[PATCH AUTOSEL 6.6 40/40] arm64: add dependency between vmlinuz.efi and Image

Sasha Levin
2023-11-28T21:10:12Z

From: Masahiro Yamada <masahiroy@kernel.org>

[ Upstream commit c0a8574204054effad6ac83cc75c02576e2985fe ]

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=arm64 Image vmlinuz.efi
[ snip ]
SORTTAB vmlinux
OBJCOPY arch/arm64/boot/Image
OBJCOPY arch/arm64/boot/Image
AS arch/arm64/boot/zboot-header.o
PAD arch/arm64/boot/vmlinux.bin
GZIP arch/arm64/boot/vmlinuz
OBJCOPY arch/arm64/boot/vmlinuz.o
LD arch/arm64/boot/vmlinuz.efi.elf
OBJCOPY arch/arm64/boot/vmlinuz.efi

The log "OBJCOPY arch/arm64/boot/Image" is displayed twice.

It indicates that two threads simultaneously enter arch/arm64/boot/
and write to arch/arm64/boot/Image.

It occasionally leads to a build failure:

$ make -j$(nproc) ARCH=arm64 Image vmlinuz.efi
[ snip ]
SORTTAB vmlinux
OBJCOPY arch/arm64/boot/Image
PAD arch/arm64/boot/vmlinux.bin
truncate: Invalid number: 'arch/arm64/boot/vmlinux.bin'
make[2]: *** [drivers/firmware/efi/libstub/Makefile.zboot:13:
arch/arm64/boot/vmlinux.bin] Error 1
make[2]: *** Deleting file 'arch/arm64/boot/vmlinux.bin'
make[1]: *** [arch/arm64/Makefile:163: vmlinuz.efi] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:234: __sub-make] Error 2

vmlinuz.efi depends on Image, but such a dependency is not specified
in arch/arm64/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: SImon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20231119053234.2367621-1-masahiroy@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 2d49aea0ff67a..26b8c7630a214 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -158,7 +158,7 @@ endif

all: $(notdir $(KBUILD_IMAGE))

-
+vmlinuz.efi: Image
Image vmlinuz.efi: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@

--
2.42.0