Re: [PATCH v3 3/4] earlycpio: lib-ify earlycpio.c

[Alejandro Vallejo <alejandro.garciavallejo@xxxxxxx>]

On Tue Jan 13, 2026 at 4:19 PM CET, Andrew Cooper wrote:
> On 13/01/2026 3:00 pm, Alejandro Vallejo wrote:
>> On Tue Jan 13, 2026 at 3:24 PM CET, Andrew Cooper wrote:
>>> On 13/01/2026 12:21 pm, Alejandro Vallejo wrote:
>>>> It's only used for microcode loading on x86. By lib-ifying it we can make
>>>> it go away automatically when microcode loading becomes an optional
>>>> feature in follow-up patches.
>>>>
>>>> Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@xxxxxxx>
>>>> ---
>>>> v3:
>>>>   * New patch. Subsumes earlier conditionalisation of earlycpio.c on
>>>>     CONFIG_MICROCODE_LOADING.
>>>> ---
>>>>  docs/misra/exclude-list.json    | 8 ++++----
>>>>  xen/common/Makefile             | 2 +-
>>>>  xen/lib/Makefile                | 1 +
>>>>  xen/{common => lib}/earlycpio.c | 0
>>>>  4 files changed, 6 insertions(+), 5 deletions(-)
>>>>  rename xen/{common => lib}/earlycpio.c (100%)
>>>>
>>>> diff --git a/docs/misra/exclude-list.json b/docs/misra/exclude-list.json
>>>> index 388397dd3b..2b874dfd3b 100644
>>>> --- a/docs/misra/exclude-list.json
>>>> +++ b/docs/misra/exclude-list.json
>>>> @@ -121,10 +121,6 @@
>>>>              "rel_path": "common/bunzip2.c",
>>>>              "comment": "Imported from Linux, ignore for now"
>>>>          },
>>>> -        {
>>>> -            "rel_path": "common/earlycpio.c",
>>>> -            "comment": "Imported from Linux, ignore for now"
>>>> -        },
>>>>          {
>>>>              "rel_path": "common/gzip/*",
>>>>              "comment": "Imported from Linux, ignore for now"
>>>> @@ -225,6 +221,10 @@
>>>>              "rel_path": "include/xen/decompress.h",
>>>>              "comment": "Imported from Linux, ignore for now"
>>>>          },
>>>> +        {
>>>> +            "rel_path": "lib/earlycpio.c",
>>>> +            "comment": "Imported from Linux, ignore for now"
>>>> +        },
>>>>          {
>>>>              "rel_path": "lib/find-next-bit.c",
>>>>              "comment": "Imported from Linux, ignore for now"
>>> Honestly, I think this needs simply dropping.  "ignore for now" isn't
>>> going to cut it with any competent evaluators.
>> That would depend on justifications and such. But regardless clearing the
>> exclusion list is a different matter aside from removing microcode loading.
>>
>>> By libryfing it, it's no longer part of the AMD target build, but it
>>> does want covering by *-allcode.
>>>
>>> Given that you noticed it for v2, I presume there's something in the
>>> file that Eclair doesn't like?
>> I didn't run Eclair on it. It's ignored as part of common, and the build
>> fails in CI if the file in common is absent. That's how I noticed it.
>>
>> I'd rather not gate this particular change on earlycpio playing ball with
>> Eclair.
>
> I'm explicitly not gating it.  *-allcode is non-blocking, but I want
> earlycpio being scanned.
>
> Simply omitting the second hunk should do this, and not explode the AMD
> target build.  (Once this patch is reordered to the end of the series.)
>
>>
>>>> diff --git a/xen/common/Makefile b/xen/common/Makefile
>>>> index 92c97d641e..4fc0c15088 100644
>>>> --- a/xen/common/Makefile
>>>> +++ b/xen/common/Makefile
>>>> @@ -65,7 +65,7 @@ obj-y += wait.o
>>>>  obj-bin-y += warning.init.o
>>>>  obj-y += xmalloc_tlsf.o
>>>>  
>>>> -obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma lzo 
>>>> unlzo unlz4 unzstd earlycpio,$(n).init.o)
>>>> +obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma lzo 
>>>> unlzo unlz4 unzstd,$(n).init.o)
>>>>  
>>>>  obj-$(CONFIG_COMPAT) += $(addprefix compat/,domain.o memory.o multicall.o 
>>>> xlat.o)
>>>>  
>>>> diff --git a/xen/lib/Makefile b/xen/lib/Makefile
>>>> index efca830d92..60cfda4dfc 100644
>>>> --- a/xen/lib/Makefile
>>>> +++ b/xen/lib/Makefile
>>>> @@ -3,6 +3,7 @@ obj-$(CONFIG_X86) += x86/
>>>>  lib-y += bsearch.o
>>>>  lib-y += ctors.o
>>>>  lib-y += ctype.o
>>>> +lib-y += earlycpio.o
>>>>  lib-y += find-next-bit.o
>>>>  lib-y += generic-ffsl.o
>>>>  lib-y += generic-flsl.o
>>>> diff --git a/xen/common/earlycpio.c b/xen/lib/earlycpio.c
>>>> similarity index 100%
>>>> rename from xen/common/earlycpio.c
>>>> rename to xen/lib/earlycpio.c
>>> What's wrong with .init here?  There's only a single string which will
>>> end up unmerged so I'm not worried on this side of things, but we now
>>> have series doing safety things getting tangled with .init and I want to
>>> get it fixed.
>> .init.o doesn't work with lib-y; only obj-y, obj-bin-y and extra-y. See 
>> below:
>>
>>   $(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): CFLAGS-y += 
>> -DINIT_SECTIONS_ONLY
>>
>>   [snip]
>>
>>   non-init-objects = $(filter-out %.init.o, $(obj-y) $(obj-bin-y) $(extra-y))
>>
>>   [snip]
>>
>>   $(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): $(obj)/%.init.o: 
>> $(obj)/%.o FORCE
>>      $(call if_changed,obj_init_o)
>>
>> That's just what I eyeballed. There might be more hidden elsewhere.
>>
>> It might want fixing, specially if something like libfdt is to turn into
>> a library. But it's just not relevant for this particular change where the
>> single contained function is already __init.
>
> *.init.o does two things:
>
> 1) For things we can tag, check everything is tagged
> 2) For things we can't tag with __section(), such as string literals,
> move them into .init
>
>
> Fixing lib init properly should just be a case of sprinkling lib-y
> through those places you mention.  If you want me to do the patch then
> fine, but I want it fixed rather than keeping on going around in circles.

I can do it, but I'll make a new series to deal with that independently
of this if that's alright. Feel free to leave this patch uncommitted until 
then. 

I care far more about the next patch going in.

Cheers,
Alejandro