6.1-stable review patch. If anyone has any objections, please let me know.
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From: Nathan Chancellor nathan@kernel.org
[ Upstream commit f0a42fbab447ed9f55bbd99751183e71f3a1f6ec ]
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, there are several warnings in the PowerPC vDSO:
clang-16: error: -Wl,-soname=linux-vdso32.so.1: 'linker' input unused [-Werror,-Wunused-command-line-argument] clang-16: error: -Wl,--hash-style=both: 'linker' input unused [-Werror,-Wunused-command-line-argument] clang-16: error: argument unused during compilation: '-shared' [-Werror,-Wunused-command-line-argument]
clang-16: error: argument unused during compilation: '-nostdinc' [-Werror,-Wunused-command-line-argument] clang-16: error: argument unused during compilation: '-Wa,-maltivec' [-Werror,-Wunused-command-line-argument]
The first group of warnings point out that linker flags were being added to all invocations of $(CC), even though they will only be used during the final vDSO link. Move those flags to ldflags-y.
The second group of warnings are compiler or assembler flags that will be unused during linking. Filter them out from KBUILD_CFLAGS so that they are not used during linking.
Additionally, '-z noexecstack' was added directly to the ld_and_check rule in commit 1d53c0192b15 ("powerpc/vdso: link with -z noexecstack") but now that there is a common ldflags variable, it can be moved there.
Signed-off-by: Nathan Chancellor nathan@kernel.org Reviewed-by: Nick Desaulniers ndesaulniers@google.com Tested-by: Linux Kernel Functional Testing lkft@linaro.org Tested-by: Anders Roxell anders.roxell@linaro.org Signed-off-by: Masahiro Yamada masahiroy@kernel.org Stable-dep-of: d677ce521334 ("powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/vdso/Makefile | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile index 45c0cc5d34b64..d4023bceec348 100644 --- a/arch/powerpc/kernel/vdso/Makefile +++ b/arch/powerpc/kernel/vdso/Makefile @@ -47,13 +47,17 @@ KCOV_INSTRUMENT := n UBSAN_SANITIZE := n KASAN_SANITIZE := n
-ccflags-y := -shared -fno-common -fno-builtin -nostdlib -Wl,--hash-style=both -ccflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld) - -CC32FLAGS := -Wl,-soname=linux-vdso32.so.1 -m32 +ccflags-y := -fno-common -fno-builtin +ldflags-y := -Wl,--hash-style=both -nostdlib -shared -z noexecstack +ldflags-$(CONFIG_LD_IS_LLD) += $(call cc-option,--ld-path=$(LD),-fuse-ld=lld) +# Filter flags that clang will warn are unused for linking +ldflags-y += $(filter-out $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CFLAGS)) + +CC32FLAGS := -m32 +LD32FLAGS := -Wl,-soname=linux-vdso32.so.1 AS32FLAGS := -D__VDSO32__
-CC64FLAGS := -Wl,-soname=linux-vdso64.so.1 +LD64FLAGS := -Wl,-soname=linux-vdso64.so.1 AS64FLAGS := -D__VDSO64__
targets += vdso32.lds @@ -92,15 +96,15 @@ include/generated/vdso64-offsets.h: $(obj)/vdso64.so.dbg FORCE
# actual build commands quiet_cmd_vdso32ld_and_check = VDSO32L $@ - cmd_vdso32ld_and_check = $(VDSOCC) $(c_flags) $(CC32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^) -z noexecstack ; $(cmd_vdso_check) + cmd_vdso32ld_and_check = $(VDSOCC) $(ldflags-y) $(CC32FLAGS) $(LD32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check) quiet_cmd_vdso32as = VDSO32A $@ cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) $(AS32FLAGS) -c -o $@ $< quiet_cmd_vdso32cc = VDSO32C $@ cmd_vdso32cc = $(VDSOCC) $(c_flags) $(CC32FLAGS) -c -o $@ $<
quiet_cmd_vdso64ld_and_check = VDSO64L $@ - cmd_vdso64ld_and_check = $(VDSOCC) $(c_flags) $(CC64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^) -z noexecstack ; $(cmd_vdso_check) + cmd_vdso64ld_and_check = $(VDSOCC) $(ldflags-y) $(LD64FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check) quiet_cmd_vdso64as = VDSO64A $@ - cmd_vdso64as = $(VDSOCC) $(a_flags) $(CC64FLAGS) $(AS64FLAGS) -c -o $@ $< + cmd_vdso64as = $(VDSOCC) $(a_flags) $(AS64FLAGS) -c -o $@ $<
OBJECT_FILES_NON_STANDARD := y