fntlnz

Seccomp BPF filter example

Use bpf programs as filters for seccomp, the one in the example will block all the write syscalls after it's loaded.

Usage

Compile it with just

gcc main.c

nathanchance

Introduction

Google has traditionally been against upgrading the compiler as it comes with new warnings and potentially changes behavior. However, these are actually good reasons to upgrade, they help shake out undefined behavior.

Process

In order to compile with a newer version of GCC, you'll need to do a few modifications to your kernel in addition to a new toolchain. I recommend using the ones available from Bootlin.

1. Remove gcc-wrapper and any instances of -Werror: gcc-wrapper is CAF's shitty way of enabling -Werror, which is unnecessary since regular -Werror will suffice. We need to remove it for the time being because there will be new warnings to fix. Pick Google's revert of it (3.18, 4.4) then remove any other instances of -Werror (such as in prima, qcacld-2.0, and qc