What’s New in Linux Kernel 5.4? Key Features and Improvements Explained

Linux Kernel 5.4 Overview

Linux Kernel 5.4, released in 2019, is the final major stable kernel of that year. It introduces a set of security, filesystem, graphics, and hardware‑support changes that affect both downstream distributions and end‑users.

Kernel Lock‑down Feature

The lock‑down mode hardens the kernel by restricting privileged operations that could be abused by compromised user‑space code. Two mutually exclusive modes are defined:

Integrity mode – disables all kernel interfaces that allow modification of the running kernel image (e.g., kexec, module loading, firmware loading from user space).

Confidentiality mode – disables interfaces that can expose kernel memory or secret material (e.g., /proc/kcore, debugfs access to raw memory, certain perf events).

By default the lock‑down module is disabled; it is intended for OEMs and enterprise‑focused distributions that need a stronger root‑of‑trust.

Native exFAT Support

Microsoft released the exFAT source code under the MIT license. Starting with kernel 5.4 the exfat driver is merged into the mainline tree, providing read/write access to exFAT partitions without external FUSE modules. This removes the previous 4 GB file‑size limitation on Linux when using exFAT‑formatted USB drives.

AMDGPU / Radeon Graphics Improvements

The AMDGPU DRM driver receives several enhancements:

Performance optimisations for existing Radeon GPUs.

Support for upcoming AMD APUs – codename Dali and Renoir – including power‑management and display‑engine updates.

Improved handling of GPU resets and better integration with the Linux graphics stack.

Early testing on Phoronix’s 5.4 builds reported measurable frame‑rate gains in OpenGL and Vulkan workloads.

Additional Notable Changes

Kernel 5.4 adds a broad set of hardware enablements and subsystem updates:

Support for Qualcomm Snapdragon 855 SoC.

Updated Intel GPU drivers and minor GPU performance tweaks.

Full mainline kernel support on ARM‑based consumer laptops.

Intel Ice Lake Thunderbolt controller support.

Driver for FlySky FS‑iA6B drone receiver.

VirtIO‑FS implementation, enabling shared directories between host and guest VMs.

Wine/Proton compatibility fixes for Windows games.

Enhanced FSCRYPT integration for per‑file encryption.

Various bug‑fixes and performance improvements were also back‑ported to existing filesystems such as Btrfs.

Acquisition

Linux distributions typically provide kernel 5.4 through their package managers. Advanced users can compile the kernel manually from

git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

(tag v5.4) and install it with

make defconfig
make -j$(nproc)
sudo make modules_install install

, but this is not required for most users.