ACK/CMNT: [SRU][Xenial][PATCH 1/3] UBUNTU: SAUCE: x86/speculation: Cleanup IBPB runtime control handling

[Juerg Haefliger]

> > +int set_ibpb_enabled(unsigned int val)
> > +{
> > +	int error = 0;
> > +
> > +	mutex_lock(&spec_ctrl_mutex);
> > +
> > +	/* Only enable IBPB if the CPU supports it */
> > +	if (boot_cpu_has(X86_FEATURE_IBPB)) {
> > +		ibpb_enabled = val;
> > +		pr_info("Spectre V2 : Spectre v2 mitigation: %s Indirect "  
> 
> I think the "Spectre V2 : " portion of this message is redundant and is
> also not present in upstream's message which could confuse user or
> scripts that are looking at log messages. Can it be removed when
> applying the patch?

This is exactly how upstream reported it until 5 days ago (commit
4c71a2b6fd7e changed that message format) :-)

$ uname -r
4.18.0-11-generic
$ dmesg | grep 'Spectre V2'
[    0.028000] Spectre V2 : Mitigation: Full generic retpoline
[    0.028000] Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
[    0.028000] Spectre V2 : Spectre v2 mitigation: Enabling Indirect Branch Prediction Barrier
[    0.028000] Spectre V2 : Enabling Restricted Speculation for firmware calls

...Juerg

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