4.18-stable review patch. If anyone has any objections, please let me know.
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From: Palmer Dabbelt palmer@sifive.com
[ Upstream commit 4938c79bd0f5f3650c8c2cd4cdc972f0a6962ce4 ]
If you use a 64-bit compiler to build a 32-bit kernel then you'll get an error when building the vDSO due to a library mismatch. The happens because the relevant "-march" argument isn't supplied to the GCC run that generates one of the vDSO intermediate files.
I'm not actually sure what the right thing to do here is as I'm not particularly familiar with the kernel build system. I poked the documentation and it appears that KCFLAGS is the correct thing to do (it's suggested that should be used when building modules), but we set KBUILD_CFLAGS in arch/riscv/Makefile.
This does at least fix the build error.
Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Palmer Dabbelt palmer@sifive.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/riscv/kernel/vdso/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -52,8 +52,8 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE # Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions. # Make sure only to export the intended __vdso_xxx symbol offsets. quiet_cmd_vdsold = VDSOLD $@ - cmd_vdsold = $(CC) $(KCFLAGS) $(call cc-option, -no-pie) -nostdlib $(SYSCFLAGS_$(@F)) \ - -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp -lgcc && \ + cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \ + -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \ $(CROSS_COMPILE)objcopy \ $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@