dl_iterate_phdr - Linux
Overview
dl_iterate_phdr
is a utility that parses ELF executable files and iterates over their program headers. It provides a structured way to examine and extract information from the headers, which are vital for understanding the layout and organization of the executable. This command is particularly useful in debugging, code analysis, and security audits.
Syntax
dl_iterate_phdr [-h] [-v] executable_file
Options/Flags
- -h, –help: Display help and usage information.
- -v, –verbose: Enable verbose output, displaying detailed information about each program header.
Examples
Simple usage:
dl_iterate_phdr example.elf
Extracting specific header data:
dl_iterate_phdr -v example.elf | grep "p_type: PT_LOAD"
Common Issues
- Permission denied: Ensure you have read permissions for the ELF file specified.
- Invalid ELF file: Verify that the provided file is a valid ELF executable.
- No program headers: Some ELF files may not contain program headers. Use
elfdump
to inspect the file structure.
Integration
dl_iterate_phdr
can be integrated with other tools for advanced tasks:
- Disassembly with IDA Pro: Load the executable into IDA Pro and use
-Sdl_iterate_phdr <file>
to parse the program headers and show the segmentation in the debugger. - Binary patching with radare2: Use
dl_iterate_phdr
to identify and modify specific program headers withrabin2 -q -a <executable_file>
.
Related Commands
readelf
: Displays ELF file information, including program headers.elfdump
: Outputs a detailed description of the ELF file structure.file
: Determines the file type of an ELF executable.objdump
: Disassembles and displays the contents of ELF files.