Re: [kvm-unit-tests BUG] lib/ldiv32.c breaks arm compilation

[Paolo Bonzini <pbonzini@redhat.com>]

On 11/05/21 19:03, Alexandru Elisei wrote:
> I think it's because I'm using the*arm-none-eabi*  toolchain for compilation
> instead of arm-linux-gnu, that's the toolchain for cross compiling arm code that
> is present in the official Arch Linux repositories. Is that unsupported? I don't
> remember any mention of it not being supported, but it's entirely possible that I
> just forgot.

No, it's just that there was no difference until now.  If you can add it 
to CI we can make sure it doesn't break.

> With rem initialized to 0 I get this:
> 
> rm-none-eabi-ld -nostdlib -Ttext=40010000 -o arm/selftest.elf -T
> /home/alex/data/repos/kvm-unit-tests/arm/flat.lds \
>      arm/selftest.o arm/cstart.o lib/libcflat.a lib/libfdt/libfdt.a
> lib/arm/libeabi.a arm/selftest.aux.o
> arm-none-eabi-ld: lib/libcflat.a(printf.o): in function `print_int':
> /home/alex/data/repos/kvm-unit-tests/lib/printf.c:72: undefined reference to
> `__aeabi_ldivmod'
> arm-none-eabi-ld: /home/alex/data/repos/kvm-unit-tests/lib/printf.c:73: undefined
> reference to `__aeabi_ldivmod'
> arm-none-eabi-ld: lib/libcflat.a(printf.o): in function `print_unsigned':
> /home/alex/data/repos/kvm-unit-tests/lib/printf.c:102: undefined reference to
> `__aeabi_uldivmod'
> arm-none-eabi-ld: lib/libcflat.a(alloc_page.o): in function `_page_alloc_init_area':
> /home/alex/data/repos/kvm-unit-tests/lib/alloc_page.c:482: undefined reference to
> `__aeabi_uldivmod'
> make: *** [/home/alex/data/repos/kvm-unit-tests/arm/Makefile.common:65:
> arm/selftest.elf] Error 1

So for this we need to include the uldivmod and ldivmod functions 
similar to those in 
https://android.googlesource.com/toolchain/compiler-rt/+/release_32/lib/arm.

The uninitialized warning is because of the division by zero case.  I've 
sent a couple patches to fix everything, please review!

Paolo