objdump — security analysis and diagnostics

A fundamental GNU binutils tool for displaying sections, symbols, and disassembly of executable and object files.

Basic information

What is this program?

objdump is a command-line tool included in GNU binutils that prints section lists, symbol tables, and disassembly code of executable and object files (.o) in a human-readable form.

It is used as a basic tool when checking whether a compiled result was produced as intended (whether symbols remain, which libraries are linked), and when tracing link problems caused by library errors. It is also a familiar name to server administrators who inspect server programs built with gcc.

What problems does it solve?

• When you need to verify that a built executable or object file has the correct structure.
• When you need to narrow down which function or code line an address in a crash log corresponds to.
• When you need to check which symbols and sections remain in a binary (such as whether debug symbols have been removed).
• When you need to record disassembly results as documentation or reports on a file basis without GDB.

Key features

Section and header information

Use the -h option to print the section list along with sizes and flags.

• Use case: Check the .text, .data, and .bss layout of an ELF file.
• What you get: A table of section layout and sizes.
• Limitations: readelf and GDB provide more detailed information for in-depth analysis.

Disassembly

Use the -d option to convert a specified section from machine code to assembly.

• Use case: Examine code near the address where a crash occurred.
• What you get: The assembly instructions and symbol labels at that address.
• Limitations: Output can reach millions of lines, so piping through grep and less is essential.

Symbol table output

Use -t to print the symbol list and -T to print dynamic symbols.

• Use case: Check dynamic linking targets (library functions).
• What you get: Narrow down the cause of link errors by checking for undefined symbols.
• Limitations: Stripped binaries have few symbols, so this is limited.

Mixed source display

Use the -S option to interleave source code with disassembly when debug information is present.

• Use case: Inspect a problem reproduced with a debug build at source level.
• What you get: Correspondence between source lines and assembly.
• Limitations: Does not work on binaries with debug information removed.

Installation and usage

Ubuntu / Debian

It is included in the binutils package and usually installed together with gcc.

sudo apt update
sudo apt install binutils

RHEL / CentOS / Fedora

Install binutils from the default repositories.

sudo dnf install binutils

Version check

Check the installed version and compare it with the latest official version.

objdump --version | head -1

Practical usage examples

Check section list

Examine the section layout of an ELF file.

objdump -h ./app-server

Disassembly (example)

Disassemble around the main symbol. The output is an example.

objdump -d --disassemble=main ./app-server

Check dynamic symbols

View the list of dynamically linked functions.

objdump -T ./app-server | head

Advantages and limitations

Advantages

• It is included by default in almost all Linux development and build environments, so there is no installation burden.
• It provides sufficient functionality for file-level static analysis from the command line.
• As a standard binutils component alongside GDB and readelf, it has abundant documentation and resources.
• It is freely used and redistributed under the GPL license.

Considerations before use

• It has no GUI or decompilation capabilities, so understanding at the human-code level requires additional tools.
• Large binaries produce massive output, requiring filtering skills.
• Symbol-based disassembly is limited for stripped files.
• PE and Mach-O support can be limited compared to ELF.

Comparison with similar programs

Official resources and further learning

• Official homepage — https://www.gnu.org/software/binutils/
• Official documentation / knowledge base — https://sourceware.org/binutils/docs/
• Official download — https://ftp.gnu.org/gnu/binutils/
• Release notes — https://sourceware.org/pipermail/binutils/
• Source / development resources — https://sourceware.org/git/binutils-gdb.git

Version and supported environment information is based on the official site as of 2026-10-18. Installation commands may vary depending on the distribution and version you use, so please also check the official installation documentation.

Actual execution screen

This is a synthetic example reconstructing the objdump section header output (-h) in a server-style view. The screen is a synthetic example and is not an actual execution result.

!objdump -h ELF section list output: a terminal showing sections such as .interp and .note

Actual production server

Source (HTML): https://games.aidebatehub.com/programs/apps/security/objdump.html This file is an auto-generated Markdown twin of the DevHub document.