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Intel Replaces its Buggy Fix for Skylake PCs (zdnet.com)
Intel has released new microcode to address the stability and reboot issues on systems after installing its initial mitigations for Variant 2 of the Meltdown and Spectre attacks. From a report: The stability issues caused by Intel's microcode updates resulted in Lenovo, HP, and Dell halting their deployment of BIOS updates last month as Intel worked to resolve the problems. Intel initially said unexpected reboots were only seen on Broadwell and Haswell chips, but later admitted newer Skylake architecture chips were also affected. Microsoft also said it had also seen Intel's updates cause data loss or corruption in some cases.
It seems to me the best way for Intel to pevent Meltdown exploits is by disabling Intel's TSX functionality (which I believe microcode can do), along with OS logic to terminate processes which generate an excessive number of protection exceptions for the same portion of code. The TSX change will force an exploit to throw exceptions for the indirect-memory access loop that probes for data values, and the OS change will then identify processes incurring these repeated exceptions inside a single block of code and then terminating it.