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      1 /* -*- mode: C; c-basic-offset: 3; indent-tabs-mode: nil; -*- */
      2 /*
      3   This file is part of drd, a thread error detector.
      4 
      5   Copyright (C) 2006-2011 Bart Van Assche <bvanassche (at) acm.org>.
      6 
      7   This program is free software; you can redistribute it and/or
      8   modify it under the terms of the GNU General Public License as
      9   published by the Free Software Foundation; either version 2 of the
     10   License, or (at your option) any later version.
     11 
     12   This program is distributed in the hope that it will be useful, but
     13   WITHOUT ANY WARRANTY; without even the implied warranty of
     14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     15   General Public License for more details.
     16 
     17   You should have received a copy of the GNU General Public License
     18   along with this program; if not, write to the Free Software
     19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     20   02111-1307, USA.
     21 
     22   The GNU General Public License is contained in the file COPYING.
     23 */
     24 
     25 
     26 #include "drd_barrier.h"
     27 #include "drd_clientobj.h"
     28 #include "drd_clientreq.h"
     29 #include "drd_cond.h"
     30 #include "drd_error.h"
     31 #include "drd_hb.h"
     32 #include "drd_load_store.h"
     33 #include "drd_malloc_wrappers.h"
     34 #include "drd_mutex.h"
     35 #include "drd_rwlock.h"
     36 #include "drd_segment.h"
     37 #include "drd_semaphore.h"
     38 #include "drd_suppression.h"
     39 #include "drd_thread.h"
     40 #include "libvex_guest_offsets.h"
     41 #include "pub_drd_bitmap.h"
     42 #include "pub_tool_vki.h"         // Must be included before pub_tool_libcproc
     43 #include "pub_tool_basics.h"
     44 #include "pub_tool_debuginfo.h"   // VG_(describe_IP)()
     45 #include "pub_tool_libcassert.h"  // tl_assert()
     46 #include "pub_tool_libcbase.h"    // VG_(strcmp)
     47 #include "pub_tool_libcprint.h"   // VG_(printf)
     48 #include "pub_tool_libcproc.h"
     49 #include "pub_tool_machine.h"
     50 #include "pub_tool_mallocfree.h"  // VG_(malloc)(), VG_(free)()
     51 #include "pub_tool_options.h"     // command line options
     52 #include "pub_tool_replacemalloc.h"
     53 #include "pub_tool_threadstate.h" // VG_(get_running_tid)()
     54 #include "pub_tool_tooliface.h"
     55 #include "pub_tool_aspacemgr.h"   // VG_(am_is_valid_for_client)
     56 
     57 
     58 /* Local variables. */
     59 
     60 static Bool s_print_stats;
     61 static Bool s_var_info;
     62 static Bool s_show_stack_usage;
     63 static Bool s_trace_alloc;
     64 
     65 
     66 /**
     67  * Implement the needs_command_line_options for drd.
     68  */
     69 static Bool DRD_(process_cmd_line_option)(Char* arg)
     70 {
     71    int check_stack_accesses   = -1;
     72    int join_list_vol          = -1;
     73    int exclusive_threshold_ms = -1;
     74    int first_race_only        = -1;
     75    int report_signal_unlocked = -1;
     76    int segment_merging        = -1;
     77    int segment_merge_interval = -1;
     78    int shared_threshold_ms    = -1;
     79    int show_confl_seg         = -1;
     80    int trace_barrier          = -1;
     81    int trace_clientobj        = -1;
     82    int trace_cond             = -1;
     83    int trace_csw              = -1;
     84    int trace_fork_join        = -1;
     85    int trace_hb               = -1;
     86    int trace_conflict_set     = -1;
     87    int trace_conflict_set_bm  = -1;
     88    int trace_mutex            = -1;
     89    int trace_rwlock           = -1;
     90    int trace_segment          = -1;
     91    int trace_semaphore        = -1;
     92    int trace_suppression      = -1;
     93    Char* trace_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-segment",       trace_segment) {}
    119    else if VG_BOOL_CLO(arg, "--trace-semaphore",     trace_semaphore) {}
    120    else if VG_BOOL_CLO(arg, "--trace-suppr",         trace_suppression) {}
    121    else if VG_BOOL_CLO(arg, "--var-info",            s_var_info) {}
    122    else if VG_INT_CLO (arg, "--exclusive-threshold", exclusive_threshold_ms) {}
    123    else if VG_INT_CLO (arg, "--shared-threshold",    shared_threshold_ms)    {}
    124    else if VG_STR_CLO (arg, "--trace-addr",          trace_address) {}
    125    else
    126       return VG_(replacement_malloc_process_cmd_line_option)(arg);
    127 
    128    if (check_stack_accesses != -1)
    129       DRD_(set_check_stack_accesses)(check_stack_accesses);
    130    if (exclusive_threshold_ms != -1)
    131    {
    132       DRD_(mutex_set_lock_threshold)(exclusive_threshold_ms);
    133       DRD_(rwlock_set_exclusive_threshold)(exclusive_threshold_ms);
    134    }
    135    if (first_race_only != -1)
    136    {
    137       DRD_(set_first_race_only)(first_race_only);
    138    }
    139    if (join_list_vol != -1)
    140       DRD_(thread_set_join_list_vol)(join_list_vol);
    141    if (report_signal_unlocked != -1)
    142    {
    143       DRD_(cond_set_report_signal_unlocked)(report_signal_unlocked);
    144    }
    145    if (shared_threshold_ms != -1)
    146    {
    147       DRD_(rwlock_set_shared_threshold)(shared_threshold_ms);
    148    }
    149    if (segment_merging != -1)
    150       DRD_(thread_set_segment_merging)(segment_merging);
    151    if (segment_merge_interval != -1)
    152       DRD_(thread_set_segment_merge_interval)(segment_merge_interval);
    153    if (show_confl_seg != -1)
    154       DRD_(set_show_conflicting_segments)(show_confl_seg);
    155    if (trace_address)
    156    {
    157       const Addr addr = VG_(strtoll16)(trace_address, 0);
    158       DRD_(start_tracing_address_range)(addr, addr + 1);
    159    }
    160    if (trace_barrier != -1)
    161       DRD_(barrier_set_trace)(trace_barrier);
    162    if (trace_clientobj != -1)
    163       DRD_(clientobj_set_trace)(trace_clientobj);
    164    if (trace_cond != -1)
    165       DRD_(cond_set_trace)(trace_cond);
    166    if (trace_csw != -1)
    167       DRD_(thread_trace_context_switches)(trace_csw);
    168    if (trace_fork_join != -1)
    169       DRD_(thread_set_trace_fork_join)(trace_fork_join);
    170    if (trace_hb != -1)
    171       DRD_(hb_set_trace)(trace_hb);
    172    if (trace_conflict_set != -1)
    173       DRD_(thread_trace_conflict_set)(trace_conflict_set);
    174    if (trace_conflict_set_bm != -1)
    175       DRD_(thread_trace_conflict_set_bm)(trace_conflict_set_bm);
    176    if (trace_mutex != -1)
    177       DRD_(mutex_set_trace)(trace_mutex);
    178    if (trace_rwlock != -1)
    179       DRD_(rwlock_set_trace)(trace_rwlock);
    180    if (trace_segment != -1)
    181       DRD_(sg_set_trace)(trace_segment);
    182    if (trace_semaphore != -1)
    183       DRD_(semaphore_set_trace)(trace_semaphore);
    184    if (trace_suppression != -1)
    185       DRD_(suppression_set_trace)(trace_suppression);
    186 
    187    return True;
    188 }
    189 
    190 static void DRD_(print_usage)(void)
    191 {
    192    VG_(printf)(
    193 "    --check-stack-var=yes|no  Whether or not to report data races on\n"
    194 "                              stack variables [no].\n"
    195 "    --exclusive-threshold=<n> Print an error message if any mutex or\n"
    196 "                              writer lock is held longer than the specified\n"
    197 "                              time (in milliseconds) [off].\n"
    198 "    --first-race-only=yes|no  Only report the first data race that occurs on\n"
    199 "                              a memory location instead of all races [no].\n"
    200 "    --free-is-write=yes|no    Whether to report races between freeing memory\n"
    201 "                              and subsequent accesses of that memory[no].\n"
    202 "    --join-list-vol=<n>       Number of threads to delay cleanup for [10].\n"
    203 "    --report-signal-unlocked=yes|no Whether to report calls to\n"
    204 "                              pthread_cond_signal() where the mutex associated\n"
    205 "                              with the signal via pthread_cond_wait() is not\n"
    206 "                              locked at the time the signal is sent [yes].\n"
    207 "    --segment-merging=yes|no  Controls segment merging [yes].\n"
    208 "        Segment merging is an algorithm to limit memory usage of the\n"
    209 "        data race detection algorithm. Disabling segment merging may\n"
    210 "        improve the accuracy of the so-called 'other segments' displayed\n"
    211 "        in race reports but can also trigger an out of memory error.\n"
    212 "    --segment-merging-interval=<n> Perform segment merging every time n new\n"
    213 "        segments have been created. Default: %d.\n"
    214 "    --shared-threshold=<n>    Print an error message if a reader lock\n"
    215 "                              is held longer than the specified time (in\n"
    216 "                              milliseconds) [off]\n"
    217 "    --show-confl-seg=yes|no   Show conflicting segments in race reports [yes].\n"
    218 "    --show-stack-usage=yes|no Print stack usage at thread exit time [no].\n"
    219 "\n"
    220 "  drd options for monitoring process behavior:\n"
    221 "    --trace-addr=<address>    Trace all load and store activity for the.\n"
    222 "                              specified address [off].\n"
    223 "    --trace-alloc=yes|no      Trace all memory allocations and deallocations\n""                              [no].\n"
    224 "    --trace-barrier=yes|no    Trace all barrier activity [no].\n"
    225 "    --trace-cond=yes|no       Trace all condition variable activity [no].\n"
    226 "    --trace-fork-join=yes|no  Trace all thread fork/join activity [no].\n"
    227 "    --trace-hb=yes|no         Trace ANNOTATE_HAPPENS_BEFORE() etc. [no].\n"
    228 "    --trace-mutex=yes|no      Trace all mutex activity [no].\n"
    229 "    --trace-rwlock=yes|no     Trace all reader-writer lock activity[no].\n"
    230 "    --trace-semaphore=yes|no  Trace all semaphore activity [no].\n",
    231 DRD_(thread_get_segment_merge_interval)()
    232 );
    233 }
    234 
    235 static void DRD_(print_debug_usage)(void)
    236 {
    237    VG_(printf)(
    238 "    --drd-stats=yes|no        Print statistics about DRD activity [no].\n"
    239 "    --trace-clientobj=yes|no  Trace all client object activity [no].\n"
    240 "    --trace-csw=yes|no        Trace all scheduler context switches [no].\n"
    241 "    --trace-conflict-set=yes|no Trace all conflict set updates [no].\n"
    242 "    --trace-conflict-set-bm=yes|no Trace all conflict set bitmap\n"
    243 "                              updates [no]. Note: enabling this option\n"
    244 "                              will generate a lot of output !\n"
    245 "    --trace-segment=yes|no    Trace segment actions [no].\n"
    246 "    --trace-suppr=yes|no      Trace all address suppression actions [no].\n"
    247 );
    248 }
    249 
    250 
    251 //
    252 // Implements the thread-related core callbacks.
    253 //
    254 
    255 static void drd_pre_mem_read(const CorePart part,
    256                              const ThreadId tid,
    257                              Char* const s,
    258                              const Addr a,
    259                              const SizeT size)
    260 {
    261    if (size > 0)
    262    {
    263       DRD_(trace_load)(a, size);
    264    }
    265 }
    266 
    267 static void drd_pre_mem_read_asciiz(const CorePart part,
    268                                     const ThreadId tid,
    269                                     Char* const s,
    270                                     const Addr a)
    271 {
    272    const char* p = (void*)a;
    273    SizeT size = 0;
    274 
    275    // Don't segfault if the string starts in an obviously stupid
    276    // place.  Actually we should check the whole string, not just
    277    // the start address, but that's too much trouble.  At least
    278    // checking the first byte is better than nothing.  See #255009.
    279    if (!VG_(am_is_valid_for_client) (a, 1, VKI_PROT_READ))
    280       return;
    281 
    282    /* Note: the expression '*p' reads client memory and may crash if the */
    283    /* client provided an invalid pointer !                               */
    284    while (*p)
    285    {
    286       p++;
    287       size++;
    288    }
    289    if (size > 0)
    290    {
    291       DRD_(trace_load)(a, size);
    292    }
    293 }
    294 
    295 static void drd_post_mem_write(const CorePart part,
    296                                const ThreadId tid,
    297                                const Addr a,
    298                                const SizeT size)
    299 {
    300    DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
    301    if (size > 0)
    302    {
    303       DRD_(trace_store)(a, size);
    304    }
    305 }
    306 
    307 static __inline__
    308 void drd_start_using_mem(const Addr a1, const SizeT len,
    309                          const Bool is_stack_mem)
    310 {
    311    const Addr a2 = a1 + len;
    312 
    313    tl_assert(a1 <= a2);
    314 
    315    if (!is_stack_mem && s_trace_alloc)
    316       DRD_(trace_msg)("Started using memory range 0x%lx + %ld%s",
    317                       a1, len, DRD_(running_thread_inside_pthread_create)()
    318                       ? " (inside pthread_create())" : "");
    319 
    320    if (!is_stack_mem && DRD_(g_free_is_write))
    321       DRD_(thread_stop_using_mem)(a1, a2);
    322 
    323    if (UNLIKELY(DRD_(any_address_is_traced)()))
    324    {
    325       DRD_(trace_mem_access)(a1, len, eStart);
    326    }
    327 
    328    if (UNLIKELY(DRD_(running_thread_inside_pthread_create)()))
    329    {
    330       DRD_(start_suppression)(a1, a2, "pthread_create()");
    331    }
    332 }
    333 
    334 static void drd_start_using_mem_w_ecu(const Addr a1,
    335                                       const SizeT len,
    336                                       UInt ec_uniq)
    337 {
    338    drd_start_using_mem(a1, len, False);
    339 }
    340 
    341 static void drd_start_using_mem_w_tid(const Addr a1,
    342                                       const SizeT len,
    343                                       ThreadId tid)
    344 {
    345    drd_start_using_mem(a1, len, False);
    346 }
    347 
    348 static __inline__
    349 void drd_stop_using_mem(const Addr a1, const SizeT len,
    350                         const Bool is_stack_mem)
    351 {
    352    const Addr a2 = a1 + len;
    353 
    354    tl_assert(a1 <= a2);
    355 
    356    if (UNLIKELY(DRD_(any_address_is_traced)()))
    357       DRD_(trace_mem_access)(a1, len, eEnd);
    358 
    359    if (!is_stack_mem && s_trace_alloc)
    360       DRD_(trace_msg)("Stopped using memory range 0x%lx + %ld",
    361                       a1, len);
    362 
    363    if (!is_stack_mem || DRD_(get_check_stack_accesses)())
    364    {
    365       if (is_stack_mem || !DRD_(g_free_is_write))
    366 	 DRD_(thread_stop_using_mem)(a1, a2);
    367       else if (DRD_(g_free_is_write))
    368 	 DRD_(trace_store)(a1, len);
    369       DRD_(clientobj_stop_using_mem)(a1, a2);
    370       DRD_(suppression_stop_using_mem)(a1, a2);
    371    }
    372 }
    373 
    374 static __inline__
    375 void drd_stop_using_nonstack_mem(const Addr a1, const SizeT len)
    376 {
    377    drd_stop_using_mem(a1, len, False);
    378 }
    379 
    380 /**
    381  * Discard all information DRD has about memory accesses and client objects
    382  * in the specified address range.
    383  */
    384 void DRD_(clean_memory)(const Addr a1, const SizeT len)
    385 {
    386    const Bool is_stack_memory = DRD_(thread_address_on_any_stack)(a1);
    387    drd_stop_using_mem(a1, len, is_stack_memory);
    388    drd_start_using_mem(a1, len, is_stack_memory);
    389 }
    390 
    391 /**
    392  * Suppress data race reports on all addresses contained in .plt and
    393  * .got.plt sections inside the address range [ a, a + len [. The data in
    394  * these sections is modified by _dl_relocate_object() every time a function
    395  * in a shared library is called for the first time. Since the first call
    396  * to a function in a shared library can happen from a multithreaded context,
    397  * such calls can cause conflicting accesses. See also Ulrich Drepper's
    398  * paper "How to Write Shared Libraries" for more information about relocation
    399  * (http://people.redhat.com/drepper/dsohowto.pdf).
    400  */
    401 static void DRD_(suppress_relocation_conflicts)(const Addr a, const SizeT len)
    402 {
    403    const DebugInfo* di;
    404 
    405 #if 0
    406    VG_(printf)("Evaluating range @ 0x%lx size %ld\n", a, len);
    407 #endif
    408 
    409    for (di = VG_(next_DebugInfo)(0); di; di = VG_(next_DebugInfo)(di))
    410    {
    411       Addr  avma;
    412       SizeT size;
    413 
    414       avma = VG_(DebugInfo_get_plt_avma)(di);
    415       size = VG_(DebugInfo_get_plt_size)(di);
    416       tl_assert((avma && size) || (avma == 0 && size == 0));
    417       if (size > 0)
    418       {
    419 #if 0
    420          VG_(printf)("Suppressing .plt @ 0x%lx size %ld\n", avma, size);
    421 #endif
    422          tl_assert(VG_(DebugInfo_sect_kind)(NULL, 0, avma) == Vg_SectPLT);
    423          DRD_(start_suppression)(avma, avma + size, ".plt");
    424       }
    425 
    426       avma = VG_(DebugInfo_get_gotplt_avma)(di);
    427       size = VG_(DebugInfo_get_gotplt_size)(di);
    428       tl_assert((avma && size) || (avma == 0 && size == 0));
    429       if (size > 0)
    430       {
    431 #if 0
    432          VG_(printf)("Suppressing .got.plt @ 0x%lx size %ld\n", avma, size);
    433 #endif
    434          tl_assert(VG_(DebugInfo_sect_kind)(NULL, 0, avma) == Vg_SectGOTPLT);
    435          DRD_(start_suppression)(avma, avma + size, ".gotplt");
    436       }
    437    }
    438 }
    439 
    440 static
    441 void drd_start_using_mem_w_perms(const Addr a, const SizeT len,
    442                                  const Bool rr, const Bool ww, const Bool xx,
    443                                  ULong di_handle)
    444 {
    445    DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
    446 
    447    drd_start_using_mem(a, len, False);
    448 
    449    DRD_(suppress_relocation_conflicts)(a, len);
    450 }
    451 
    452 /* Called by the core when the stack of a thread grows, to indicate that */
    453 /* the addresses in range [ a, a + len [ may now be used by the client.  */
    454 /* Assumption: stacks grow downward.                                     */
    455 static __inline__
    456 void drd_start_using_mem_stack(const Addr a, const SizeT len)
    457 {
    458    DRD_(thread_set_stack_min)(DRD_(thread_get_running_tid)(),
    459                               a - VG_STACK_REDZONE_SZB);
    460    drd_start_using_mem(a - VG_STACK_REDZONE_SZB,
    461                        len + VG_STACK_REDZONE_SZB,
    462                        True);
    463 }
    464 
    465 /* Called by the core when the stack of a thread shrinks, to indicate that */
    466 /* the addresses [ a, a + len [ are no longer accessible for the client.   */
    467 /* Assumption: stacks grow downward.                                       */
    468 static __inline__
    469 void drd_stop_using_mem_stack(const Addr a, const SizeT len)
    470 {
    471    DRD_(thread_set_stack_min)(DRD_(thread_get_running_tid)(),
    472                               a + len - VG_STACK_REDZONE_SZB);
    473    drd_stop_using_mem(a - VG_STACK_REDZONE_SZB, len + VG_STACK_REDZONE_SZB,
    474                       True);
    475 }
    476 
    477 static
    478 Bool on_alt_stack(const Addr a)
    479 {
    480    ThreadId vg_tid;
    481    Addr alt_min;
    482    SizeT alt_size;
    483 
    484    vg_tid = VG_(get_running_tid)();
    485    alt_min = VG_(thread_get_altstack_min)(vg_tid);
    486    alt_size = VG_(thread_get_altstack_size)(vg_tid);
    487    return (SizeT)(a - alt_min) < alt_size;
    488 }
    489 
    490 static
    491 void drd_start_using_mem_alt_stack(const Addr a, const SizeT len)
    492 {
    493    if (!on_alt_stack(a))
    494       drd_start_using_mem_stack(a, len);
    495 }
    496 
    497 static
    498 void drd_stop_using_mem_alt_stack(const Addr a, const SizeT len)
    499 {
    500    if (!on_alt_stack(a))
    501       drd_stop_using_mem_stack(a, len);
    502 }
    503 
    504 /**
    505  * Callback function invoked by the Valgrind core before a signal is delivered.
    506  */
    507 static
    508 void drd_pre_deliver_signal(const ThreadId vg_tid, const Int sigNo,
    509                             const Bool alt_stack)
    510 {
    511    DrdThreadId drd_tid;
    512 
    513    drd_tid = DRD_(VgThreadIdToDrdThreadId)(vg_tid);
    514    DRD_(thread_set_on_alt_stack)(drd_tid, alt_stack);
    515    if (alt_stack)
    516    {
    517       /*
    518        * As soon a signal handler has been invoked on the alternate stack,
    519        * switch to stack memory handling functions that can handle the
    520        * alternate stack.
    521        */
    522       VG_(track_new_mem_stack)(drd_start_using_mem_alt_stack);
    523       VG_(track_die_mem_stack)(drd_stop_using_mem_alt_stack);
    524    }
    525 }
    526 
    527 /**
    528  * Callback function invoked by the Valgrind core after a signal is delivered,
    529  * at least if the signal handler did not longjmp().
    530  */
    531 static
    532 void drd_post_deliver_signal(const ThreadId vg_tid, const Int sigNo)
    533 {
    534    DrdThreadId drd_tid;
    535 
    536    drd_tid = DRD_(VgThreadIdToDrdThreadId)(vg_tid);
    537    DRD_(thread_set_on_alt_stack)(drd_tid, False);
    538    if (DRD_(thread_get_threads_on_alt_stack)() == 0)
    539    {
    540       VG_(track_new_mem_stack)(drd_start_using_mem_stack);
    541       VG_(track_die_mem_stack)(drd_stop_using_mem_stack);
    542    }
    543 }
    544 
    545 /**
    546  * Callback function called by the Valgrind core before a stack area is
    547  * being used by a signal handler.
    548  *
    549  * @param[in] a   Start of address range.
    550  * @param[in] len Address range length.
    551  * @param[in] tid Valgrind thread ID for whom the signal frame is being
    552  *                constructed.
    553  */
    554 static void drd_start_using_mem_stack_signal(const Addr a, const SizeT len,
    555                                              ThreadId tid)
    556 {
    557    DRD_(thread_set_vg_running_tid)(VG_(get_running_tid)());
    558    drd_start_using_mem(a, len, True);
    559 }
    560 
    561 static void drd_stop_using_mem_stack_signal(Addr a, SizeT len)
    562 {
    563    drd_stop_using_mem(a, len, True);
    564 }
    565 
    566 static
    567 void drd_pre_thread_create(const ThreadId creator, const ThreadId created)
    568 {
    569    const DrdThreadId drd_creator = DRD_(VgThreadIdToDrdThreadId)(creator);
    570    tl_assert(created != VG_INVALID_THREADID);
    571    DRD_(thread_pre_create)(drd_creator, created);
    572    if (DRD_(IsValidDrdThreadId)(drd_creator))
    573    {
    574       DRD_(thread_new_segment)(drd_creator);
    575    }
    576    if (DRD_(thread_get_trace_fork_join)())
    577    {
    578       DRD_(trace_msg)("drd_pre_thread_create creator = %d, created = %d",
    579                       drd_creator, created);
    580    }
    581 }
    582 
    583 /* Called by Valgrind's core before any loads or stores are performed on */
    584 /* the context of thread "created". At startup, this function is called  */
    585 /* with arguments (0,1).                                                 */
    586 static
    587 void drd_post_thread_create(const ThreadId vg_created)
    588 {
    589    DrdThreadId drd_created;
    590 
    591    tl_assert(vg_created != VG_INVALID_THREADID);
    592 
    593    drd_created = DRD_(thread_post_create)(vg_created);
    594    if (DRD_(thread_get_trace_fork_join)())
    595    {
    596       DRD_(trace_msg)("drd_post_thread_create created = %d", drd_created);
    597    }
    598    if (! DRD_(get_check_stack_accesses)())
    599    {
    600       DRD_(start_suppression)(DRD_(thread_get_stack_max)(drd_created)
    601                               - DRD_(thread_get_stack_size)(drd_created),
    602                               DRD_(thread_get_stack_max)(drd_created),
    603                               "stack");
    604    }
    605 }
    606 
    607 /* Called after a thread has performed its last memory access. */
    608 static void drd_thread_finished(ThreadId vg_tid)
    609 {
    610    DrdThreadId drd_tid;
    611 
    612    tl_assert(VG_(get_running_tid)() == vg_tid);
    613 
    614    drd_tid = DRD_(VgThreadIdToDrdThreadId)(vg_tid);
    615    if (DRD_(thread_get_trace_fork_join)())
    616    {
    617       DRD_(trace_msg)("drd_thread_finished tid = %d%s", drd_tid,
    618                       DRD_(thread_get_joinable)(drd_tid)
    619                       ? "" : " (which is a detached thread)");
    620    }
    621    if (s_show_stack_usage && !VG_(clo_xml)) {
    622       const SizeT stack_size = DRD_(thread_get_stack_size)(drd_tid);
    623       const SizeT used_stack
    624          = (DRD_(thread_get_stack_max)(drd_tid)
    625             - DRD_(thread_get_stack_min_min)(drd_tid));
    626       VG_(message)(Vg_UserMsg,
    627                    "thread %d%s finished and used %ld bytes out of %ld"
    628                    " on its stack. Margin: %ld bytes.\n",
    629                    drd_tid,
    630                    DRD_(thread_get_joinable)(drd_tid)
    631                    ? "" : " (which is a detached thread)",
    632                    used_stack, stack_size, stack_size - used_stack);
    633 
    634    }
    635    drd_stop_using_mem(DRD_(thread_get_stack_min)(drd_tid),
    636                       DRD_(thread_get_stack_max)(drd_tid)
    637                       - DRD_(thread_get_stack_min)(drd_tid),
    638                       True);
    639    DRD_(thread_set_record_loads)(drd_tid, False);
    640    DRD_(thread_set_record_stores)(drd_tid, False);
    641    DRD_(thread_finished)(drd_tid);
    642 }
    643 
    644 /*
    645  * Called immediately after fork for the child process only. 'tid' is the
    646  * only surviving thread in the child process. Cleans up thread state.
    647  * See also http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_atfork.html for a detailed discussion of using fork() in combination with mutexes.
    648  */
    649 static
    650 void drd__atfork_child(ThreadId tid)
    651 {
    652    DRD_(drd_thread_atfork_child)(tid);
    653 }
    654 
    655 
    656 //
    657 // Implementation of the tool interface.
    658 //
    659 
    660 static void DRD_(post_clo_init)(void)
    661 {
    662 #if defined(VGO_linux) || defined(VGO_darwin)
    663    /* fine */
    664 #else
    665    VG_(printf)("\nWARNING: DRD has not yet been tested on this operating system.\n\n");
    666 #  endif
    667 
    668    if (s_var_info)
    669    {
    670       VG_(needs_var_info)();
    671    }
    672 }
    673 
    674 static void drd_start_client_code(const ThreadId tid, const ULong bbs_done)
    675 {
    676    tl_assert(tid == VG_(get_running_tid)());
    677    DRD_(thread_set_vg_running_tid)(tid);
    678 }
    679 
    680 static void DRD_(fini)(Int exitcode)
    681 {
    682    // thread_print_all();
    683    if (VG_(clo_verbosity) == 1 && !VG_(clo_xml)) {
    684       VG_(message)(Vg_UserMsg, "For counts of detected and suppressed errors, "
    685                    "rerun with: -v\n");
    686    }
    687 
    688    if ((VG_(clo_stats) || s_print_stats) && !VG_(clo_xml))
    689    {
    690       ULong pu = DRD_(thread_get_update_conflict_set_count)();
    691       ULong pu_seg_cr = DRD_(thread_get_update_conflict_set_new_sg_count)();
    692       ULong pu_mtx_cv = DRD_(thread_get_update_conflict_set_sync_count)();
    693       ULong pu_join   = DRD_(thread_get_update_conflict_set_join_count)();
    694 
    695       VG_(message)(Vg_UserMsg,
    696                    "   thread: %lld context switches.\n",
    697                    DRD_(thread_get_context_switch_count)());
    698       VG_(message)(Vg_UserMsg,
    699                    "confl set: %lld full updates and %lld partial updates;\n",
    700                    DRD_(thread_get_compute_conflict_set_count)(),
    701                    pu);
    702       VG_(message)(Vg_UserMsg,
    703                    "           %lld partial updates during segment creation,\n",
    704                    pu_seg_cr);
    705       VG_(message)(Vg_UserMsg,
    706                    "           %lld because of mutex/sema/cond.var. operations,\n",
    707                    pu_mtx_cv);
    708       VG_(message)(Vg_UserMsg,
    709                    "           %lld because of barrier/rwlock operations and\n",
    710 		   pu - pu_seg_cr - pu_mtx_cv - pu_join);
    711       VG_(message)(Vg_UserMsg,
    712                    "           %lld partial updates because of thread join"
    713                    " operations.\n",
    714                    pu_join);
    715       VG_(message)(Vg_UserMsg,
    716                    " segments: created %lld segments, max %lld alive,\n",
    717                    DRD_(sg_get_segments_created_count)(),
    718                    DRD_(sg_get_max_segments_alive_count)());
    719       VG_(message)(Vg_UserMsg,
    720                    "           %lld discard points and %lld merges.\n",
    721                    DRD_(thread_get_discard_ordered_segments_count)(),
    722                    DRD_(sg_get_segment_merge_count)());
    723       VG_(message)(Vg_UserMsg,
    724                    "segmnt cr: %lld mutex, %lld rwlock, %lld semaphore and"
    725                    " %lld barrier.\n",
    726                    DRD_(get_mutex_segment_creation_count)(),
    727                    DRD_(get_rwlock_segment_creation_count)(),
    728                    DRD_(get_semaphore_segment_creation_count)(),
    729                    DRD_(get_barrier_segment_creation_count)());
    730       VG_(message)(Vg_UserMsg,
    731                    "  bitmaps: %lld level one"
    732                    " and %lld level two bitmaps were allocated.\n",
    733                    DRD_(bm_get_bitmap_creation_count)(),
    734                    DRD_(bm_get_bitmap2_creation_count)());
    735       VG_(message)(Vg_UserMsg,
    736                    "    mutex: %lld non-recursive lock/unlock events.\n",
    737                    DRD_(get_mutex_lock_count)());
    738       DRD_(print_malloc_stats)();
    739    }
    740 }
    741 
    742 static
    743 void drd_pre_clo_init(void)
    744 {
    745    // Basic tool stuff.
    746    VG_(details_name)            ("drd");
    747    VG_(details_version)         (NULL);
    748    VG_(details_description)     ("a thread error detector");
    749    VG_(details_copyright_author)("Copyright (C) 2006-2011, and GNU GPL'd,"
    750                                  " by Bart Van Assche.");
    751    VG_(details_bug_reports_to)  (VG_BUGS_TO);
    752 
    753    VG_(basic_tool_funcs)        (DRD_(post_clo_init),
    754                                  DRD_(instrument),
    755                                  DRD_(fini));
    756 
    757    // Command line stuff.
    758    VG_(needs_command_line_options)(DRD_(process_cmd_line_option),
    759                                    DRD_(print_usage),
    760                                    DRD_(print_debug_usage));
    761    VG_(needs_xml_output)          ();
    762 
    763    // Error handling.
    764    DRD_(register_error_handlers)();
    765 
    766    // Core event tracking.
    767    VG_(track_pre_mem_read)         (drd_pre_mem_read);
    768    VG_(track_pre_mem_read_asciiz)  (drd_pre_mem_read_asciiz);
    769    VG_(track_post_mem_write)       (drd_post_mem_write);
    770    VG_(track_new_mem_brk)          (drd_start_using_mem_w_tid);
    771    VG_(track_new_mem_mmap)         (drd_start_using_mem_w_perms);
    772    VG_(track_new_mem_stack)        (drd_start_using_mem_stack);
    773    VG_(track_new_mem_stack_signal) (drd_start_using_mem_stack_signal);
    774    VG_(track_new_mem_startup)      (drd_start_using_mem_w_perms);
    775    VG_(track_die_mem_brk)          (drd_stop_using_nonstack_mem);
    776    VG_(track_die_mem_munmap)       (drd_stop_using_nonstack_mem);
    777    VG_(track_die_mem_stack)        (drd_stop_using_mem_stack);
    778    VG_(track_die_mem_stack_signal) (drd_stop_using_mem_stack_signal);
    779    VG_(track_pre_deliver_signal)   (drd_pre_deliver_signal);
    780    VG_(track_post_deliver_signal)  (drd_post_deliver_signal);
    781    VG_(track_start_client_code)    (drd_start_client_code);
    782    VG_(track_pre_thread_ll_create) (drd_pre_thread_create);
    783    VG_(track_pre_thread_first_insn)(drd_post_thread_create);
    784    VG_(track_pre_thread_ll_exit)   (drd_thread_finished);
    785    VG_(atfork)                     (NULL/*pre*/, NULL/*parent*/,
    786 				    drd__atfork_child/*child*/);
    787 
    788    // Other stuff.
    789    DRD_(register_malloc_wrappers)(drd_start_using_mem_w_ecu,
    790                                   drd_stop_using_nonstack_mem);
    791 
    792    DRD_(clientreq_init)();
    793 
    794    DRD_(suppression_init)();
    795 
    796    DRD_(clientobj_init)();
    797 
    798    {
    799       Char* const smi = VG_(getenv)("DRD_SEGMENT_MERGING_INTERVAL");
    800       if (smi)
    801          DRD_(thread_set_segment_merge_interval)(VG_(strtoll10)(smi, NULL));
    802    }
    803 }
    804 
    805 
    806 VG_DETERMINE_INTERFACE_VERSION(drd_pre_clo_init)
    807