Messages in this thread | | | Subject | Re: [PATCH 0/3] arm64:msr: Add MSR driver | From | Rongwei Wang <> | Date | Thu, 3 Dec 2020 10:09:36 +0800 |
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> 2020年12月1日 下午11:25,Borislav Petkov <bp@alien8.de> 写道: > > On Tue, Dec 01, 2020 at 11:17:39PM +0800, Rongwei Wang wrote: >> In ARM, the system registers can only be accessed through msr and mrs, >> so the problem created by MSR driver (depend on rdmsr and wrmsr) in >> x86 is not necessarily present in ARM, which is very different from >> x86. > > No, the point I'm making is that it doesn't matter what the architecture > does or does not, register *writes* from userspace are a bad bad idea > for the reasons I described. Sorry, I was away for two days and didn't reply in time. In fact, we find MSR in the x86 architecture to be a particularly useful interface. It helped us a lot when we were doing some kernel debugging. So we consider implementing a similar feature in ARM. So as a debugging tool, could it exist, e.g. if I change CONFIG_ARM64_MSR to CONFIG_ARM64_MSR_DEBUG or others. Do you think this adjustment is possible? > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette
Regards, Rongwei Wang.
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