Renamed exp-drd directory into drd. Moved drd from the experimental tool class to the class of regular tools.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@8361 a5019735-40e9-0310-863c-91ae7b9d1cf9

1 files changed, 1268 insertions, 0 deletions

diff --git a/drd/drd_main.c b/drd/drd_main.c
new file mode 100644
index 000000000..f27f76dd8
--- /dev/null
+++ b/drd/drd_main.c
@@ -0,0 +1,1268 @@
+/*
+  This file is part of drd, a data race detector.
+
+  Copyright (C) 2006-2008 Bart Van Assche
+  bart.vanassche@gmail.com
+
+  This program is free software; you can redistribute it and/or
+  modify it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 2 of the
+  License, or (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+  02111-1307, USA.
+
+  The GNU General Public License is contained in the file COPYING.
+*/
+
+
+#include "drd_barrier.h"
+#include "drd_clientreq.h"
+#include "drd_clientobj.h"
+#include "drd_cond.h"
+#include "drd_error.h"
+#include "drd_malloc_wrappers.h"
+#include "drd_mutex.h"
+#include "drd_rwlock.h"
+#include "drd_segment.h"
+#include "drd_semaphore.h"
+#include "drd_suppression.h"
+#include "drd_thread.h"
+#include "drd_thread_bitmap.h"
+#include "drd_track.h"
+#include "drd_vc.h"
+#include "libvex_guest_offsets.h"
+#include "pub_drd_bitmap.h"
+#include "pub_tool_vki.h"         // Must be included before pub_tool_libcproc
+#include "pub_tool_basics.h"
+#include "pub_tool_debuginfo.h"   // VG_(describe_IP)()
+#include "pub_tool_libcassert.h"  // tl_assert()
+#include "pub_tool_libcbase.h"    // VG_(strcmp)
+#include "pub_tool_libcprint.h"   // VG_(printf)
+#include "pub_tool_libcproc.h"
+#include "pub_tool_machine.h"
+#include "pub_tool_mallocfree.h"  // VG_(malloc)(), VG_(free)()
+#include "pub_tool_options.h"     // command line options
+#include "pub_tool_replacemalloc.h"
+#include "pub_tool_threadstate.h" // VG_(get_running_tid)()
+#include "pub_tool_tooliface.h"
+
+
+/* Include several source files here in order to allow the compiler to */
+/* do more inlining.                                                   */
+#include "drd_bitmap.c"
+#include "drd_segment.c"
+#include "drd_thread.c"
+#include "drd_vc.c"
+
+
+
+// Function declarations.
+
+static void drd_start_client_code(const ThreadId tid, const ULong bbs_done);
+
+
+// Local variables.
+
+static Bool s_drd_check_stack_accesses = False;
+static Bool s_drd_print_stats          = False;
+static Bool s_drd_trace_fork_join      = False;
+static Bool s_drd_var_info             = False;
+static Bool s_show_stack_usage         = False;
+
+
+//
+// Implement the needs_command_line_options for drd.
+//
+
+static Bool drd_process_cmd_line_option(Char* arg)
+{
+  int exclusive_threshold_ms = -1;
+  int segment_merging        = -1;
+  int shared_threshold_ms    = -1;
+  int show_confl_seg         = -1;
+  int trace_barrier          = -1;
+  int trace_clientobj        = -1;
+  int trace_cond             = -1;
+  int trace_csw              = -1;
+  int trace_conflict_set     = -1;
+  int trace_mutex            = -1;
+  int trace_rwlock           = -1;
+  int trace_segment          = -1;
+  int trace_semaphore        = -1;
+  int trace_suppression      = -1;
+  Char* trace_address        = 0;
+
+  VG_BOOL_CLO     (arg, "--check-stack-var",     s_drd_check_stack_accesses)
+  else VG_BOOL_CLO(arg, "--drd-stats",           s_drd_print_stats)
+  else VG_BOOL_CLO(arg,"--report-signal-unlocked",s_drd_report_signal_unlocked)
+  else VG_BOOL_CLO(arg, "--segment-merging",     segment_merging)
+  else VG_BOOL_CLO(arg, "--show-confl-seg",      show_confl_seg)
+  else VG_BOOL_CLO(arg, "--show-stack-usage",    s_show_stack_usage)
+  else VG_BOOL_CLO(arg, "--trace-barrier",       trace_barrier)
+  else VG_BOOL_CLO(arg, "--trace-clientobj",     trace_clientobj)
+  else VG_BOOL_CLO(arg, "--trace-cond",          trace_cond)
+  else VG_BOOL_CLO(arg, "--trace-conflict-set",  trace_conflict_set)
+  else VG_BOOL_CLO(arg, "--trace-csw",           trace_csw)
+  else VG_BOOL_CLO(arg, "--trace-fork-join",     s_drd_trace_fork_join)
+  else VG_BOOL_CLO(arg, "--trace-mutex",         trace_mutex)
+  else VG_BOOL_CLO(arg, "--trace-rwlock",        trace_rwlock)
+  else VG_BOOL_CLO(arg, "--trace-segment",       trace_segment)
+  else VG_BOOL_CLO(arg, "--trace-semaphore",     trace_semaphore)
+  else VG_BOOL_CLO(arg, "--trace-suppr",         trace_suppression)
+  else VG_BOOL_CLO(arg, "--var-info",            s_drd_var_info)
+  else VG_NUM_CLO (arg, "--exclusive-threshold", exclusive_threshold_ms)
+  else VG_NUM_CLO (arg, "--shared-threshold",    shared_threshold_ms)
+  else VG_STR_CLO (arg, "--trace-addr",          trace_address)
+  else
+    return VG_(replacement_malloc_process_cmd_line_option)(arg);
+
+  if (exclusive_threshold_ms != -1)
+  {
+    mutex_set_lock_threshold(exclusive_threshold_ms);
+    rwlock_set_exclusive_threshold(exclusive_threshold_ms);
+  }
+  if (shared_threshold_ms != -1)
+  {
+    rwlock_set_shared_threshold(shared_threshold_ms);
+  }
+  if (segment_merging != -1)
+    thread_set_segment_merging(segment_merging);
+  if (show_confl_seg != -1)
+    set_show_conflicting_segments(show_confl_seg);
+  if (trace_address)
+  {
+    const Addr addr = VG_(strtoll16)(trace_address, 0);
+    drd_start_tracing_address_range(addr, addr + 1);
+  }
+  if (trace_barrier != -1)
+    barrier_set_trace(trace_barrier);
+  if (trace_clientobj != -1)
+    clientobj_set_trace(trace_clientobj);
+  if (trace_cond != -1)
+    cond_set_trace(trace_cond);
+  if (trace_csw != -1)
+    thread_trace_context_switches(trace_csw);
+  if (trace_conflict_set != -1)
+    thread_trace_conflict_set(trace_conflict_set);
+  if (trace_mutex != -1)
+    mutex_set_trace(trace_mutex);
+  if (trace_rwlock != -1)
+    rwlock_set_trace(trace_rwlock);
+  if (trace_segment != -1)
+    sg_set_trace(trace_segment);
+  if (trace_semaphore != -1)
+    semaphore_set_trace(trace_semaphore);
+  if (trace_suppression != -1)
+    suppression_set_trace(trace_suppression);
+
+  return True;
+}
+
+static void drd_print_usage(void)
+{
+  VG_(printf)(
+"    --check-stack-var=yes|no  Whether or not to report data races on\n"
+"                              stack variables [no].\n"
+"    --exclusive-threshold=<n> Print an error message if any mutex or\n"
+"        writer lock is held longer than the specified time (in milliseconds).\n"
+"    --report-signal-unlocked=yes|no Whether to report calls to\n"
+"                              pthread_cond_signal() where the mutex associated\n"
+"                              with the signal via pthread_cond_wait() is not\n"
+"                              locked at the time the signal is sent [yes].\n"
+"    --segment-merging=yes|no  Controls segment merging [yes].\n"
+"        Segment merging is an algorithm to limit memory usage of the\n"
+"        data race detection algorithm. Disabling segment merging may\n"
+"        improve the accuracy of the so-called 'other segments' displayed\n"
+"        in race reports but can also trigger an out of memory error.\n"
+"    --shared-threshold=<n>    Print an error message if a reader lock\n"
+"        is held longer than the specified time (in milliseconds).\n"
+"    --show-confl-seg=yes|no   Show conflicting segments in race reports [yes].\n"
+"    --show-stack-usage=yes|no Print stack usage at thread exit time [no].\n"
+"    --var-info=yes|no         Display the names of global, static and\n"
+"        stack variables when a race is reported on such a variable. This\n"
+"        information is by default not displayed since for big programs\n"
+"        reading in all debug information at once may cause an out of\n"
+"        memory error [no].\n"
+"\n"
+"  exp-drd options for monitoring process behavior:\n"
+"    --trace-addr=<address>    Trace all load and store activity for the.\n"
+"                              specified address [off].\n"
+"    --trace-barrier=yes|no    Trace all barrier activity [no].\n"
+"    --trace-cond=yes|no       Trace all condition variable activity [no].\n"
+"    --trace-fork-join=yes|no  Trace all thread fork/join activity [no].\n"
+"    --trace-mutex=yes|no      Trace all mutex activity [no].\n"
+"    --trace-rwlock=yes|no     Trace all reader-writer lock activity[no].\n"
+"    --trace-semaphore=yes|no  Trace all semaphore activity [no].\n"
+              );
+   VG_(replacement_malloc_print_usage)();
+}
+
+static void drd_print_debug_usage(void)
+{  
+  VG_(printf)(
+"    --drd-stats=yes|no        Print statistics about DRD activity [no].\n"
+"    --trace-clientobj=yes|no  Trace all client object activity [no].\n"
+"    --trace-csw=yes|no        Trace all scheduler context switches [no].\n"
+"    --trace-conflict-set=yes|no Trace all conflict set updates [no].\n"
+"    --trace-segment=yes|no    Trace segment actions [no].\n"
+"    --trace-suppr=yes|no      Trace all address suppression actions [no].\n"
+              );
+   VG_(replacement_malloc_print_debug_usage)();
+}
+
+
+//
+// Implements the thread-related core callbacks.
+//
+
+static void drd_trace_mem_access(const Addr addr, const SizeT size,
+                                 const BmAccessTypeT access_type)
+{
+  if (drd_is_any_traced(addr, addr + size))
+  {
+    char vc[80];
+    vc_snprint(vc, sizeof(vc), thread_get_vc(thread_get_running_tid()));
+    VG_(message)(Vg_UserMsg,
+                 "%s 0x%lx size %ld (vg %d / drd %d / vc %s)",
+                 access_type == eLoad
+                 ? "load "
+                 : access_type == eStore
+                 ? "store"
+                 : access_type == eStart
+                 ? "start"
+                 : access_type == eEnd
+                 ? "end  "
+                 : "????",
+                 addr,
+                 size,
+                 VG_(get_running_tid)(),
+                 thread_get_running_tid(),
+                 vc);
+    VG_(get_and_pp_StackTrace)(VG_(get_running_tid)(),
+                               VG_(clo_backtrace_size));
+    tl_assert(DrdThreadIdToVgThreadId(thread_get_running_tid())
+              == VG_(get_running_tid)());
+  }
+}
+
+static VG_REGPARM(2) void drd_trace_mem_load(const Addr addr, const SizeT size)
+{
+  return drd_trace_mem_access(addr, size, eLoad);
+}
+
+static VG_REGPARM(2) void drd_trace_mem_store(const Addr addr,const SizeT size)
+{
+  return drd_trace_mem_access(addr, size, eStore);
+}
+
+static void drd_report_race(const Addr addr, const SizeT size,
+                            const BmAccessTypeT access_type)
+{
+  DataRaceErrInfo drei;
+
+  drei.tid  = thread_get_running_tid();
+  drei.addr = addr;
+  drei.size = size;
+  drei.access_type = access_type;
+  VG_(maybe_record_error)(VG_(get_running_tid)(),
+                          DataRaceErr,
+                          VG_(get_IP)(VG_(get_running_tid)()),
+                          "Conflicting accesses",
+                          &drei);
+}
+
+static VG_REGPARM(2) void drd_trace_load(Addr addr, SizeT size)
+{
+#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
+  /* The assert below has been commented out because of performance reasons.*/
+  tl_assert(thread_get_running_tid()
+            == VgThreadIdToDrdThreadId(VG_(get_running_tid())));
+#endif
+
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_load_triggers_conflict(addr, addr + size)
+      && ! drd_is_suppressed(addr, addr + size))
+  {
+    drd_report_race(addr, size, eLoad);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_load_1(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_load_1_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 1))
+  {
+    drd_report_race(addr, 1, eLoad);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_load_2(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_load_2_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 2))
+  {
+    drd_report_race(addr, 2, eLoad);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_load_4(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_load_4_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 4))
+  {
+    drd_report_race(addr, 4, eLoad);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_load_8(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_load_8_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 8))
+  {
+    drd_report_race(addr, 8, eLoad);
+  }
+}
+
+static
+VG_REGPARM(2) void drd_trace_store(Addr addr, SizeT size)
+{
+#ifdef ENABLE_DRD_CONSISTENCY_CHECKS
+  /* The assert below has been commented out because of performance reasons.*/
+  tl_assert(thread_get_running_tid()
+            == VgThreadIdToDrdThreadId(VG_(get_running_tid())));
+#endif
+
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_store_triggers_conflict(addr, addr + size)
+      && ! drd_is_suppressed(addr, addr + size))
+  {
+    drd_report_race(addr, size, eStore);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_store_1(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_store_1_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 1))
+  {
+    drd_report_race(addr, 1, eStore);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_store_2(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_store_2_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 2))
+  {
+    drd_report_race(addr, 2, eStore);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_store_4(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_store_4_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 4))
+  {
+    drd_report_race(addr, 4, eStore);
+  }
+}
+
+static VG_REGPARM(1) void drd_trace_store_8(Addr addr)
+{
+  if (running_thread_is_recording()
+      && (s_drd_check_stack_accesses || ! thread_address_on_stack(addr))
+      && bm_access_store_8_triggers_conflict(addr)
+      && ! drd_is_suppressed(addr, addr + 8))
+  {
+    drd_report_race(addr, 8, eStore);
+  }
+}
+
+static void drd_pre_mem_read(const CorePart part,
+                             const ThreadId tid,
+                             Char* const s,
+                             const Addr a,
+                             const SizeT size)
+{
+  if (size > 0)
+  {
+    drd_trace_load(a, size);
+  }
+}
+
+static void drd_pre_mem_read_asciiz(const CorePart part,
+                                    const ThreadId tid,
+                                    Char* const s,
+                                    const Addr a)
+{
+  const char* p = (void*)a;
+  SizeT size = 0;
+
+  /* Note: the expression '*p' reads client memory and may crash if the */
+  /* client provided an invalid pointer !                               */
+  while (*p)
+  {
+    p++;
+    size++;
+  }
+  // To do: find out what a reasonable upper limit on 'size' is.
+  tl_assert(size < 4096);
+  if (size > 0)
+  {
+    drd_trace_load(a, size);
+  }
+}
+
+static void drd_post_mem_write(const CorePart part,
+                               const ThreadId tid,
+                               const Addr a,
+                               const SizeT size)
+{
+  thread_set_vg_running_tid(VG_(get_running_tid)());
+  if (size > 0)
+  {
+    drd_trace_store(a, size);
+  }
+}
+
+static __inline__
+void drd_start_using_mem(const Addr a1, const SizeT len)
+{
+  tl_assert(a1 < a1 + len);
+
+  if (UNLIKELY(drd_any_address_is_traced()))
+  {
+    drd_trace_mem_access(a1, len, eStart);
+  }
+}
+
+static void drd_start_using_mem_w_ecu(const Addr a1,
+                                      const SizeT len,
+                                      UInt ec_uniq)
+{
+  drd_start_using_mem(a1, len);
+}
+
+static void drd_start_using_mem_w_tid(const Addr a1,
+                                      const SizeT len,
+                                      ThreadId tid)
+{
+  drd_start_using_mem(a1, len);
+}
+
+static __inline__
+void drd_stop_using_mem(const Addr a1, const SizeT len,
+                        const Bool is_stack_mem)
+{
+  const Addr a2 = a1 + len;
+
+  tl_assert(a1 < a2);
+
+  if (UNLIKELY(drd_any_address_is_traced()))
+  {
+    drd_trace_mem_access(a1, len, eEnd);
+  }
+  if (! is_stack_mem || s_drd_check_stack_accesses)
+  {
+    thread_stop_using_mem(a1, a2);
+    clientobj_stop_using_mem(a1, a2);
+    drd_suppression_stop_using_mem(a1, a2);
+  }
+}
+
+static __inline__
+void drd_stop_using_nonstack_mem(const Addr a1, const SizeT len)
+{
+  drd_stop_using_mem(a1, len, False);
+}
+
+/** Suppress data race reports on all addresses contained in .plt and
+ *  .got.plt sections inside the address range [ a, a + len [. The data in
+ *  these sections is modified by _dl_relocate_object() every time a function
+ *  in a shared library is called for the first time. Since the first call
+ *  to a function in a shared library can happen from a multithreaded context,
+ *  such calls can cause conflicting accesses. See also Ulrich Drepper's
+ *  paper "How to Write Shared Libraries" for more information about relocation
+ *  (http://people.redhat.com/drepper/dsohowto.pdf).
+ */
+static void suppress_relocation_conflicts(const Addr a, const SizeT len)
+{
+  const DebugInfo* di;
+
+#if 0
+  VG_(printf)("Evaluating range @ 0x%lx size %ld\n", a, len);
+#endif
+
+  for (di = VG_(next_seginfo)(0); di; di = VG_(next_seginfo)(di))
+  {
+    Addr  avma;
+    SizeT size;
+
+    avma = VG_(seginfo_get_plt_avma)(di);
+    size = VG_(seginfo_get_plt_size)(di);
+    if (size > 0 && a <= avma && avma + size <= a + len)
+    {
+#if 0
+      VG_(printf)("Suppressing .plt @ 0x%lx size %ld\n", avma, size);
+#endif
+      tl_assert(VG_(seginfo_sect_kind)(NULL, 0, avma) == Vg_SectPLT);
+      drd_start_suppression(avma, avma + size, ".plt");
+    }
+
+    avma = VG_(seginfo_get_gotplt_avma)(di);
+    size = VG_(seginfo_get_gotplt_size)(di);
+    if (size > 0 && a <= avma && avma + size <= a + len)
+    {
+#if 0
+      VG_(printf)("Suppressing .got.plt @ 0x%lx size %ld\n", avma, size);
+#endif
+      tl_assert(VG_(seginfo_sect_kind)(NULL, 0, avma) == Vg_SectGOTPLT);
+      drd_start_suppression(avma, avma + size, ".gotplt");
+    }
+  }
+}
+
+static
+void drd_start_using_mem_w_perms(const Addr a, const SizeT len,
+                                 const Bool rr, const Bool ww, const Bool xx)
+{
+  thread_set_vg_running_tid(VG_(get_running_tid)());
+
+  drd_start_using_mem(a, len);
+
+  suppress_relocation_conflicts(a, len);
+}
+
+/* Called by the core when the stack of a thread grows, to indicate that */
+/* the addresses in range [ a, a + len [ may now be used by the client.  */
+/* Assumption: stacks grow downward.                                     */
+static __inline__
+void drd_start_using_mem_stack(const Addr a, const SizeT len)
+{
+  thread_set_stack_min(thread_get_running_tid(), a - VG_STACK_REDZONE_SZB);
+  drd_start_using_mem(a - VG_STACK_REDZONE_SZB, 
+                      len + VG_STACK_REDZONE_SZB);
+}
+
+/* Called by the core when the stack of a thread shrinks, to indicate that */
+/* the addresses [ a, a + len [ are no longer accessible for the client.   */
+/* Assumption: stacks grow downward.                                       */
+static __inline__
+void drd_stop_using_mem_stack(const Addr a, const SizeT len)
+{
+  thread_set_stack_min(thread_get_running_tid(),
+                       a + len - VG_STACK_REDZONE_SZB);
+  drd_stop_using_mem(a - VG_STACK_REDZONE_SZB, len + VG_STACK_REDZONE_SZB,
+                     True);
+}
+
+static void drd_start_using_mem_stack_signal(
+               const Addr a, const SizeT len,
+               ThreadId tid_for_whom_the_signal_frame_is_being_constructed)
+{
+  thread_set_vg_running_tid(VG_(get_running_tid)());
+  drd_start_using_mem(a, len);
+}
+
+static void drd_stop_using_mem_stack_signal(Addr a, SizeT len)
+{
+  drd_stop_using_mem(a, len, True);
+}
+
+static
+void drd_pre_thread_create(const ThreadId creator, const ThreadId created)
+{
+  const DrdThreadId drd_creator = VgThreadIdToDrdThreadId(creator);
+  tl_assert(created != VG_INVALID_THREADID);
+  thread_pre_create(drd_creator, created);
+  if (IsValidDrdThreadId(drd_creator))
+  {
+    thread_new_segment(drd_creator);
+  }
+  if (s_drd_trace_fork_join)
+  {
+    VG_(message)(Vg_DebugMsg,
+                 "drd_pre_thread_create creator = %d/%d, created = %d",
+                 creator, drd_creator, created);
+  }
+}
+
+/* Called by Valgrind's core before any loads or stores are performed on */
+/* the context of thread "created". At startup, this function is called  */
+/* with arguments (0,1).                                                 */
+static
+void drd_post_thread_create(const ThreadId vg_created)
+{
+  DrdThreadId drd_created;
+
+  tl_assert(vg_created != VG_INVALID_THREADID);
+
+  drd_created = thread_post_create(vg_created);
+  if (s_drd_trace_fork_join)
+  {
+    VG_(message)(Vg_DebugMsg,
+                 "drd_post_thread_create created = %d/%d",
+                 vg_created, drd_created);
+  }
+  if (! s_drd_check_stack_accesses)
+  {
+    drd_start_suppression(thread_get_stack_max(drd_created)
+                          - thread_get_stack_size(drd_created),
+                          thread_get_stack_max(drd_created),
+                          "stack");
+  }
+}
+
+/* Process VG_USERREQ__POST_THREAD_JOIN. This client request is invoked just */
+/* after thread drd_joiner joined thread drd_joinee.                         */
+void drd_post_thread_join(DrdThreadId drd_joiner, DrdThreadId drd_joinee)
+{
+  tl_assert(IsValidDrdThreadId(drd_joiner));
+  tl_assert(IsValidDrdThreadId(drd_joinee));
+  thread_new_segment(drd_joinee);
+  thread_combine_vc(drd_joiner, drd_joinee);
+  thread_new_segment(drd_joiner);
+
+  if (s_drd_trace_fork_join)
+  {
+    const ThreadId joiner = DrdThreadIdToVgThreadId(drd_joiner);
+    const ThreadId joinee = DrdThreadIdToVgThreadId(drd_joinee);
+    const unsigned msg_size = 256;
+    char* msg;
+
+    msg = VG_(malloc)(msg_size);
+    tl_assert(msg);
+    VG_(snprintf)(msg, msg_size,
+                  "drd_post_thread_join joiner = %d/%d, joinee = %d/%d",
+                  joiner, drd_joiner, joinee, drd_joinee);
+    if (joiner)
+    {
+      VG_(snprintf)(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg),
+                    ", new vc: ");
+      vc_snprint(msg + VG_(strlen)(msg), msg_size - VG_(strlen)(msg),
+                 thread_get_vc(drd_joiner));
+    }
+    VG_(message)(Vg_DebugMsg, msg);
+    VG_(free)(msg);
+  }
+
+  if (! s_drd_check_stack_accesses)
+  {
+    drd_finish_suppression(thread_get_stack_max(drd_joinee)
+                           - thread_get_stack_size(drd_joinee),
+                           thread_get_stack_max(drd_joinee));
+  }
+  thread_delete(drd_joinee);
+  mutex_thread_delete(drd_joinee);
+  cond_thread_delete(drd_joinee);
+  semaphore_thread_delete(drd_joinee);
+  barrier_thread_delete(drd_joinee);
+}
+
+
+/* Called after a thread has performed its last memory access. */
+static void drd_thread_finished(ThreadId vg_tid)
+{
+  DrdThreadId drd_tid;
+
+  tl_assert(VG_(get_running_tid)() == vg_tid);
+
+  drd_tid = VgThreadIdToDrdThreadId(vg_tid);
+  if (s_drd_trace_fork_join)
+  {
+    VG_(message)(Vg_DebugMsg,
+                 "drd_thread_finished tid = %d/%d%s",
+                 vg_tid,
+                 drd_tid,
+                 thread_get_joinable(drd_tid)
+                 ? ""
+                 : " (which is a detached thread)");
+  }
+  if (s_show_stack_usage)
+  {
+    const SizeT stack_size = thread_get_stack_size(drd_tid);
+    const SizeT used_stack
+      = thread_get_stack_max(drd_tid) - thread_get_stack_min_min(drd_tid);
+    VG_(message)(Vg_UserMsg,
+                 "thread %d/%d%s finished and used %ld bytes out of %ld"
+                 " on its stack. Margin: %ld bytes.",
+                 vg_tid,
+                 drd_tid,
+                 thread_get_joinable(drd_tid)
+                 ? ""
+                 : " (which is a detached thread)",
+                 used_stack,
+                 stack_size,
+                 stack_size - used_stack);
+
+  }
+  drd_stop_using_mem(thread_get_stack_min(drd_tid),
+                     thread_get_stack_max(drd_tid)
+                     - thread_get_stack_min(drd_tid),
+                     True);
+  thread_stop_recording(drd_tid);
+  thread_finished(drd_tid);
+}
+
+void drd_pre_mutex_init(const Addr mutex, const MutexT mutex_type)
+{
+  mutex_init(mutex, mutex_type);
+}
+
+void drd_post_mutex_destroy(const Addr mutex, const MutexT mutex_type)
+{
+  mutex_post_destroy(mutex);
+}
+
+void drd_pre_mutex_lock(const Addr mutex, const MutexT mutex_type,
+                        const Bool trylock)
+{
+  mutex_pre_lock(mutex, mutex_type, trylock);
+}
+
+void drd_post_mutex_lock(const Addr mutex, const Bool took_lock)
+{
+  mutex_post_lock(mutex, took_lock, False);
+}
+
+void drd_pre_mutex_unlock(const Addr mutex, const MutexT mutex_type)
+{
+  mutex_unlock(mutex, mutex_type);
+}
+
+void drd_pre_cond_init(Addr cond)
+{
+  cond_pre_init(cond);
+}
+
+void drd_post_cond_destroy(Addr cond)
+{
+  cond_post_destroy(cond);
+}
+
+void drd_semaphore_init(const Addr semaphore,
+                        const Word pshared, const Word value)
+{
+  semaphore_init(semaphore, pshared, value);
+}
+
+void drd_semaphore_destroy(const Addr semaphore)
+{
+  semaphore_destroy(semaphore);
+}
+
+void drd_semaphore_pre_wait(const DrdThreadId tid, const Addr semaphore)
+{
+  semaphore_pre_wait(semaphore);
+}
+
+void drd_semaphore_post_wait(const DrdThreadId tid, const Addr semaphore,
+                             const Bool waited)
+{
+  semaphore_post_wait(tid, semaphore, waited);
+}
+
+void drd_semaphore_pre_post(const DrdThreadId tid, const Addr semaphore)
+{
+  semaphore_pre_post(tid, semaphore);
+}
+
+void drd_semaphore_post_post(const DrdThreadId tid, const Addr semaphore,
+                             const Bool waited)
+{
+  semaphore_post_post(tid, semaphore, waited);
+}
+
+
+void drd_barrier_init(const Addr barrier,
+                      const BarrierT barrier_type, const Word count,
+                      const Bool reinitialization)
+{
+  barrier_init(barrier, barrier_type, count, reinitialization);
+}
+
+void drd_barrier_destroy(const Addr barrier, const BarrierT barrier_type)
+{
+  barrier_destroy(barrier, barrier_type);
+}
+
+void drd_barrier_pre_wait(const DrdThreadId tid, const Addr barrier,
+                          const BarrierT barrier_type)
+{
+  barrier_pre_wait(tid, barrier, barrier_type);
+}
+
+void drd_barrier_post_wait(const DrdThreadId tid, const Addr barrier,
+                           const BarrierT barrier_type, const Bool waited)
+{
+  barrier_post_wait(tid, barrier, barrier_type, waited);
+}
+
+
+//
+// Implementation of the tool interface.
+//
+
+static
+void drd_post_clo_init(void)
+{
+#  if defined(VGP_x86_linux) || defined(VGP_amd64_linux) \
+      || defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux)
+  /* fine */
+#  else
+  VG_(printf)("\nWARNING: DRD has only been tested on Linux.\n\n");
+#  endif
+
+  if (s_drd_var_info)
+  {
+    VG_(needs_var_info)();
+  }
+}
+
+#if defined(VGA_x86)
+#define STACK_POINTER_OFFSET OFFSET_x86_ESP
+#elif defined(VGA_amd64)
+#define STACK_POINTER_OFFSET OFFSET_amd64_RSP
+#elif defined(VGA_ppc32)
+#define STACK_POINTER_OFFSET ((OFFSET_ppc32_GPR0 + OFFSET_ppc32_GPR2) / 2)
+#elif defined(VGA_ppc64)
+#define STACK_POINTER_OFFSET ((OFFSET_ppc64_GPR0 + OFFSET_ppc64_GPR2) / 2)
+#else
+#error Unknown architecture.
+#endif
+
+
+/** Return true if and only if addr_expr matches the pattern (SP) or
+ *  <offset>(SP).
+ */
+static Bool is_stack_access(IRSB* const bb, IRExpr* const addr_expr)
+{
+  Bool result = False;
+
+  if (addr_expr->tag == Iex_RdTmp)
+  {
+    int i;
+    for (i = 0; i < bb->stmts_size; i++)
+    {
+      if (bb->stmts[i]
+          && bb->stmts[i]->tag == Ist_WrTmp
+          && bb->stmts[i]->Ist.WrTmp.tmp == addr_expr->Iex.RdTmp.tmp)
+      {
+        IRExpr* e = bb->stmts[i]->Ist.WrTmp.data;
+        if (e->tag == Iex_Get && e->Iex.Get.offset == STACK_POINTER_OFFSET)
+        {
+          result = True;
+        }
+
+        //ppIRExpr(e);
+        //VG_(printf)(" (%s)\n", result ? "True" : "False");
+        break;
+      }
+    }
+  }
+  return result;
+}
+
+static void instrument_load(IRSB* const bb,
+                            IRExpr* const addr_expr,
+                            const HWord size)
+{
+  IRExpr* size_expr;
+  IRExpr** argv;
+  IRDirty* di;
+
+  if (UNLIKELY(drd_any_address_is_traced()))
+  {
+    addStmtToIRSB(bb,
+		  IRStmt_Dirty(
+		    unsafeIRDirty_0_N(/*regparms*/2,
+				      "drd_trace_load",
+				      VG_(fnptr_to_fnentry)
+				      (drd_trace_mem_load),
+				      mkIRExprVec_2(addr_expr,
+						    mkIRExpr_HWord(size)))));
+  }
+
+  if (! s_drd_check_stack_accesses && is_stack_access(bb, addr_expr))
+    return;
+
+  switch (size)
+  {
+  case 1:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_load_1",
+                           VG_(fnptr_to_fnentry)(drd_trace_load_1),
+                           argv);
+    break;
+  case 2:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_load_2",
+                           VG_(fnptr_to_fnentry)(drd_trace_load_2),
+                           argv);
+    break;
+  case 4:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_load_4",
+                           VG_(fnptr_to_fnentry)(drd_trace_load_4),
+                           argv);
+    break;
+  case 8:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_load_8",
+                           VG_(fnptr_to_fnentry)(drd_trace_load_8),
+                           argv);
+    break;
+  default:
+    size_expr = mkIRExpr_HWord(size);
+    argv = mkIRExprVec_2(addr_expr, size_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/2,
+                           "drd_trace_load",
+                           VG_(fnptr_to_fnentry)(drd_trace_load),
+                           argv);
+    break;
+  }
+  addStmtToIRSB(bb, IRStmt_Dirty(di));
+}
+
+static void instrument_store(IRSB* const bb,
+                             IRExpr* const addr_expr,
+                             const HWord size)
+{
+  IRExpr* size_expr;
+  IRExpr** argv;
+  IRDirty* di;
+
+  if (UNLIKELY(drd_any_address_is_traced()))
+  {
+    addStmtToIRSB(bb,
+		  IRStmt_Dirty(
+		    unsafeIRDirty_0_N(/*regparms*/2,
+				      "drd_trace_store",
+				      VG_(fnptr_to_fnentry)
+				      (drd_trace_mem_store),
+				      mkIRExprVec_2(addr_expr,
+						    mkIRExpr_HWord(size)))));
+  }
+
+  if (! s_drd_check_stack_accesses && is_stack_access(bb, addr_expr))
+    return;
+
+  switch (size)
+  {
+  case 1:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_store_1",
+                           VG_(fnptr_to_fnentry)(drd_trace_store_1),
+                           argv);
+    break;
+  case 2:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_store_2",
+                           VG_(fnptr_to_fnentry)(drd_trace_store_2),
+                           argv);
+    break;
+  case 4:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_store_4",
+                           VG_(fnptr_to_fnentry)(drd_trace_store_4),
+                           argv);
+    break;
+  case 8:
+    argv = mkIRExprVec_1(addr_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/1,
+                           "drd_trace_store_8",
+                           VG_(fnptr_to_fnentry)(drd_trace_store_8),
+                           argv);
+    break;
+  default:
+    size_expr = mkIRExpr_HWord(size);
+    argv = mkIRExprVec_2(addr_expr, size_expr);
+    di = unsafeIRDirty_0_N(/*regparms*/2,
+                           "drd_trace_store",
+                           VG_(fnptr_to_fnentry)(drd_trace_store),
+                           argv);
+    break;
+  }
+  addStmtToIRSB(bb, IRStmt_Dirty(di));
+}
+
+static
+IRSB* drd_instrument(VgCallbackClosure* const closure,
+                     IRSB* const bb_in,
+                     VexGuestLayout* const layout,
+                     VexGuestExtents* const vge, 
+                     IRType const gWordTy,
+                     IRType const hWordTy)
+{
+  IRDirty* di;
+  Int      i;
+  IRSB*    bb;
+  IRExpr** argv;
+  Bool     instrument = True;
+  Bool     bus_locked = False;
+
+  /* Set up BB */
+  bb           = emptyIRSB();
+  bb->tyenv    = deepCopyIRTypeEnv(bb_in->tyenv);
+  bb->next     = deepCopyIRExpr(bb_in->next);
+  bb->jumpkind = bb_in->jumpkind;
+
+  for (i = 0; i < bb_in->stmts_used; i++)
+  {
+    IRStmt* const st = bb_in->stmts[i];
+    tl_assert(st);
+    if (st->tag == Ist_NoOp)
+      continue;
+
+    switch (st->tag)
+    {
+    /* Note: the code for not instrumenting the code in .plt          */
+    /* sections is only necessary on CentOS 3.0 x86 (kernel 2.4.21    */
+    /* + glibc 2.3.2 + NPTL 0.60 + binutils 2.14.90.0.4).             */
+    /* This is because on this platform dynamic library symbols are   */
+    /* relocated in another way than by later binutils versions. The  */
+    /* linker e.g. does not generate .got.plt sections on CentOS 3.0. */
+    case Ist_IMark:
+      instrument = VG_(seginfo_sect_kind)(NULL, 0, st->Ist.IMark.addr)
+        != Vg_SectPLT;
+      addStmtToIRSB(bb, st);
+      break;
+
+    case Ist_MBE:
+      switch (st->Ist.MBE.event)
+      {
+      case Imbe_Fence:
+        break; /* not interesting */
+      case Imbe_BusLock:
+      case Imbe_SnoopedStoreBegin:
+        tl_assert(! bus_locked);
+        bus_locked = True;
+        break;
+      case Imbe_BusUnlock:
+      case Imbe_SnoopedStoreEnd:
+        tl_assert(bus_locked);
+        bus_locked = False;
+        break;
+      default:
+        tl_assert(0);
+      }
+      addStmtToIRSB(bb, st);
+      break;
+
+    case Ist_Store:
+      if (instrument && ! bus_locked)
+      {
+        instrument_store(bb,
+                         st->Ist.Store.addr,
+                         sizeofIRType(typeOfIRExpr(bb->tyenv,
+                                                   st->Ist.Store.data)));
+      }
+      addStmtToIRSB(bb, st);
+      break;
+
+    case Ist_WrTmp:
+      if (instrument)
+      {
+        const IRExpr* const data = st->Ist.WrTmp.data;
+        if (data->tag == Iex_Load)
+        {
+          instrument_load(bb,
+                          data->Iex.Load.addr,
+                          sizeofIRType(data->Iex.Load.ty));
+        }
+      }
+      addStmtToIRSB(bb, st);
+      break;
+
+    case Ist_Dirty:
+      if (instrument)
+      {
+        IRDirty* d = st->Ist.Dirty.details;
+        IREffect const mFx = d->mFx;
+        switch (mFx) {
+        case Ifx_None:
+          break;
+        case Ifx_Read:
+        case Ifx_Write:
+        case Ifx_Modify:
+          tl_assert(d->mAddr);
+          tl_assert(d->mSize > 0);
+          argv = mkIRExprVec_2(d->mAddr, mkIRExpr_HWord(d->mSize));
+          if (mFx == Ifx_Read || mFx == Ifx_Modify) {
+            di = unsafeIRDirty_0_N(
+                                   /*regparms*/2,
+                                   "drd_trace_load",
+                                   VG_(fnptr_to_fnentry)(drd_trace_load),
+                                   argv);
+            addStmtToIRSB(bb, IRStmt_Dirty(di));
+          }
+          if ((mFx == Ifx_Write || mFx == Ifx_Modify)
+              && ! bus_locked)
+          {
+            di = unsafeIRDirty_0_N(
+                                   /*regparms*/2,
+                                   "drd_trace_store",
+                                   VG_(fnptr_to_fnentry)(drd_trace_store),
+                                   argv);
+            addStmtToIRSB(bb, IRStmt_Dirty(di));
+          }
+          break;
+        default:
+          tl_assert(0);
+        }
+      }
+      addStmtToIRSB(bb, st);
+      break;
+
+    default:
+      addStmtToIRSB(bb, st);
+      break;
+    }
+  }
+
+  tl_assert(! bus_locked);
+
+  return bb;
+}
+
+static void drd_start_client_code(const ThreadId tid, const ULong bbs_done)
+{
+  tl_assert(tid == VG_(get_running_tid)());
+  thread_set_vg_running_tid(tid);
+}
+
+static
+void drd_fini(Int exitcode)
+{
+  // thread_print_all();
+  if (VG_(clo_verbosity) > 1 || s_drd_print_stats)
+  {
+    ULong update_conflict_set_count;
+    ULong dsnsc;
+    ULong dscvc;
+
+    update_conflict_set_count
+      = thread_get_update_conflict_set_count(&dsnsc, &dscvc);
+
+    VG_(message)(Vg_UserMsg,
+                 "   thread: %lld context switches"
+                 " / %lld updates of the conflict set",
+                 thread_get_context_switch_count(),
+                 update_conflict_set_count);
+    VG_(message)(Vg_UserMsg,
+                 "           (%lld new sg + %lld combine vc + %lld csw).",
+                 dsnsc,
+                 dscvc,
+                 update_conflict_set_count - dsnsc - dscvc);
+    VG_(message)(Vg_UserMsg,
+                 " segments: created %lld segments, max %lld alive,"
+                 " %lld discard points.",
+                 sg_get_created_segments_count(),
+                 sg_get_max_alive_segments_count(),
+                 thread_get_discard_ordered_segments_count());
+    VG_(message)(Vg_UserMsg,
+                 "           (%lld m, %lld rw, %lld s, %lld b)",
+                 get_mutex_segment_creation_count(),
+                 get_rwlock_segment_creation_count(),
+                 get_semaphore_segment_creation_count(),
+                 get_barrier_segment_creation_count());
+    VG_(message)(Vg_UserMsg,
+                 "  bitmaps: %lld level 1 / %lld level 2 bitmap refs",
+                 bm_get_bitmap_creation_count(),
+                 bm_get_bitmap2_node_creation_count());
+    VG_(message)(Vg_UserMsg,
+                 "           and %lld level 2 bitmaps were allocated.",
+                 bm_get_bitmap2_creation_count());
+    VG_(message)(Vg_UserMsg,
+                 "    mutex: %lld non-recursive lock/unlock events.",
+                 get_mutex_lock_count());
+    drd_print_malloc_stats();
+  }
+}
+
+static
+void drd_pre_clo_init(void)
+{
+  // Basic tool stuff.
+
+  VG_(details_name)            ("exp-drd");
+  VG_(details_version)         (NULL);
+  VG_(details_description)     ("a thread error detector");
+  VG_(details_copyright_author)("Copyright (C) 2006-2008, and GNU GPL'd,"
+                                " by Bart Van Assche.");
+  VG_(details_bug_reports_to)  (VG_BUGS_TO);
+
+  VG_(basic_tool_funcs)        (drd_post_clo_init,
+                                drd_instrument,
+                                drd_fini);
+
+  // Command line stuff.
+  VG_(needs_command_line_options)(drd_process_cmd_line_option,
+                                  drd_print_usage,
+                                  drd_print_debug_usage);
+
+  // Error handling.
+  drd_register_error_handlers();
+
+  // Core event tracking.
+  VG_(track_pre_mem_read)         (drd_pre_mem_read);
+  VG_(track_pre_mem_read_asciiz)  (drd_pre_mem_read_asciiz);
+  VG_(track_post_mem_write)       (drd_post_mem_write);
+  VG_(track_new_mem_brk)          (drd_start_using_mem_w_tid);
+  VG_(track_new_mem_mmap)         (drd_start_using_mem_w_perms);
+  VG_(track_new_mem_stack)        (drd_start_using_mem_stack);
+  VG_(track_new_mem_stack_signal) (drd_start_using_mem_stack_signal);
+  VG_(track_new_mem_startup)      (drd_start_using_mem_w_perms);
+  VG_(track_die_mem_brk)          (drd_stop_using_nonstack_mem);
+  VG_(track_die_mem_munmap)       (drd_stop_using_nonstack_mem);
+  VG_(track_die_mem_stack)        (drd_stop_using_mem_stack);
+  VG_(track_die_mem_stack_signal) (drd_stop_using_mem_stack_signal);
+  VG_(track_start_client_code)    (drd_start_client_code);
+  VG_(track_pre_thread_ll_create) (drd_pre_thread_create);
+  VG_(track_pre_thread_first_insn)(drd_post_thread_create);
+  VG_(track_pre_thread_ll_exit)   (drd_thread_finished);
+
+  // Other stuff.
+  drd_register_malloc_wrappers(drd_start_using_mem_w_ecu,
+                               drd_stop_using_nonstack_mem);
+
+  drd_clientreq_init();
+
+  drd_suppression_init();
+
+  clientobj_init();
+}
+
+
+VG_DETERMINE_INTERFACE_VERSION(drd_pre_clo_init)