zstd: Fixing mixed module-builtin objects

With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in
a situation when files from lib/zstd/common/ are compiled once to be
linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module)
even though CFLAGS are different for builtins and modules.
So far somehow this was not a problem but enabling LLVM LTO exposes
the problem as:

ld.lld: error: linking module flags 'Code Model': IDs have conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and 'ld-temp.o'

This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs.
KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on
POWERPC as explained at
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127
but the current use of common files is wrong anyway.

This works around the issue by introducing a zstd_common module with
shared code.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Alexey Kardashevskiy
2022-09-29 12:08:23 +10:00
committed by Masahiro Yamada
parent d32b55f4bb
commit 637a642f5c
4 changed files with 27 additions and 12 deletions

View File

@@ -10,14 +10,10 @@
# ################################################################
obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o
obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o
obj-$(CONFIG_ZSTD_COMMON) += zstd_common.o
zstd_compress-y := \
zstd_compress_module.o \
common/debug.o \
common/entropy_common.o \
common/error_private.o \
common/fse_decompress.o \
common/zstd_common.o \
compress/fse_compress.o \
compress/hist.o \
compress/huf_compress.o \
@@ -33,12 +29,14 @@ zstd_compress-y := \
zstd_decompress-y := \
zstd_decompress_module.o \
decompress/huf_decompress.o \
decompress/zstd_ddict.o \
decompress/zstd_decompress.o \
decompress/zstd_decompress_block.o \
zstd_common-y := \
common/debug.o \
common/entropy_common.o \
common/error_private.o \
common/fse_decompress.o \
common/zstd_common.o \
decompress/huf_decompress.o \
decompress/zstd_ddict.o \
decompress/zstd_decompress.o \
decompress/zstd_decompress_block.o \