21 Jul
2018
21 Jul
'18
12:48 p.m.
On Fri, 20 Jul 2018 22:02:05 -1000, david wrote:
On 07/19/2018 11:56 PM, Ralf Mardorf wrote:
At the moment I test 'nopti' again for a non-audio session.
[rocketmouse@archlinux ~]$ ls -hAl /sys/devices/system/cpu/vulnerabilities/; cat
/sys/devices/system/cpu/vulnerabilities/*
total 0
-r--r--r-- 1 root root 4.0K Jul 21 02:34 meltdown
-r--r--r-- 1 root root 4.0K Jul 21 02:34 spec_store_bypass
-r--r--r-- 1 root root 4.0K Jul 21 02:34 spectre_v1
-r--r--r-- 1 root root 4.0K Jul 21 02:34 spectre_v2
Vulnerable
Vulnerable
Mitigation: __user pointer sanitization
Mitigation: Full generic retpoline, IBPB, IBRS_FW
It doesn't solve some issues on my machine and at least for non-audio a
possible better performance of my computer isn't of value to disable
PTI.
I'll build 4.16.18-rt10 now, maybe it takes less time than I needed to
build 4.16.18-rt9 with PTI enabled.
Mitigation: PTI
Vulnerable
Mitigation: __user pointer sanitization
Mitigation: Full generic retpoline, IBPB, IBRS_FW
'nopti' only would disable PTI, but keep the spectre mitigations.
While PTI is part of the kernel, the spectre mitigations are likely
part of the µcode. However, if I would run my CPU without the µcode,
I perhaps would get rid of the spectre mitigation, but IIRC I
unfortunately would get rid of TSC, too.
The Spectre mitigations don't seem to affect the performance on my
desktop, which is running with PTI off but with the mitigation
microcode patches. I also have Spectre mitigations on my Intel laptop
with no performance impact.