On 2023-11-19 4:00 AM, Masahiro Yamada wrote:
> A common issue in Makefile is a race in parallel building.
>
> You need to be careful to prevent multiple threads from writing to the
> same file simultaneously.
>
> Commit 3939f3345050 ("ARM: 8418/1: add boot image dependencies to not
> generate invalid images") addressed such a bad scenario.
>
> A similar symptom occurs with the following command:
>
> $ make -j$(nproc) ARCH=riscv Image Image.gz loader loader.bin vmlinuz.efi
> [ snip ]
> SORTTAB vmlinux
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> GZIP arch/riscv/boot/Image.gz
> AS arch/riscv/boot/loader.o
> AS arch/riscv/boot/loader.o
> Kernel: arch/riscv/boot/Image is ready
> PAD arch/riscv/boot/vmlinux.bin
> GZIP arch/riscv/boot/vmlinuz
> Kernel: arch/riscv/boot/loader is ready
> OBJCOPY arch/riscv/boot/loader.bin
> Kernel: arch/riscv/boot/loader.bin is ready
> Kernel: arch/riscv/boot/Image.gz is ready
> OBJCOPY arch/riscv/boot/vmlinuz.o
> LD arch/riscv/boot/vmlinuz.efi.elf
> OBJCOPY arch/riscv/boot/vmlinuz.efi
> Kernel: arch/riscv/boot/vmlinuz.efi is ready
>
> The log "OBJCOPY arch/riscv/boot/Image" is displayed 5 times.
> (also "AS arch/riscv/boot/loader.o" twice.)
>
> It indicates that 5 threads simultaneously enter arch/riscv/boot/
> and write to arch/riscv/boot/Image.
>
> It occasionally leads to a build failure:
>
> $ make -j$(nproc) ARCH=riscv Image Image.gz loader loader.bin vmlinuz.efi
> [ snip ]
> SORTTAB vmlinux
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> OBJCOPY arch/riscv/boot/Image
> PAD arch/riscv/boot/vmlinux.bin
> truncate: Invalid number: 'arch/riscv/boot/vmlinux.bin'
> make[2]: *** [drivers/firmware/efi/libstub/Makefile.zboot:13: arch/riscv/boot/vmlinux.bin] Error 1
> make[2]: *** Deleting file 'arch/riscv/boot/vmlinux.bin'
> make[1]: *** [arch/riscv/Makefile:167: vmlinuz.efi] Error 2
> make[1]: *** Waiting for unfinished jobs....
> Kernel: arch/riscv/boot/Image is ready
> GZIP arch/riscv/boot/Image.gz
> AS arch/riscv/boot/loader.o
> AS arch/riscv/boot/loader.o
> Kernel: arch/riscv/boot/loader is ready
> OBJCOPY arch/riscv/boot/loader.bin
> Kernel: arch/riscv/boot/loader.bin is ready
> Kernel: arch/riscv/boot/Image.gz is ready
> make: *** [Makefile:234: __sub-make] Error 2
>
> Image.gz, loader, vmlinuz.efi depend on Image. loader.bin depends
> on loader. Such dependencies are not specified in arch/riscv/Makefile.
>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
> Changes in v2:
> - Fix commit log
>
> arch/riscv/Makefile | 2 ++
> 1 file changed, 2 insertions(+)
Reviewed-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
Tested-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
