RISC-V With Linux 6.7 Gains Optimized TLB Flushing, Software Shadow Call Stacks

Written by Michael Larabel in RISC-V on 10 November 2023 at 01:48 PM EST. 6 Comments
In addition to the many x86/x86_64 and AArch64 improvements this round for Linux 6.7, on the RISC-V architecture side are some exciting kernel advancements too.

On the RISC-V hardware side as already mentioned is initial support for Sophgo RISC-V chips including that forthcoming 64 core RISC-V CPU. On the RISC-V architecture side are also some continued innovations for Linux 6.7.

Milk-V Pioneer

The Milk-V Pioneer is a very interesting 64-bot mATX workstation board that should begin shipping next month at $1499 USD. I've since confirmed there will be review hardware coming to Phoronix for checking out this interesting creation.

Merged last week was support for cbo.zero in user-space, support for CBOs on ACPI-based RISC-V systems, support for software shadow call stacks, improvements for the T-Head cache flushing operations, and other clean-ups and fixes.

This software-based Shadow Call Stack support for RISC-V relies on compiler instrumentation for storing and checking the return memory address for enhancing the security. The RISC-V Shadow Call Stack support as with SCS for other CPU architectures is intended to help fend off accidental or malicious overwrites. The RISC-V SCS support depends on LLVM Clang 17 and later for compiling the kernel with no GCC support currently for this functionality on RISC-V.

Meanwhile sent out today was a secondary pull request of more RISC-V changes for Linux 6.7. This latest pull has support for handling misaligned accesses in S-mode, performance improvements for TLB flushing, support for many new relocations in the module loader, and other enhancements.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via MichaelLarabel.com.

Popular News This Week