Re: [PATCH v5 1/2] xen: Allow lib-y targets to also be .init.o

[Alejandro Vallejo <alejandro.garciavallejo@amd.com>]

On Thu Jan 22, 2026 at 11:01 AM CET, Jan Beulich wrote:
> On 22.01.2026 10:49, Jan Beulich wrote:
>> On 21.01.2026 16:47, Alejandro Vallejo wrote:
>>> There's some assumptions as to which targets may be init-only. But
>>> there's little reason to preclude libraries from being init-only.
>>>
>>> Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@amd.com>
>>> Reviewed-by: Jan Beulich <jbeulich@suse.com>
>> 
>> I can't tell (yet) what it is, but as per CI something's clearly wrong with this
>> change. Both xilinx-smoke-dom0less-arm64-* and qemu-smoke-dom0*-debug* fail with
>> it in place. qemu-smoke-dom0-arm64-gcc (no "debug") was fine, suggesting it may
>> be an early assertion triggering.
>
> Or an early UBSAN failure. I think ...
>
>>> --- a/xen/Rules.mk
>>> +++ b/xen/Rules.mk
>>> @@ -130,9 +130,9 @@ endif
>>>  
>>>  targets += $(targets-for-builtin)
>>>  
>>> -$(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y)): CFLAGS-y += -DINIT_SECTIONS_ONLY
>>> +$(filter %.init.o,$(obj-y) $(obj-bin-y) $(extra-y) $(lib-y)): CFLAGS-y += -DINIT_SECTIONS_ONLY
>>>  
>>> -non-init-objects = $(filter-out %.init.o, $(obj-y) $(obj-bin-y) $(extra-y))
>>> +non-init-objects = $(filter-out %.init.o, $(obj-y) $(obj-bin-y) $(extra-y) $(lib-y))
>
> ... this is the problem: You're _adding_ library files here which weren't there
> before. Why $(lib-y) isn't here I don't really known, but as per the CI results
> there must be a reason for this.

Apologies for the unintended breakage. I should've checked the baseline for
arm before ruling out this patch being the cause (it did fire in my pipeline,
but didn't consider how this could affect arm and attributed it to a spurious
failure).

So we're neither doing UBSAN nor collecting coverage data from libs? Great. One
more task to the pile, I guess. Seeing how...

 $(non-init-objects): _c_flags += $(cov-cflags-y)
 [snip]
 $(non-init-objects): _c_flags += $(UBSAN_FLAGS)

I'll try to clean this mess. :/

Cheers,
Alejandro