How to read Crashlogs

[rusfighter]

Hey , i have some crashes that i want to solve but how to read the crash logs that GDB produce?

AND DONT give me guide of GDB please, i already have that.

I just need to know where to read so i can fix the crashes , crash very often now and that is annoying

[Gotisch]

how about example of crashlog you have problem with? i can only show you example from one of our crashdumps:

nice -n 19 gdb $srv_dir/bin/mangos-worldd --core $f --batch --quiet -ex "info threads" -ex "thread apply all bt full" -ex "quit" &>  $log_file && rm $f

results in

warning: Can't read pathname for load map: Input/output error.
Core was generated by `/home/gcuser/gc_mangos/mangos_server/bin/mangos-worldd'.
Program terminated with signal 6, Aborted.
[New process 24998]
[New process 25003]
[New process 25002]
[New process 25001]
[New process 25000]
[New process 24999]
[New process 24756]
[New process 24760]
[New process 24759]
[New process 24758]
#0  0x00007f65e255ff55 in raise () from /lib/libc.so.6
 10 process 24758  0x00007f65e3035131 in nanosleep ()
  from /lib/libpthread.so.0
 9 process 24759  0x00007f65e3035131 in nanosleep ()
  from /lib/libpthread.so.0
 8 process 24760  0x00007f65e3035131 in nanosleep ()
  from /lib/libpthread.so.0
 7 process 24756  0x00007f65e302e99d in pthread_join ()
  from /lib/libpthread.so.0
 6 process 24999  0x00007f65e25cac91 in nanosleep () from /lib/libc.so.6
 5 process 25000  0x00007f65e25f2f82 in select () from /lib/libc.so.6
 4 process 25001  0x00007f65e3035131 in nanosleep ()
  from /lib/libpthread.so.0
 3 process 25002  0x00007f65e25f9cd8 in epoll_wait () from /lib/libc.so.6
 2 process 25003  0x00007f65e25f9cd8 in epoll_wait () from /lib/libc.so.6
* 1 process 24998  0x00007f65e255ff55 in raise () from /lib/libc.so.6
... a lot more text ...

the numbered list shows all running processes and what method they are currently in. * shows you where the crash occured. so in rest of dump only is interesting what happens in process 1 (24998)

So you scroll through file until you get to

Thread 1 (process 24998):
#0  0x00007f65e255ff55 in raise () from /lib/libc.so.6
No symbol table info available.
#1  0x00007f65e2562d90 in abort () from /lib/libc.so.6
No symbol table info available.
#2  0x00007f65e255907a in __assert_fail () from /lib/libc.so.6
No symbol table info available.
#3  0x00000000004fbcce in Map::getNGrid (this=<value optimized out>, 
   x=<value optimized out>, y=<value optimized out>)
   at ../../../src/game/Map.h:451
   st = {static SYMBUFSIZ = 4096, 
 buf_ = "/home/gcuser/gc_mangos/mangos_server/bin/mangos-worldd(_ZNK3Map9GetHeightEfffb+0x8f) [0x5fbaff]\\n/home/gcuser/gc_mangos/mangos_server/bin/mangos-worldd(_ZNK11WorldObject21UpdateGroundPositionZEffRf+0x4"..., buflen_ = 1754, 
 static UNSUPPORTED = 0x7f65e46075e0 "<stack traces unsupported platform>", 
 static UNABLE_TO_GET_TRACE = 0x7f65e4607610 "<unable to get trace>"}
   __FUNCTION__ = "getNGrid"
   __PRETTY_FUNCTION__ = "NGridType* Map::getNGrid(uint32, uint32) const"
#4  0x00000000005f9c4a in Map::EnsureGridCreated (this=0x60b4, 
   p=@0x7f65d92afae0) at ../../../src/game/Map.cpp:354
No locals.
#5  0x00000000005fbaff in Map::GetHeight (this=0x60b4, x=-nan(0x400000), 
   y=-nan(0x400000), z=110.864998, pUseVmaps=true)
   at ../../../src/game/Map.cpp:1639
   gmap = <value optimized out>
   mapHeight = <value optimized out>
   vmapHeight = <value optimized out>
#6  0x000000000061ef42 in WorldObject::UpdateGroundPositionZ (
   this=<value optimized out>, x=-nan(0x400000), y=-nan(0x400000), 
   z=@0x7f65d92afbdc) at ../../../src/game/Object.cpp:1467
   new_z = 9.14767638e-41
#7  0x000000000076d6cd in Unit::KnockBackFrom (this=0x7f65bf674d60, 
   target=<value optimized out>, horizontalSpeed=0, verticalSpeed=0)
   at ../../../src/game/Unit.cpp:14069
   fx = -nan(0x400000)
   fz = 110.864998
   fy2 = nan(0x400000)
   dis = <value optimized out>
   fy = -nan(0x400000)
   fx2 = nan(0x400000)
   fz2 = 0
   angle = <value optimized out>
#8  0x00000000006ffa9a in Spell::DoSpellHitOnUnit (this=0x7f65b64711f0, 
   unit=0x7f65bf674d60, effectMask=1) at ../../../src/game/Spell.cpp:1162
   effectNumber = 0
   realCaster = (class Unit *) 0x7f65bf6773f0
#9  0x000000000070013b in Spell::DoAllEffectOnTarget (this=0x7f65b64711f0, 
   target=0x7f65b64036e0) at ../../../src/game/Spell.cpp:961
   mask = 6
   unit = (class Unit *) 0x7f65bf674d60
   real_caster = (class Unit *) 0x7f65bf6773f0
   caster = (class Unit *) 0x7f65bf6773f0
   missInfo = SPELL_MISS_NONE
   procAttacker = 256
   procVictim = 512
   procEx = <value optimized out>
#10 0x000000000070ed6c in Spell::handle_delayed (this=0x7f65b64711f0, 
   t_offset=850) at ../../../src/game/Spell.cpp:2825
   next_time = 0
#11 0x000000000070fa5e in SpellEvent::Execute (this=0x7f65c02b4950, 
   e_time=121621, p_time=<value optimized out>)
   at ../../../src/game/Spell.cpp:6271
   n_offset = <value optimized out>
#12 0x00000000008484ef in EventProcessor::Update (this=0x7f65bf677500, 
   p_time=101) at ../../../src/framework/Utilities/EventProcessor.cpp:47
   Event = (BasicEvent *) 0x7f65c02b4950
#13 0x000000000076cc5c in Unit::Update (this=0x7f65bf6773f0, p_time=101)
   at ../../../src/game/Unit.cpp:319
No locals.
#14 0x0000000000538cdb in Creature::Update (this=0x7f65bf6773f0, diff=101)
   at ../../../src/game/Creature.cpp:468
No locals.
#15 0x00000000006092a6 in VisitorHelper<MaNGOS::ObjectUpdater, Creature> (
   v=@0x7f65d92aff90, c=<value optimized out>)
   at ../../../src/game/GridNotifiersImpl.h:48
No locals.
#16 0x000000000060839c in Map::Update (this=0x7f65ddc07a40, 
   t_diff=@0x7f65d92affec)
   at ../../../src/game/../framework/GameSystem/TypeContainerVisitor.h:53
   cell = {data = {Part = {grid_x = 24, grid_y = 36, cell_x = 3, 
     cell_y = 0, nocreate = 1, reserved = 16}, All = 553662744}}
   y = 288
   x = 195
   plr = <value optimized out>
   area = {right_offset = 2, left_offset = 1, upper_offset = 1, 
 lower_offset = 2}
   updater = {i_timeDiff = 101}
   grid_object_update = {i_visitor = @0x7f65d92aff90}
   world_object_update = {i_visitor = @0x7f65d92aff90}
   __PRETTY_FUNCTION__ = "virtual void Map::Update(const uint32&)"
#17 0x0000000000612967 in MapManager::Update (this=0x7f65ddbd3790, 
   diff=<value optimized out>) at ../../../src/game/MapManager.cpp:258
No locals.
#18 0x000000000078c5c4 in World::Update (this=0x7f65dc0193f0, diff=39)
   at ../../../src/game/World.cpp:1416
No locals.
#19 0x00000000004f1a51 in WorldRunnable::run (this=<value optimized out>)
   at ../../../src/mangosd/WorldRunnable.cpp:60
   diff = 39
   realCurrTime = 4154334358
   realPrevTime = <value optimized out>
   prevSleepTime = 37
#20 0x000000000082d75c in ACE_Based::Thread::ThreadTask (param=0x60b4)
   at ../../../src/shared/Threading.cpp:183
   _task = (class ACE_Based::Runnable *) 0x7f65de8becd0
#21 0x00007f65e302d73a in start_thread () from /lib/libpthread.so.0
No symbol table info available.
#22 0x00007f65e25f969d in clone () from /lib/libc.so.6
No symbol table info available.
#23 0x0000000000000000 in ?? ()
No symbol table info available.

This is a stacktrace. Shows you the calling three of current execution. The error occurs in item furthest down, here: raise(). This is just helper function though to raise a exception. First real mangos method found in three (going upwards) is

#3  0x00000000004fbcce in Map::getNGrid (this=<value optimized out>, 
   x=<value optimized out>, y=<value optimized out>)

Since all is optimized out it doesn't help much.

But more upwards we can see what methods called this one and by who they where called. Finally we get to

#5  0x00000000005fbaff in Map::GetHeight (this=0x60b4, x=-nan(0x400000), 
   y=-nan(0x400000), z=110.864998, pUseVmaps=true)
   at ../../../src/game/Map.cpp:1639

This looks weird, why should mangos try to getHeight with a not avaible x and y value? if we look further up we find

#7  0x000000000076d6cd in Unit::KnockBackFrom (this=0x7f65bf674d60, 
   target=<value optimized out>, horizontalSpeed=0, verticalSpeed=0)
   at ../../../src/game/Unit.cpp:14069
   fx = -nan(0x400000)
   fz = 110.864998
   fy2 = nan(0x400000)
   dis = <value optimized out>
   fy = -nan(0x400000)
   fx2 = nan(0x400000)
   fz2 = 0
   angle = <value optimized out>

And see here that in line 14069 of file unit.cpp the method further down callstack is called and local

variables are already NaN.

// line 14052 to 14074
float g = 19.23f;// seems that physic constant g(earth's gravity) in world of warcraft is about 2 times larger than real
       float dh = verticalSpeed*verticalSpeed / (2*g); // maximum parabola height
       float time = sqrtf(dh/(0.124976 * verticalSpeed)); //full move time in seconds // should be time = 2*Vert_speed/g, but..

       float dis = time * horizontalSpeed;

       float ox, oy, oz;
       GetPosition(ox, oy, oz);

       float fx = ox + dis * vcos;
       float fy = oy + dis * vsin;
       float fz = oz;

       float fx2, fy2, fz2; // getObjectHitPos overwrite last args in any result case
       if(VMAP::VMapFactory::createOrGetVMapManager()->getObjectHitPos(GetMapId(), ox,oy,oz+0.5f, fx,fy,oz+0.5f,fx2,fy2,fz2, -0.5f))
       {
           fx = fx2;
           fy = fy2;
           fz = fz2;
       }

then you just need to find what is actually wrong and then lastly you finally fix bug and everyone is happy:

http://github.com/gc/mangos/commit/a235c807651f65f377aa11e85fa5e974dcfb2bf6

hope that helps

[rusfighter]

Thx for your reply , i still dont understand it exactly because i dont get the first code that you have i just get this

[New Thread 18977]
[New Thread 18976]
[New Thread 18975]
[New Thread 18974]
[New Thread 18973]
[New Thread 18972]
[New Thread 18971]
[New Thread 18964]
[New Thread 18968]
[New Thread 18967]
[New Thread 18966]
Core was generated by `/home/Luwow/server/bin/funserver -c ../etc/mangosd.conf'.
Program terminated with signal 11, Segmentation fault.
#0  std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>::_M_find_node (
   this=0xa9fed58, pl=0xa0567390, update_players=...)
   at /usr/include/c++/4.3/tr1_impl/hashtable:896
896        if (this->_M_compare(__k, __code, __p))
#0  std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>::_M_find_node (
   this=0xa9fed58, pl=0xa0567390, update_players=...)
   at /usr/include/c++/4.3/tr1_impl/hashtable:896
No locals.
#1  std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>::find (this=0xa9fed58, 
   pl=0xa0567390, update_players=...)
   at /usr/include/c++/4.3/tr1_impl/hashtable:764
No locals.
#2  Object::BuildUpdateDataForPlayer (this=0xa9fed58, pl=0xa0567390, 
   update_players=...) at ../../../src/game/Object.cpp:1059
       __PRETTY_FUNCTION__ = "void Object::BuildUpdateDataForPlayer(Player*, UpdateDataMapType&)"
#3  0x0825a6ab in void Map::Visit<WorldObjectChangeAccumulator, TypeMapContainer<TypeList<Player, TypeList<Creature, TypeList<Corpse, TypeNull> > > > >(Cell const&, TypeContainerVisitor<WorldObjectChangeAccumulator, TypeMapContainer<TypeList<Player, TypeList<Creature, TypeList<Corpse, TypeNull> > > > >&) ()
No symbol table info available.
#4  0x08257842 in Visit<WorldObjectChangeAccumulator, TypeMapContainer<TypeList<Player, TypeList<Creature, TypeList<Corpse, TypeNull> > > > > (this=0xa9fed58, 
   update_players=...) at ../../../src/game/CellImpl.h:210
No locals.
#5  WorldObject::BuildUpdateData (this=0xa9fed58, update_players=...)
   at ../../../src/game/Object.cpp:1957
       cell = {data = {Part = {grid_x = 6, grid_y = 32, cell_x = 7, 
             cell_y = 1, nocreate = 1, reserved = 31}, All = 1057257478}}
       notifier = {i_updateDatas = @0xa7bff120, i_object = @0xa9fed58}
       player_notifier = {i_visitor = @0xa7bff0a8}
       aMap = 0xad900018
#6  0x08229912 in Map::SendObjectUpdates (this=0xad900018)
   at ../../../src/game/Map.cpp:3568
       update_players = {<std::tr1::__unordered_map<Player*, UpdateData, std::tr1::hash<Player*>, std::equal_to<Player*>, std::allocator<std::Pair<Player* const, UpdateData> >, false>> = {<std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>> = {<std::tr1::__detail::_Rehash_base<std::tr1::__detail::_Prime_rehash_policy, std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true> >> = {<No data fields>}, <std::tr1::__detail::_Hash_code_base<Player*, std::Pair<Player* const, UpdateData>, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, false>> = {
               _M_extract = {<std::unary_function<std::Pair<Player* const, UpdateData>, Player* const>> = {<No data fields>}, <No data fields>}, 
               _M_eq = {<std::binary_function<Player*, Player*, bool>> = {<No data fields>}, <No data fields>}, 
               _M_h1 = {<std::unary_function<Player*, unsigned int>> = {<No data fields>}, <No data fields>}, 
               _M_h2 = {<No data fields>}}, <std::tr1::__detail::_Map_base<Player*, std::Pair<Player* const, UpdateData>, std::_Select1st<std::Pair<Player* const, UpdateData> >, true, std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true> >> = {<No data fields>}, 
             _M_node_allocator = {<__gnu_cxx::new_allocator<std::tr1::__detail::_Hash_node<std::Pair<Player* const, UpdateData>, false> >> = {<No data fields>}, <No data fields>}, _M_buckets = 0xa0598e68, _M_bucket_count = 11, 
             _M_element_count = 1, _M_rehash_policy = {
               _M_max_load_factor = 1, _M_growth_factor = 2, 
               _M_next_resize = 11}}, <No data fields>}, <No data fields>}
       packet = {<ByteBuffer> = {static DEFAULT_SIZE = 4096, _rpos = 2, 
           _wpos = 1065353216, 
           _storage = {<std::_Vector_base<unsigned char, std::allocator<unsigned char> >> = {
               _M_impl = {<std::allocator<unsigned char>> = {<__gnu_cxx::new_allocator<unsigned char>> = {<No data fields>}, <No data fields>}, 
                 _M_start = 0x2 <Address 0x2 out of bounds>, 
                 _M_finish = 0x37f0c7f <Address 0x37f0c7f out of bounds>, 
                 _M_end_of_storage = 0xad900018 "\\b\\206K\\b¸o\\215\\n"}}, <No data fields>}}, m_opcode = 7}
#7  0x08235703 in Map::Update (this=0xad900018, t_diff=@0xa0ebbbd0)
   at ../../../src/game/Map.cpp:698
       updater = {i_timeDiff = 101}
       grid_object_update = {i_visitor = @0xa7bff2bc}
       world_object_update = {i_visitor = @0xa7bff2bc}
       __PRETTY_FUNCTION__ = "virtual void Map::Update(const uint32&)"
#8  0x0824352c in MapUpdateRequest::call (this=0xa0ebbbc0)
   at ../../../src/game/MapUpdater.cpp:47
No locals.
#9  0x084514b8 in DelayExecutor::svc (this=0xadc01108)
   at ../../../src/shared/DelayExecutor.cpp:60
       rq = 0xa0ebbbc0
#10 0xb7eb0952 in ACE_Task_Base::svc_run (args=0xadc01108)
   at ../../ace/Task.cpp:275
       svc_status = <value optimized out>
#11 0xb7eb1e1d in ACE_Thread_Adapter::invoke_i (this=0xae17c608)
   at ../../ace/Thread_Adapter.cpp:149
       hook = 0x4548a1c3
       func = 0xb7eb0900 <ACE_Task_Base::svc_run(void*)>
       arg = 0xadc01108
       status = 0xe937ede
#12 0xb7eb1e96 in ACE_Thread_Adapter::invoke (this=0xae17c608)
   at ../../ace/Thread_Adapter.cpp:98
       exit_hook_instance = 0x8f93070
       exit_hook_maybe = {instance_ = 0x0}
       exit_hook_ptr = <value optimized out>
#13 0xb7e0f0d1 in ace_thread_adapter (args=0xae17c608)
   at ../../ace/Base_Thread_Adapter.cpp:124
       status = 0xe937ede
#14 0xb78504c0 in start_thread () from /lib/i686/cmov/libpthread.so.0
No symbol table info available.
#15 0xb76ad6de in clone () from /lib/i686/cmov/libc.so.6
No symbol table info available.

[Gotisch]

well you might want to look at

#2  Object::BuildUpdateDataForPlayer (this=0xa9fed58, pl=0xa0567390,
   update_players=...) at ../../../src/game/Object.cpp:1059

Tbh. i dont know enough about c++ what segmentation fault in context of

Program terminated with signal 11, Segmentation fault.
#0  std::tr1::_Hashtable<Player*, std::Pair<Player* const, UpdateData>, std::allocator<std::Pair<Player* const, UpdateData> >, std::_Select1st<std::Pair<Player* const, UpdateData> >, std::equal_to<Player*>, std::tr1::hash<Player*>, std::tr1::__detail::_Mod_range_hashing, std::tr1::__detail::_Default_ranged_hash, std::tr1::__detail::_Prime_rehash_policy, false, false, true>::_M_find_node (
   this=0xa9fed58, pl=0xa0567390, update_players=...)
   at /usr/include/c++/4.3/tr1_impl/hashtable:896

But irrc segmentation fault means you try to access memory that you are not allowed to access.