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

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:

quoted

Hi Bhupesh,

I am sorry this review mail skipped my attention due to holidays and 
focus on other urgent issues.

quoted

On 29/11/2019 19:59, Bhupesh Sharma wrote:

quoted

Add documentation for TCR_EL1.T1SZ variable being added to
vmcoreinfo.

It indicates the size offset of the memory region addressed by 
TTBR1_EL1

quoted

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.

quoted

quoted

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

  The kernel randomization offset. Used to compute the page offset. If
  KASLR is disabled, this value is zero.
  +TCR_EL1.T1SZ
+------------
+
+Indicates the size offset of the memory region addressed by TTBR1_EL1

quoted

+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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel