blob: 41c9b71208c58fb87915f55078301ba39c552856 [file] [log] [blame]
njn43c799e2003-04-08 00:08:52 +00001
2/*--------------------------------------------------------------------*/
njn1d0825f2006-03-27 11:37:07 +00003/*--- The leak checker. mc_leakcheck.c ---*/
njn43c799e2003-04-08 00:08:52 +00004/*--------------------------------------------------------------------*/
5
6/*
nethercote137bc552003-11-14 17:47:54 +00007 This file is part of MemCheck, a heavyweight Valgrind tool for
njn1d0825f2006-03-27 11:37:07 +00008 detecting memory errors.
njn43c799e2003-04-08 00:08:52 +00009
sewardj9eecbbb2010-05-03 21:37:12 +000010 Copyright (C) 2000-2010 Julian Seward
njn43c799e2003-04-08 00:08:52 +000011 jseward@acm.org
12
13 This program is free software; you can redistribute it and/or
14 modify it under the terms of the GNU General Public License as
15 published by the Free Software Foundation; either version 2 of the
16 License, or (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful, but
19 WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26 02111-1307, USA.
27
28 The GNU General Public License is contained in the file COPYING.
29*/
30
njnc7561b92005-06-19 01:24:32 +000031#include "pub_tool_basics.h"
sewardj4cfea4f2006-10-14 19:26:10 +000032#include "pub_tool_vki.h"
njnac1e0332009-05-08 00:39:31 +000033#include "pub_tool_aspacehl.h"
njn4802b382005-06-11 04:58:29 +000034#include "pub_tool_aspacemgr.h"
njn1d0825f2006-03-27 11:37:07 +000035#include "pub_tool_execontext.h"
36#include "pub_tool_hashtable.h"
njn97405b22005-06-02 03:39:33 +000037#include "pub_tool_libcbase.h"
njn132bfcc2005-06-04 19:16:06 +000038#include "pub_tool_libcassert.h"
njn36a20fa2005-06-03 03:08:39 +000039#include "pub_tool_libcprint.h"
njnde62cbf2005-06-10 22:08:14 +000040#include "pub_tool_libcsignal.h"
njn6ace3ea2005-06-17 03:06:27 +000041#include "pub_tool_machine.h"
njnc7561b92005-06-19 01:24:32 +000042#include "pub_tool_mallocfree.h"
43#include "pub_tool_options.h"
njn29a5c012009-05-06 06:15:55 +000044#include "pub_tool_oset.h"
njn73c51342005-06-18 15:18:15 +000045#include "pub_tool_signals.h"
sewardj6c591e12011-04-11 16:17:51 +000046#include "pub_tool_libcsetjmp.h" // setjmp facilities
njn1d0825f2006-03-27 11:37:07 +000047#include "pub_tool_tooliface.h" // Needed for mc_include.h
njn43c799e2003-04-08 00:08:52 +000048
njn1d0825f2006-03-27 11:37:07 +000049#include "mc_include.h"
njnc7561b92005-06-19 01:24:32 +000050
njn8225cc02009-03-09 22:52:24 +000051/*------------------------------------------------------------*/
52/*--- An overview of leak checking. ---*/
53/*------------------------------------------------------------*/
njnc7561b92005-06-19 01:24:32 +000054
njn8225cc02009-03-09 22:52:24 +000055// Leak-checking is a directed-graph traversal problem. The graph has
56// two kinds of nodes:
57// - root-set nodes:
58// - GP registers of all threads;
59// - valid, aligned, pointer-sized data words in valid client memory,
60// including stacks, but excluding words within client heap-allocated
61// blocks (they are excluded so that later on we can differentiate
62// between heap blocks that are indirectly leaked vs. directly leaked).
63// - heap-allocated blocks. A block is a mempool chunk or a malloc chunk
64// that doesn't contain a mempool chunk. Nb: the terms "blocks" and
65// "chunks" are used interchangeably below.
66//
67// There are two kinds of edges:
68// - start-pointers, i.e. pointers to the start of a block;
69// - interior-pointers, i.e. pointers to the interior of a block.
70//
71// We use "pointers" rather than "edges" below.
72//
73// Root set nodes only point to blocks. Blocks only point to blocks;
74// a block can point to itself.
75//
76// The aim is to traverse the graph and determine the status of each block.
77//
78// There are 9 distinct cases. See memcheck/docs/mc-manual.xml for details.
79// Presenting all nine categories to the user is probably too much.
80// Currently we do this:
81// - definitely lost: case 3
82// - indirectly lost: case 4, 9
83// - possibly lost: cases 5..8
84// - still reachable: cases 1, 2
85//
86// It's far from clear that this is the best possible categorisation; it's
87// accreted over time without any central guiding principle.
88
89/*------------------------------------------------------------*/
90/*--- XXX: Thoughts for improvement. ---*/
91/*------------------------------------------------------------*/
92
93// From the user's point of view:
94// - If they aren't using interior-pointers, they just have to fix the
95// directly lost blocks, and the indirectly lost ones will be fixed as
96// part of that. Any possibly lost blocks will just be due to random
97// pointer garbage and can be ignored.
98//
99// - If they are using interior-pointers, the fact that they currently are not
100// being told which ones might be directly lost vs. indirectly lost makes
101// it hard to know where to begin.
102//
103// All this makes me wonder if new option is warranted:
104// --follow-interior-pointers. By default it would be off, the leak checker
105// wouldn't follow interior-pointers and there would only be 3 categories:
106// R, DL, IL.
107//
108// If turned on, then it would show 7 categories (R, DL, IL, DR/DL, IR/IL,
109// IR/IL/DL, IL/DL). That output is harder to understand but it's your own
110// damn fault for using interior-pointers...
111//
112// ----
113//
114// Also, why are two blank lines printed between each loss record?
njnc2f8b1b2009-08-10 06:47:00 +0000115// [bug 197930]
njn8225cc02009-03-09 22:52:24 +0000116//
117// ----
118//
119// Also, --show-reachable is a bad name because it also turns on the showing
120// of indirectly leaked blocks(!) It would be better named --show-all or
121// --show-all-heap-blocks, because that's the end result.
122//
123// ----
124//
125// Also, the VALGRIND_LEAK_CHECK and VALGRIND_QUICK_LEAK_CHECK aren't great
126// names. VALGRIND_FULL_LEAK_CHECK and VALGRIND_SUMMARY_LEAK_CHECK would be
127// better.
128//
129// ----
130//
131// Also, VALGRIND_COUNT_LEAKS and VALGRIND_COUNT_LEAK_BLOCKS aren't great as
132// they combine direct leaks and indirect leaks into one. New, more precise
133// ones (they'll need new names) would be good. If more categories are
134// used, as per the --follow-interior-pointers option, they should be
135// updated accordingly. And they should use a struct to return the values.
136//
137// ----
138//
139// Also, for this case:
140//
141// (4) p4 BBB ---> AAA
142//
143// BBB is definitely directly lost. AAA is definitely indirectly lost.
144// Here's the relevant loss records printed for a full check (each block is
145// 16 bytes):
146//
147// ==20397== 16 bytes in 1 blocks are indirectly lost in loss record 9 of 15
148// ==20397== at 0x4C2694E: malloc (vg_replace_malloc.c:177)
149// ==20397== by 0x400521: mk (leak-cases.c:49)
150// ==20397== by 0x400578: main (leak-cases.c:72)
151//
152// ==20397== 32 (16 direct, 16 indirect) bytes in 1 blocks are definitely
153// lost in loss record 14 of 15
154// ==20397== at 0x4C2694E: malloc (vg_replace_malloc.c:177)
155// ==20397== by 0x400521: mk (leak-cases.c:49)
156// ==20397== by 0x400580: main (leak-cases.c:72)
157//
158// The first one is fine -- it describes AAA.
159//
160// The second one is for BBB. It's correct in that 16 bytes in 1 block are
161// directly lost. It's also correct that 16 are indirectly lost as a result,
162// but it means that AAA is being counted twice in the loss records. (It's
163// not, thankfully, counted twice in the summary counts). Argh.
164//
165// This would be less confusing for the second one:
166//
167// ==20397== 16 bytes in 1 blocks are definitely lost in loss record 14
168// of 15 (and 16 bytes in 1 block are indirectly lost as a result; they
169// are mentioned elsewhere (if --show-reachable=yes is given!))
170// ==20397== at 0x4C2694E: malloc (vg_replace_malloc.c:177)
171// ==20397== by 0x400521: mk (leak-cases.c:49)
172// ==20397== by 0x400580: main (leak-cases.c:72)
173//
174// But ideally we'd present the loss record for the directly lost block and
175// then the resultant indirectly lost blocks and make it clear the
176// dependence. Double argh.
177
178/*------------------------------------------------------------*/
179/*--- The actual algorithm. ---*/
180/*------------------------------------------------------------*/
181
182// - Find all the blocks (a.k.a. chunks) to check. Mempool chunks require
183// some special treatment because they can be within malloc'd blocks.
184// - Scan every word in the root set (GP registers and valid
185// non-heap memory words).
186// - First, we skip if it doesn't point to valid memory.
187// - Then, we see if it points to the start or interior of a block. If
188// so, we push the block onto the mark stack and mark it as having been
189// reached.
190// - Then, we process the mark stack, repeating the scanning for each block;
191// this can push more blocks onto the mark stack. We repeat until the
192// mark stack is empty. Each block is marked as definitely or possibly
193// reachable, depending on whether interior-pointers were required to
194// reach it.
195// - At this point we know for every block if it's reachable or not.
196// - We then push each unreached block onto the mark stack, using the block
197// number as the "clique" number.
198// - We process the mark stack again, this time grouping blocks into cliques
199// in order to facilitate the directly/indirectly lost categorisation.
200// - We group blocks by their ExeContexts and categorisation, and print them
201// if --leak-check=full. We also print summary numbers.
202//
203// A note on "cliques":
204// - A directly lost block is one with no pointers to it. An indirectly
205// lost block is one that is pointed to by a directly or indirectly lost
206// block.
207// - Each directly lost block has zero or more indirectly lost blocks
208// hanging off it. All these blocks together form a "clique". The
209// directly lost block is called the "clique leader". The clique number
210// is the number (in lc_chunks[]) of the clique leader.
211// - Actually, a directly lost block may be pointed to if it's part of a
212// cycle. In that case, there may be more than one choice for the clique
213// leader, and the choice is arbitrary. Eg. if you have A-->B and B-->A
214// either A or B could be the clique leader.
215// - Cliques cannot overlap, and will be truncated to avoid this. Eg. if we
216// have A-->C and B-->C, the two cliques will be {A,C} and {B}, or {A} and
217// {B,C} (again the choice is arbitrary). This is because we don't want
218// to count a block as indirectly lost more than once.
219//
220// A note on 'is_prior_definite':
221// - This is a boolean used in various places that indicates if the chain
222// up to the prior node (prior to the one being considered) is definite.
223// - In the clique == -1 case:
224// - if True it means that the prior node is a root-set node, or that the
225// prior node is a block which is reachable from the root-set via
226// start-pointers.
227// - if False it means that the prior node is a block that is only
228// reachable from the root-set via a path including at least one
229// interior-pointer.
230// - In the clique != -1 case, currently it's always True because we treat
231// start-pointers and interior-pointers the same for direct/indirect leak
232// checking. If we added a PossibleIndirectLeak state then this would
233// change.
234
235
236// Define to debug the memory-leak-detector.
sewardjb5f6f512005-03-10 23:59:00 +0000237#define VG_DEBUG_LEAKCHECK 0
njn8225cc02009-03-09 22:52:24 +0000238#define VG_DEBUG_CLIQUE 0
239
sewardjb5f6f512005-03-10 23:59:00 +0000240
njn43c799e2003-04-08 00:08:52 +0000241/*------------------------------------------------------------*/
njn8225cc02009-03-09 22:52:24 +0000242/*--- Getting the initial chunks, and searching them. ---*/
njn43c799e2003-04-08 00:08:52 +0000243/*------------------------------------------------------------*/
244
njn8225cc02009-03-09 22:52:24 +0000245// Compare the MC_Chunks by 'data' (i.e. the address of the block).
246static Int compare_MC_Chunks(void* n1, void* n2)
njn43c799e2003-04-08 00:08:52 +0000247{
njn8225cc02009-03-09 22:52:24 +0000248 MC_Chunk* mc1 = *(MC_Chunk**)n1;
249 MC_Chunk* mc2 = *(MC_Chunk**)n2;
250 if (mc1->data < mc2->data) return -1;
251 if (mc1->data > mc2->data) return 1;
252 return 0;
njn43c799e2003-04-08 00:08:52 +0000253}
254
njn8225cc02009-03-09 22:52:24 +0000255#if VG_DEBUG_LEAKCHECK
256// Used to sanity-check the fast binary-search mechanism.
257static
258Int find_chunk_for_OLD ( Addr ptr,
259 MC_Chunk** chunks,
260 Int n_chunks )
261
262{
263 Int i;
264 Addr a_lo, a_hi;
265 PROF_EVENT(70, "find_chunk_for_OLD");
266 for (i = 0; i < n_chunks; i++) {
267 PROF_EVENT(71, "find_chunk_for_OLD(loop)");
268 a_lo = chunks[i]->data;
269 a_hi = ((Addr)chunks[i]->data) + chunks[i]->szB;
270 if (a_lo <= ptr && ptr < a_hi)
271 return i;
272 }
273 return -1;
274}
275#endif
276
277// Find the i such that ptr points at or inside the block described by
278// chunks[i]. Return -1 if none found. This assumes that chunks[]
279// has been sorted on the 'data' field.
280static
281Int find_chunk_for ( Addr ptr,
282 MC_Chunk** chunks,
283 Int n_chunks )
284{
285 Addr a_mid_lo, a_mid_hi;
286 Int lo, mid, hi, retVal;
287 // VG_(printf)("find chunk for %p = ", ptr);
288 retVal = -1;
289 lo = 0;
290 hi = n_chunks-1;
291 while (True) {
292 // Invariant: current unsearched space is from lo to hi, inclusive.
293 if (lo > hi) break; // not found
294
295 mid = (lo + hi) / 2;
296 a_mid_lo = chunks[mid]->data;
297 a_mid_hi = chunks[mid]->data + chunks[mid]->szB;
298 // Extent of block 'mid' is [a_mid_lo .. a_mid_hi).
299 // Special-case zero-sized blocks - treat them as if they had
300 // size 1. Not doing so causes them to not cover any address
301 // range at all and so will never be identified as the target of
302 // any pointer, which causes them to be incorrectly reported as
303 // definitely leaked.
304 if (chunks[mid]->szB == 0)
305 a_mid_hi++;
306
307 if (ptr < a_mid_lo) {
308 hi = mid-1;
309 continue;
310 }
311 if (ptr >= a_mid_hi) {
312 lo = mid+1;
313 continue;
314 }
315 tl_assert(ptr >= a_mid_lo && ptr < a_mid_hi);
316 retVal = mid;
317 break;
318 }
319
320# if VG_DEBUG_LEAKCHECK
321 tl_assert(retVal == find_chunk_for_OLD ( ptr, chunks, n_chunks ));
322# endif
323 // VG_(printf)("%d\n", retVal);
324 return retVal;
325}
326
327
328static MC_Chunk**
329find_active_chunks(UInt* pn_chunks)
330{
331 // Our goal is to construct a set of chunks that includes every
332 // mempool chunk, and every malloc region that *doesn't* contain a
333 // mempool chunk.
334 MC_Mempool *mp;
335 MC_Chunk **mallocs, **chunks, *mc;
336 UInt n_mallocs, n_chunks, m, s;
337 Bool *malloc_chunk_holds_a_pool_chunk;
338
339 // First we collect all the malloc chunks into an array and sort it.
340 // We do this because we want to query the chunks by interior
341 // pointers, requiring binary search.
342 mallocs = (MC_Chunk**) VG_(HT_to_array)( MC_(malloc_list), &n_mallocs );
343 if (n_mallocs == 0) {
344 tl_assert(mallocs == NULL);
345 *pn_chunks = 0;
346 return NULL;
347 }
348 VG_(ssort)(mallocs, n_mallocs, sizeof(VgHashNode*), compare_MC_Chunks);
349
350 // Then we build an array containing a Bool for each malloc chunk,
351 // indicating whether it contains any mempools.
352 malloc_chunk_holds_a_pool_chunk = VG_(calloc)( "mc.fas.1",
353 n_mallocs, sizeof(Bool) );
354 n_chunks = n_mallocs;
355
356 // Then we loop over the mempool tables. For each chunk in each
357 // pool, we set the entry in the Bool array corresponding to the
358 // malloc chunk containing the mempool chunk.
359 VG_(HT_ResetIter)(MC_(mempool_list));
360 while ( (mp = VG_(HT_Next)(MC_(mempool_list))) ) {
361 VG_(HT_ResetIter)(mp->chunks);
362 while ( (mc = VG_(HT_Next)(mp->chunks)) ) {
363
364 // We'll need to record this chunk.
365 n_chunks++;
366
367 // Possibly invalidate the malloc holding the beginning of this chunk.
368 m = find_chunk_for(mc->data, mallocs, n_mallocs);
369 if (m != -1 && malloc_chunk_holds_a_pool_chunk[m] == False) {
370 tl_assert(n_chunks > 0);
371 n_chunks--;
372 malloc_chunk_holds_a_pool_chunk[m] = True;
373 }
374
375 // Possibly invalidate the malloc holding the end of this chunk.
376 if (mc->szB > 1) {
377 m = find_chunk_for(mc->data + (mc->szB - 1), mallocs, n_mallocs);
378 if (m != -1 && malloc_chunk_holds_a_pool_chunk[m] == False) {
379 tl_assert(n_chunks > 0);
380 n_chunks--;
381 malloc_chunk_holds_a_pool_chunk[m] = True;
382 }
383 }
384 }
385 }
386 tl_assert(n_chunks > 0);
387
388 // Create final chunk array.
389 chunks = VG_(malloc)("mc.fas.2", sizeof(VgHashNode*) * (n_chunks));
390 s = 0;
391
392 // Copy the mempool chunks and the non-marked malloc chunks into a
393 // combined array of chunks.
394 VG_(HT_ResetIter)(MC_(mempool_list));
395 while ( (mp = VG_(HT_Next)(MC_(mempool_list))) ) {
396 VG_(HT_ResetIter)(mp->chunks);
397 while ( (mc = VG_(HT_Next)(mp->chunks)) ) {
398 tl_assert(s < n_chunks);
399 chunks[s++] = mc;
400 }
401 }
402 for (m = 0; m < n_mallocs; ++m) {
403 if (!malloc_chunk_holds_a_pool_chunk[m]) {
404 tl_assert(s < n_chunks);
405 chunks[s++] = mallocs[m];
406 }
407 }
408 tl_assert(s == n_chunks);
409
410 // Free temporaries.
411 VG_(free)(mallocs);
412 VG_(free)(malloc_chunk_holds_a_pool_chunk);
413
414 *pn_chunks = n_chunks;
415
416 return chunks;
417}
418
419/*------------------------------------------------------------*/
420/*--- The leak detector proper. ---*/
421/*------------------------------------------------------------*/
422
423// Holds extra info about each block during leak checking.
424typedef
425 struct {
426 UInt state:2; // Reachedness.
tom1d0f3f62010-10-04 20:55:21 +0000427 UInt pending:1; // Scan pending.
428 SizeT indirect_szB : (sizeof(SizeT)*8)-3; // If Unreached, how many bytes
njn8225cc02009-03-09 22:52:24 +0000429 // are unreachable from here.
430 }
431 LC_Extra;
432
433// An array holding pointers to every chunk we're checking. Sorted by address.
434static MC_Chunk** lc_chunks;
435// How many chunks we're dealing with.
436static Int lc_n_chunks;
sewardjc8bd1df2011-06-26 12:41:33 +0000437// chunks will be converted and merged in loss record, maintained in lr_table
438// lr_table elements are kept from one leak_search to another to implement
439// the "print new/changed leaks" client request
440static OSet* lr_table;
441
442// DeltaMode used the last time we called detect_memory_leaks.
443// The recorded leak errors must be output using a logic based on this delta_mode.
444// The below avoids replicating the delta_mode in each LossRecord.
445LeakCheckDeltaMode MC_(detect_memory_leaks_last_delta_mode);
446
njn8225cc02009-03-09 22:52:24 +0000447
448// This has the same number of entries as lc_chunks, and each entry
449// in lc_chunks corresponds with the entry here (ie. lc_chunks[i] and
450// lc_extras[i] describe the same block).
451static LC_Extra* lc_extras;
452
453// Records chunks that are currently being processed. Each element in the
454// stack is an index into lc_chunks and lc_extras. Its size is
455// 'lc_n_chunks' because in the worst case that's how many chunks could be
456// pushed onto it (actually I think the maximum is lc_n_chunks-1 but let's
457// be conservative).
458static Int* lc_markstack;
459// The index of the top element of the stack; -1 if the stack is empty, 0 if
460// the stack has one element, 1 if it has two, etc.
461static Int lc_markstack_top;
462
463// Keeps track of how many bytes of memory we've scanned, for printing.
464// (Nb: We don't keep track of how many register bytes we've scanned.)
465static SizeT lc_scanned_szB;
466
467
468SizeT MC_(bytes_leaked) = 0;
469SizeT MC_(bytes_indirect) = 0;
470SizeT MC_(bytes_dubious) = 0;
471SizeT MC_(bytes_reachable) = 0;
472SizeT MC_(bytes_suppressed) = 0;
473
474SizeT MC_(blocks_leaked) = 0;
475SizeT MC_(blocks_indirect) = 0;
476SizeT MC_(blocks_dubious) = 0;
477SizeT MC_(blocks_reachable) = 0;
478SizeT MC_(blocks_suppressed) = 0;
479
sewardj45f4e7c2005-09-27 19:20:21 +0000480
njn8225cc02009-03-09 22:52:24 +0000481// Determines if a pointer is to a chunk. Returns the chunk number et al
482// via call-by-reference.
483static Bool
484lc_is_a_chunk_ptr(Addr ptr, Int* pch_no, MC_Chunk** pch, LC_Extra** pex)
njn43c799e2003-04-08 00:08:52 +0000485{
njn8225cc02009-03-09 22:52:24 +0000486 Int ch_no;
487 MC_Chunk* ch;
488 LC_Extra* ex;
njn43c799e2003-04-08 00:08:52 +0000489
njn8225cc02009-03-09 22:52:24 +0000490 // Quick filter.
491 if (!VG_(am_is_valid_for_client)(ptr, 1, VKI_PROT_READ)) {
492 return False;
sewardjb5f6f512005-03-10 23:59:00 +0000493 } else {
njn8225cc02009-03-09 22:52:24 +0000494 ch_no = find_chunk_for(ptr, lc_chunks, lc_n_chunks);
495 tl_assert(ch_no >= -1 && ch_no < lc_n_chunks);
496
497 if (ch_no == -1) {
498 return False;
499 } else {
500 // Ok, we've found a pointer to a chunk. Get the MC_Chunk and its
501 // LC_Extra.
502 ch = lc_chunks[ch_no];
503 ex = &(lc_extras[ch_no]);
504
505 tl_assert(ptr >= ch->data);
506 tl_assert(ptr < ch->data + ch->szB + (ch->szB==0 ? 1 : 0));
507
508 if (VG_DEBUG_LEAKCHECK)
509 VG_(printf)("ptr=%#lx -> block %d\n", ptr, ch_no);
510
511 *pch_no = ch_no;
512 *pch = ch;
513 *pex = ex;
514
515 return True;
516 }
sewardjb5f6f512005-03-10 23:59:00 +0000517 }
518}
519
njn8225cc02009-03-09 22:52:24 +0000520// Push a chunk (well, just its index) onto the mark stack.
521static void lc_push(Int ch_no, MC_Chunk* ch)
sewardjb5f6f512005-03-10 23:59:00 +0000522{
tom1d0f3f62010-10-04 20:55:21 +0000523 if (!lc_extras[ch_no].pending) {
524 if (0) {
525 VG_(printf)("pushing %#lx-%#lx\n", ch->data, ch->data + ch->szB);
526 }
527 lc_markstack_top++;
528 tl_assert(lc_markstack_top < lc_n_chunks);
529 lc_markstack[lc_markstack_top] = ch_no;
530 tl_assert(!lc_extras[ch_no].pending);
531 lc_extras[ch_no].pending = True;
njn8225cc02009-03-09 22:52:24 +0000532 }
sewardjb5f6f512005-03-10 23:59:00 +0000533}
534
njn8225cc02009-03-09 22:52:24 +0000535// Return the index of the chunk on the top of the mark stack, or -1 if
536// there isn't one.
537static Bool lc_pop(Int* ret)
sewardjb5f6f512005-03-10 23:59:00 +0000538{
njn8225cc02009-03-09 22:52:24 +0000539 if (-1 == lc_markstack_top) {
540 return False;
541 } else {
542 tl_assert(0 <= lc_markstack_top && lc_markstack_top < lc_n_chunks);
543 *ret = lc_markstack[lc_markstack_top];
544 lc_markstack_top--;
tom1d0f3f62010-10-04 20:55:21 +0000545 tl_assert(lc_extras[*ret].pending);
546 lc_extras[*ret].pending = False;
njn8225cc02009-03-09 22:52:24 +0000547 return True;
548 }
549}
sewardjb5f6f512005-03-10 23:59:00 +0000550
njn8225cc02009-03-09 22:52:24 +0000551
552// If 'ptr' is pointing to a heap-allocated block which hasn't been seen
553// before, push it onto the mark stack.
554static void
555lc_push_without_clique_if_a_chunk_ptr(Addr ptr, Bool is_prior_definite)
556{
557 Int ch_no;
558 MC_Chunk* ch;
559 LC_Extra* ex;
560
561 if ( ! lc_is_a_chunk_ptr(ptr, &ch_no, &ch, &ex) )
562 return;
tom1d0f3f62010-10-04 20:55:21 +0000563
njn8225cc02009-03-09 22:52:24 +0000564 // Possibly upgrade the state, ie. one of:
565 // - Unreached --> Possible
566 // - Unreached --> Reachable
567 // - Possible --> Reachable
tom1d0f3f62010-10-04 20:55:21 +0000568 if (ptr == ch->data && is_prior_definite && ex->state != Reachable) {
njn8225cc02009-03-09 22:52:24 +0000569 // 'ptr' points to the start of the block, and the prior node is
570 // definite, which means that this block is definitely reachable.
571 ex->state = Reachable;
572
tom1d0f3f62010-10-04 20:55:21 +0000573 // State has changed to Reachable so (re)scan the block to make
574 // sure any blocks it points to are correctly marked.
575 lc_push(ch_no, ch);
576
njn8225cc02009-03-09 22:52:24 +0000577 } else if (ex->state == Unreached) {
578 // Either 'ptr' is a interior-pointer, or the prior node isn't definite,
579 // which means that we can only mark this block as possibly reachable.
580 ex->state = Possible;
tom1d0f3f62010-10-04 20:55:21 +0000581
582 // State has changed to Possible so (re)scan the block to make
583 // sure any blocks it points to are correctly marked.
584 lc_push(ch_no, ch);
njn8225cc02009-03-09 22:52:24 +0000585 }
586}
587
588static void
589lc_push_if_a_chunk_ptr_register(Addr ptr)
590{
591 lc_push_without_clique_if_a_chunk_ptr(ptr, /*is_prior_definite*/True);
592}
593
594// If ptr is pointing to a heap-allocated block which hasn't been seen
595// before, push it onto the mark stack. Clique is the index of the
596// clique leader.
597static void
598lc_push_with_clique_if_a_chunk_ptr(Addr ptr, Int clique)
599{
600 Int ch_no;
601 MC_Chunk* ch;
602 LC_Extra* ex;
603
604 tl_assert(0 <= clique && clique < lc_n_chunks);
605
606 if ( ! lc_is_a_chunk_ptr(ptr, &ch_no, &ch, &ex) )
607 return;
608
609 // If it's not Unreached, it's already been handled so ignore it.
610 // If ch_no==clique, it's the clique leader, which means this is a cyclic
611 // structure; again ignore it because it's already been handled.
612 if (ex->state == Unreached && ch_no != clique) {
613 // Note that, unlike reachable blocks, we currently don't distinguish
614 // between start-pointers and interior-pointers here. We probably
615 // should, though.
616 ex->state = IndirectLeak;
617 lc_push(ch_no, ch);
618
619 // Add the block to the clique, and add its size to the
620 // clique-leader's indirect size. Also, if the new block was
621 // itself a clique leader, it isn't any more, so add its
622 // indirect_szB to the new clique leader.
623 if (VG_DEBUG_CLIQUE) {
624 if (ex->indirect_szB > 0)
625 VG_(printf)(" clique %d joining clique %d adding %lu+%lu\n",
626 ch_no, clique, (SizeT)ch->szB, (SizeT)ex->indirect_szB);
627 else
628 VG_(printf)(" block %d joining clique %d adding %lu\n",
629 ch_no, clique, (SizeT)ch->szB);
630 }
631
632 lc_extras[clique].indirect_szB += ch->szB;
633 lc_extras[clique].indirect_szB += ex->indirect_szB;
634 ex->indirect_szB = 0; // Shouldn't matter.
635 }
636}
637
638static void
639lc_push_if_a_chunk_ptr(Addr ptr, Int clique, Bool is_prior_definite)
640{
641 if (-1 == clique)
642 lc_push_without_clique_if_a_chunk_ptr(ptr, is_prior_definite);
643 else
644 lc_push_with_clique_if_a_chunk_ptr(ptr, clique);
sewardjb5f6f512005-03-10 23:59:00 +0000645}
646
sewardj45d94cc2005-04-20 14:44:11 +0000647
sewardj97d3ebb2011-04-11 18:36:34 +0000648static VG_MINIMAL_JMP_BUF(memscan_jmpbuf);
sewardjb5f6f512005-03-10 23:59:00 +0000649
njn8225cc02009-03-09 22:52:24 +0000650static
651void scan_all_valid_memory_catcher ( Int sigNo, Addr addr )
sewardjb5f6f512005-03-10 23:59:00 +0000652{
njn8225cc02009-03-09 22:52:24 +0000653 if (0)
654 VG_(printf)("OUCH! sig=%d addr=%#lx\n", sigNo, addr);
655 if (sigNo == VKI_SIGSEGV || sigNo == VKI_SIGBUS)
sewardj6c591e12011-04-11 16:17:51 +0000656 VG_MINIMAL_LONGJMP(memscan_jmpbuf);
njn8225cc02009-03-09 22:52:24 +0000657}
658
659// Scan a block of memory between [start, start+len). This range may
660// be bogus, inaccessable, or otherwise strange; we deal with it. For each
661// valid aligned word we assume it's a pointer to a chunk a push the chunk
662// onto the mark stack if so.
663static void
664lc_scan_memory(Addr start, SizeT len, Bool is_prior_definite, Int clique)
665{
666 Addr ptr = VG_ROUNDUP(start, sizeof(Addr));
njn13bfd852005-06-02 03:52:53 +0000667 Addr end = VG_ROUNDDN(start+len, sizeof(Addr));
sewardjb5f6f512005-03-10 23:59:00 +0000668 vki_sigset_t sigmask;
669
670 if (VG_DEBUG_LEAKCHECK)
njn8225cc02009-03-09 22:52:24 +0000671 VG_(printf)("scan %#lx-%#lx (%lu)\n", start, end, len);
672
sewardjb5f6f512005-03-10 23:59:00 +0000673 VG_(sigprocmask)(VKI_SIG_SETMASK, NULL, &sigmask);
njn695c16e2005-03-27 03:40:28 +0000674 VG_(set_fault_catcher)(scan_all_valid_memory_catcher);
sewardjb5f6f512005-03-10 23:59:00 +0000675
njn8225cc02009-03-09 22:52:24 +0000676 // We might be in the middle of a page. Do a cheap check to see if
677 // it's valid; if not, skip onto the next page.
sewardj45f4e7c2005-09-27 19:20:21 +0000678 if (!VG_(am_is_valid_for_client)(ptr, sizeof(Addr), VKI_PROT_READ))
njn8225cc02009-03-09 22:52:24 +0000679 ptr = VG_PGROUNDUP(ptr+1); // First page is bad - skip it.
sewardjb5f6f512005-03-10 23:59:00 +0000680
sewardj05fe85e2005-04-27 22:46:36 +0000681 while (ptr < end) {
sewardjb5f6f512005-03-10 23:59:00 +0000682 Addr addr;
683
njn8225cc02009-03-09 22:52:24 +0000684 // Skip invalid chunks.
685 if ( ! MC_(is_within_valid_secondary)(ptr) ) {
686 ptr = VG_ROUNDUP(ptr+1, SM_SIZE);
687 continue;
sewardjb5f6f512005-03-10 23:59:00 +0000688 }
689
njn8225cc02009-03-09 22:52:24 +0000690 // Look to see if this page seems reasonable.
sewardjb5f6f512005-03-10 23:59:00 +0000691 if ((ptr % VKI_PAGE_SIZE) == 0) {
njn8225cc02009-03-09 22:52:24 +0000692 if (!VG_(am_is_valid_for_client)(ptr, sizeof(Addr), VKI_PROT_READ)) {
693 ptr += VKI_PAGE_SIZE; // Bad page - skip it.
694 continue;
695 }
sewardjb5f6f512005-03-10 23:59:00 +0000696 }
697
sewardj6c591e12011-04-11 16:17:51 +0000698 if (VG_MINIMAL_SETJMP(memscan_jmpbuf) == 0) {
njn8225cc02009-03-09 22:52:24 +0000699 if ( MC_(is_valid_aligned_word)(ptr) ) {
700 lc_scanned_szB += sizeof(Addr);
701 addr = *(Addr *)ptr;
702 // If we get here, the scanned word is in valid memory. Now
703 // let's see if its contents point to a chunk.
704 lc_push_if_a_chunk_ptr(addr, clique, is_prior_definite);
705 } else if (0 && VG_DEBUG_LEAKCHECK) {
706 VG_(printf)("%#lx not valid\n", ptr);
707 }
708 ptr += sizeof(Addr);
sewardjb5f6f512005-03-10 23:59:00 +0000709 } else {
njn8225cc02009-03-09 22:52:24 +0000710 // We need to restore the signal mask, because we were
711 // longjmped out of a signal handler.
712 VG_(sigprocmask)(VKI_SIG_SETMASK, &sigmask, NULL);
sewardjb5f6f512005-03-10 23:59:00 +0000713
njn8225cc02009-03-09 22:52:24 +0000714 ptr = VG_PGROUNDUP(ptr+1); // Bad page - skip it.
sewardjb5f6f512005-03-10 23:59:00 +0000715 }
716 }
717
718 VG_(sigprocmask)(VKI_SIG_SETMASK, &sigmask, NULL);
719 VG_(set_fault_catcher)(NULL);
720}
721
sewardj45d94cc2005-04-20 14:44:11 +0000722
njn8225cc02009-03-09 22:52:24 +0000723// Process the mark stack until empty.
724static void lc_process_markstack(Int clique)
sewardjb5f6f512005-03-10 23:59:00 +0000725{
njne3675d62009-05-19 02:08:25 +0000726 Int top = -1; // shut gcc up
njn8225cc02009-03-09 22:52:24 +0000727 Bool is_prior_definite;
sewardjb5f6f512005-03-10 23:59:00 +0000728
njn8225cc02009-03-09 22:52:24 +0000729 while (lc_pop(&top)) {
tom1d0f3f62010-10-04 20:55:21 +0000730 tl_assert(top >= 0 && top < lc_n_chunks);
sewardjb5f6f512005-03-10 23:59:00 +0000731
njn8225cc02009-03-09 22:52:24 +0000732 // See comment about 'is_prior_definite' at the top to understand this.
733 is_prior_definite = ( Possible != lc_extras[top].state );
sewardjb5f6f512005-03-10 23:59:00 +0000734
njn8225cc02009-03-09 22:52:24 +0000735 lc_scan_memory(lc_chunks[top]->data, lc_chunks[top]->szB,
736 is_prior_definite, clique);
sewardjb5f6f512005-03-10 23:59:00 +0000737 }
738}
739
njn29a5c012009-05-06 06:15:55 +0000740static Word cmp_LossRecordKey_LossRecord(const void* key, const void* elem)
741{
742 LossRecordKey* a = (LossRecordKey*)key;
743 LossRecordKey* b = &(((LossRecord*)elem)->key);
744
745 // Compare on states first because that's fast.
746 if (a->state < b->state) return -1;
747 if (a->state > b->state) return 1;
748 // Ok, the states are equal. Now compare the locations, which is slower.
749 if (VG_(eq_ExeContext)(
750 MC_(clo_leak_resolution), a->allocated_at, b->allocated_at))
751 return 0;
752 // Different locations. Ordering is arbitrary, just use the ec pointer.
753 if (a->allocated_at < b->allocated_at) return -1;
754 if (a->allocated_at > b->allocated_at) return 1;
755 VG_(tool_panic)("bad LossRecord comparison");
756}
757
758static Int cmp_LossRecords(void* va, void* vb)
759{
760 LossRecord* lr_a = *(LossRecord**)va;
761 LossRecord* lr_b = *(LossRecord**)vb;
762 SizeT total_szB_a = lr_a->szB + lr_a->indirect_szB;
763 SizeT total_szB_b = lr_b->szB + lr_b->indirect_szB;
764
765 // First compare by sizes.
766 if (total_szB_a < total_szB_b) return -1;
767 if (total_szB_a > total_szB_b) return 1;
768 // If size are equal, compare by states.
769 if (lr_a->key.state < lr_b->key.state) return -1;
770 if (lr_a->key.state > lr_b->key.state) return 1;
njne10c7f82009-05-06 06:52:47 +0000771 // If they're still equal here, it doesn't matter that much, but we keep
772 // comparing other things so that regtests are as deterministic as
773 // possible. So: compare num_blocks.
774 if (lr_a->num_blocks < lr_b->num_blocks) return -1;
775 if (lr_a->num_blocks > lr_b->num_blocks) return 1;
776 // Finally, compare ExeContext addresses... older ones are likely to have
777 // lower addresses.
778 if (lr_a->key.allocated_at < lr_b->key.allocated_at) return -1;
779 if (lr_a->key.allocated_at > lr_b->key.allocated_at) return 1;
njn29a5c012009-05-06 06:15:55 +0000780 return 0;
781}
782
sewardjc8bd1df2011-06-26 12:41:33 +0000783static void print_results(ThreadId tid, LeakCheckParams lcp)
sewardjb5f6f512005-03-10 23:59:00 +0000784{
njn29a5c012009-05-06 06:15:55 +0000785 Int i, n_lossrecords;
njn29a5c012009-05-06 06:15:55 +0000786 LossRecord** lr_array;
787 LossRecord* lr;
788 Bool is_suppressed;
sewardjc8bd1df2011-06-26 12:41:33 +0000789 SizeT old_bytes_leaked = MC_(bytes_leaked); /* to report delta in summary */
790 SizeT old_bytes_indirect = MC_(bytes_indirect);
791 SizeT old_bytes_dubious = MC_(bytes_dubious);
792 SizeT old_bytes_reachable = MC_(bytes_reachable);
793 SizeT old_bytes_suppressed = MC_(bytes_suppressed);
794 SizeT old_blocks_leaked = MC_(blocks_leaked);
795 SizeT old_blocks_indirect = MC_(blocks_indirect);
796 SizeT old_blocks_dubious = MC_(blocks_dubious);
797 SizeT old_blocks_reachable = MC_(blocks_reachable);
798 SizeT old_blocks_suppressed = MC_(blocks_suppressed);
sewardjb5f6f512005-03-10 23:59:00 +0000799
sewardjc8bd1df2011-06-26 12:41:33 +0000800 if (lr_table == NULL)
801 // Create the lr_table, which holds the loss records.
802 // If the lr_table already exists, it means it contains
803 // loss_records from the previous leak search. The old_*
804 // values in these records are used to implement the
805 // leak check delta mode
806 lr_table =
807 VG_(OSetGen_Create)(offsetof(LossRecord, key),
808 cmp_LossRecordKey_LossRecord,
809 VG_(malloc), "mc.pr.1",
810 VG_(free));
811
njn29a5c012009-05-06 06:15:55 +0000812
813 // Convert the chunks into loss records, merging them where appropriate.
njn8225cc02009-03-09 22:52:24 +0000814 for (i = 0; i < lc_n_chunks; i++) {
njn29a5c012009-05-06 06:15:55 +0000815 MC_Chunk* ch = lc_chunks[i];
816 LC_Extra* ex = &(lc_extras)[i];
817 LossRecord* old_lr;
818 LossRecordKey lrkey;
819 lrkey.state = ex->state;
820 lrkey.allocated_at = ch->where;
sewardjb5f6f512005-03-10 23:59:00 +0000821
njn29a5c012009-05-06 06:15:55 +0000822 old_lr = VG_(OSetGen_Lookup)(lr_table, &lrkey);
823 if (old_lr) {
824 // We found an existing loss record matching this chunk. Update the
825 // loss record's details in-situ. This is safe because we don't
826 // change the elements used as the OSet key.
827 old_lr->szB += ch->szB;
828 old_lr->indirect_szB += ex->indirect_szB;
829 old_lr->num_blocks++;
sewardjb5f6f512005-03-10 23:59:00 +0000830 } else {
njn29a5c012009-05-06 06:15:55 +0000831 // No existing loss record matches this chunk. Create a new loss
832 // record, initialise it from the chunk, and insert it into lr_table.
833 lr = VG_(OSetGen_AllocNode)(lr_table, sizeof(LossRecord));
834 lr->key = lrkey;
835 lr->szB = ch->szB;
836 lr->indirect_szB = ex->indirect_szB;
837 lr->num_blocks = 1;
sewardjc8bd1df2011-06-26 12:41:33 +0000838 lr->old_szB = 0;
839 lr->old_indirect_szB = 0;
840 lr->old_num_blocks = 0;
njn29a5c012009-05-06 06:15:55 +0000841 VG_(OSetGen_Insert)(lr_table, lr);
sewardjb5f6f512005-03-10 23:59:00 +0000842 }
843 }
njn29a5c012009-05-06 06:15:55 +0000844 n_lossrecords = VG_(OSetGen_Size)(lr_table);
sewardjb5f6f512005-03-10 23:59:00 +0000845
njn29a5c012009-05-06 06:15:55 +0000846 // Create an array of pointers to the loss records.
847 lr_array = VG_(malloc)("mc.pr.2", n_lossrecords * sizeof(LossRecord*));
848 i = 0;
849 VG_(OSetGen_ResetIter)(lr_table);
850 while ( (lr = VG_(OSetGen_Next)(lr_table)) ) {
851 lr_array[i++] = lr;
852 }
853 tl_assert(i == n_lossrecords);
854
855 // Sort the array by loss record sizes.
856 VG_(ssort)(lr_array, n_lossrecords, sizeof(LossRecord*),
857 cmp_LossRecords);
858
859 // Zero totals.
njn8225cc02009-03-09 22:52:24 +0000860 MC_(blocks_leaked) = MC_(bytes_leaked) = 0;
861 MC_(blocks_indirect) = MC_(bytes_indirect) = 0;
862 MC_(blocks_dubious) = MC_(bytes_dubious) = 0;
863 MC_(blocks_reachable) = MC_(bytes_reachable) = 0;
864 MC_(blocks_suppressed) = MC_(bytes_suppressed) = 0;
865
njn29a5c012009-05-06 06:15:55 +0000866 // Print the loss records (in size order) and collect summary stats.
sewardjb5f6f512005-03-10 23:59:00 +0000867 for (i = 0; i < n_lossrecords; i++) {
sewardjc8bd1df2011-06-26 12:41:33 +0000868 Bool count_as_error, print_record, delta_considered;
njn8225cc02009-03-09 22:52:24 +0000869 // Rules for printing:
870 // - We don't show suppressed loss records ever (and that's controlled
871 // within the error manager).
872 // - We show non-suppressed loss records that are not "reachable" if
873 // --leak-check=yes.
874 // - We show all non-suppressed loss records if --leak-check=yes and
875 // --show-reachable=yes.
876 //
877 // Nb: here "reachable" means Reachable *or* IndirectLeak; note that
878 // this is different to "still reachable" used elsewhere because it
879 // includes indirectly lost blocks!
880 //
njn29a5c012009-05-06 06:15:55 +0000881 lr = lr_array[i];
sewardjc8bd1df2011-06-26 12:41:33 +0000882 switch (lcp.deltamode) {
883 case LCD_Any:
884 delta_considered = lr->num_blocks > 0;
885 break;
886 case LCD_Increased:
887 delta_considered
888 = lr_array[i]->szB > lr_array[i]->old_szB
889 || lr_array[i]->indirect_szB > lr_array[i]->old_indirect_szB
890 || lr->num_blocks > lr->old_num_blocks;
891 break;
892 case LCD_Changed:
893 delta_considered = lr_array[i]->szB != lr_array[i]->old_szB
894 || lr_array[i]->indirect_szB != lr_array[i]->old_indirect_szB
895 || lr->num_blocks != lr->old_num_blocks;
896 break;
897 default:
898 tl_assert(0);
899 }
900
901 print_record = lcp.mode == LC_Full && delta_considered &&
902 ( lcp.show_reachable ||
njn26670552009-08-13 00:02:30 +0000903 Unreached == lr->key.state ||
sewardjc8bd1df2011-06-26 12:41:33 +0000904 ( lcp.show_possibly_lost &&
bart3cedf572010-08-26 10:56:27 +0000905 Possible == lr->key.state ) );
sewardjc8bd1df2011-06-26 12:41:33 +0000906 // We don't count a leaks as errors with lcp.mode==LC_Summary.
njn26670552009-08-13 00:02:30 +0000907 // Otherwise you can get high error counts with few or no error
908 // messages, which can be confusing. Also, you could argue that
909 // indirect leaks should be counted as errors, but it seems better to
910 // make the counting criteria similar to the printing criteria. So we
911 // don't count them.
sewardjc8bd1df2011-06-26 12:41:33 +0000912 count_as_error = lcp.mode == LC_Full && delta_considered &&
njn26670552009-08-13 00:02:30 +0000913 ( Unreached == lr->key.state ||
914 Possible == lr->key.state );
sewardjb5f6f512005-03-10 23:59:00 +0000915 is_suppressed =
njn18afe5d2009-08-10 08:25:39 +0000916 MC_(record_leak_error) ( tid, i+1, n_lossrecords, lr, print_record,
917 count_as_error );
sewardjb5f6f512005-03-10 23:59:00 +0000918
919 if (is_suppressed) {
njn29a5c012009-05-06 06:15:55 +0000920 MC_(blocks_suppressed) += lr->num_blocks;
921 MC_(bytes_suppressed) += lr->szB;
sewardjb5f6f512005-03-10 23:59:00 +0000922
njn29a5c012009-05-06 06:15:55 +0000923 } else if (Unreached == lr->key.state) {
924 MC_(blocks_leaked) += lr->num_blocks;
925 MC_(bytes_leaked) += lr->szB;
sewardjb5f6f512005-03-10 23:59:00 +0000926
njn29a5c012009-05-06 06:15:55 +0000927 } else if (IndirectLeak == lr->key.state) {
928 MC_(blocks_indirect) += lr->num_blocks;
929 MC_(bytes_indirect) += lr->szB;
sewardjb5f6f512005-03-10 23:59:00 +0000930
njn29a5c012009-05-06 06:15:55 +0000931 } else if (Possible == lr->key.state) {
932 MC_(blocks_dubious) += lr->num_blocks;
933 MC_(bytes_dubious) += lr->szB;
sewardjb5f6f512005-03-10 23:59:00 +0000934
njn29a5c012009-05-06 06:15:55 +0000935 } else if (Reachable == lr->key.state) {
936 MC_(blocks_reachable) += lr->num_blocks;
937 MC_(bytes_reachable) += lr->szB;
sewardjb5f6f512005-03-10 23:59:00 +0000938
939 } else {
njn8225cc02009-03-09 22:52:24 +0000940 VG_(tool_panic)("unknown loss mode");
sewardjb5f6f512005-03-10 23:59:00 +0000941 }
sewardjb5f6f512005-03-10 23:59:00 +0000942 }
sewardjb5f6f512005-03-10 23:59:00 +0000943
sewardjc8bd1df2011-06-26 12:41:33 +0000944 for (i = 0; i < n_lossrecords; i++)
945 {
946 if (lr->num_blocks == 0)
947 // remove from lr_table the old loss_records with 0 bytes found
948 VG_(OSetGen_Remove) (lr_table, &lr_array[i]->key);
949 else
950 {
951 // move the leak sizes to old_* and zero the current sizes
952 // for next leak search
953 lr_array[i]->old_szB = lr_array[i]->szB;
954 lr_array[i]->old_indirect_szB = lr_array[i]->indirect_szB;
955 lr_array[i]->old_num_blocks = lr_array[i]->num_blocks;
956 lr_array[i]->szB = 0;
957 lr_array[i]->indirect_szB = 0;
958 lr_array[i]->num_blocks = 0;
959 }
960 }
961 VG_(free)(lr_array);
962
njn8225cc02009-03-09 22:52:24 +0000963 if (VG_(clo_verbosity) > 0 && !VG_(clo_xml)) {
sewardjc8bd1df2011-06-26 12:41:33 +0000964 char d_bytes[20];
965 char d_blocks[20];
966
sewardj6b523cd2009-07-15 14:49:40 +0000967 VG_(umsg)("LEAK SUMMARY:\n");
sewardjc8bd1df2011-06-26 12:41:33 +0000968 VG_(umsg)(" definitely lost: %'lu%s bytes in %'lu%s blocks\n",
969 MC_(bytes_leaked),
970 MC_(snprintf_delta) (d_bytes, 20, MC_(bytes_leaked), old_bytes_leaked, lcp.deltamode),
971 MC_(blocks_leaked),
972 MC_(snprintf_delta) (d_blocks, 20, MC_(blocks_leaked), old_blocks_leaked, lcp.deltamode));
973 VG_(umsg)(" indirectly lost: %'lu%s bytes in %'lu%s blocks\n",
974 MC_(bytes_indirect),
975 MC_(snprintf_delta) (d_bytes, 20, MC_(bytes_indirect), old_bytes_indirect, lcp.deltamode),
976 MC_(blocks_indirect),
977 MC_(snprintf_delta) (d_blocks, 20, MC_(blocks_indirect), old_blocks_indirect, lcp.deltamode) );
978 VG_(umsg)(" possibly lost: %'lu%s bytes in %'lu%s blocks\n",
979 MC_(bytes_dubious),
980 MC_(snprintf_delta) (d_bytes, 20, MC_(bytes_dubious), old_bytes_dubious, lcp.deltamode),
981 MC_(blocks_dubious),
982 MC_(snprintf_delta) (d_blocks, 20, MC_(blocks_dubious), old_blocks_dubious, lcp.deltamode) );
983 VG_(umsg)(" still reachable: %'lu%s bytes in %'lu%s blocks\n",
984 MC_(bytes_reachable),
985 MC_(snprintf_delta) (d_bytes, 20, MC_(bytes_reachable), old_bytes_reachable, lcp.deltamode),
986 MC_(blocks_reachable),
987 MC_(snprintf_delta) (d_blocks, 20, MC_(blocks_reachable), old_blocks_reachable, lcp.deltamode) );
988 VG_(umsg)(" suppressed: %'lu%s bytes in %'lu%s blocks\n",
989 MC_(bytes_suppressed),
990 MC_(snprintf_delta) (d_bytes, 20, MC_(bytes_suppressed), old_bytes_suppressed, lcp.deltamode),
991 MC_(blocks_suppressed),
992 MC_(snprintf_delta) (d_blocks, 20, MC_(blocks_suppressed), old_blocks_suppressed, lcp.deltamode) );
993 if (lcp.mode != LC_Full &&
njn8225cc02009-03-09 22:52:24 +0000994 (MC_(blocks_leaked) + MC_(blocks_indirect) +
995 MC_(blocks_dubious) + MC_(blocks_reachable)) > 0) {
sewardjc8bd1df2011-06-26 12:41:33 +0000996 if (lcp.requested_by_monitor_command)
997 VG_(umsg)("To see details of leaked memory, give 'full' arg to mc.leak_check\n");
998 else
999 VG_(umsg)("Rerun with --leak-check=full to see details "
1000 "of leaked memory\n");
njn8225cc02009-03-09 22:52:24 +00001001 }
sewardjc8bd1df2011-06-26 12:41:33 +00001002 if (lcp.mode == LC_Full &&
1003 MC_(blocks_reachable) > 0 && !lcp.show_reachable)
njn8225cc02009-03-09 22:52:24 +00001004 {
sewardj6b523cd2009-07-15 14:49:40 +00001005 VG_(umsg)("Reachable blocks (those to which a pointer "
1006 "was found) are not shown.\n");
sewardjc8bd1df2011-06-26 12:41:33 +00001007 if (lcp.requested_by_monitor_command)
1008 VG_(umsg)("To see them, add 'reachable any' args to mc.leak_check\n");
1009 else
1010 VG_(umsg)("To see them, rerun with: --leak-check=full "
1011 "--show-reachable=yes\n");
sewardjb5f6f512005-03-10 23:59:00 +00001012 }
njnb6267bd2009-08-12 00:14:16 +00001013 VG_(umsg)("\n");
sewardjb5f6f512005-03-10 23:59:00 +00001014 }
1015}
1016
njn8225cc02009-03-09 22:52:24 +00001017/*------------------------------------------------------------*/
1018/*--- Top-level entry point. ---*/
1019/*------------------------------------------------------------*/
sewardj3cf26a52006-07-27 23:48:53 +00001020
sewardjc8bd1df2011-06-26 12:41:33 +00001021void MC_(detect_memory_leaks) ( ThreadId tid, LeakCheckParams lcp)
njn43c799e2003-04-08 00:08:52 +00001022{
njnb965efb2009-08-10 07:36:54 +00001023 Int i, j;
njn43c799e2003-04-08 00:08:52 +00001024
sewardjc8bd1df2011-06-26 12:41:33 +00001025 tl_assert(lcp.mode != LC_Off);
1026
1027 MC_(detect_memory_leaks_last_delta_mode) = lcp.deltamode;
njn43c799e2003-04-08 00:08:52 +00001028
njn8225cc02009-03-09 22:52:24 +00001029 // Get the chunks, stop if there were none.
1030 lc_chunks = find_active_chunks(&lc_n_chunks);
1031 if (lc_n_chunks == 0) {
1032 tl_assert(lc_chunks == NULL);
sewardjc8bd1df2011-06-26 12:41:33 +00001033 if (lr_table != NULL) {
1034 // forget the previous recorded LossRecords as next leak search will in any case
1035 // just create new leaks.
1036 // Maybe it would be better to rather call print_result ?
1037 // (at least when leak decrease are requested)
1038 // This will then output all LossRecords with a size decreasing to 0
1039 VG_(OSetGen_Destroy) (lr_table);
1040 }
sewardj71bc3cb2005-05-19 00:25:45 +00001041 if (VG_(clo_verbosity) >= 1 && !VG_(clo_xml)) {
njnb6267bd2009-08-12 00:14:16 +00001042 VG_(umsg)("All heap blocks were freed -- no leaks are possible\n");
sewardj2d9e8742009-08-07 15:46:56 +00001043 VG_(umsg)("\n");
sewardj37d06f22003-09-17 21:48:26 +00001044 }
njn43c799e2003-04-08 00:08:52 +00001045 return;
1046 }
1047
njn8225cc02009-03-09 22:52:24 +00001048 // Sort the array so blocks are in ascending order in memory.
1049 VG_(ssort)(lc_chunks, lc_n_chunks, sizeof(VgHashNode*), compare_MC_Chunks);
njn43c799e2003-04-08 00:08:52 +00001050
njn8225cc02009-03-09 22:52:24 +00001051 // Sanity check -- make sure they're in order.
1052 for (i = 0; i < lc_n_chunks-1; i++) {
1053 tl_assert( lc_chunks[i]->data <= lc_chunks[i+1]->data);
1054 }
njn43c799e2003-04-08 00:08:52 +00001055
njnb965efb2009-08-10 07:36:54 +00001056 // Sanity check -- make sure they don't overlap. The one exception is that
1057 // we allow a MALLOCLIKE block to sit entirely within a malloc() block.
1058 // This is for bug 100628. If this occurs, we ignore the malloc() block
1059 // for leak-checking purposes. This is a hack and probably should be done
1060 // better, but at least it's consistent with mempools (which are treated
1061 // like this in find_active_chunks). Mempools have a separate VgHashTable
1062 // for mempool chunks, but if custom-allocated blocks are put in a separate
1063 // table from normal heap blocks it makes free-mismatch checking more
1064 // difficult.
1065 //
1066 // If this check fails, it probably means that the application
njn8225cc02009-03-09 22:52:24 +00001067 // has done something stupid with VALGRIND_MALLOCLIKE_BLOCK client
njnb965efb2009-08-10 07:36:54 +00001068 // requests, eg. has made overlapping requests (which are
1069 // nonsensical), or used VALGRIND_MALLOCLIKE_BLOCK for stack locations;
1070 // again nonsensical.
1071 //
njn8225cc02009-03-09 22:52:24 +00001072 for (i = 0; i < lc_n_chunks-1; i++) {
1073 MC_Chunk* ch1 = lc_chunks[i];
1074 MC_Chunk* ch2 = lc_chunks[i+1];
njnb965efb2009-08-10 07:36:54 +00001075
1076 Addr start1 = ch1->data;
1077 Addr start2 = ch2->data;
1078 Addr end1 = ch1->data + ch1->szB - 1;
1079 Addr end2 = ch2->data + ch2->szB - 1;
1080 Bool isCustom1 = ch1->allockind == MC_AllocCustom;
1081 Bool isCustom2 = ch2->allockind == MC_AllocCustom;
1082
1083 if (end1 < start2) {
1084 // Normal case - no overlap.
1085
1086 // We used to allow exact duplicates, I'm not sure why. --njn
1087 //} else if (start1 == start2 && end1 == end2) {
1088 // Degenerate case: exact duplicates.
1089
1090 } else if (start1 >= start2 && end1 <= end2 && isCustom1 && !isCustom2) {
1091 // Block i is MALLOCLIKE and entirely within block i+1.
1092 // Remove block i+1.
1093 for (j = i+1; j < lc_n_chunks-1; j++) {
1094 lc_chunks[j] = lc_chunks[j+1];
1095 }
1096 lc_n_chunks--;
1097
1098 } else if (start2 >= start1 && end2 <= end1 && isCustom2 && !isCustom1) {
1099 // Block i+1 is MALLOCLIKE and entirely within block i.
1100 // Remove block i.
1101 for (j = i; j < lc_n_chunks-1; j++) {
1102 lc_chunks[j] = lc_chunks[j+1];
1103 }
1104 lc_n_chunks--;
1105
1106 } else {
1107 VG_(umsg)("Block 0x%lx..0x%lx overlaps with block 0x%lx..0x%lx",
bart3c4fa9f2011-05-09 10:46:55 +00001108 start1, end1, start2, end2);
njnb965efb2009-08-10 07:36:54 +00001109 VG_(umsg)("This is usually caused by using VALGRIND_MALLOCLIKE_BLOCK");
1110 VG_(umsg)("in an inappropriate way.");
1111 tl_assert (0);
njn8225cc02009-03-09 22:52:24 +00001112 }
njn8225cc02009-03-09 22:52:24 +00001113 }
1114
1115 // Initialise lc_extras.
1116 lc_extras = VG_(malloc)( "mc.dml.2", lc_n_chunks * sizeof(LC_Extra) );
1117 for (i = 0; i < lc_n_chunks; i++) {
1118 lc_extras[i].state = Unreached;
tom1d0f3f62010-10-04 20:55:21 +00001119 lc_extras[i].pending = False;
njn8225cc02009-03-09 22:52:24 +00001120 lc_extras[i].indirect_szB = 0;
1121 }
1122
1123 // Initialise lc_markstack.
1124 lc_markstack = VG_(malloc)( "mc.dml.2", lc_n_chunks * sizeof(Int) );
1125 for (i = 0; i < lc_n_chunks; i++) {
1126 lc_markstack[i] = -1;
sewardjb5f6f512005-03-10 23:59:00 +00001127 }
1128 lc_markstack_top = -1;
njn43c799e2003-04-08 00:08:52 +00001129
njn8225cc02009-03-09 22:52:24 +00001130 // Verbosity.
sewardj2d9e8742009-08-07 15:46:56 +00001131 if (VG_(clo_verbosity) > 1 && !VG_(clo_xml)) {
njnb6267bd2009-08-12 00:14:16 +00001132 VG_(umsg)( "Searching for pointers to %'d not-freed blocks\n",
sewardj6b523cd2009-07-15 14:49:40 +00001133 lc_n_chunks );
sewardj2d9e8742009-08-07 15:46:56 +00001134 }
sewardjb5f6f512005-03-10 23:59:00 +00001135
njn8225cc02009-03-09 22:52:24 +00001136 // Scan the memory root-set, pushing onto the mark stack any blocks
1137 // pointed to.
1138 {
1139 Int n_seg_starts;
njnac1e0332009-05-08 00:39:31 +00001140 Addr* seg_starts = VG_(get_segment_starts)( &n_seg_starts );
sewardjb5f6f512005-03-10 23:59:00 +00001141
njn8225cc02009-03-09 22:52:24 +00001142 tl_assert(seg_starts && n_seg_starts > 0);
sewardjde3ad732006-07-27 23:12:17 +00001143
njn8225cc02009-03-09 22:52:24 +00001144 lc_scanned_szB = 0;
sewardjde3ad732006-07-27 23:12:17 +00001145
njn8225cc02009-03-09 22:52:24 +00001146 // VG_(am_show_nsegments)( 0, "leakcheck");
1147 for (i = 0; i < n_seg_starts; i++) {
1148 SizeT seg_size;
1149 NSegment const* seg = VG_(am_find_nsegment)( seg_starts[i] );
1150 tl_assert(seg);
1151
1152 if (seg->kind != SkFileC && seg->kind != SkAnonC) continue;
1153 if (!(seg->hasR && seg->hasW)) continue;
1154 if (seg->isCH) continue;
1155
1156 // Don't poke around in device segments as this may cause
1157 // hangs. Exclude /dev/zero just in case someone allocated
1158 // memory by explicitly mapping /dev/zero.
1159 if (seg->kind == SkFileC
1160 && (VKI_S_ISCHR(seg->mode) || VKI_S_ISBLK(seg->mode))) {
1161 HChar* dev_name = VG_(am_get_filename)( (NSegment*)seg );
1162 if (dev_name && 0 == VG_(strcmp)(dev_name, "/dev/zero")) {
1163 // Don't skip /dev/zero.
1164 } else {
1165 // Skip this device mapping.
1166 continue;
1167 }
1168 }
1169
1170 if (0)
1171 VG_(printf)("ACCEPT %2d %#lx %#lx\n", i, seg->start, seg->end);
1172
1173 // Scan the segment. We use -1 for the clique number, because this
1174 // is a root-set.
1175 seg_size = seg->end - seg->start + 1;
1176 if (VG_(clo_verbosity) > 2) {
1177 VG_(message)(Vg_DebugMsg,
sewardj6b523cd2009-07-15 14:49:40 +00001178 " Scanning root segment: %#lx..%#lx (%lu)\n",
njn8225cc02009-03-09 22:52:24 +00001179 seg->start, seg->end, seg_size);
1180 }
1181 lc_scan_memory(seg->start, seg_size, /*is_prior_definite*/True, -1);
1182 }
sewardj45f4e7c2005-09-27 19:20:21 +00001183 }
sewardjb5f6f512005-03-10 23:59:00 +00001184
njn8225cc02009-03-09 22:52:24 +00001185 // Scan GP registers for chunk pointers.
1186 VG_(apply_to_GP_regs)(lc_push_if_a_chunk_ptr_register);
sewardjb5f6f512005-03-10 23:59:00 +00001187
njn8225cc02009-03-09 22:52:24 +00001188 // Process the pushed blocks. After this, every block that is reachable
1189 // from the root-set has been traced.
1190 lc_process_markstack(/*clique*/-1);
njn43c799e2003-04-08 00:08:52 +00001191
njnb6267bd2009-08-12 00:14:16 +00001192 if (VG_(clo_verbosity) > 1 && !VG_(clo_xml)) {
1193 VG_(umsg)("Checked %'lu bytes\n", lc_scanned_szB);
1194 VG_(umsg)( "\n" );
1195 }
njn43c799e2003-04-08 00:08:52 +00001196
njn8225cc02009-03-09 22:52:24 +00001197 // Trace all the leaked blocks to determine which are directly leaked and
1198 // which are indirectly leaked. For each Unreached block, push it onto
1199 // the mark stack, and find all the as-yet-Unreached blocks reachable
1200 // from it. These form a clique and are marked IndirectLeak, and their
1201 // size is added to the clique leader's indirect size. If one of the
1202 // found blocks was itself a clique leader (from a previous clique), then
1203 // the cliques are merged.
1204 for (i = 0; i < lc_n_chunks; i++) {
1205 MC_Chunk* ch = lc_chunks[i];
1206 LC_Extra* ex = &(lc_extras[i]);
njn43c799e2003-04-08 00:08:52 +00001207
njn8225cc02009-03-09 22:52:24 +00001208 if (VG_DEBUG_CLIQUE)
1209 VG_(printf)("cliques: %d at %#lx -> Loss state %d\n",
1210 i, ch->data, ex->state);
njn43c799e2003-04-08 00:08:52 +00001211
njn8225cc02009-03-09 22:52:24 +00001212 tl_assert(lc_markstack_top == -1);
1213
1214 if (ex->state == Unreached) {
1215 if (VG_DEBUG_CLIQUE)
1216 VG_(printf)("%d: gathering clique %#lx\n", i, ch->data);
1217
1218 // Push this Unreached block onto the stack and process it.
1219 lc_push(i, ch);
1220 lc_process_markstack(i);
1221
1222 tl_assert(lc_markstack_top == -1);
1223 tl_assert(ex->state == Unreached);
nethercote0f19bce2003-12-02 10:17:44 +00001224 }
njn43c799e2003-04-08 00:08:52 +00001225 }
njn8225cc02009-03-09 22:52:24 +00001226
sewardjc8bd1df2011-06-26 12:41:33 +00001227 print_results( tid, lcp);
njn43c799e2003-04-08 00:08:52 +00001228
njn8225cc02009-03-09 22:52:24 +00001229 VG_(free) ( lc_chunks );
1230 VG_(free) ( lc_extras );
sewardjb5f6f512005-03-10 23:59:00 +00001231 VG_(free) ( lc_markstack );
njn43c799e2003-04-08 00:08:52 +00001232}
1233
1234/*--------------------------------------------------------------------*/
njn1d0825f2006-03-27 11:37:07 +00001235/*--- end ---*/
njn43c799e2003-04-08 00:08:52 +00001236/*--------------------------------------------------------------------*/
1237