List command is not loading source code of assembly program in gdb

Question

I am using gdb [7.11.1] kali linux 32-bit when I use list command to lload the source of my assembly program in gdb it displays the following error message: 'No symbol table is loaded. Use the "file" command'

I have tried the command as:

list list line_number

In both the cases the error is same.

Please help me

Thanks! in advance

Answer 1

I use list command to lload the source of my assembly

List command does nothing of the sort. Rather, it lists sources that GDB has already loaded.

as -o progname.o progname.s

In your case, GDB does not load any sources because you compiled your program without any debug info. You likely want:

as -g -o progname.o progname.s

From man as :

  -g
   --gen-debug
       Generate debugging information for each assembler source line
       using whichever debug format is preferred by the target.  This
       currently means either STABS, ECOFF or DWARF2.

Answer 2

I was incurring same problem while I was trying to debug my c code for buffer overflow stuffs. That error rises because of clean compiling without generating any debug info. For c program, rather than normal compiling as gcc program.c try to run gcc -g -fno-stack-protector -z exec stack -o buffer program.c .

-g tells GCC to add extra information for GDB
-fno-stack-protector flag to turn off stack protection mechanism
-z execstack , it makes stack executable

This command will create a buffer binary file of your c program and hence it will fulfil all the criteria for running the list command in gdb.
Start the gdb with gdb ./buffer then type list command. It will work!!