1/*
2  This file is part of drd, a thread error detector.
3
4  Copyright (C) 2006-2013 Bart Van Assche <bvanassche@acm.org>.
5
6  This program is free software; you can redistribute it and/or
7  modify it under the terms of the GNU General Public License as
8  published by the Free Software Foundation; either version 2 of the
9  License, or (at your option) any later version.
10
11  This program is distributed in the hope that it will be useful, but
12  WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  General Public License for more details.
15
16  You should have received a copy of the GNU General Public License
17  along with this program; if not, write to the Free Software
18  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19  02111-1307, USA.
20
21  The GNU General Public License is contained in the file COPYING.
22*/
23
24
25#include "drd_barrier.h"
26#include "drd_clientobj.h"
27#include "drd_clientreq.h"
28#include "drd_cond.h"
29#include "drd_error.h"
30#include "drd_hb.h"
31#include "drd_load_store.h"
32#include "drd_malloc_wrappers.h"
33#include "drd_mutex.h"
34#include "drd_rwlock.h"
35#include "drd_segment.h"
36#include "drd_semaphore.h"
37#include "drd_suppression.h"
38#include "drd_thread.h"
39#include "libvex_guest_offsets.h"
40#include "pub_drd_bitmap.h"
41#include "pub_tool_vki.h"         // Must be included before pub_tool_libcproc
42#include "pub_tool_basics.h"
43#include "pub_tool_libcassert.h"  // tl_assert()
44#include "pub_tool_libcbase.h"    // VG_(strcmp)
45#include "pub_tool_libcprint.h"   // VG_(printf)
46#include "pub_tool_libcproc.h"    // VG_(getenv)()
47#include "pub_tool_machine.h"
48#include "pub_tool_mallocfree.h"  // VG_(malloc)(), VG_(free)()
49#include "pub_tool_options.h"     // command line options
50#include "pub_tool_replacemalloc.h"
51#include "pub_tool_threadstate.h" // VG_(get_running_tid)()
52#include "pub_tool_tooliface.h"
53#include "pub_tool_aspacemgr.h"   // VG_(am_is_valid_for_client)
54
55
56/* Local variables. */
57
58static Bool s_print_stats;
59static Bool s_var_info;
60static Bool s_show_stack_usage;
61static Bool s_trace_alloc;
62static Bool trace_sectsuppr;
63
64
65/**
66 * Implement the needs_command_line_options for drd.
67 */
68static Bool DRD_(process_cmd_line_option)(const HChar* arg)
69{
70   int check_stack_accesses   = -1;
71   int join_list_vol          = -1;
72   int exclusive_threshold_ms = -1;
73   int first_race_only        = -1;
74   int report_signal_unlocked = -1;
75   int segment_merging        = -1;
76   int segment_merge_interval = -1;
77   int shared_threshold_ms    = -1;
78   int show_confl_seg         = -1;
79   int trace_barrier          = -1;
80   int trace_clientobj        = -1;
81   int trace_cond             = -1;
82   int trace_csw              = -1;
83   int trace_fork_join        = -1;
84   int trace_hb               = -1;
85   int trace_conflict_set     = -1;
86   int trace_conflict_set_bm  = -1;
87   int trace_mutex            = -1;
88   int trace_rwlock           = -1;
89   int trace_segment          = -1;
90   int trace_semaphore        = -1;
91   int trace_suppression      = -1;
92   const HChar* trace_address = 0;
93   const HChar* ptrace_address= 0;
94
95   if      VG_BOOL_CLO(arg, "--check-stack-var",     check_stack_accesses) {}
96   else if VG_INT_CLO (arg, "--join-list-vol",       join_list_vol) {}
97   else if VG_BOOL_CLO(arg, "--drd-stats",           s_print_stats) {}
98   else if VG_BOOL_CLO(arg, "--first-race-only",     first_race_only) {}
99   else if VG_BOOL_CLO(arg, "--free-is-write",       DRD_(g_free_is_write)) {}
100   else if VG_BOOL_CLO(arg,"--report-signal-unlocked",report_signal_unlocked)
101   {}
102   else if VG_BOOL_CLO(arg, "--segment-merging",     segment_merging) {}
103   else if VG_INT_CLO (arg, "--segment-merging-interval", segment_merge_interval)
104   {}
105   else if VG_BOOL_CLO(arg, "--show-confl-seg",      show_confl_seg) {}
106   else if VG_BOOL_CLO(arg, "--show-stack-usage",    s_show_stack_usage) {}
107   else if VG_BOOL_CLO(arg, "--trace-alloc",         s_trace_alloc) {}
108   else if VG_BOOL_CLO(arg, "--trace-barrier",       trace_barrier) {}
109   else if VG_BOOL_CLO(arg, "--trace-clientobj",     trace_clientobj) {}
110   else if VG_BOOL_CLO(arg, "--trace-cond",          trace_cond) {}
111   else if VG_BOOL_CLO(arg, "--trace-conflict-set",  trace_conflict_set) {}
112   else if VG_BOOL_CLO(arg, "--trace-conflict-set-bm", trace_conflict_set_bm){}
113   else if VG_BOOL_CLO(arg, "--trace-csw",           trace_csw) {}
114   else if VG_BOOL_CLO(arg, "--trace-fork-join",     trace_fork_join) {}
115   else if VG_BOOL_CLO(arg, "--trace-hb",            trace_hb) {}
116   else if VG_BOOL_CLO(arg, "--trace-mutex",         trace_mutex) {}
117   else if VG_BOOL_CLO(arg, "--trace-rwlock",        trace_rwlock) {}
118   else if VG_BOOL_CLO(arg, "--trace-sectsuppr",     trace_sectsuppr) {}
119   else if VG_BOOL_CLO(arg, "--trace-segment",       trace_segment) {}
120   else if VG_BOOL_CLO(arg, "--trace-semaphore",     trace_semaphore) {}
121   else if VG_BOOL_CLO(arg, "--trace-suppr",         trace_suppression) {}
122   else if VG_BOOL_CLO(arg, "--var-info",            s_var_info) {}
123   else if VG_BOOL_CLO(arg, "--verify-conflict-set", DRD_(verify_conflict_set))
124   {}
125   else if VG_INT_CLO (arg, "--exclusive-threshold", exclusive_threshold_ms) {}
126   else if VG_STR_CLO (arg, "--ptrace-addr",         ptrace_address) {}
127   else if VG_INT_CLO (arg, "--shared-threshold",    shared_threshold_ms)    {}
128   else if VG_STR_CLO (arg, "--trace-addr",          trace_address) {}
129   else
130      return VG_(replacement_malloc_process_cmd_line_option)(arg);
131
132   if (check_stack_accesses != -1)
133      DRD_(set_check_stack_accesses)(check_stack_accesses);
134   if (exclusive_threshold_ms != -1)
135   {
136      DRD_(mutex_set_lock_threshold)(exclusive_threshold_ms);
137      DRD_(rwlock_set_exclusive_threshold)(exclusive_threshold_ms);
138   }
139   if (first_race_only != -1)
140   {
141      DRD_(set_first_race_only)(first_race_only);
142   }
143   if (join_list_vol != -1)
144      DRD_(thread_set_join_list_vol)(join_list_vol);
145   if (report_signal_unlocked != -1)
146   {
147      DRD_(cond_set_report_signal_unlocked)(report_signal_unlocked);
148   }
149   if (shared_threshold_ms != -1)
150   {
151      DRD_(rwlock_set_shared_threshold)(shared_threshold_ms);
152   }
153   if (segment_merging != -1)
154      DRD_(thread_set_segment_merging)(segment_merging);
155   if (segment_merge_interval != -1)
156      DRD_(thread_set_segment_merge_interval)(segment_merge_interval);
157   if (show_confl_seg != -1)
158      DRD_(set_show_conflicting_segments)(show_confl_seg);
159   if (trace_address) {
160      const Addr addr = VG_(strtoll16)(trace_address, 0);
161      DRD_(start_tracing_address_range)(addr, addr + 1, False);
162   }
163   if (ptrace_address) {
164      char *plus = VG_(strchr)(ptrace_address, '+');
165      Addr addr, length;
166      if (plus)
167         *plus = '\0';
168      addr = VG_(strtoll16)(ptrace_address, 0);
169      length = plus ? VG_(strtoll16)(plus + 1, 0) : 1;
170      DRD_(start_tracing_address_range)(addr, addr + length, True);
171   }
172   if (trace_barrier != -1)
173      DRD_(barrier_set_trace)(trace_barrier);
174   if (trace_clientobj != -1)
175      DRD_(clientobj_set_trace)(trace_clientobj);
176   if (trace_cond != -1)
177      DRD_(cond_set_trace)(trace_cond);
178   if (trace_csw != -1)
179      DRD_(thread_trace_context_switches)(trace_csw);
180   if (trace_fork_join != -1)
181      DRD_(thread_set_trace_fork_join)(trace_fork_join);
182   if (trace_hb != -1)
183      DRD_(hb_set_trace)(trace_hb);
184   if (trace_conflict_set != -1)
185      DRD_(thread_trace_conflict_set)(trace_conflict_set);
186   if (trace_conflict_set_bm != -1)
187      DRD_(thread_trace_conflict_set_bm)(trace_conflict_set_bm);
188   if (trace_mutex != -1)
189      DRD_(mutex_set_trace)(trace_mutex);
190   if (trace_rwlock != -1)
191      DRD_(rwlock_set_trace)(trace_rwlock);
192   if (trace_segment != -1)
193      DRD_(sg_set_trace)(trace_segment);
194   if (trace_semaphore != -1)
195      DRD_(semaphore_set_trace)(trace_semaphore);
196   if (trace_suppression != -1)
197      DRD_(suppression_set_trace)(trace_suppression);
198
199   return True;
200}
201
202static void DRD_(print_usage)(void)
203{
204   VG_(printf)(
205"    --check-stack-var=yes|no  Whether or not to report data races on\n"
206"                              stack variables [no].\n"
207"    --exclusive-threshold=<n> Print an error message if any mutex or\n"
208"                              writer lock is held longer than the specified\n"
209"                              time (in milliseconds) [off].\n"
210"    --first-race-only=yes|no  Only report the first data race that occurs on\n"
211"                              a memory location instead of all races [no].\n"
212"    --free-is-write=yes|no    Whether to report races between freeing memory\n"
213"                              and subsequent accesses of that memory[no].\n"
214"    --join-list-vol=<n>       Number of threads to delay cleanup for [10].\n"
215"    --report-signal-unlocked=yes|no Whether to report calls to\n"
216"                              pthread_cond_signal() where the mutex associated\n"
217"                              with the signal via pthread_cond_wait() is not\n"
218"                              locked at the time the signal is sent [yes].\n"
219"    --segment-merging=yes|no  Controls segment merging [yes].\n"
220"        Segment merging is an algorithm to limit memory usage of the\n"
221"        data race detection algorithm. Disabling segment merging may\n"
222"        improve the accuracy of the so-called 'other segments' displayed\n"
223"        in race reports but can also trigger an out of memory error.\n"
224"    --segment-merging-interval=<n> Perform segment merging every time n new\n"
225"        segments have been created. Default: %d.\n"
226"    --shared-threshold=<n>    Print an error message if a reader lock\n"
227"                              is held longer than the specified time (in\n"
228"                              milliseconds) [off]\n"
229"    --show-confl-seg=yes|no   Show conflicting segments in race reports [yes].\n"
230"    --show-stack-usage=yes|no Print stack usage at thread exit time [no].\n"
231"\n"
232"  drd options for monitoring process behavior:\n"
233"    --ptrace-addr=<address>[+<length>] Trace all load and store activity for\n"
234"                              the specified address range and keep doing that\n"
235"                              even after the memory at that address has been\n"
236"                              freed and reallocated [off].\n"
237"    --trace-addr=<address>    Trace all load and store activity for the\n"
238"                              specified address [off].\n"
239"    --trace-alloc=yes|no      Trace all memory allocations and deallocations\n"
240"                              [no].\n"
241"    --trace-barrier=yes|no    Trace all barrier activity [no].\n"
242"    --trace-cond=yes|no       Trace all condition variable activity [no].\n"
243"    --trace-fork-join=yes|no  Trace all thread fork/join activity [no].\n"
244"    --trace-hb=yes|no         Trace ANNOTATE_HAPPENS_BEFORE() etc. [no].\n"
245"    --trace-mutex=yes|no      Trace all mutex activity [no].\n"
246"    --trace-rwlock=yes|no     Trace all reader-writer lock activity[no].\n"
247"    --trace-semaphore=yes|no  Trace all semaphore activity [no].\n",
248DRD_(thread_get_segment_merge_interval)()
249);
250}
251
252static void DRD_(print_debug_usage)(void)
253{
254   VG_(printf)(
255"    --drd-stats=yes|no        Print statistics about DRD activity [no].\n"
256"    --trace-clientobj=yes|no  Trace all client object activity [no].\n"
257"    --trace-csw=yes|no        Trace all scheduler context switches [no].\n"
258"    --trace-conflict-set=yes|no Trace all conflict set updates [no].\n"
259"    --trace-conflict-set-bm=yes|no Trace all conflict set bitmap\n"
260"                              updates [no]. Note: enabling this option\n"
261"                              will generate a lot of output !\n"
262"    --trace-sectsuppr=yes|no  Trace which the dynamic library sections on\n"
263"                              which data race detection is suppressed.\n"
264"    --trace-segment=yes|no    Trace segment actions [no].\n"
265"    --trace-suppr=yes|no      Trace all address suppression actions [no].\n"
266"    --verify-conflict-set=yes|no Verify conflict set consistency [no].\n"
267);
268}
269
270
271//
272// Implements the thread-related core callbacks.
273//
274
275static void drd_pre_mem_read(const CorePart part,
276                             const ThreadId tid,
277                             const HChar* const s,
278                             const Addr a,
279                             const SizeT size)
280{
281   DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
282   if (size > 0)
283   {
284      DRD_(trace_load)(a, size);
285   }
286}
287
288static void drd_pre_mem_read_asciiz(const CorePart part,
289                                    const ThreadId tid,
290                                    const HChar* const s,
291                                    const Addr a)
292{
293   const HChar* p = (void*)a;
294   SizeT size = 0;
295
296   // Don't segfault if the string starts in an obviously stupid
297   // place.  Actually we should check the whole string, not just
298   // the start address, but that's too much trouble.  At least
299   // checking the first byte is better than nothing.  See #255009.
300   if (!VG_(am_is_valid_for_client) (a, 1, VKI_PROT_READ))
301      return;
302
303   /* Note: the expression '*p' reads client memory and may crash if the */
304   /* client provided an invalid pointer !                               */
305   while (*p)
306   {
307      p++;
308      size++;
309   }
310   if (size > 0)
311   {
312      DRD_(trace_load)(a, size);
313   }
314}
315
316static void drd_post_mem_write(const CorePart part,
317                               const ThreadId tid,
318                               const Addr a,
319                               const SizeT size)
320{
321   DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
322   if (size > 0)
323   {
324      DRD_(trace_store)(a, size);
325   }
326}
327
328static __inline__
329void drd_start_using_mem(const Addr a1, const SizeT len,
330                         const Bool is_stack_mem)
331{
332   const Addr a2 = a1 + len;
333
334   tl_assert(a1 <= a2);
335
336   if (!is_stack_mem && s_trace_alloc)
337      DRD_(trace_msg)("Started using memory range 0x%lx + %ld%s",
338                      a1, len, DRD_(running_thread_inside_pthread_create)()
339                      ? " (inside pthread_create())" : "");
340
341   if (!is_stack_mem && DRD_(g_free_is_write))
342      DRD_(thread_stop_using_mem)(a1, a2);
343
344   if (UNLIKELY(DRD_(any_address_is_traced)()))
345   {
346      DRD_(trace_mem_access)(a1, len, eStart, 0, 0);
347   }
348
349   if (UNLIKELY(DRD_(running_thread_inside_pthread_create)()))
350   {
351      DRD_(start_suppression)(a1, a2, "pthread_create()");
352   }
353}
354
355static void drd_start_using_mem_w_ecu(const Addr a1,
356                                      const SizeT len,
357                                      UInt ec_uniq)
358{
359   drd_start_using_mem(a1, len, False);
360}
361
362static void drd_start_using_mem_w_tid(const Addr a1,
363                                      const SizeT len,
364                                      ThreadId tid)
365{
366   drd_start_using_mem(a1, len, False);
367}
368
369static __inline__
370void drd_stop_using_mem(const Addr a1, const SizeT len,
371                        const Bool is_stack_mem)
372{
373   const Addr a2 = a1 + len;
374
375   tl_assert(a1 <= a2);
376
377   if (UNLIKELY(DRD_(any_address_is_traced)()))
378      DRD_(trace_mem_access)(a1, len, eEnd, 0, 0);
379
380   if (!is_stack_mem && s_trace_alloc)
381      DRD_(trace_msg)("Stopped using memory range 0x%lx + %ld",
382                      a1, len);
383
384   if (!is_stack_mem || DRD_(get_check_stack_accesses)())
385   {
386      if (is_stack_mem || !DRD_(g_free_is_write))
387	 DRD_(thread_stop_using_mem)(a1, a2);
388      else if (DRD_(g_free_is_write))
389	 DRD_(trace_store)(a1, len);
390      DRD_(clientobj_stop_using_mem)(a1, a2);
391      DRD_(suppression_stop_using_mem)(a1, a2);
392   }
393}
394
395static __inline__
396void drd_stop_using_nonstack_mem(const Addr a1, const SizeT len)
397{
398   drd_stop_using_mem(a1, len, False);
399}
400
401/**
402 * Discard all information DRD has about memory accesses and client objects
403 * in the specified address range.
404 */
405void DRD_(clean_memory)(const Addr a1, const SizeT len)
406{
407   const Bool is_stack_memory = DRD_(thread_address_on_any_stack)(a1);
408   drd_stop_using_mem(a1, len, is_stack_memory);
409   drd_start_using_mem(a1, len, is_stack_memory);
410}
411
412/**
413 * Suppress data race reports on all addresses contained in .plt, .got and
414 * .got.plt sections inside the address range [ a, a + len [. The data in
415 * these sections is modified by _dl_relocate_object() every time a function
416 * in a shared library is called for the first time. Since the first call
417 * to a function in a shared library can happen from a multithreaded context,
418 * such calls can cause conflicting accesses. See also Ulrich Drepper's
419 * paper "How to Write Shared Libraries" for more information about relocation
420 * (http://people.redhat.com/drepper/dsohowto.pdf).
421 * Note: the contents of the .got section is only modified by the MIPS resolver.
422 */
423static void DRD_(suppress_relocation_conflicts)(const Addr a, const SizeT len)
424{
425   const DebugInfo* di;
426
427   if (trace_sectsuppr)
428      VG_(dmsg)("Evaluating range @ 0x%lx size %ld\n", a, len);
429
430   for (di = VG_(next_DebugInfo)(0); di; di = VG_(next_DebugInfo)(di)) {
431      Addr  avma;
432      SizeT size;
433
434      if (trace_sectsuppr)
435	 VG_(dmsg)("Examining %s / %s\n", VG_(DebugInfo_get_filename)(di),
436		   VG_(DebugInfo_get_soname)(di));
437
438      /*
439       * Suppress the race report on the libpthread global variable
440       * __pthread_multiple_threads. See also
441       * http://bugs.kde.org/show_bug.cgi?id=323905.
442       */
443      avma = VG_(DebugInfo_get_bss_avma)(di);
444      size = VG_(DebugInfo_get_bss_size)(di);
445      tl_assert((avma && size) || (avma == 0 && size == 0));
446      if (size > 0 &&
447          VG_(strcmp)(VG_(DebugInfo_get_soname)(di), "libpthread.so.0") == 0) {
448	 if (trace_sectsuppr)
449	    VG_(dmsg)("Suppressing .bss @ 0x%lx size %ld\n", avma, size);
450         tl_assert(VG_(DebugInfo_sect_kind)(NULL, avma) == Vg_SectBSS);
451         DRD_(start_suppression)(avma, avma + size, ".bss");
452      }
453
454      avma = VG_(DebugInfo_get_plt_avma)(di);
455      size = VG_(DebugInfo_get_plt_size)(di);
456      tl_assert((avma && size) || (avma == 0 && size == 0));
457      if (size > 0) {
458	 if (trace_sectsuppr)
459	    VG_(dmsg)("Suppressing .plt @ 0x%lx size %ld\n", avma, size);
460         tl_assert(VG_(DebugInfo_sect_kind)(NULL, avma) == Vg_SectPLT);
461         DRD_(start_suppression)(avma, avma + size, ".plt");
462      }
463
464      avma = VG_(DebugInfo_get_gotplt_avma)(di);
465      size = VG_(DebugInfo_get_gotplt_size)(di);
466      tl_assert((avma && size) || (avma == 0 && size == 0));
467      if (size > 0) {
468	 if (trace_sectsuppr)
469	    VG_(dmsg)("Suppressing .got.plt @ 0x%lx size %ld\n", avma, size);
470         tl_assert(VG_(DebugInfo_sect_kind)(NULL, avma) == Vg_SectGOTPLT);
471         DRD_(start_suppression)(avma, avma + size, ".gotplt");
472      }
473
474      avma = VG_(DebugInfo_get_got_avma)(di);
475      size = VG_(DebugInfo_get_got_size)(di);
476      tl_assert((avma && size) || (avma == 0 && size == 0));
477      if (size > 0) {
478	 if (trace_sectsuppr)
479	    VG_(dmsg)("Suppressing .got @ 0x%lx size %ld\n", avma, size);
480         tl_assert(VG_(DebugInfo_sect_kind)(NULL, avma) == Vg_SectGOT);
481         DRD_(start_suppression)(avma, avma + size, ".got");
482      }
483   }
484}
485
486static
487void drd_start_using_mem_w_perms(const Addr a, const SizeT len,
488                                 const Bool rr, const Bool ww, const Bool xx,
489                                 ULong di_handle)
490{
491   DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
492
493   drd_start_using_mem(a, len, False);
494
495   DRD_(suppress_relocation_conflicts)(a, len);
496}
497
498/**
499 * Called by the core when the stack of a thread grows, to indicate that
500 * the addresses in range [ a, a + len [ may now be used by the client.
501 * Assumption: stacks grow downward.
502 */
503static __inline__
504void drd_start_using_mem_stack2(const DrdThreadId tid, const Addr a,
505                                const SizeT len)
506{
507   DRD_(thread_set_stack_min)(tid, a - VG_STACK_REDZONE_SZB);
508   drd_start_using_mem(a - VG_STACK_REDZONE_SZB, len + VG_STACK_REDZONE_SZB,
509                       True);
510}
511
512static __inline__
513void drd_start_using_mem_stack(const Addr a, const SizeT len)
514{
515   drd_start_using_mem_stack2(DRD_(thread_get_running_tid)(), a, len);
516}
517
518/**
519 * Called by the core when the stack of a thread shrinks, to indicate that
520 * the addresses [ a, a + len [ are no longer accessible for the client.
521 * Assumption: stacks grow downward.
522 */
523static __inline__
524void drd_stop_using_mem_stack2(const DrdThreadId tid, const Addr a,
525                               const SizeT len)
526{
527   DRD_(thread_set_stack_min)(tid, a + len - VG_STACK_REDZONE_SZB);
528   drd_stop_using_mem(a - VG_STACK_REDZONE_SZB, len + VG_STACK_REDZONE_SZB,
529                      True);
530}
531
532static __inline__
533void drd_stop_using_mem_stack(const Addr a, const SizeT len)
534{
535   drd_stop_using_mem_stack2(DRD_(thread_get_running_tid)(), a, len);
536}
537
538static
539Bool on_alt_stack(const Addr a)
540{
541   ThreadId vg_tid;
542   Addr alt_min;
543   SizeT alt_size;
544
545   vg_tid = VG_(get_running_tid)();
546   alt_min = VG_(thread_get_altstack_min)(vg_tid);
547   alt_size = VG_(thread_get_altstack_size)(vg_tid);
548   return (SizeT)(a - alt_min) < alt_size;
549}
550
551static
552void drd_start_using_mem_alt_stack(const Addr a, const SizeT len)
553{
554   if (!on_alt_stack(a))
555      drd_start_using_mem_stack(a, len);
556}
557
558static
559void drd_stop_using_mem_alt_stack(const Addr a, const SizeT len)
560{
561   if (!on_alt_stack(a))
562      drd_stop_using_mem_stack(a, len);
563}
564
565/**
566 * Callback function invoked by the Valgrind core before a signal is delivered.
567 */
568static
569void drd_pre_deliver_signal(const ThreadId vg_tid, const Int sigNo,
570                            const Bool alt_stack)
571{
572   DrdThreadId drd_tid;
573
574   drd_tid = DRD_(VgThreadIdToDrdThreadId)(vg_tid);
575   DRD_(thread_set_on_alt_stack)(drd_tid, alt_stack);
576   if (alt_stack)
577   {
578      /*
579       * As soon a signal handler has been invoked on the alternate stack,
580       * switch to stack memory handling functions that can handle the
581       * alternate stack.
582       */
583      VG_(track_new_mem_stack)(drd_start_using_mem_alt_stack);
584      VG_(track_die_mem_stack)(drd_stop_using_mem_alt_stack);
585   }
586}
587
588/**
589 * Callback function invoked by the Valgrind core after a signal is delivered,
590 * at least if the signal handler did not longjmp().
591 */
592static
593void drd_post_deliver_signal(const ThreadId vg_tid, const Int sigNo)
594{
595   DrdThreadId drd_tid;
596
597   drd_tid = DRD_(VgThreadIdToDrdThreadId)(vg_tid);
598   DRD_(thread_set_on_alt_stack)(drd_tid, False);
599   if (DRD_(thread_get_threads_on_alt_stack)() == 0)
600   {
601      VG_(track_new_mem_stack)(drd_start_using_mem_stack);
602      VG_(track_die_mem_stack)(drd_stop_using_mem_stack);
603   }
604}
605
606/**
607 * Callback function called by the Valgrind core before a stack area is
608 * being used by a signal handler.
609 *
610 * @param[in] a   Start of address range - VG_STACK_REDZONE_SZB.
611 * @param[in] len Address range length + VG_STACK_REDZONE_SZB.
612 * @param[in] tid Valgrind thread ID for whom the signal frame is being
613 *                constructed.
614 */
615static void drd_start_using_mem_stack_signal(const Addr a, const SizeT len,
616                                             ThreadId tid)
617{
618   DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
619   drd_start_using_mem(a + VG_STACK_REDZONE_SZB, len - VG_STACK_REDZONE_SZB,
620                       True);
621}
622
623static void drd_stop_using_mem_stack_signal(Addr a, SizeT len)
624{
625   drd_stop_using_mem(a + VG_STACK_REDZONE_SZB, len - VG_STACK_REDZONE_SZB,
626                      True);
627}
628
629static
630void drd_pre_thread_create(const ThreadId creator, const ThreadId created)
631{
632   const DrdThreadId drd_creator = DRD_(VgThreadIdToDrdThreadId)(creator);
633   tl_assert(created != VG_INVALID_THREADID);
634   DRD_(thread_pre_create)(drd_creator, created);
635   if (DRD_(IsValidDrdThreadId)(drd_creator))
636   {
637      DRD_(thread_new_segment)(drd_creator);
638   }
639   if (DRD_(thread_get_trace_fork_join)())
640   {
641      DRD_(trace_msg)("drd_pre_thread_create creator = %d, created = %d",
642                      drd_creator, created);
643   }
644}
645
646/**
647 * Called by Valgrind's core before any loads or stores are performed on
648 * the context of thread "created".
649 */
650static
651void drd_post_thread_create(const ThreadId vg_created)
652{
653   DrdThreadId drd_created;
654   Addr stack_max;
655
656   tl_assert(vg_created != VG_INVALID_THREADID);
657
658   drd_created = DRD_(thread_post_create)(vg_created);
659
660   /* Set up red zone before the code in glibc's clone.S is run. */
661   stack_max = DRD_(thread_get_stack_max)(drd_created);
662   drd_start_using_mem_stack2(drd_created, stack_max, 0);
663
664   if (DRD_(thread_get_trace_fork_join)())
665   {
666      DRD_(trace_msg)("drd_post_thread_create created = %d", drd_created);
667   }
668   if (! DRD_(get_check_stack_accesses)())
669   {
670      DRD_(start_suppression)(DRD_(thread_get_stack_max)(drd_created)
671                              - DRD_(thread_get_stack_size)(drd_created),
672                              DRD_(thread_get_stack_max)(drd_created),
673                              "stack");
674   }
675}
676
677/* Called after a thread has performed its last memory access. */
678static void drd_thread_finished(ThreadId vg_tid)
679{
680   DrdThreadId drd_tid;
681
682   /*
683    * Ignore if invoked because thread creation failed. See e.g.
684    * coregrind/m_syswrap/syswrap-amd64-linux.c
685    */
686   if (VG_(get_running_tid)() != vg_tid)
687      return;
688
689   drd_tid = DRD_(VgThreadIdToDrdThreadId)(vg_tid);
690   tl_assert(drd_tid != DRD_INVALID_THREADID);
691   if (DRD_(thread_get_trace_fork_join)())
692   {
693      DRD_(trace_msg)("drd_thread_finished tid = %d%s", drd_tid,
694                      DRD_(thread_get_joinable)(drd_tid)
695                      ? "" : " (which is a detached thread)");
696   }
697   if (s_show_stack_usage && !VG_(clo_xml)) {
698      const SizeT stack_size = DRD_(thread_get_stack_size)(drd_tid);
699      const SizeT used_stack
700         = (DRD_(thread_get_stack_max)(drd_tid)
701            - DRD_(thread_get_stack_min_min)(drd_tid));
702      VG_(message)(Vg_UserMsg,
703                   "thread %d%s finished and used %ld bytes out of %ld"
704                   " on its stack. Margin: %ld bytes.\n",
705                   drd_tid,
706                   DRD_(thread_get_joinable)(drd_tid)
707                   ? "" : " (which is a detached thread)",
708                   used_stack, stack_size, stack_size - used_stack);
709
710   }
711   drd_stop_using_mem(DRD_(thread_get_stack_min)(drd_tid),
712                      DRD_(thread_get_stack_max)(drd_tid)
713                      - DRD_(thread_get_stack_min)(drd_tid),
714                      True);
715   DRD_(thread_set_record_loads)(drd_tid, False);
716   DRD_(thread_set_record_stores)(drd_tid, False);
717   DRD_(thread_finished)(drd_tid);
718}
719
720/*
721 * Called immediately after fork for the child process only. 'tid' is the
722 * only surviving thread in the child process. Cleans up thread state.
723 * See also http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_atfork.html for a detailed discussion of using fork() in combination with mutexes.
724 */
725static
726void drd__atfork_child(ThreadId tid)
727{
728   DRD_(drd_thread_atfork_child)(tid);
729}
730
731
732//
733// Implementation of the tool interface.
734//
735
736static void DRD_(post_clo_init)(void)
737{
738#if defined(VGO_linux) || defined(VGO_darwin)
739   /* fine */
740#else
741   VG_(printf)("\nWARNING: DRD has not yet been tested on this operating system.\n\n");
742#  endif
743
744   if (s_var_info)
745   {
746      VG_(needs_var_info)();
747   }
748}
749
750static void drd_start_client_code(const ThreadId tid, const ULong bbs_done)
751{
752   tl_assert(tid == VG_(get_running_tid)());
753   DRD_(thread_set_vg_running_tid)(tid);
754}
755
756static void DRD_(fini)(Int exitcode)
757{
758   // thread_print_all();
759   if (VG_(clo_verbosity) == 1 && !VG_(clo_xml)) {
760      VG_(message)(Vg_UserMsg, "For counts of detected and suppressed errors, "
761                   "rerun with: -v\n");
762   }
763
764   if ((VG_(clo_stats) || s_print_stats) && !VG_(clo_xml))
765   {
766      ULong pu = DRD_(thread_get_update_conflict_set_count)();
767      ULong pu_seg_cr = DRD_(thread_get_update_conflict_set_new_sg_count)();
768      ULong pu_mtx_cv = DRD_(thread_get_update_conflict_set_sync_count)();
769      ULong pu_join   = DRD_(thread_get_update_conflict_set_join_count)();
770
771      VG_(message)(Vg_UserMsg,
772                   "   thread: %lld context switches.\n",
773                   DRD_(thread_get_context_switch_count)());
774      VG_(message)(Vg_UserMsg,
775                   "confl set: %lld full updates and %lld partial updates;\n",
776                   DRD_(thread_get_compute_conflict_set_count)(),
777                   pu);
778      VG_(message)(Vg_UserMsg,
779                   "           %lld partial updates during segment creation,\n",
780                   pu_seg_cr);
781      VG_(message)(Vg_UserMsg,
782                   "           %lld because of mutex/sema/cond.var. operations,\n",
783                   pu_mtx_cv);
784      VG_(message)(Vg_UserMsg,
785                   "           %lld because of barrier/rwlock operations and\n",
786		   pu - pu_seg_cr - pu_mtx_cv - pu_join);
787      VG_(message)(Vg_UserMsg,
788                   "           %lld partial updates because of thread join"
789                   " operations.\n",
790                   pu_join);
791      VG_(message)(Vg_UserMsg,
792                   " segments: created %lld segments, max %lld alive,\n",
793                   DRD_(sg_get_segments_created_count)(),
794                   DRD_(sg_get_max_segments_alive_count)());
795      VG_(message)(Vg_UserMsg,
796                   "           %lld discard points and %lld merges.\n",
797                   DRD_(thread_get_discard_ordered_segments_count)(),
798                   DRD_(sg_get_segment_merge_count)());
799      VG_(message)(Vg_UserMsg,
800                   "segmnt cr: %lld mutex, %lld rwlock, %lld semaphore and"
801                   " %lld barrier.\n",
802                   DRD_(get_mutex_segment_creation_count)(),
803                   DRD_(get_rwlock_segment_creation_count)(),
804                   DRD_(get_semaphore_segment_creation_count)(),
805                   DRD_(get_barrier_segment_creation_count)());
806      VG_(message)(Vg_UserMsg,
807                   "  bitmaps: %lld level one"
808                   " and %lld level two bitmaps were allocated.\n",
809                   DRD_(bm_get_bitmap_creation_count)(),
810                   DRD_(bm_get_bitmap2_creation_count)());
811      VG_(message)(Vg_UserMsg,
812                   "    mutex: %lld non-recursive lock/unlock events.\n",
813                   DRD_(get_mutex_lock_count)());
814      DRD_(print_malloc_stats)();
815   }
816
817   DRD_(bm_module_cleanup)();
818}
819
820static
821void drd_pre_clo_init(void)
822{
823   // Basic tool stuff.
824   VG_(details_name)            ("drd");
825   VG_(details_version)         (NULL);
826   VG_(details_description)     ("a thread error detector");
827   VG_(details_copyright_author)("Copyright (C) 2006-2013, and GNU GPL'd,"
828                                 " by Bart Van Assche.");
829   VG_(details_bug_reports_to)  (VG_BUGS_TO);
830
831   VG_(basic_tool_funcs)        (DRD_(post_clo_init),
832                                 DRD_(instrument),
833                                 DRD_(fini));
834
835   // Command line stuff.
836   VG_(needs_command_line_options)(DRD_(process_cmd_line_option),
837                                   DRD_(print_usage),
838                                   DRD_(print_debug_usage));
839   VG_(needs_xml_output)          ();
840
841   // Error handling.
842   DRD_(register_error_handlers)();
843
844   // Core event tracking.
845   VG_(track_pre_mem_read)         (drd_pre_mem_read);
846   VG_(track_pre_mem_read_asciiz)  (drd_pre_mem_read_asciiz);
847   VG_(track_post_mem_write)       (drd_post_mem_write);
848   VG_(track_new_mem_brk)          (drd_start_using_mem_w_tid);
849   VG_(track_new_mem_mmap)         (drd_start_using_mem_w_perms);
850   VG_(track_new_mem_stack)        (drd_start_using_mem_stack);
851   VG_(track_new_mem_stack_signal) (drd_start_using_mem_stack_signal);
852   VG_(track_new_mem_startup)      (drd_start_using_mem_w_perms);
853   VG_(track_die_mem_brk)          (drd_stop_using_nonstack_mem);
854   VG_(track_die_mem_munmap)       (drd_stop_using_nonstack_mem);
855   VG_(track_die_mem_stack)        (drd_stop_using_mem_stack);
856   VG_(track_die_mem_stack_signal) (drd_stop_using_mem_stack_signal);
857   VG_(track_pre_deliver_signal)   (drd_pre_deliver_signal);
858   VG_(track_post_deliver_signal)  (drd_post_deliver_signal);
859   VG_(track_start_client_code)    (drd_start_client_code);
860   VG_(track_pre_thread_ll_create) (drd_pre_thread_create);
861   VG_(track_pre_thread_first_insn)(drd_post_thread_create);
862   VG_(track_pre_thread_ll_exit)   (drd_thread_finished);
863   VG_(atfork)                     (NULL/*pre*/, NULL/*parent*/,
864				    drd__atfork_child/*child*/);
865
866   // Other stuff.
867   DRD_(register_malloc_wrappers)(drd_start_using_mem_w_ecu,
868                                  drd_stop_using_nonstack_mem);
869
870   DRD_(bm_module_init)();
871
872   DRD_(clientreq_init)();
873
874   DRD_(suppression_init)();
875
876   DRD_(clientobj_init)();
877
878   DRD_(thread_init)();
879
880   {
881      HChar* const smi = VG_(getenv)("DRD_SEGMENT_MERGING_INTERVAL");
882      if (smi)
883         DRD_(thread_set_segment_merge_interval)(VG_(strtoll10)(smi, NULL));
884   }
885
886   if (VG_(getenv)("DRD_VERIFY_CONFLICT_SET"))
887      DRD_(verify_conflict_set) = True;
888
889}
890
891
892VG_DETERMINE_INTERFACE_VERSION(drd_pre_clo_init)
893