New round of 64-bit ARM Patches Merged into Linux 4.19 Kernel, Includes GCC Stackleak Plugin Support

A new round of changes for 64-bit ARM architecture (ARM64/AArch64) were just loaded into the Linux 4.19 kernel merge window, and its generally some pretty good stuff being included.

The 64-bit ARM space on Linux as been fairly busy, and there’s likely more to come before Linux 4.19 kernel is released.

Some highlights of the 64-bit ARM merges include:

  • ARM64 support for the new GCC STACKLEAK plug-inthat was merged into gcc-plugins for Linux 4.19. The STACKLEAK compiler plug-in is able to fend off possible flaws/attacks pertaining to uninitialized stack usage, stack content leaking, and stack exhaustion/guard-page skipping. This mainline kernel STACKLEAK was ported from old GrSecurity/PaX code.
  • Support for the Restartable Sequences system call. This new system call was originally added in Linux 4.18 and “RSEQ” allows for faster user-space operations on per-CPU data by providing a shared data structure ABI between each user-space thread and the kernel.
  • A rewrite of their syscall entry code in C in order to zero out the GPR registers on entry from user-space.
  • Kexec and Kdump now work on systems started without ACPI support.
  • Qspinlock to replace their old ticket lock code.
  • Support for chained PMU counters.
  • Re-enabled support for huge vmalloc/IO mappings.

To see the full changelog for this list of patches, check out the kernel mailing list.

Kamil Anwar
Kamil is a certified MCITP, CCNA (W), CCNA (S) and a former British Computer Society Member with over 9 years of experience Configuring, Deploying and Managing Switches, Firewalls and Domain Controllers also an old-school still active on FreeNode.