Can some please help me to understand this:-
(gdb) info frame Stack level 0, frame at 0xb75f7390: eip = 0x804877f in base::func() (testing.cpp:16); saved ei
To understand what "ebp, eip Locals at and Previous Frame's sp" mean, you need to understand the x86 calling convention.
Once you understand how frames are laid out, all the other things will be obvious.