termux-elf-cleaner

Utility for Android ELF files to remove unused parts that the linker warns about.

WARNING: This repo is strictly for Android 5.x

This repo is targated for Android 5.x , hence it removes dynamic section entries that are not supported in Android 5.x. Some of which are supported/may be required in Android 6.0 and later versions. So it is advised not to use this tool IF you are running Android version 6.0 or higher.

Description

When loading ELF files, the Android linker warns about unsupported dynamic section entries with warnings such as:

WARNING: linker: /data/data/org.kost.nmap.android.networkmapper/bin/nmap: unused DT entry: type 0x6ffffffe arg 0x8a7d4
WARNING: linker: /data/data/org.kost.nmap.android.networkmapper/bin/nmap: unused DT entry: type 0x6fffffff arg 0x3

This utility strips away the following dynamic section entries:

• DT_RPATH -------- not supported in any Android version.
• DT_RUNPATH ----- supported from Android 7.0.
• DT_VERDEF ------ supported from Android 6.0.
• DT_VERDEFNUM -- supported from Android 6.0.
• DT_VERNEEDED--- supported from Android 6.0.
• DT_VERNEEDNUM-- supported from Android 6.0.
• DT_VERSYM ------- supported from Android 6.0.
• DT_GNU_HASH ---- causes warnings in Android 5.x
• DF_1_NODELETE-- supported from Android 6.0. Causes warnings in Android 5.x.

It also removes the three ELF sections of type:

• SHT_GNU_verdef
• SHT_GNU_verneed
• SHT_GNU_versym

Usage

usage: termux-elf-cleaner <filenames>

Processes ELF files to remove unsupported section types and
dynamic section entries which the Android linker warns about.

Author

Fredrik Fornwall (@fornwall).