No existing RISC-V designs are susceptible to Spectre. There's nothing in the RISC-V ISA that makes it magically immune to Spectre. If someone implements a RISC-V CPU that has speculative execution and caches, then it's open to Spectre-class attacks, unless specific (expensive) steps are taken to block them.
Some ARM CPUs have Spectre vulnerabilities. Others do not, and the ARM whitepaper on Spectre describes the mitigations they've already designed for the Spectre variants described in the original Spectre paper.
No non-Intel CPUs are susceptible to Meltdown, as far as I've seen; Meltdown is a specific design error, allowing speculative loads across privilege boundaries, while Spectre is a family of issues with speculative execution and side channels.
Freedom demands Open Hardware also (Score:0)
OpenCores.org
J-Core.org
riscv.org
gaisler.com
OpenSPARC
There is a path forward, but it will take Fab relationships and people willing to test and then buy the first practical and fully open systems...
Re: (Score:4, Informative)
Not sure about others but some are available for purchase.
"SiFive has declared that 2018 will be the year of RISC V Linux processors" [slashdot.org] - Linux Now Has its First Open Source RISC-V Processor, Slashdot.
To answer AC's question a few moths later: "What's the big advantage with RISC over ARM or x86?"
Meltdown, Spetre.
Re:Freedom demands Open Hardware also (Score:1)
No existing RISC-V designs are susceptible to Spectre. There's nothing in the RISC-V ISA that makes it magically immune to Spectre. If someone implements a RISC-V CPU that has speculative execution and caches, then it's open to Spectre-class attacks, unless specific (expensive) steps are taken to block them.
Some ARM CPUs have Spectre vulnerabilities. Others do not, and the ARM whitepaper on Spectre describes the mitigations they've already designed for the Spectre variants described in the original Spectre paper.
No non-Intel CPUs are susceptible to Meltdown, as far as I've seen; Meltdown is a specific design error, allowing speculative loads across privilege boundaries, while Spectre is a family of issues with speculative execution and side channels.