On Fri, Feb 19, 2021 at 10:57 AM Lakshmi Ramasubramanian
<nramas@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On 2/19/21 6:16 AM, Rob Herring wrote:
> > On Thu, Feb 18, 2021 at 8:53 PM Lakshmi Ramasubramanian
> > <nramas@xxxxxxxxxxxxxxxxxxx> wrote:
> >>
> >> On 2/18/21 5:13 PM, Thiago Jung Bauermann wrote:
> >>>
> >>> Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx> writes:
> >>>
> >>>> On 2/18/21 4:07 PM, Mimi Zohar wrote:
> >>>>
> >>>> Hi Mimi,
> >>>>
> >>>>> On Thu, 2021-02-18 at 14:33 -0800, Lakshmi Ramasubramanian wrote:
> >>>>>> of_kexec_alloc_and_setup_fdt() defined in drivers/of/kexec.c builds
> >>>>>> a new device tree object that includes architecture specific data
> >>>>>> for kexec system call. This should be defined only if the architecture
> >>>>>> being built defines kexec architecture structure "struct kimage_arch".
> >>>>>>
> >>>>>> Define a new boolean config OF_KEXEC that is enabled if
> >>>>>> CONFIG_KEXEC_FILE and CONFIG_OF_FLATTREE are enabled, and
> >>>>>> the architecture is arm64 or powerpc64. Build drivers/of/kexec.c
> >>>>>> if CONFIG_OF_KEXEC is enabled.
> >>>>>>
> >>>>>> Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
> >>>>>> Fixes: 33488dc4d61f ("of: Add a common kexec FDT setup function")
> >>>>>> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >>>>>> ---
> >>>>>> drivers/of/Kconfig | 6 ++++++
> >>>>>> drivers/of/Makefile | 7 +------
> >>>>>> 2 files changed, 7 insertions(+), 6 deletions(-)
> >>>>>>
> >>>>>> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> >>>>>> index 18450437d5d5..f2e8fa54862a 100644
> >>>>>> --- a/drivers/of/Kconfig
> >>>>>> +++ b/drivers/of/Kconfig
> >>>>>> @@ -100,4 +100,10 @@ config OF_DMA_DEFAULT_COHERENT
> >>>>>> # arches should select this if DMA is coherent by default for OF devices
> >>>>>> bool
> >>>>>> +config OF_KEXEC
> >>>>>> + bool
> >>>>>> + depends on KEXEC_FILE
> >>>>>> + depends on OF_FLATTREE
> >>>>>> + default y if ARM64 || PPC64
> >>>>>> +
> >>>>>> endif # OF
> >>>>>> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> >>>>>> index c13b982084a3..287579dd1695 100644
> >>>>>> --- a/drivers/of/Makefile
> >>>>>> +++ b/drivers/of/Makefile
> >>>>>> @@ -13,11 +13,6 @@ obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
> >>>>>> obj-$(CONFIG_OF_RESOLVE) += resolver.o
> >>>>>> obj-$(CONFIG_OF_OVERLAY) += overlay.o
> >>>>>> obj-$(CONFIG_OF_NUMA) += of_numa.o
> >>>>>> -
> >>>>>> -ifdef CONFIG_KEXEC_FILE
> >>>>>> -ifdef CONFIG_OF_FLATTREE
> >>>>>> -obj-y += kexec.o
> >>>>>> -endif
> >>>>>> -endif
> >>>>>> +obj-$(CONFIG_OF_KEXEC) += kexec.o
> >>>>>> obj-$(CONFIG_OF_UNITTEST) += unittest-data/
> >>>>> Is it possible to reuse CONFIG_HAVE_IMA_KEXEC here?
> >>>>>
> >>>>
> >>>> For ppc64 CONFIG_HAVE_IMA_KEXEC is selected when CONFIG_KEXEC_FILE is enabled.
> >>>> So I don't see a problem in reusing CONFIG_HAVE_IMA_KEXEC for ppc.
> >>>>
> >>>> But for arm64, CONFIG_HAVE_IMA_KEXEC is enabled in the final patch in the patch
> >>>> set (the one for carrying forward IMA log across kexec for arm64). arm64 calls
> >>>> of_kexec_alloc_and_setup_fdt() prior to enabling CONFIG_HAVE_IMA_KEXEC and hence
> >>>> breaks the build for arm64.
> >>>
> >>> One problem is that I believe that this patch won't placate the robot,
> >>> because IIUC it generates config files at random and this change still
> >>> allows hppa and s390 to enable CONFIG_OF_KEXEC.
> >>
> >> I enabled CONFIG_OF_KEXEC for s390. With my patch applied,
> >> CONFIG_OF_KEXEC is removed. So I think the robot enabling this config
> >> would not be a problem.
> >>
> >>>
> >>> Perhaps a new CONFIG_HAVE_KIMAGE_ARCH option? Not having that option
> >>> would still allow building kexec.o, but would be used inside kexec.c to
> >>> avoid accessing kimage.arch members.
> >>>
> >>
> >> I think this is a good idea - a new CONFIG_HAVE_KIMAGE_ARCH, which will
> >> be selected by arm64 and ppc for now. I tried this, and it fixes the
> >> build issue.
> >>
> >> Although, the name for the new config can be misleading since PARISC,
> >> for instance, also defines "struct kimage_arch". Perhaps,
> >> CONFIG_HAVE_ELF_KIMAGE_ARCH since of_kexec_alloc_and_setup_fdt() is
> >> accessing ELF specific fields in "struct kimage_arch"?
> >>
> >> Rob/Mimi - please let us know which approach you think is better.
> >
> > I'd just move the fields to kimage.
> >
>
> I think Mimi's suggestion to use CONFIG_HAVE_IMA_KEXEC for building
> drivers/of/kexec.c would work and also avoid the bisect issue if we do
> the following:
That seems wrong given only a portion of the file depends on IMA. And
it reduces our compile coverage.
> - In the patch set for carrying forward the IMA log on kexec, move the
> following patch to a later point in the set
>
> "[PATCH v18 04/11] arm64: Use common of_kexec_alloc_and_setup_fdt()"
>
> and merge the above patch with the following patch
> "[PATCH v18 11/11] arm64: Enable passing IMA log to next kernel on kexec"
If we're doing all that, then I'm dropping all this for 5.12.
Rob
