KernelNewbies:

Linux 5.4 changelog.

This release includes the kernel lockdown mode, intended to strengthen the boundary between UID 0 and the kernel; virtio-fs, a high-performance virtio driver which allows a virtualized guest to mount a directory that has been exported on the host;

1. Coolest features

1.1. Kernel lockdown mode

This release introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 (root) and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The original purpose of this feature was to honour the anti-tampering protections expected in a secure-boot environment, but it is not tied to that. The majority of mainstream distributions have been carrying variants of this patchset for many years now.

Kernel lockdown is implemented as a Linux Security Module that can be configured in integrity or lockdown mode. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. Configuration can be done at runtime (through securityfs), boot time (via a kernel parameter) or build time (via a kconfig option).

Recommended LWN article: Lockdown as a security module

1.2. virtio-fs, a bridge to share file systems with virtualized guests

This release includes virtio-fs, a FUSE-based virtio driver for guest <-> host file system sharing. It allows a guest to mount a directory that has been exported on the host. Although there are existing technologies that allow this kind of funcionality (NFS, virtio-9P), virtio-fs takes advantage of the proximity of VMs to achieve API semantics and performance more like local file systems. This is desirable both for performance and for application compatibility.

For more details, see the documentation, the design documentation and the official web site

2. Core (various)

3. File systems

4. Memory management

5. Block layer

6. Tracing, perf and BPF

7. Virtualization

8. Cryptography

9. Security

10. Power Management

11. Networking

12. Architectures

13. Drivers

13.1. Graphics

13.2. Storage

13.3. Drivers in the Staging area

13.4. Networking

13.5. Audio

13.6. Tablets, touch screens, keyboards, mouses

13.7. TV tuners, webcams, video capturers

13.8. Universal Serial Bus

13.9. Serial Peripheral Interface (SPI)

13.10. Watchdog

13.11. Serial

13.12. CPU Frequency Scaling

13.13. Device Voltage and Frequency Scaling

13.14. Real Time Clock (RTC)

13.15. Voltage, current regulators, power capping, power supply

13.16. Pin Controllers (pinctrl)

13.17. Multi Media Card (MMC)

13.18. Memory Technology Devices (MTD)

13.19. Industrial I/O (iio)

13.20. Multi Function Devices (MFD)

13.21. Pulse-Width Modulation (PWM)

13.22. Inter-Integrated Circuit (I2C + I3C)

13.23. Hardware monitoring (hwmon)

13.24. General Purpose I/O (gpio)

13.25. Leds

13.26. DMA engines

13.27. Cryptography hardware acceleration

13.28. PCI

13.29. Non-Transparent Bridge (NTB)

13.30. Thunderbolt

13.31. Clock

13.32. PHY ("physical layer" framework)

13.33. EDAC (Error Detection And Correction)

13.34. Various

14. List of Pull Requests

15. Other news sites

KernelNewbies: Linux_5.4 (last edited 2019-11-24 22:37:09 by diegocalleja)