Re: [PATCH v6 3/4] MIPS: vmlinuz: Use generic ashldi3

Re: [PATCH v6 3/4] MIPS: vmlinuz: Use generic ashldi3

[James Hogan]

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On Wed, Apr 11, 2018 at 08:50:18AM +0100, Matt Redfearn wrote:
> diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
> index adce180f3ee4..e03f522c33ac 100644
> --- a/arch/mips/boot/compressed/Makefile
> +++ b/arch/mips/boot/compressed/Makefile
> @@ -46,9 +46,12 @@ $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c
>  
>  vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o
>  
> -extra-y += ashldi3.c bswapsi.c
> -$(obj)/ashldi3.o $(obj)/bswapsi.o: KBUILD_CFLAGS += -I$(srctree)/arch/mips/lib
> -$(obj)/ashldi3.c $(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
> +extra-y += ashldi3.c
> +$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c
> +	$(call cmd,shipped)
> +
> +extra-y += bswapsi.c
> +$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
>  	$(call cmd,shipped)

ci20_defconfig:

arch/mips/boot/compressed/ashldi3.c:4:10: fatal error: libgcc.h: No such file or directory
 #include "libgcc.h"
           ^~~~~~~~~~

It looks like it had already copied ashldi3.c from arch/mips/lib/ when
building an older commit, and it hasn't been regenerated from lib/ since
the Makefile changed, so its still using the old version.

I think it should be using FORCE and if_changed like this:

diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
index e03f522c33ac..abe77add8789 100644
--- a/arch/mips/boot/compressed/Makefile
+++ b/arch/mips/boot/compressed/Makefile
@@ -47,12 +47,12 @@ $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c
 vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o
 
 extra-y += ashldi3.c
-$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c
-	$(call cmd,shipped)
+$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c FORCE
+	$(call if_changed,shipped)
 
 extra-y += bswapsi.c
-$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
-	$(call cmd,shipped)
+$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c FORCE
+	$(call if_changed,shipped)
 
 targets := $(notdir $(vmlinuzobjs-y))
 
That resolves the build failures when checking out old -> new without
cleaning, since the .ashldi3.c.cmd is missing so it gets rebuilt.

It should also resolve issues if the path it copies from is updated in
future since the .ashldi3.c.cmd will get updated.

If you checkout new -> old without cleaning, the now removed
arch/mips/lib/ashldi3.c will get added which will trigger regeneration,
so it won't error.

However if you do new -> old -> new then the .ashldi3.cmd file isn't
updated while at old, so you get the same error as above. I'm not sure
there's much we can practically do about that, aside perhaps avoiding
the issue in future by somehow auto-deleting stale .*.cmd files.

Cc'ing kbuild folk in case they have any bright ideas.

At least the straightforward old->new upgrade will work with the above
fixup though. If you're okay with it I'm happy to apply as a fixup.

Cheers
James

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Re: [PATCH v6 3/4] MIPS: vmlinuz: Use generic ashldi3

[Masahiro Yamada]

2018-04-18 8:09 GMT+09:00 James Hogan <jhogan@kernel.org>:
> On Wed, Apr 11, 2018 at 08:50:18AM +0100, Matt Redfearn wrote:
>> diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
>> index adce180f3ee4..e03f522c33ac 100644
>> --- a/arch/mips/boot/compressed/Makefile
>> +++ b/arch/mips/boot/compressed/Makefile
>> @@ -46,9 +46,12 @@ $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c
>>
>>  vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o
>>
>> -extra-y += ashldi3.c bswapsi.c
>> -$(obj)/ashldi3.o $(obj)/bswapsi.o: KBUILD_CFLAGS += -I$(srctree)/arch/mips/lib
>> -$(obj)/ashldi3.c $(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
>> +extra-y += ashldi3.c
>> +$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c
>> +     $(call cmd,shipped)
>> +
>> +extra-y += bswapsi.c
>> +$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
>>       $(call cmd,shipped)
>
> ci20_defconfig:
>
> arch/mips/boot/compressed/ashldi3.c:4:10: fatal error: libgcc.h: No such file or directory
>  #include "libgcc.h"
>            ^~~~~~~~~~
>
> It looks like it had already copied ashldi3.c from arch/mips/lib/ when
> building an older commit, and it hasn't been regenerated from lib/ since
> the Makefile changed, so its still using the old version.
>
> I think it should be using FORCE and if_changed like this:
>
> diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
> index e03f522c33ac..abe77add8789 100644
> --- a/arch/mips/boot/compressed/Makefile
> +++ b/arch/mips/boot/compressed/Makefile
> @@ -47,12 +47,12 @@ $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c
>  vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o
>
>  extra-y += ashldi3.c
> -$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c
> -       $(call cmd,shipped)
> +$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c FORCE
> +       $(call if_changed,shipped)
>
>  extra-y += bswapsi.c
> -$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
> -       $(call cmd,shipped)
> +$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c FORCE
> +       $(call if_changed,shipped)
>
>  targets := $(notdir $(vmlinuzobjs-y))
>
> That resolves the build failures when checking out old -> new without
> cleaning, since the .ashldi3.c.cmd is missing so it gets rebuilt.
>
> It should also resolve issues if the path it copies from is updated in
> future since the .ashldi3.c.cmd will get updated.
>
> If you checkout new -> old without cleaning, the now removed
> arch/mips/lib/ashldi3.c will get added which will trigger regeneration,
> so it won't error.
>
> However if you do new -> old -> new then the .ashldi3.cmd file isn't
> updated while at old, so you get the same error as above. I'm not sure
> there's much we can practically do about that, aside perhaps avoiding
> the issue in future by somehow auto-deleting stale .*.cmd files.
>
> Cc'ing kbuild folk in case they have any bright ideas.



I do not have any idea better than if_changed.




> At least the straightforward old->new upgrade will work with the above
> fixup though. If you're okay with it I'm happy to apply as a fixup.
>






-- 
Best Regards
Masahiro Yamada

Re: [PATCH v6 3/4] MIPS: vmlinuz: Use generic ashldi3

[Matt Redfearn]

Hi James,

On 18/04/18 00:09, James Hogan wrote:
> On Wed, Apr 11, 2018 at 08:50:18AM +0100, Matt Redfearn wrote:
>> diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
>> index adce180f3ee4..e03f522c33ac 100644
>> --- a/arch/mips/boot/compressed/Makefile
>> +++ b/arch/mips/boot/compressed/Makefile
>> @@ -46,9 +46,12 @@ $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c
>>   
>>   vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o
>>   
>> -extra-y += ashldi3.c bswapsi.c
>> -$(obj)/ashldi3.o $(obj)/bswapsi.o: KBUILD_CFLAGS += -I$(srctree)/arch/mips/lib
>> -$(obj)/ashldi3.c $(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
>> +extra-y += ashldi3.c
>> +$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c
>> +	$(call cmd,shipped)
>> +
>> +extra-y += bswapsi.c
>> +$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
>>   	$(call cmd,shipped)
> 
> ci20_defconfig:
> 
> arch/mips/boot/compressed/ashldi3.c:4:10: fatal error: libgcc.h: No such file or directory
>   #include "libgcc.h"
>             ^~~~~~~~~~
> 
> It looks like it had already copied ashldi3.c from arch/mips/lib/ when
> building an older commit, and it hasn't been regenerated from lib/ since
> the Makefile changed, so its still using the old version.
> 
> I think it should be using FORCE and if_changed like this:
> 
> diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
> index e03f522c33ac..abe77add8789 100644
> --- a/arch/mips/boot/compressed/Makefile
> +++ b/arch/mips/boot/compressed/Makefile
> @@ -47,12 +47,12 @@ $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c
>   vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o
>   
>   extra-y += ashldi3.c
> -$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c
> -	$(call cmd,shipped)
> +$(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c FORCE
> +	$(call if_changed,shipped)
>   
>   extra-y += bswapsi.c
> -$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c
> -	$(call cmd,shipped)
> +$(obj)/bswapsi.c: $(obj)/%.c: $(srctree)/arch/mips/lib/%.c FORCE
> +	$(call if_changed,shipped)
>   
>   targets := $(notdir $(vmlinuzobjs-y))
>   
> That resolves the build failures when checking out old -> new without
> cleaning, since the .ashldi3.c.cmd is missing so it gets rebuilt.
> 
> It should also resolve issues if the path it copies from is updated in
> future since the .ashldi3.c.cmd will get updated.
> 
> If you checkout new -> old without cleaning, the now removed
> arch/mips/lib/ashldi3.c will get added which will trigger regeneration,
> so it won't error.
> 
> However if you do new -> old -> new then the .ashldi3.cmd file isn't
> updated while at old, so you get the same error as above. I'm not sure
> there's much we can practically do about that, aside perhaps avoiding
> the issue in future by somehow auto-deleting stale .*.cmd files.
> 
> Cc'ing kbuild folk in case they have any bright ideas.
> 
> At least the straightforward old->new upgrade will work with the above
> fixup though. If you're okay with it I'm happy to apply as a fixup.

Unbelievable how fragile this change is proving to be :-/
Yeah fixup looks good to me.

Thanks,
Matt

> 
> Cheers
> James
>