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I am new to this unix and gdb. I have a coredump file generated.I am using gdb to debug, but there is no meaningful information found. I am getting output as 

(gdb) thread apply all bt full 

Thread 7 (LWP 12190):
#0  0x00007fa2eae29896 in ?? ()
No symbol table info available.
#1  0x000000000000019a in ?? ()
No symbol table info available.
#2  0x00007fa2e9906ce0 in ?? ()
No symbol table info available.

There are 7 seven threads. and for all I am getting the same. I am not getting the way forward to proceed.Please help me. OR please explain me what does this mean.

Armali
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user3913114
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  • possible duplicate of [gdb no symbol table loaded for core file](http://stackoverflow.com/questions/11935075/gdb-no-symbol-table-loaded-for-core-file) – TartanLlama Sep 08 '14 at 09:15

1 Answers1

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This means that there is not a symbol table loaded for the coredump. Chances are you invoked gdb directly on the coredump rather than like this:

gdb <executable> <coredump>
TartanLlama
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  • Thank you for your response. Ya I have invoked gdb directly on coredump. Bec I dont get executable. Their will be a coredump file generated remotely, which I copied and debuged in locally. – user3913114 Sep 08 '14 at 09:24
  • In order to debug the coredump, you need access to an executable built with debug symbols, otherwise the data is meaningless. – TartanLlama Sep 08 '14 at 09:29
  • Now, gdb /opt/bin/ core.old.2014 is the command i gave. Which means i gave execuatable rite? even then their is no meaningful data found. I am still getting the same error – user3913114 Sep 08 '14 at 09:49
  • `/opt/bin/` is a directory, not an executable. You need the program which the dump was generated from. – TartanLlama Sep 08 '14 at 09:51
  • No in this directory only all the executable are saved. I work on a big code where all the binaries will be saved in this path. so i gave the path followed by coredump name. – user3913114 Sep 08 '14 at 09:54
  • You need to point _directly_ at the program the coredump was generated from, otherwise, how would gdb know where to look for symbols or how to resolve name conflicts? – TartanLlama Sep 08 '14 at 09:56
  • Ya I gave correct command.But i end up in same output. Please tel me the way to dig up this problem. Where no stack trace is found. what should i do to get proper info – user3913114 Sep 08 '14 at 10:19
  • Assuming that you are now passing the correct executable to gdb, that executable may not have been compiled with debug symbols (-g). – TartanLlama Sep 08 '14 at 10:24
  • Hi Tartan. According to your suggestion, I made the executable compiled with -g. and checked for the coredump. But i got the same output. No changes:( – user3913114 Sep 09 '14 at 04:44
  • Edit your compiler and gdb invocations into your question, that should give me more information. – TartanLlama Sep 09 '14 at 07:50
  • For for disturbing you again. And thanks for your reply.Actually i am using cmake then make, so i checked in cmake file and saw i am using -g flag also. Its just my bad luck that their is no back trace – user3913114 Sep 09 '14 at 11:00
  • If you `dwarfdump` the executable do you get any symbols out? – TartanLlama Sep 09 '14 at 11:01
  • what will dwarfdump do?sorry i dont know.:( – user3913114 Sep 09 '14 at 11:11