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c4db7ff7a9
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 3939f33450 ("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@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231119100024.2370992-1-masahiroy@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.