From: Arnd Bergmann arnd@arndb.de
stable inclusion from linux-4.19.198 commit 7c5bc66b33f6ab5f8792920beb821e1041586b44
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[ Upstream commit cddc40f5617e53f97ef019d5b29c1bd6cbb031ec ]
My series to clean up the unaligned access implementation across architectures caused some mips randconfig builds to fail with:
mips64-linux-ld: arch/mips/boot/compressed/decompress.o: in function `decompress_kernel': decompress.c:(.text.decompress_kernel+0x54): undefined reference to `__bswapsi2'
It turns out that this problem has already been fixed for the XZ decompressor but now it also shows up in (at least) LZO and LZ4. From my analysis I concluded that the compiler could always have emitted those calls, but the different implementation allowed it to make otherwise better decisions about not inlining the byteswap, which results in the link error when the out-of-line code is missing.
While it could be addressed by adding it to the two decompressor implementations that are known to be affected, but as this only adds 112 bytes to the kernel, the safer choice is to always add them.
Fixes: c50ec6787536 ("MIPS: zboot: Fix the build with XZ compression on older GCC versions") Fixes: 0652035a5794 ("asm-generic: unaligned: remove byteshift helpers") Link: https://lore.kernel.org/linux-mm/202106301304.gz2wVY9w-lkp@intel.com/ Link: https://lore.kernel.org/linux-mm/202106260659.TyMe8mjr-lkp@intel.com/ Link: https://lore.kernel.org/linux-mm/202106172016.onWT6Tza-lkp@intel.com/ Link: https://lore.kernel.org/linux-mm/202105231743.JJcALnhS-lkp@intel.com/ Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/mips/boot/compressed/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile index 378cbfb31ee70..1d6ebbc2a5d02 100644 --- a/arch/mips/boot/compressed/Makefile +++ b/arch/mips/boot/compressed/Makefile @@ -33,7 +33,7 @@ KBUILD_AFLAGS := $(KBUILD_AFLAGS) -D__ASSEMBLY__ \ KCOV_INSTRUMENT := n
# decompressor objects (linked with vmlinuz) -vmlinuzobjs-y := $(obj)/head.o $(obj)/decompress.o $(obj)/string.o +vmlinuzobjs-y := $(obj)/head.o $(obj)/decompress.o $(obj)/string.o $(obj)/bswapsi.o
ifdef CONFIG_DEBUG_ZBOOT vmlinuzobjs-$(CONFIG_DEBUG_ZBOOT) += $(obj)/dbg.o @@ -47,7 +47,7 @@ extra-y += uart-ath79.c $(obj)/uart-ath79.c: $(srctree)/arch/mips/ath79/early_printk.c $(call cmd,shipped)
-vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o $(obj)/bswapsi.o +vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o
extra-y += ashldi3.c $(obj)/ashldi3.c: $(obj)/%.c: $(srctree)/lib/%.c FORCE