riscv: fix building external modules

[ Upstream commit 5a19c7e06236a9c55dfc001bb4d1a8f1950d23e7 ]

When building external modules, vdso_prepare should not be run.  If the
kernel sources are read-only, it will fail.

Fixes: fde9c59aebaf ("riscv: explicitly use symbol offsets for VDSO")
Signed-off-by: Andreas Schwab <schwab@suse.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 0eb4568fbd290c79e121a5c6f0f803c9fc8597df..41f3a75fe2ec86c70add1b182aeabed596e76d71 100644 (file)
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -108,11 +108,13 @@ PHONY += vdso_install
 vdso_install:
        $(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@
 
+ifeq ($(KBUILD_EXTMOD),)
 ifeq ($(CONFIG_MMU),y)
 prepare: vdso_prepare
 vdso_prepare: prepare0
        $(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso include/generated/vdso-offsets.h
 endif
+endif
 
 ifneq ($(CONFIG_XIP_KERNEL),y)
 ifeq ($(CONFIG_RISCV_M_MODE)$(CONFIG_SOC_CANAAN),yy)