Re: [PATCH v8 1/4] powerpc: Refactor kexec functions to move arch independent code to drivers/of

Mimi Zohar
2020-11-03T20:00:25Z

On Tue, 2020-11-03 at 11:15 -0800, Lakshmi Ramasubramanian wrote:
> On 11/3/20 6:55 AM, Mimi Zohar wrote:
>
> Hi Mimi,
>
> Thanks for reviewing the patches.
>
> > On Fri, 2020-10-30 at 10:44 -0700, Lakshmi Ramasubramanian wrote:
> >> The functions remove_ima_buffer() and delete_fdt_mem_rsv() that handle
> >> carrying forward the IMA measurement logs on kexec for powerpc do not
> >> have architecture specific code, but they are currently defined for
> >> powerpc only.
> >
> > ^ ... logs on kexec, do not have architecture specific code, but are
> > currently limited to powerpc.
> Will make this change.
>
> >
> >>
> >> remove_ima_buffer() and delete_fdt_mem_rsv() are used to remove
> >> the IMA log entry from the device tree and free the memory reserved
> >> for the log. These functions need to be defined even if the current
> >> kernel does not support carrying forward IMA log across kexec since
> >> the previous kernel could have supported that and therefore the current
> >> kernel needs to free the allocation.
> >
> > The first paragraph describes these function as "handle carrying
> > forward the IMA measurement logs on kexec", while this paragraph says
> > "are used to remove the IMA log entry". Consider listing all of the
> > functions being moved in the first paragrah, then "handle carrying
> > forward" could be expanded to "carrying ... and removing".
> Sure.

Sorry, even with naming do_get_kexec_buffer(), the measurement list
isn't being carried across kexec. Please adjust the wording.

>
> >
> >>
> >> Rename remove_ima_buffer() to remove_ima_kexec_buffer().
> >> Define remove_ima_kexec_buffer() and delete_fdt_mem_rsv() in
> >> drivers/of/fdt.c. A later patch in this series will use these functions
> >> to free the allocation, if any, made by the previous kernel for ARM64.
> >
> > - ^Define -> Move
> > - Three functions are being moved, but only two are listed.
> > "do_get_kexec_buffer" is not mentioned.
> > - Don't refer to a later patch, but explain the purpose here. For
> > example, "Move ... , making them accessible to other archs."
> Sure.
>
> >
> >>
> >> Define FDT_PROP_IMA_KEXEC_BUFFER for the chosen node, namely
> >> "linux,ima-kexec-buffer", that is added to the DTB to hold
> >> the address and the size of the memory reserved to carry
> >> the IMA measurement log.
> >
> > The above two paragraphs describe renaming a function and defining a
> > chosen node. These two preparatory changes should be made,
> > independently of each other, prior to this patch. This patch should be
> > limited to moving code, with the subject line truncated to "move arch
> > independent code to drivers/of".
> >
>
> Just to be clear -
>
> Split this patch into 3 parts as listed below:
>
> PATCH #1: Rename remove_ima_buffer() to remove_ima_kexec_buffer()
> PATCH #2: Define the chosen node
> PATCH #3: Move the functions to drivers/of/fdt.c

yes, thanks.

Mimi

>
> Sure - I'll make the above changes and update patch descriptions
> accordingly.