
263                                          "all",
264                                          &all);
265       tl_assert (parseok && all);
266    }
267 
268    return all;
269 }
270 
pp_Reachedness_for_leak_kinds(Reachedness r)271 static const HChar* pp_Reachedness_for_leak_kinds(Reachedness r)
272 {
273    switch(r) {
274    case Reachable:    return "reachable";
275    case Possible:     return "possible";
276    case IndirectLeak: return "indirect";
277    case Unreached:    return "definite";
278    default:           tl_assert(0);
279    }
280 }
281 
mc_pp_origin(ExeContext * ec,UInt okind)282 static void mc_pp_origin ( ExeContext* ec, UInt okind )
283 {
284    const HChar* src = NULL;
285    tl_assert(ec);
286 
287    switch (okind) {
288       case MC_OKIND_STACK:   src = " by a stack allocation"; break;
289       case MC_OKIND_HEAP:    src = " by a heap allocation"; break;
290       case MC_OKIND_USER:    src = " by a client request"; break;
291       case MC_OKIND_UNKNOWN: src = ""; break;
292    }
293    tl_assert(src); /* guards against invalid 'okind' */
294 
295    if (VG_(clo_xml)) {
296       emit( "  <auxwhat>Uninitialised value was created%s</auxwhat>\n",
297             src);
298       VG_(pp_ExeContext)( ec );
299    } else {
300       emit( " Uninitialised value was created%s\n", src);
301       VG_(pp_ExeContext)( ec );
302    }
303 }
304 
MC_(snprintf_delta)305 HChar * MC_(snprintf_delta) (HChar * buf, Int size,
306                              SizeT current_val, SizeT old_val,
307                              LeakCheckDeltaMode delta_mode)
308 {
309    // Make sure the buffer size is large enough. With old_val == 0 and
310    // current_val == ULLONG_MAX the delta including inserted commas is:
311    // 18,446,744,073,709,551,615
312    // whose length is 26. Therefore:
313    tl_assert(size >= 26 + 4 + 1);
314 
315    if (delta_mode == LCD_Any)
316       buf[0] = '\0';
317    else if (current_val >= old_val)
318       VG_(snprintf) (buf, size, " (+%'lu)", current_val - old_val);
319    else
320       VG_(snprintf) (buf, size, " (-%'lu)", old_val - current_val);
321 
322    return buf;
323 }
324 
pp_LossRecord(UInt n_this_record,UInt n_total_records,LossRecord * lr,Bool xml)325 static void pp_LossRecord(UInt n_this_record, UInt n_total_records,
326                           LossRecord* lr, Bool xml)
327 {
328    // char arrays to produce the indication of increase/decrease in case
329    // of delta_mode != LCD_Any
330    HChar d_bytes[31];
331    HChar d_direct_bytes[31];
332    HChar d_indirect_bytes[31];
333    HChar d_num_blocks[31];
334 
335    MC_(snprintf_delta) (d_bytes, sizeof(d_bytes),
336                         lr->szB + lr->indirect_szB,
337                         lr->old_szB + lr->old_indirect_szB,
338                         MC_(detect_memory_leaks_last_delta_mode));
339    MC_(snprintf_delta) (d_direct_bytes, sizeof(d_direct_bytes),
340                         lr->szB,
341                         lr->old_szB,
342                         MC_(detect_memory_leaks_last_delta_mode));
343    MC_(snprintf_delta) (d_indirect_bytes, sizeof(d_indirect_bytes),
344                         lr->indirect_szB,
345                         lr->old_indirect_szB,
346                         MC_(detect_memory_leaks_last_delta_mode));
347    MC_(snprintf_delta) (d_num_blocks, sizeof(d_num_blocks),
348                         (SizeT) lr->num_blocks,
349                         (SizeT) lr->old_num_blocks,
350                         MC_(detect_memory_leaks_last_delta_mode));
351 
352    if (xml) {
353       emit("  <kind>%s</kind>\n", xml_leak_kind(lr->key.state));
354       if (lr->indirect_szB > 0) {
355          emit( "  <xwhat>\n" );
356          emit( "    <text>%'lu%s (%'lu%s direct, %'lu%s indirect) bytes "
357                "in %'u%s blocks"
358                " are %s in loss record %'u of %'u</text>\n",
359                lr->szB + lr->indirect_szB, d_bytes,
360                lr->szB, d_direct_bytes,
361                lr->indirect_szB, d_indirect_bytes,
362                lr->num_blocks, d_num_blocks,
363                str_leak_lossmode(lr->key.state),
364                n_this_record, n_total_records );
365          // Nb: don't put commas in these XML numbers
366          emit( "    <leakedbytes>%lu</leakedbytes>\n",
367                lr->szB + lr->indirect_szB );
368          emit( "    <leakedblocks>%u</leakedblocks>\n", lr->num_blocks );
369          emit( "  </xwhat>\n" );
370       } else {
371          emit( "  <xwhat>\n" );
372          emit( "    <text>%'lu%s bytes in %'u%s blocks"
373                " are %s in loss record %'u of %'u</text>\n",
374                lr->szB, d_direct_bytes,
375                lr->num_blocks, d_num_blocks,
376                str_leak_lossmode(lr->key.state),
377                n_this_record, n_total_records );
378          emit( "    <leakedbytes>%lu</leakedbytes>\n", lr->szB);
379          emit( "    <leakedblocks>%u</leakedblocks>\n", lr->num_blocks);
380          emit( "  </xwhat>\n" );
381       }
382       VG_(pp_ExeContext)(lr->key.allocated_at);
383    } else { /* ! if (xml) */
384       if (lr->indirect_szB > 0) {
385          emit(
386             "%'lu%s (%'lu%s direct, %'lu%s indirect) bytes in %'u%s blocks"
387             " are %s in loss record %'u of %'u\n",
388             lr->szB + lr->indirect_szB, d_bytes,
389             lr->szB, d_direct_bytes,
390             lr->indirect_szB, d_indirect_bytes,
391             lr->num_blocks, d_num_blocks,
392             str_leak_lossmode(lr->key.state),
393             n_this_record, n_total_records
394          );
395       } else {
396          emit(
397             "%'lu%s bytes in %'u%s blocks are %s in loss record %'u of %'u\n",
398             lr->szB, d_direct_bytes,
399             lr->num_blocks, d_num_blocks,
400             str_leak_lossmode(lr->key.state),
401             n_this_record, n_total_records
402          );
403       }
404       VG_(pp_ExeContext)(lr->key.allocated_at);
405    } /* if (xml) */
406 }
407 
MC_(pp_LossRecord)408 void MC_(pp_LossRecord)(UInt n_this_record, UInt n_total_records,
409                         LossRecord* l)
410 {
411    pp_LossRecord (n_this_record, n_total_records, l, /* xml */ False);
412 }
413 
MC_(pp_Error)414 void MC_(pp_Error) ( const Error* err )
415 {
416    const Bool xml  = VG_(clo_xml); /* a shorthand */
417    MC_Error* extra = VG_(get_error_extra)(err);
418 
419    switch (VG_(get_error_kind)(err)) {
420       case Err_CoreMem:
421          /* What the hell *is* a CoreMemError? jrs 2005-May-18 */
422          /* As of 2006-Dec-14, it's caused by unaddressable bytes in a
423             signal handler frame.  --njn */
424          // JRS 17 May 09: None of our regtests exercise this; hence AFAIK
425          // the following code is untested.  Bad.
426          if (xml) {
427             emit( "  <kind>CoreMemError</kind>\n" );
428             emit( "  <what>%pS contains unaddressable byte(s)</what>\n",
429                   VG_(get_error_string)(err));
430             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
431          } else {
432             emit( "%s contains unaddressable byte(s)\n",
433                   VG_(get_error_string)(err));
434             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
435          }
436          break;
437 
438       case Err_Value:
439          MC_(any_value_errors) = True;
440          if (xml) {
441             emit( "  <kind>UninitValue</kind>\n" );
442             emit( "  <what>Use of uninitialised value of size %lu</what>\n",
443                   extra->Err.Value.szB );
444             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
445             if (extra->Err.Value.origin_ec)
446                mc_pp_origin( extra->Err.Value.origin_ec,
447                             extra->Err.Value.otag & 3 );
448          } else {
449             /* Could also show extra->Err.Cond.otag if debugging origin
450                tracking */
451             emit( "Use of uninitialised value of size %lu\n",
452                   extra->Err.Value.szB );
453             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
454             if (extra->Err.Value.origin_ec)
455                mc_pp_origin( extra->Err.Value.origin_ec,
456                             extra->Err.Value.otag & 3 );
457          }
458          break;
459 
460       case Err_Cond:
461          MC_(any_value_errors) = True;
462          if (xml) {
463             emit( "  <kind>UninitCondition</kind>\n" );
464             emit( "  <what>Conditional jump or move depends"
465                   " on uninitialised value(s)</what>\n" );
466             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
467             if (extra->Err.Cond.origin_ec)
468                mc_pp_origin( extra->Err.Cond.origin_ec,
469                              extra->Err.Cond.otag & 3 );
470          } else {
471             /* Could also show extra->Err.Cond.otag if debugging origin
472                tracking */
473             emit( "Conditional jump or move depends"
474                   " on uninitialised value(s)\n" );
475             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
476             if (extra->Err.Cond.origin_ec)
477                mc_pp_origin( extra->Err.Cond.origin_ec,
478                              extra->Err.Cond.otag & 3 );
479          }
480          break;
481 
482       case Err_RegParam:
483          MC_(any_value_errors) = True;
484          if (xml) {
485             emit( "  <kind>SyscallParam</kind>\n" );
486             emit( "  <what>Syscall param %pS contains "
487                   "uninitialised byte(s)</what>\n",
488                   VG_(get_error_string)(err) );
489             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
490             if (extra->Err.RegParam.origin_ec)
491                mc_pp_origin( extra->Err.RegParam.origin_ec,
492                              extra->Err.RegParam.otag & 3 );
493          } else {
494             emit( "Syscall param %s contains uninitialised byte(s)\n",
495                   VG_(get_error_string)(err) );
496             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
497             if (extra->Err.RegParam.origin_ec)
498                mc_pp_origin( extra->Err.RegParam.origin_ec,
499                              extra->Err.RegParam.otag & 3 );
500          }
501          break;
502 
503       case Err_MemParam:
504          if (!extra->Err.MemParam.isAddrErr)
505             MC_(any_value_errors) = True;
506          if (xml) {
507             emit( "  <kind>SyscallParam</kind>\n" );
508             emit( "  <what>Syscall param %pS points to %s byte(s)</what>\n",
509                   VG_(get_error_string)(err),
510                   extra->Err.MemParam.isAddrErr
511                      ? "unaddressable" : "uninitialised" );
512             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
513             VG_(pp_addrinfo_mc)(VG_(get_error_address)(err),
514                                 &extra->Err.MemParam.ai, False);
515             if (extra->Err.MemParam.origin_ec
516                 && !extra->Err.MemParam.isAddrErr)
517                mc_pp_origin( extra->Err.MemParam.origin_ec,
518                              extra->Err.MemParam.otag & 3 );
519          } else {
520             emit( "Syscall param %s points to %s byte(s)\n",
521                   VG_(get_error_string)(err),
522                   extra->Err.MemParam.isAddrErr
523                      ? "unaddressable" : "uninitialised" );
524             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
525             VG_(pp_addrinfo_mc)(VG_(get_error_address)(err),
526                                 &extra->Err.MemParam.ai, False);
527             if (extra->Err.MemParam.origin_ec
528                 && !extra->Err.MemParam.isAddrErr)
529                mc_pp_origin( extra->Err.MemParam.origin_ec,
530                              extra->Err.MemParam.otag & 3 );
531          }
532          break;
533 
534       case Err_User:
535          if (!extra->Err.User.isAddrErr)
536             MC_(any_value_errors) = True;
537          if (xml) {
538             emit( "  <kind>ClientCheck</kind>\n" );
539             emit( "  <what>%s byte(s) found "
540                   "during client check request</what>\n",
541                    extra->Err.User.isAddrErr
542                       ? "Unaddressable" : "Uninitialised" );
543             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
544             VG_(pp_addrinfo_mc)(VG_(get_error_address)(err), &extra->Err.User.ai,
545                                 False);
546             if (extra->Err.User.origin_ec && !extra->Err.User.isAddrErr)
547                mc_pp_origin( extra->Err.User.origin_ec,
548                              extra->Err.User.otag & 3 );
549          } else {
550             emit( "%s byte(s) found during client check request\n",
551                    extra->Err.User.isAddrErr
552                       ? "Unaddressable" : "Uninitialised" );
553             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
554             VG_(pp_addrinfo_mc)(VG_(get_error_address)(err), &extra->Err.User.ai,
555                                 False);
556             if (extra->Err.User.origin_ec && !extra->Err.User.isAddrErr)
557                mc_pp_origin( extra->Err.User.origin_ec,
558                              extra->Err.User.otag & 3 );
559          }
560          break;
561 
562       case Err_Free:
563          if (xml) {
564             emit( "  <kind>InvalidFree</kind>\n" );
565             emit( "  <what>Invalid free() / delete / delete[]"
566                   " / realloc()</what>\n" );
567             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
568             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err),
569                                  &extra->Err.Free.ai, False );
570          } else {
571             emit( "Invalid free() / delete / delete[] / realloc()\n" );
572             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
573             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err),
574                                  &extra->Err.Free.ai, False );
575          }
576          break;
577 
578       case Err_FreeMismatch:
579          if (xml) {
580             emit( "  <kind>MismatchedFree</kind>\n" );
581             emit( "  <what>Mismatched free() / delete / delete []</what>\n" );
582             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
583             VG_(pp_addrinfo_mc)(VG_(get_error_address)(err),
584                                 &extra->Err.FreeMismatch.ai, False);
585          } else {
586             emit( "Mismatched free() / delete / delete []\n" );
587             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
588             VG_(pp_addrinfo_mc)(VG_(get_error_address)(err),
589                                 &extra->Err.FreeMismatch.ai, False);
590          }
591          break;
592 
593       case Err_Addr:
594          if (xml) {
595             emit( "  <kind>Invalid%s</kind>\n",
596                   extra->Err.Addr.isWrite ? "Write" : "Read"  );
597             emit( "  <what>Invalid %s of size %lu</what>\n",
598                   extra->Err.Addr.isWrite ? "write" : "read",
599                   extra->Err.Addr.szB );
600             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
601             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err),
602                                  &extra->Err.Addr.ai,
603                                  extra->Err.Addr.maybe_gcc );
604          } else {
605             emit( "Invalid %s of size %lu\n",
606                   extra->Err.Addr.isWrite ? "write" : "read",
607                   extra->Err.Addr.szB );
608             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
609 
610             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err),
611                                  &extra->Err.Addr.ai,
612                                  extra->Err.Addr.maybe_gcc );
613          }
614          break;
615 
616       case Err_Jump:
617          if (xml) {
618             emit( "  <kind>InvalidJump</kind>\n" );
619             emit( "  <what>Jump to the invalid address stated "
620                   "on the next line</what>\n" );
621             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
622             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err), &extra->Err.Jump.ai,
623                                  False );
624          } else {
625             emit( "Jump to the invalid address stated on the next line\n" );
626             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
627             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err), &extra->Err.Jump.ai,
628                                  False );
629          }
630          break;
631 
632       case Err_Overlap:
633          if (xml) {
634             emit( "  <kind>Overlap</kind>\n" );
635             if (extra->Err.Overlap.szB == 0) {
636                emit( "  <what>Source and destination overlap "
637                      "in %pS(%#lx, %#lx)\n</what>\n",
638                      VG_(get_error_string)(err),
639                      extra->Err.Overlap.dst, extra->Err.Overlap.src );
640             } else {
641                emit( "  <what>Source and destination overlap "
642                      "in %pS(%#lx, %#lx, %lu)</what>\n",
643                      VG_(get_error_string)(err),
644                      extra->Err.Overlap.dst, extra->Err.Overlap.src,
645                      extra->Err.Overlap.szB );
646             }
647             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
648          } else {
649             if (extra->Err.Overlap.szB == 0) {
650                emit( "Source and destination overlap in %s(%#lx, %#lx)\n",
651                      VG_(get_error_string)(err),
652                      extra->Err.Overlap.dst, extra->Err.Overlap.src );
653             } else {
654                emit( "Source and destination overlap in %s(%#lx, %#lx, %lu)\n",
655                      VG_(get_error_string)(err),
656                      extra->Err.Overlap.dst, extra->Err.Overlap.src,
657                      extra->Err.Overlap.szB );
658             }
659             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
660          }
661          break;
662 
663       case Err_IllegalMempool:
664          // JRS 17 May 09: None of our regtests exercise this; hence AFAIK
665          // the following code is untested.  Bad.
666          if (xml) {
667             emit( "  <kind>InvalidMemPool</kind>\n" );
668             emit( "  <what>Illegal memory pool address</what>\n" );
669             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
670             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err),
671                                  &extra->Err.IllegalMempool.ai, False );
672          } else {
673             emit( "Illegal memory pool address\n" );
674             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
675             VG_(pp_addrinfo_mc)( VG_(get_error_address)(err),
676                                  &extra->Err.IllegalMempool.ai, False );
677          }
678          break;
679 
680       case Err_Leak: {
681          UInt        n_this_record   = extra->Err.Leak.n_this_record;
682          UInt        n_total_records = extra->Err.Leak.n_total_records;
683          LossRecord* lr              = extra->Err.Leak.lr;
684          pp_LossRecord (n_this_record, n_total_records, lr, xml);
685          break;
686       }
687 
688       case Err_FishyValue:
689          if (xml) {
690             emit( "  <kind>FishyValue</kind>\n" );
691             emit( "  <what>");
692             emit( "Argument '%s' of function %s has a fishy "
693                   "(possibly negative) value: %ld\n",
694                   extra->Err.FishyValue.argument_name,
695                   extra->Err.FishyValue.function_name,
696                   (SSizeT)extra->Err.FishyValue.value);
697             emit( "</what>");
698             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
699          } else {
700             emit( "Argument '%s' of function %s has a fishy "
701                   "(possibly negative) value: %ld\n",
702                   extra->Err.FishyValue.argument_name,
703                   extra->Err.FishyValue.function_name,
704                   (SSizeT)extra->Err.FishyValue.value);
705             VG_(pp_ExeContext)( VG_(get_error_where)(err) );
706          }
707          break;
708 
709       default:
710          VG_(printf)("Error:\n  unknown Memcheck error code %d\n",
711                      VG_(get_error_kind)(err));
712          VG_(tool_panic)("unknown error code in mc_pp_Error)");
713    }
714 }
715 
716 /*------------------------------------------------------------*/
717 /*--- Recording errors                                     ---*/
718 /*------------------------------------------------------------*/
719 
720 /* These many bytes below %ESP are considered addressible if we're
721    doing the --workaround-gcc296-bugs hack. */
722 #define VG_GCC296_BUG_STACK_SLOP 1024
723 
724 /* Is this address within some small distance below %ESP?  Used only
725    for the --workaround-gcc296-bugs kludge. */
is_just_below_ESP(Addr esp,Addr aa)726 static Bool is_just_below_ESP( Addr esp, Addr aa )
727 {
728    esp -= VG_STACK_REDZONE_SZB;
729    if (esp > aa && (esp - aa) <= VG_GCC296_BUG_STACK_SLOP)
730       return True;
731    else
732       return False;
733 }
734 
735 /* --- Called from generated and non-generated code --- */
736 
MC_(record_address_error)737 void MC_(record_address_error) ( ThreadId tid, Addr a, Int szB,
738                                  Bool isWrite )
739 {
740    MC_Error extra;
741    Bool     just_below_esp;
742 
743    if (MC_(in_ignored_range)(a))
744       return;
745 
746    if (VG_(is_watched)( (isWrite ? write_watchpoint : read_watchpoint), a, szB))
747       return;
748 
749    just_below_esp = is_just_below_ESP( VG_(get_SP)(tid), a );
750 
751    /* If this is caused by an access immediately below %ESP, and the
752       user asks nicely, we just ignore it. */
753    if (MC_(clo_workaround_gcc296_bugs) && just_below_esp)
754       return;
755 
756    extra.Err.Addr.isWrite   = isWrite;
757    extra.Err.Addr.szB       = szB;
758    extra.Err.Addr.maybe_gcc = just_below_esp;
759    extra.Err.Addr.ai.tag    = Addr_Undescribed;
760    VG_(maybe_record_error)( tid, Err_Addr, a, /*s*/NULL, &extra );
761 }
762 
MC_(record_value_error)763 void MC_(record_value_error) ( ThreadId tid, Int szB, UInt otag )
764 {
765    MC_Error extra;
766    tl_assert( MC_(clo_mc_level) >= 2 );
767    if (otag > 0)
768       tl_assert( MC_(clo_mc_level) == 3 );
769    extra.Err.Value.szB       = szB;
770    extra.Err.Value.otag      = otag;
771    extra.Err.Value.origin_ec = NULL;  /* Filled in later */
772    VG_(maybe_record_error)( tid, Err_Value, /*addr*/0, /*s*/NULL, &extra );
773 }
774 
MC_(record_cond_error)775 void MC_(record_cond_error) ( ThreadId tid, UInt otag )
776 {
777    MC_Error extra;
778    tl_assert( MC_(clo_mc_level) >= 2 );
779    if (otag > 0)
780       tl_assert( MC_(clo_mc_level) == 3 );
781    extra.Err.Cond.otag      = otag;
782    extra.Err.Cond.origin_ec = NULL;  /* Filled in later */
783    VG_(maybe_record_error)( tid, Err_Cond, /*addr*/0, /*s*/NULL, &extra );
784 }
785 
786 /* --- Called from non-generated code --- */
787 
788 /* This is for memory errors in signal-related memory. */
MC_(record_core_mem_error)789 void MC_(record_core_mem_error) ( ThreadId tid, const HChar* msg )
790 {
791    VG_(maybe_record_error)( tid, Err_CoreMem, /*addr*/0, msg, /*extra*/NULL );
792 }
793 
MC_(record_regparam_error)794 void MC_(record_regparam_error) ( ThreadId tid, const HChar* msg, UInt otag )
795 {
796    MC_Error extra;
797    tl_assert(VG_INVALID_THREADID != tid);
798    if (otag > 0)
799       tl_assert( MC_(clo_mc_level) == 3 );
800    extra.Err.RegParam.otag      = otag;
801    extra.Err.RegParam.origin_ec = NULL;  /* Filled in later */
802    VG_(maybe_record_error)( tid, Err_RegParam, /*addr*/0, msg, &extra );
803 }
804 
MC_(record_memparam_error)805 void MC_(record_memparam_error) ( ThreadId tid, Addr a,
806                                   Bool isAddrErr, const HChar* msg, UInt otag )
807 {
808    MC_Error extra;
809    tl_assert(VG_INVALID_THREADID != tid);
810    if (!isAddrErr)
811       tl_assert( MC_(clo_mc_level) >= 2 );
812    if (otag != 0) {
813       tl_assert( MC_(clo_mc_level) == 3 );
814       tl_assert( !isAddrErr );
815    }
816    extra.Err.MemParam.isAddrErr = isAddrErr;
817    extra.Err.MemParam.ai.tag    = Addr_Undescribed;
818    extra.Err.MemParam.otag      = otag;
819    extra.Err.MemParam.origin_ec = NULL;  /* Filled in later */
820    VG_(maybe_record_error)( tid, Err_MemParam, a, msg, &extra );
821 }
822 
MC_(record_jump_error)823 void MC_(record_jump_error) ( ThreadId tid, Addr a )
824 {
825    MC_Error extra;
826    tl_assert(VG_INVALID_THREADID != tid);
827    extra.Err.Jump.ai.tag = Addr_Undescribed;
828    VG_(maybe_record_error)( tid, Err_Jump, a, /*s*/NULL, &extra );
829 }
830 
MC_(record_free_error)831 void MC_(record_free_error) ( ThreadId tid, Addr a )
832 {
833    MC_Error extra;
834    tl_assert(VG_INVALID_THREADID != tid);
835    extra.Err.Free.ai.tag = Addr_Undescribed;
836    VG_(maybe_record_error)( tid, Err_Free, a, /*s*/NULL, &extra );
837 }
838 
MC_(record_freemismatch_error)839 void MC_(record_freemismatch_error) ( ThreadId tid, MC_Chunk* mc )
840 {
841    MC_Error extra;
842    AddrInfo* ai = &extra.Err.FreeMismatch.ai;
843    tl_assert(VG_INVALID_THREADID != tid);
844    ai->tag = Addr_Block;
845    ai->Addr.Block.block_kind = Block_Mallocd;  // Nb: Not 'Block_Freed'
846    ai->Addr.Block.block_desc = "block";
847    ai->Addr.Block.block_szB  = mc->szB;
848    ai->Addr.Block.rwoffset   = 0;
849    ai->Addr.Block.allocated_at = MC_(allocated_at) (mc);
850    VG_(initThreadInfo) (&ai->Addr.Block.alloc_tinfo);
851    ai->Addr.Block.freed_at = MC_(freed_at) (mc);
852    VG_(maybe_record_error)( tid, Err_FreeMismatch, mc->data, /*s*/NULL,
853                             &extra );
854 }
855 
MC_(record_illegal_mempool_error)856 void MC_(record_illegal_mempool_error) ( ThreadId tid, Addr a )
857 {
858    MC_Error extra;
859    tl_assert(VG_INVALID_THREADID != tid);
860    extra.Err.IllegalMempool.ai.tag = Addr_Undescribed;
861    VG_(maybe_record_error)( tid, Err_IllegalMempool, a, /*s*/NULL, &extra );
862 }
863 
MC_(record_overlap_error)864 void MC_(record_overlap_error) ( ThreadId tid, const HChar* function,
865                                  Addr src, Addr dst, SizeT szB )
866 {
867    MC_Error extra;
868    tl_assert(VG_INVALID_THREADID != tid);
869    extra.Err.Overlap.src = src;
870    extra.Err.Overlap.dst = dst;
871    extra.Err.Overlap.szB = szB;
872    VG_(maybe_record_error)(
873       tid, Err_Overlap, /*addr*/0, /*s*/function, &extra );
874 }
875 
MC_(record_leak_error)876 Bool MC_(record_leak_error) ( ThreadId tid, UInt n_this_record,
877                               UInt n_total_records, LossRecord* lr,
878                               Bool print_record, Bool count_error )
879 {
880    MC_Error extra;
881    extra.Err.Leak.n_this_record   = n_this_record;
882    extra.Err.Leak.n_total_records = n_total_records;
883    extra.Err.Leak.lr              = lr;
884    return
885    VG_(unique_error) ( tid, Err_Leak, /*Addr*/0, /*s*/NULL, &extra,
886                        lr->key.allocated_at, print_record,
887                        /*allow_GDB_attach*/False, count_error );
888 }
889 
MC_(record_fishy_value_error)890 Bool MC_(record_fishy_value_error) ( ThreadId tid, const HChar *function_name,
891                                      const HChar *argument_name, SizeT value)
892 {
893    MC_Error extra;
894 
895    tl_assert(VG_INVALID_THREADID != tid);
896 
897    if ((SSizeT)value >= 0) return False;  // not a fishy value
898 
899    extra.Err.FishyValue.function_name = function_name;
900    extra.Err.FishyValue.argument_name = argument_name;
901    extra.Err.FishyValue.value = value;
902 
903    VG_(maybe_record_error)(
904       tid, Err_FishyValue, /*addr*/0, /*s*/NULL, &extra );
905 
906    return True;
907 }
908 
MC_(record_user_error)909 void MC_(record_user_error) ( ThreadId tid, Addr a,
910                               Bool isAddrErr, UInt otag )
911 {
912    MC_Error extra;
913    if (otag != 0) {
914       tl_assert(!isAddrErr);
915       tl_assert( MC_(clo_mc_level) == 3 );
916    }
917    if (!isAddrErr) {
918       tl_assert( MC_(clo_mc_level) >= 2 );
919    }
920    tl_assert(VG_INVALID_THREADID != tid);
921    extra.Err.User.isAddrErr = isAddrErr;
922    extra.Err.User.ai.tag    = Addr_Undescribed;
923    extra.Err.User.otag      = otag;
924    extra.Err.User.origin_ec = NULL;  /* Filled in later */
925    VG_(maybe_record_error)( tid, Err_User, a, /*s*/NULL, &extra );
926 }
927 
928 /*------------------------------------------------------------*/
929 /*--- Other error operations                               ---*/
930 /*------------------------------------------------------------*/
931 
932 /* Compare error contexts, to detect duplicates.  Note that if they
933    are otherwise the same, the faulting addrs and associated rwoffsets
934    are allowed to be different.  */
MC_(eq_Error)935 Bool MC_(eq_Error) ( VgRes res, const Error* e1, const Error* e2 )
936 {
937    MC_Error* extra1 = VG_(get_error_extra)(e1);
938    MC_Error* extra2 = VG_(get_error_extra)(e2);
939 
940    /* Guaranteed by calling function */
941    tl_assert(VG_(get_error_kind)(e1) == VG_(get_error_kind)(e2));
942 
943    switch (VG_(get_error_kind)(e1)) {
944       case Err_CoreMem: {
945          const HChar *e1s, *e2s;
946          e1s = VG_(get_error_string)(e1);
947          e2s = VG_(get_error_string)(e2);
948          if (e1s == e2s)                   return True;
949          if (VG_STREQ(e1s, e2s))           return True;
950          return False;
951       }
952 
953       case Err_RegParam:
954          return VG_STREQ(VG_(get_error_string)(e1), VG_(get_error_string)(e2));
955 
956       // Perhaps we should also check the addrinfo.akinds for equality.
957       // That would result in more error reports, but only in cases where
958       // a register contains uninitialised bytes and points to memory
959       // containing uninitialised bytes.  Currently, the 2nd of those to be
960       // detected won't be reported.  That is (nearly?) always the memory
961       // error, which is good.
962       case Err_MemParam:
963          if (!VG_STREQ(VG_(get_error_string)(e1),
964                        VG_(get_error_string)(e2))) return False;
965          // fall through
966       case Err_User:
967          return ( extra1->Err.User.isAddrErr == extra2->Err.User.isAddrErr
968                 ? True : False );
969 
970       case Err_Free:
971       case Err_FreeMismatch:
972       case Err_Jump:
973       case Err_IllegalMempool:
974       case Err_Overlap:
975       case Err_Cond:
976          return True;
977 
978       case Err_FishyValue:
979          return VG_STREQ(extra1->Err.FishyValue.function_name,
980                          extra2->Err.FishyValue.function_name) &&
981                 VG_STREQ(extra1->Err.FishyValue.argument_name,
982                          extra2->Err.FishyValue.argument_name);
983 
984       case Err_Addr:
985          return ( extra1->Err.Addr.szB == extra2->Err.Addr.szB
986                 ? True : False );
987 
988       case Err_Value:
989          return ( extra1->Err.Value.szB == extra2->Err.Value.szB
990                 ? True : False );
991 
992       case Err_Leak:
993          VG_(tool_panic)("Shouldn't get Err_Leak in mc_eq_Error,\n"
994                          "since it's handled with VG_(unique_error)()!");
995 
996       default:
997          VG_(printf)("Error:\n  unknown error code %d\n",
998                      VG_(get_error_kind)(e1));
999          VG_(tool_panic)("unknown error code in mc_eq_Error");
1000    }
1001 }
1002 
1003 /* Functions used when searching MC_Chunk lists */
1004 static
addr_is_in_MC_Chunk_default_REDZONE_SZB(MC_Chunk * mc,Addr a)1005 Bool addr_is_in_MC_Chunk_default_REDZONE_SZB(MC_Chunk* mc, Addr a)
1006 {
1007    return VG_(addr_is_in_block)( a, mc->data, mc->szB,
1008                                  MC_(Malloc_Redzone_SzB) );
1009 }
1010 static
addr_is_in_MC_Chunk_with_REDZONE_SZB(MC_Chunk * mc,Addr a,SizeT rzB)1011 Bool addr_is_in_MC_Chunk_with_REDZONE_SZB(MC_Chunk* mc, Addr a, SizeT rzB)
1012 {
1013    return VG_(addr_is_in_block)( a, mc->data, mc->szB,
1014                                  rzB );
1015 }
1016 
1017 // Forward declarations
1018 static Bool client_block_maybe_describe( Addr a, AddrInfo* ai );
1019 static Bool mempool_block_maybe_describe( Addr a, AddrInfo* ai );
1020 
1021 
1022 /* Describe an address as best you can, for error messages,
1023    putting the result in ai. */
describe_addr(Addr a,AddrInfo * ai)1024 static void describe_addr ( Addr a, /*OUT*/AddrInfo* ai )
1025 {
1026    MC_Chunk*  mc;
1027 
1028    tl_assert(Addr_Undescribed == ai->tag);
1029 
1030    /* -- Perhaps it's a user-named block? -- */
1031    if (client_block_maybe_describe( a, ai )) {
1032       return;
1033    }
1034    /* -- Perhaps it's in mempool block? -- */
1035    if (mempool_block_maybe_describe( a, ai )) {
1036       return;
1037    }
1038    /* Blocks allocated by memcheck malloc functions are either
1039       on the recently freed list or on the malloc-ed list.
1040       Custom blocks can be on both : a recently freed block might
1041       have been just re-allocated.
1042       So, first search the malloc-ed block, as the most recent
1043       block is the probable cause of error.
1044       We however detect and report that this is a recently re-allocated
1045       block. */
1046    /* -- Search for a currently malloc'd block which might bracket it. -- */
1047    VG_(HT_ResetIter)(MC_(malloc_list));
1048    while ( (mc = VG_(HT_Next)(MC_(malloc_list))) ) {
1049       if (addr_is_in_MC_Chunk_default_REDZONE_SZB(mc, a)) {
1050          ai->tag = Addr_Block;
1051          ai->Addr.Block.block_kind = Block_Mallocd;
1052          if (MC_(get_freed_block_bracketting)( a ))
1053             ai->Addr.Block.block_desc = "recently re-allocated block";
1054          else
1055             ai->Addr.Block.block_desc = "block";
1056          ai->Addr.Block.block_szB  = mc->szB;
1057          ai->Addr.Block.rwoffset   = (Word)a - (Word)mc->data;
1058          ai->Addr.Block.allocated_at = MC_(allocated_at)(mc);
1059          VG_(initThreadInfo) (&ai->Addr.Block.alloc_tinfo);
1060          ai->Addr.Block.freed_at = MC_(freed_at)(mc);
1061          return;
1062       }
1063    }
1064    /* -- Search for a recently freed block which might bracket it. -- */
1065    mc = MC_(get_freed_block_bracketting)( a );
1066    if (mc) {
1067       ai->tag = Addr_Block;
1068       ai->Addr.Block.block_kind = Block_Freed;
1069       ai->Addr.Block.block_desc = "block";
1070       ai->Addr.Block.block_szB  = mc->szB;
1071       ai->Addr.Block.rwoffset   = (Word)a - (Word)mc->data;
1072       ai->Addr.Block.allocated_at = MC_(allocated_at)(mc);
1073       VG_(initThreadInfo) (&ai->Addr.Block.alloc_tinfo);
1074       ai->Addr.Block.freed_at = MC_(freed_at)(mc);
1075       return;
1076    }
1077 
1078    /* No block found. Search a non-heap block description. */
1079    VG_(describe_addr) (a, ai);
1080 }
1081 
MC_(pp_describe_addr)1082 void MC_(pp_describe_addr) ( Addr a )
1083 {
1084    AddrInfo ai;
1085 
1086    ai.tag = Addr_Undescribed;
1087    describe_addr (a, &ai);
1088    VG_(pp_addrinfo_mc) (a, &ai, /* maybe_gcc */ False);
1089    VG_(clear_addrinfo) (&ai);
1090 }
1091 
1092 /* Fill in *origin_ec as specified by otag, or NULL it out if otag
1093    does not refer to a known origin. */
update_origin(ExeContext ** origin_ec,UInt otag)1094 static void update_origin ( /*OUT*/ExeContext** origin_ec,
1095                             UInt otag )
1096 {
1097    UInt ecu = otag & ~3;
1098    *origin_ec = NULL;
1099    if (VG_(is_plausible_ECU)(ecu)) {
1100       *origin_ec = VG_(get_ExeContext_from_ECU)( ecu );
1101    }
1102 }
1103 
1104 /* Updates the copy with address info if necessary (but not for all errors). */
MC_(update_Error_extra)1105 UInt MC_(update_Error_extra)( const Error* err )
1106 {
1107    MC_Error* extra = VG_(get_error_extra)(err);
1108 
1109    switch (VG_(get_error_kind)(err)) {
1110    // These ones don't have addresses associated with them, and so don't
1111    // need any updating.
1112    case Err_CoreMem:
1113    //case Err_Value:
1114    //case Err_Cond:
1115    case Err_Overlap:
1116    case Err_FishyValue:
1117    // For Err_Leaks the returned size does not matter -- they are always
1118    // shown with VG_(unique_error)() so they 'extra' not copied.  But
1119    // we make it consistent with the others.
1120    case Err_Leak:
1121       return sizeof(MC_Error);
1122 
1123    // For value errors, get the ExeContext corresponding to the
1124    // origin tag.  Note that it is a kludge to assume that
1125    // a length-1 trace indicates a stack origin.  FIXME.
1126    case Err_Value:
1127       update_origin( &extra->Err.Value.origin_ec,
1128                      extra->Err.Value.otag );
1129       return sizeof(MC_Error);
1130    case Err_Cond:
1131       update_origin( &extra->Err.Cond.origin_ec,
1132                      extra->Err.Cond.otag );
1133       return sizeof(MC_Error);
1134    case Err_RegParam:
1135       update_origin( &extra->Err.RegParam.origin_ec,
1136                      extra->Err.RegParam.otag );
1137       return sizeof(MC_Error);
1138 
1139    // These ones always involve a memory address.
1140    case Err_Addr:
1141       describe_addr ( VG_(get_error_address)(err),
1142                       &extra->Err.Addr.ai );
1143       return sizeof(MC_Error);
1144    case Err_MemParam:
1145       describe_addr ( VG_(get_error_address)(err),
1146                       &extra->Err.MemParam.ai );
1147       update_origin( &extra->Err.MemParam.origin_ec,
1148                      extra->Err.MemParam.otag );
1149       return sizeof(MC_Error);
1150    case Err_Jump:
1151       describe_addr ( VG_(get_error_address)(err),
1152                       &extra->Err.Jump.ai );
1153       return sizeof(MC_Error);
1154    case Err_User:
1155       describe_addr ( VG_(get_error_address)(err),
1156                       &extra->Err.User.ai );
1157       update_origin( &extra->Err.User.origin_ec,
1158                      extra->Err.User.otag );
1159       return sizeof(MC_Error);
1160    case Err_Free:
1161       describe_addr ( VG_(get_error_address)(err),
1162                       &extra->Err.Free.ai );
1163       return sizeof(MC_Error);
1164    case Err_IllegalMempool:
1165       describe_addr ( VG_(get_error_address)(err),
1166                       &extra->Err.IllegalMempool.ai );
1167       return sizeof(MC_Error);
1168 
1169    // Err_FreeMismatches have already had their address described;  this is
1170    // possible because we have the MC_Chunk on hand when the error is
1171    // detected.  However, the address may be part of a user block, and if so
1172    // we override the pre-determined description with a user block one.
1173    case Err_FreeMismatch: {
1174       tl_assert(extra && Block_Mallocd ==
1175                 extra->Err.FreeMismatch.ai.Addr.Block.block_kind);
1176       (void)client_block_maybe_describe( VG_(get_error_address)(err),
1177                                         &extra->Err.FreeMismatch.ai );
1178       return sizeof(MC_Error);
1179    }
1180 
1181    default: VG_(tool_panic)("mc_update_extra: bad errkind");
1182    }
1183 }
1184 
1185 
client_block_maybe_describe(Addr a,AddrInfo * ai)1186 static Bool client_block_maybe_describe( Addr a,
1187                                          /*OUT*/AddrInfo* ai )
1188 {
1189    UWord      i;
1190    CGenBlock* cgbs = NULL;
1191    UWord      cgb_used = 0;
1192 
1193    MC_(get_ClientBlock_array)( &cgbs, &cgb_used );
1194    if (cgbs == NULL)
1195       tl_assert(cgb_used == 0);
1196 
1197    /* Perhaps it's a general block ? */
1198    for (i = 0; i < cgb_used; i++) {
1199       if (cgbs[i].start == 0 && cgbs[i].size == 0)
1200          continue;
1201       // Use zero as the redzone for client blocks.
1202       if (VG_(addr_is_in_block)(a, cgbs[i].start, cgbs[i].size, 0)) {
1203          ai->tag = Addr_Block;
1204          ai->Addr.Block.block_kind = Block_UserG;
1205          ai->Addr.Block.block_desc = cgbs[i].desc;
1206          ai->Addr.Block.block_szB  = cgbs[i].size;
1207          ai->Addr.Block.rwoffset   = (Word)(a) - (Word)(cgbs[i].start);
1208          ai->Addr.Block.allocated_at = cgbs[i].where;
1209          VG_(initThreadInfo) (&ai->Addr.Block.alloc_tinfo);
1210          ai->Addr.Block.freed_at = VG_(null_ExeContext)();;
1211          return True;
1212       }
1213    }
1214    return False;
1215 }
1216 
1217 
mempool_block_maybe_describe(Addr a,AddrInfo * ai)1218 static Bool mempool_block_maybe_describe( Addr a,
1219                                           /*OUT*/AddrInfo* ai )
1220 {
1221    MC_Mempool* mp;
1222    tl_assert( MC_(mempool_list) );
1223 
1224    VG_(HT_ResetIter)( MC_(mempool_list) );
1225    while ( (mp = VG_(HT_Next)(MC_(mempool_list))) ) {
1226       if (mp->chunks != NULL) {
1227          MC_Chunk* mc;
1228          VG_(HT_ResetIter)(mp->chunks);
1229          while ( (mc = VG_(HT_Next)(mp->chunks)) ) {
1230             if (addr_is_in_MC_Chunk_with_REDZONE_SZB(mc, a, mp->rzB)) {
1231                ai->tag = Addr_Block;
1232                ai->Addr.Block.block_kind = Block_MempoolChunk;
1233                ai->Addr.Block.block_desc = "block";
1234                ai->Addr.Block.block_szB  = mc->szB;
1235                ai->Addr.Block.rwoffset   = (Word)a - (Word)mc->data;
1236                ai->Addr.Block.allocated_at = MC_(allocated_at)(mc);
1237                VG_(initThreadInfo) (&ai->Addr.Block.alloc_tinfo);
1238                ai->Addr.Block.freed_at = MC_(freed_at)(mc);
1239                return True;
1240             }
1241          }
1242       }
1243    }
1244    return False;
1245 }
1246 
1247 
1248 /*------------------------------------------------------------*/
1249 /*--- Suppressions                                         ---*/
1250 /*------------------------------------------------------------*/
1251 
1252 typedef
1253    enum {
1254       ParamSupp,     // Bad syscall params
1255       UserSupp,      // Errors arising from client-request checks
1256       CoreMemSupp,   // Memory errors in core (pthread ops, signal handling)
1257 
1258       // Undefined value errors of given size
1259       Value1Supp, Value2Supp, Value4Supp, Value8Supp, Value16Supp, Value32Supp,
1260 
1261       // Undefined value error in conditional.
1262       CondSupp,
1263 
1264       // Unaddressable read/write attempt at given size
1265       Addr1Supp, Addr2Supp, Addr4Supp, Addr8Supp, Addr16Supp, Addr32Supp,
1266 
1267       JumpSupp,      // Jump to unaddressable target
1268       FreeSupp,      // Invalid or mismatching free
1269       OverlapSupp,   // Overlapping blocks in memcpy(), strcpy(), etc
1270       LeakSupp,      // Something to be suppressed in a leak check.
1271       MempoolSupp,   // Memory pool suppression.
1272       FishyValueSupp,// Fishy value suppression.
1273    }
1274    MC_SuppKind;
1275 
MC_(is_recognised_suppression)1276 Bool MC_(is_recognised_suppression) ( const HChar* name, Supp* su )
1277 {
1278    SuppKind skind;
1279 
1280    if      (VG_STREQ(name, "Param"))   skind = ParamSupp;
1281    else if (VG_STREQ(name, "User"))    skind = UserSupp;
1282    else if (VG_STREQ(name, "CoreMem")) skind = CoreMemSupp;
1283    else if (VG_STREQ(name, "Addr1"))   skind = Addr1Supp;
1284    else if (VG_STREQ(name, "Addr2"))   skind = Addr2Supp;
1285    else if (VG_STREQ(name, "Addr4"))   skind = Addr4Supp;
1286    else if (VG_STREQ(name, "Addr8"))   skind = Addr8Supp;
1287    else if (VG_STREQ(name, "Addr16"))  skind = Addr16Supp;
1288    else if (VG_STREQ(name, "Addr32"))  skind = Addr32Supp;
1289    else if (VG_STREQ(name, "Jump"))    skind = JumpSupp;
1290    else if (VG_STREQ(name, "Free"))    skind = FreeSupp;
1291    else if (VG_STREQ(name, "Leak"))    skind = LeakSupp;
1292    else if (VG_STREQ(name, "Overlap")) skind = OverlapSupp;
1293    else if (VG_STREQ(name, "Mempool")) skind = MempoolSupp;
1294    else if (VG_STREQ(name, "Cond"))    skind = CondSupp;
1295    else if (VG_STREQ(name, "Value0"))  skind = CondSupp; /* backwards compat */
1296    else if (VG_STREQ(name, "Value1"))  skind = Value1Supp;
1297    else if (VG_STREQ(name, "Value2"))  skind = Value2Supp;
1298    else if (VG_STREQ(name, "Value4"))  skind = Value4Supp;
1299    else if (VG_STREQ(name, "Value8"))  skind = Value8Supp;
1300    else if (VG_STREQ(name, "Value16")) skind = Value16Supp;
1301    else if (VG_STREQ(name, "Value32")) skind = Value32Supp;
1302    else if (VG_STREQ(name, "FishyValue")) skind = FishyValueSupp;
1303    else
1304       return False;
1305 
1306    VG_(set_supp_kind)(su, skind);
1307    return True;
1308 }
1309 
1310 typedef struct _MC_LeakSuppExtra MC_LeakSuppExtra;
1311 
1312 struct _MC_LeakSuppExtra {
1313    UInt match_leak_kinds;
1314 
1315    /* Maintains nr of blocks and bytes suppressed with this suppression
1316       during the leak search identified by leak_search_gen.
1317       blocks_suppressed and bytes_suppressed are reset to 0 when
1318       used the first time during a leak search. */
1319    SizeT blocks_suppressed;
1320    SizeT bytes_suppressed;
1321    UInt  leak_search_gen;
1322 };
1323 
1324 typedef struct {
1325    const HChar *function_name;
1326    const HChar *argument_name;
1327 } MC_FishyValueExtra;
1328 
MC_(read_extra_suppression_info)1329 Bool MC_(read_extra_suppression_info) ( Int fd, HChar** bufpp,
1330                                         SizeT* nBufp, Int* lineno, Supp *su )
1331 {
1332    Bool eof;
1333    Int i;
1334 
1335    if (VG_(get_supp_kind)(su) == ParamSupp) {
1336       eof = VG_(get_line) ( fd, bufpp, nBufp, lineno );
1337       if (eof) return False;
1338       VG_(set_supp_string)(su, VG_(strdup)("mc.resi.1", *bufpp));
1339    } else if (VG_(get_supp_kind)(su) == LeakSupp) {
1340       // We might have the optional match-leak-kinds line
1341       MC_LeakSuppExtra* lse;
1342       lse = VG_(malloc)("mc.resi.2", sizeof(MC_LeakSuppExtra));
1343       lse->match_leak_kinds = MC_(all_Reachedness)();
1344       lse->blocks_suppressed = 0;
1345       lse->bytes_suppressed = 0;
1346       lse->leak_search_gen = 0;
1347       VG_(set_supp_extra)(su, lse); // By default, all kinds will match.
1348       eof = VG_(get_line) ( fd, bufpp, nBufp, lineno );
1349       if (eof) return True; // old LeakSupp style, no match-leak-kinds line.
1350       if (0 == VG_(strncmp)(*bufpp, "match-leak-kinds:", 17)) {
1351          i = 17;
1352          while ((*bufpp)[i] && VG_(isspace((*bufpp)[i])))
1353             i++;
1354          if (!VG_(parse_enum_set)(MC_(parse_leak_kinds_tokens),
1355                                   True/*allow_all*/,
1356                                   (*bufpp)+i, &lse->match_leak_kinds)) {
1357             return False;
1358          }
1359       } else {
1360          return False; // unknown extra line.
1361       }
1362    } else if (VG_(get_supp_kind)(su) == FishyValueSupp) {
1363       MC_FishyValueExtra *extra;
1364       HChar *p, *function_name, *argument_name = NULL;
1365 
1366       eof = VG_(get_line) ( fd, bufpp, nBufp, lineno );
1367       if (eof) return True;
1368 
1369       // The suppression string is: function_name(argument_name)
1370       function_name = VG_(strdup)("mv.resi.4", *bufpp);
1371       p = VG_(strchr)(function_name, '(');
1372       if (p != NULL) {
1373          *p++ = '\0';
1374          argument_name = p;
1375          p = VG_(strchr)(p, ')');
1376          if (p != NULL)
1377             *p = '\0';
1378       }
1379       if (p == NULL) {    // malformed suppression string
1380          VG_(free)(function_name);
1381          return False;
1382       }
1383 
1384       extra = VG_(malloc)("mc.resi.3", sizeof *extra);
1385       extra->function_name = function_name;
1386       extra->argument_name = argument_name;
1387 
1388       VG_(set_supp_extra)(su, extra);
1389    }
1390    return True;
1391 }
1392 
MC_(error_matches_suppression)1393 Bool MC_(error_matches_suppression) ( const Error* err, const Supp* su )
1394 {
1395    Int       su_szB;
1396    MC_Error* extra = VG_(get_error_extra)(err);
1397    ErrorKind ekind = VG_(get_error_kind )(err);
1398 
1399    switch (VG_(get_supp_kind)(su)) {
1400       case ParamSupp:
1401          return ((ekind == Err_RegParam || ekind == Err_MemParam)
1402               && VG_STREQ(VG_(get_error_string)(err),
1403                           VG_(get_supp_string)(su)));
1404 
1405       case UserSupp:
1406          return (ekind == Err_User);
1407 
1408       case CoreMemSupp:
1409          return (ekind == Err_CoreMem
1410               && VG_STREQ(VG_(get_error_string)(err),
1411                           VG_(get_supp_string)(su)));
1412 
1413       case Value1Supp: su_szB = 1; goto value_case;
1414       case Value2Supp: su_szB = 2; goto value_case;
1415       case Value4Supp: su_szB = 4; goto value_case;
1416       case Value8Supp: su_szB = 8; goto value_case;
1417       case Value16Supp:su_szB =16; goto value_case;
1418       case Value32Supp:su_szB =32; goto value_case;
1419       value_case:
1420          return (ekind == Err_Value && extra->Err.Value.szB == su_szB);
1421 
1422       case CondSupp:
1423          return (ekind == Err_Cond);
1424 
1425       case Addr1Supp: su_szB = 1; goto addr_case;
1426       case Addr2Supp: su_szB = 2; goto addr_case;
1427       case Addr4Supp: su_szB = 4; goto addr_case;
1428       case Addr8Supp: su_szB = 8; goto addr_case;
1429       case Addr16Supp:su_szB =16; goto addr_case;
1430       case Addr32Supp:su_szB =32; goto addr_case;
1431       addr_case:
1432          return (ekind == Err_Addr && extra->Err.Addr.szB == su_szB);
1433 
1434       case JumpSupp:
1435          return (ekind == Err_Jump);
1436 
1437       case FreeSupp:
1438          return (ekind == Err_Free || ekind == Err_FreeMismatch);
1439 
1440       case OverlapSupp:
1441          return (ekind == Err_Overlap);
1442 
1443       case LeakSupp:
1444          if (ekind == Err_Leak) {
1445             MC_LeakSuppExtra* lse = (MC_LeakSuppExtra*) VG_(get_supp_extra)(su);
1446             if (lse->leak_search_gen != MC_(leak_search_gen)) {
1447                // First time we see this suppression during this leak search.
1448                // => reset the counters to 0.
1449                lse->blocks_suppressed = 0;
1450                lse->bytes_suppressed = 0;
1451                lse->leak_search_gen = MC_(leak_search_gen);
1452             }
1453             return RiS(extra->Err.Leak.lr->key.state, lse->match_leak_kinds);
1454          } else
1455             return False;
1456 
1457       case MempoolSupp:
1458          return (ekind == Err_IllegalMempool);
1459 
1460       case FishyValueSupp: {
1461          MC_FishyValueExtra *supp_extra = VG_(get_supp_extra)(su);
1462 
1463          return (ekind == Err_FishyValue) &&
1464                 VG_STREQ(extra->Err.FishyValue.function_name,
1465                          supp_extra->function_name) &&
1466                 VG_STREQ(extra->Err.FishyValue.argument_name,
1467                          supp_extra->argument_name);
1468       }
1469 
1470       default:
1471          VG_(printf)("Error:\n"
1472                      "  unknown suppression type %d\n",
1473                      VG_(get_supp_kind)(su));
1474          VG_(tool_panic)("unknown suppression type in "
1475                          "MC_(error_matches_suppression)");
1476    }
1477 }
1478 
MC_(get_error_name)1479 const HChar* MC_(get_error_name) ( const Error* err )
1480 {
1481    switch (VG_(get_error_kind)(err)) {
1482    case Err_RegParam:       return "Param";
1483    case Err_MemParam:       return "Param";
1484    case Err_User:           return "User";
1485    case Err_FreeMismatch:   return "Free";
1486    case Err_IllegalMempool: return "Mempool";
1487    case Err_Free:           return "Free";
1488    case Err_Jump:           return "Jump";
1489    case Err_CoreMem:        return "CoreMem";
1490    case Err_Overlap:        return "Overlap";
1491    case Err_Leak:           return "Leak";
1492    case Err_Cond:           return "Cond";
1493    case Err_FishyValue:     return "FishyValue";
1494    case Err_Addr: {
1495       MC_Error* extra = VG_(get_error_extra)(err);
1496       switch ( extra->Err.Addr.szB ) {
1497       case 1:               return "Addr1";
1498       case 2:               return "Addr2";
1499       case 4:               return "Addr4";
1500       case 8:               return "Addr8";
1501       case 16:              return "Addr16";
1502       case 32:              return "Addr32";
1503       default:              VG_(tool_panic)("unexpected size for Addr");
1504       }
1505    }
1506    case Err_Value: {
1507       MC_Error* extra = VG_(get_error_extra)(err);
1508       switch ( extra->Err.Value.szB ) {
1509       case 1:               return "Value1";
1510       case 2:               return "Value2";
1511       case 4:               return "Value4";
1512       case 8:               return "Value8";
1513       case 16:              return "Value16";
1514       case 32:              return "Value32";
1515       default:              VG_(tool_panic)("unexpected size for Value");
1516       }
1517    }
1518    default:                 VG_(tool_panic)("get_error_name: unexpected type");
1519    }
1520 }
1521 
MC_(get_extra_suppression_info)1522 SizeT MC_(get_extra_suppression_info) ( const Error* err,
1523                                         /*OUT*/HChar* buf, Int nBuf )
1524 {
1525    ErrorKind ekind = VG_(get_error_kind )(err);
1526    tl_assert(buf);
1527    tl_assert(nBuf >= 1);
1528 
1529    if (Err_RegParam == ekind || Err_MemParam == ekind) {
1530       const HChar* errstr = VG_(get_error_string)(err);
1531       tl_assert(errstr);
1532       return VG_(snprintf)(buf, nBuf, "%s", errstr);
1533    } else if (Err_Leak == ekind) {
1534       MC_Error* extra = VG_(get_error_extra)(err);
1535       return VG_(snprintf) (buf, nBuf, "match-leak-kinds: %s",
1536           pp_Reachedness_for_leak_kinds(extra->Err.Leak.lr->key.state));
1537    } else if (Err_FishyValue == ekind) {
1538       MC_Error* extra = VG_(get_error_extra)(err);
1539       return VG_(snprintf) (buf, nBuf, "%s(%s)",
1540                             extra->Err.FishyValue.function_name,
1541                             extra->Err.FishyValue.argument_name);
1542    } else {
1543       buf[0] = '\0';
1544       return 0;
1545    }
1546 }
1547 
MC_(print_extra_suppression_use)1548 SizeT MC_(print_extra_suppression_use) ( const Supp *su,
1549                                          /*OUT*/HChar *buf, Int nBuf )
1550 {
1551    tl_assert(nBuf >= 1);
1552 
1553    if (VG_(get_supp_kind)(su) == LeakSupp) {
1554       MC_LeakSuppExtra *lse = (MC_LeakSuppExtra*) VG_(get_supp_extra) (su);
1555 
1556       if (lse->leak_search_gen == MC_(leak_search_gen)
1557           && lse->blocks_suppressed > 0) {
1558          return VG_(snprintf) (buf, nBuf,
1559                                "suppressed: %'lu bytes in %'lu blocks",
1560                                lse->bytes_suppressed,
1561                                lse->blocks_suppressed);
1562       }
1563    }
1564 
1565    buf[0] = '\0';
1566    return 0;
1567 }
1568 
MC_(update_extra_suppression_use)1569 void MC_(update_extra_suppression_use) ( const Error* err, const Supp* su)
1570 {
1571    if (VG_(get_supp_kind)(su) == LeakSupp) {
1572       MC_LeakSuppExtra *lse = (MC_LeakSuppExtra*) VG_(get_supp_extra) (su);
1573       MC_Error* extra = VG_(get_error_extra)(err);
1574 
1575       tl_assert (lse->leak_search_gen == MC_(leak_search_gen));
1576       lse->blocks_suppressed += extra->Err.Leak.lr->num_blocks;
1577       lse->bytes_suppressed
1578          += extra->Err.Leak.lr->szB + extra->Err.Leak.lr->indirect_szB;
1579    }
1580 }
1581 
1582 /*--------------------------------------------------------------------*/
1583 /*--- end                                              mc_errors.c ---*/
1584 /*--------------------------------------------------------------------*/
1585