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| author | Sumanth Korikkar <sumanthk@linux.ibm.com> | 2024-04-25 16:59:31 +0200 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2024-04-29 17:33:30 +0200 |
| commit | 00cda11d3b2ea07295490b7d67942014f1cbc5c1 (patch) | |
| tree | eb27959101e584b9ff882be1b4d5f8b09b864cb2 /arch/s390/Makefile | |
| parent | 5f90003f09042b504d90ee38618cfd380ce16f4a (diff) | |
| download | linux-00cda11d3b2ea07295490b7d67942014f1cbc5c1.tar.gz linux-00cda11d3b2ea07295490b7d67942014f1cbc5c1.tar.bz2 linux-00cda11d3b2ea07295490b7d67942014f1cbc5c1.zip | |
s390: Compile kernel with -fPIC and link with -no-pie
When the kernel is built with CONFIG_PIE_BUILD option enabled it
uses dynamic symbols, for which the linker does not allow more
than 64K number of entries. This can break features like kpatch.
Hence, whenever possible the kernel is built with CONFIG_PIE_BUILD
option disabled. For that support of unaligned symbols generated by
linker scripts in the compiler is necessary.
However, older compilers might lack such support. In that case the
build process resorts to CONFIG_PIE_BUILD option-enabled build.
Compile object files with -fPIC option and then link the kernel
binary with -no-pie linker option.
As result, the dynamic symbols are not generated and not only kpatch
feature succeeds, but also the whole CONFIG_PIE_BUILD option-enabled
code could be dropped.
[ agordeev: Reworded the commit message ]
Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'arch/s390/Makefile')
| -rw-r--r-- | arch/s390/Makefile | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/arch/s390/Makefile b/arch/s390/Makefile index 64821f54f1e0..f2b21c7a70ef 100644 --- a/arch/s390/Makefile +++ b/arch/s390/Makefile @@ -14,14 +14,9 @@ KBUILD_AFLAGS_MODULE += -fPIC KBUILD_CFLAGS_MODULE += -fPIC KBUILD_AFLAGS += -m64 KBUILD_CFLAGS += -m64 -ifdef CONFIG_PIE_BUILD -KBUILD_CFLAGS += -fPIE -LDFLAGS_vmlinux := -pie -z notext -else -KBUILD_CFLAGS += $(call cc-option,-munaligned-symbols,) -LDFLAGS_vmlinux := --emit-relocs --discard-none +KBUILD_CFLAGS += -fPIC +LDFLAGS_vmlinux := -no-pie --emit-relocs --discard-none extra_tools := relocs -endif aflags_dwarf := -Wa,-gdwarf-2 KBUILD_AFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -D__ASSEMBLY__ ifndef CONFIG_AS_IS_LLVM |