Re: Re: [RESEND PATCH v5 5/5] Documentation/vmcoreinfo: Add documentation for 'TCR_EL1.T1SZ'

[Scott Branden]

Hi Bhupesh,

Would be great to get this patch series upstreamed?

On 2019-12-25 10:49 a.m., Bhupesh Sharma wrote:
> Hi James,
>
> On 12/12/2019 04:02 PM, James Morse wrote:
> > Hi Bhupesh,
>
> I am sorry this review mail skipped my attention due to holidays and 
> focus on other urgent issues.
>
> > On 29/11/2019 19:59, Bhupesh Sharma wrote:
> > > Add documentation for TCR_EL1.T1SZ variable being added to
> > > vmcoreinfo.
> > >
> > > It indicates the size offset of the memory region addressed by 
> > > TTBR1_EL1
> >
> > > and hence can be used for determining the vabits_actual value.
> >
> > used for determining random-internal-kernel-variable, that might not 
> > exist tomorrow.
> >
> > Could you describe how this is useful/necessary if a debugger wants 
> > to walk the page
> > tables from the core file? I think this is a better argument.
> >
> > Wouldn't the documentation be better as part of the patch that adds 
> > the export?
> > (... unless these have to go via different trees? ..)
>
> Ok, will fix the same in v6 version.
>
> > > diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst 
> > > b/Documentation/admin-guide/kdump/vmcoreinfo.rst
> > > index 447b64314f56..f9349f9d3345 100644
> > > --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
> > > +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
> > > @@ -398,6 +398,12 @@ KERNELOFFSET
> > > Â The kernel randomization offset. Used to compute the page offset. If
> > > Â KASLR is disabled, this value is zero.
> > > Â +TCR_EL1.T1SZ
> > > +------------
> > > +
> > > +Indicates the size offset of the memory region addressed by TTBR1_EL1
> >
> > > +and hence can be used for determining the vabits_actual value.
> >
> > 'vabits_actual' may not exist when the next person comes to read this 
> > documentation (its
> > going to rot really quickly).
> >
> > I think the first half of this text is enough to say what this is 
> > for. You should include
> > words to the effect that its the hardware value that goes with 
> > swapper_pg_dir. You may
> > want to point readers to the arm-arm for more details on what the 
> > value means.
>
> Ok, got it. Fixed this in v6, which should be on its way shortly.
I can't seem to find v6?
> Thanks,
> Bhupesh
>
>
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