Re: [PATCH] arm64/crypto: fix makefile rule for aes-glue-%.o

From: Ard Biesheuvel
Date: Mon Jul 28 2014 - 13:00:25 EST


On 27 July 2014 20:40, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
>>
>> > Btw. the current solution is already faulty - even with the fix.
>> > There are no support for make C=2 arch/.../crypto/
>> >
>>
>> So can you elaborate on how it is faulty?
>
> When you run "make C=2 arch/.../crypto/" then sparse shall be run
> for all .c files also if they are already built.
> But due to the re-implementation of some parts of the kbuild logic
> in the makefile this does not happen with the -glue file.
>
> A minor detail - but this may not be the only wreckage we see over time.
>

I agree. Any suggestions for a generic way to solve this? Perhaps
something like this in scripts/Makefile.build

template_rule = $(obj)/$(tmpl)%.c: $(src)/$(tmpl).c ; @cp $$(^) $$(@)
$(eval $(foreach tmpl,$(TEMPLATES),$(template_rule)))

so that arch/arm64/crypto/Makefile only has to define

TEMPLATES += aes-glue

so that all dependencies on aes-glueXXX.c are satisfied by aes-glue.c?

BTW, while looking into this issue, I noticed something else that is strange:
after touch'ing sha1-ce-glue.c in arch/arm64/crypto and re-executing
'make V=2', this is what I get

make[1]: Entering directory `/home/ard/linux-arm64-build'
CHK include/config/kernel.release
Using /home/ard/linux-2.6 as source for kernel
GEN ./Makefile
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
CALL /home/ard/linux-2.6/scripts/checksyscalls.sh - due to target missing
CHK include/generated/compile.h
CC arch/arm64/crypto/sha1-ce-glue.o - due to:
/home/ard/linux-2.6/arch/arm64/crypto/sha1-ce-glue.c
LD arch/arm64/crypto/sha1-ce.o - due to: arch/arm64/crypto/sha1-ce-glue.o
LD arch/arm64/crypto/sha2-ce.o - due to: arch/arm64/crypto/sha1-ce-glue.o
LD arch/arm64/crypto/ghash-ce.o - due to:
arch/arm64/crypto/sha1-ce-glue.o
LD arch/arm64/crypto/aes-ce-ccm.o - due to:
arch/arm64/crypto/sha1-ce-glue.o
LD arch/arm64/crypto/built-in.o - due to:
arch/arm64/crypto/sha1-ce.o arch/arm64/crypto/sha2-ce.o
arch/arm64/crypto/ghash-ce.o arch/arm64/crypto/aes-ce-ccm.o
CHK kernel/config_data.h
LINK vmlinux - due to: arch/arm64/crypto/built-in.o

IOW, unrelated object files are detected as being out of date. (This
is after running make mrproper, and with the aes-glue-% related rules
and definitions commented out, just to make sure this is not related
to the issue you have identified)

Any ideas?

--
Ard.
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