mips: always link byteswap helpers into decompressor
authorArnd Bergmann <arnd@arndb.de>
Fri, 2 Jul 2021 14:28:37 +0000 (16:28 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 20 Jul 2021 14:05:58 +0000 (16:05 +0200)
commit4e2764e96a1561d44635eb4d2c27f8b9bd000cd0
tree465c367c3d582f4622a265648bcba208554f2b02
parent53c5c2496fc9953ca1e67d3435f7d3f111da86d3
mips: always link byteswap helpers into decompressor

[ 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>
arch/mips/boot/compressed/Makefile