diff options
author | Masahiro Yamada <masahiroy@kernel.org> | 2020-11-22 04:36:55 +0900 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-19 18:26:14 +0100 |
commit | ca2fc0dc1cec3860c4a997c53b39a26f2ac1f102 (patch) | |
tree | 2b8cab32aed96492c1fd4d3e4b54661cd60598a1 /arch/arc | |
parent | 6265a0f2410fce381a2a84f1b69992f204deecb9 (diff) |
ARC: build: move symlink creation to arch/arc/Makefile to avoid race
[ Upstream commit c5e6ae563c802c4d828d42e134af64004db2e58c ]
If you run 'make uImage uImage.gz' with the parallel option, uImage.gz
will be created by two threads simultaneously.
This is because arch/arc/Makefile does not specify the dependency
between uImage and uImage.gz. Hence, GNU Make assumes they can be
built in parallel. One thread descends into arch/arc/boot/ to create
uImage, and another to create uImage.gz.
Please notice the same log is displayed twice in the following steps:
$ export CROSS_COMPILE=<your-arc-compiler-prefix>
$ make -s ARCH=arc defconfig
$ make -j$(nproc) ARCH=arc uImage uImage.gz
[ snip ]
LD vmlinux
SORTTAB vmlinux
SYSMAP System.map
OBJCOPY arch/arc/boot/vmlinux.bin
OBJCOPY arch/arc/boot/vmlinux.bin
GZIP arch/arc/boot/vmlinux.bin.gz
GZIP arch/arc/boot/vmlinux.bin.gz
UIMAGE arch/arc/boot/uImage.gz
UIMAGE arch/arc/boot/uImage.gz
Image Name: Linux-5.10.0-rc4-00003-g62f23044
Created: Sun Nov 22 02:52:26 2020
Image Type: ARC Linux Kernel Image (gzip compressed)
Data Size: 2109376 Bytes = 2059.94 KiB = 2.01 MiB
Load Address: 80000000
Entry Point: 80004000
Image arch/arc/boot/uImage is ready
Image Name: Linux-5.10.0-rc4-00003-g62f23044
Created: Sun Nov 22 02:52:26 2020
Image Type: ARC Linux Kernel Image (gzip compressed)
Data Size: 2815455 Bytes = 2749.47 KiB = 2.69 MiB
Load Address: 80000000
Entry Point: 80004000
This is a race between the two threads trying to write to the same file
arch/arc/boot/uImage.gz. This is a potential problem that can generate
a broken file.
I fixed a similar problem for ARM by commit 3939f3345050 ("ARM: 8418/1:
add boot image dependencies to not generate invalid images").
I highly recommend to avoid such build rules that cause a race condition.
Move the uImage rule to arch/arc/Makefile.
Another strangeness is that arch/arc/boot/Makefile compares the
timestamps between $(obj)/uImage and $(obj)/uImage.*:
$(obj)/uImage: $(obj)/uImage.$(suffix-y)
@ln -sf $(notdir $<) $@
@echo ' Image $@ is ready'
This does not work as expected since $(obj)/uImage is a symlink.
The symlink should be created in a phony target rule.
I used $(kecho) instead of echo to suppress the message
'Image arch/arc/boot/uImage is ready' when the -s option is given.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/arc')
-rw-r--r-- | arch/arc/Makefile | 13 | ||||
-rw-r--r-- | arch/arc/boot/Makefile | 11 |
2 files changed, 13 insertions, 11 deletions
diff --git a/arch/arc/Makefile b/arch/arc/Makefile index c95b950389ba..6f05e509889f 100644 --- a/arch/arc/Makefile +++ b/arch/arc/Makefile @@ -90,11 +90,22 @@ libs-y += arch/arc/lib/ $(LIBGCC) boot := arch/arc/boot -boot_targets := uImage uImage.bin uImage.gz uImage.lzma +boot_targets := uImage.bin uImage.gz uImage.lzma PHONY += $(boot_targets) $(boot_targets): vmlinux $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@ +uimage-default-y := uImage.bin +uimage-default-$(CONFIG_KERNEL_GZIP) := uImage.gz +uimage-default-$(CONFIG_KERNEL_LZMA) := uImage.lzma + +PHONY += uImage +uImage: $(uimage-default-y) + @ln -sf $< $(boot)/uImage + @$(kecho) ' Image $(boot)/uImage is ready' + +CLEAN_FILES += $(boot)/uImage + archclean: $(Q)$(MAKE) $(clean)=$(boot) diff --git a/arch/arc/boot/Makefile b/arch/arc/boot/Makefile index 538b92f4dd25..3b1f8a69a89e 100644 --- a/arch/arc/boot/Makefile +++ b/arch/arc/boot/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -targets := vmlinux.bin vmlinux.bin.gz uImage +targets := vmlinux.bin vmlinux.bin.gz # uImage build relies on mkimage being availble on your host for ARC target # You will need to build u-boot for ARC, rename mkimage to arc-elf32-mkimage @@ -13,11 +13,6 @@ LINUX_START_TEXT = $$(readelf -h vmlinux | \ UIMAGE_LOADADDR = $(CONFIG_LINUX_LINK_BASE) UIMAGE_ENTRYADDR = $(LINUX_START_TEXT) -suffix-y := bin -suffix-$(CONFIG_KERNEL_GZIP) := gz -suffix-$(CONFIG_KERNEL_LZMA) := lzma - -targets += uImage targets += uImage.bin targets += uImage.gz targets += uImage.lzma @@ -42,7 +37,3 @@ $(obj)/uImage.gz: $(obj)/vmlinux.bin.gz FORCE $(obj)/uImage.lzma: $(obj)/vmlinux.bin.lzma FORCE $(call if_changed,uimage,lzma) - -$(obj)/uImage: $(obj)/uImage.$(suffix-y) - @ln -sf $(notdir $<) $@ - @echo ' Image $@ is ready' |