Disassembly of sections in a c program

Question

I wrote a very basic Hello World program to know about sections. After using objdump I got all sections. I am using ubuntu 12.04.

in output I found it like that :

Disassembly of section .init

Disassembly of section .plt

Disassembly of section .text

__do_global_dtors_aux

Disassembly of section .fini

I want to know what those sections are? what data they store? Specially .plt and .fini. About .init and .text I can guess, but what about others?

first `gcc -o objectfile programname.c` then `objdump objectfile`. — someone, Jul 04 '13 at 10:05

nouney · Accepted Answer · 2013-07-04T09:50:57.940

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You should google it : here is the first result. It's a good start to learn more about ELF format.

About .init and .fini, it's here.

Here is a list of the ELF sections with a brief description.

edited Jul 04 '13 at 09:50

answered Jul 04 '13 at 09:41

nouney

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`dtor` means destructor, and I am using c, then how come I am getting `__do_global_dtors_aux`. Is it destructor or something else? – someone Jul 04 '13 at 09:48
What's your compiler ? – nouney Jul 04 '13 at 09:52
I am using gcc on ubuntu 12.04 – someone Jul 04 '13 at 09:53
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@Krishna Take a look at [question](http://stackoverflow.com/questions/6477494/do-global-dtors-aux-and-do-global-ctors-aux), this may help you. [This one](http://stackoverflow.com/questions/2741417/do-global-dtors-aux-in-c) can be interesting too. – nouney Jul 04 '13 at 09:55
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I googled it and this thread was the first link ¯\\_(ツ)_/¯ – Josh Desmond Apr 04 '20 at 22:51

score 1 · Answer 2 · edited Jun 20 '20 at 09:12

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From this handy page:

The next section I want to mention is the .plt section. This contains the jump table that is used when we call functions in the shared library.

And from this page:

.fini

This section holds executable instructions that contribute to the process termination code. That is, when a program exits normally, the system arranges to execute the code in this section.

edited Jun 20 '20 at 09:12

Community

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answered Jul 04 '13 at 09:43

unwind

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score 0 · Answer 3 · answered Jul 04 '13 at 16:12

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you might find this brief tutorial helpful. It also contains links to related literature.

"The linker demystified, part 1": http://www.rtos.be/?p=2166

I hope it helps.

Fernando

answered Jul 04 '13 at 16:12

Fernando

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Disassembly of sections in a c program

3 Answers3