The patch below does not apply to the 5.11-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 772d7891e8b3b0baae7bb88a294d61fd07ba6d15 Mon Sep 17 00:00:00 2001
From: Jisheng Zhang jszhang@kernel.org Date: Fri, 2 Apr 2021 21:29:08 +0800 Subject: [PATCH] riscv: vdso: fix and clean-up Makefile
Running "make" on an already compiled kernel tree will rebuild the kernel even without any modifications:
CALL linux/scripts/checksyscalls.sh CALL linux/scripts/atomic/check-atomics.sh CHK include/generated/compile.h SO2S arch/riscv/kernel/vdso/vdso-syms.S AS arch/riscv/kernel/vdso/vdso-syms.o AR arch/riscv/kernel/vdso/built-in.a AR arch/riscv/kernel/built-in.a AR arch/riscv/built-in.a GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o
The reason is "Any target that utilizes if_changed must be listed in $(targets), otherwise the command line check will fail, and the target will always be built" as explained by Documentation/kbuild/makefiles.rst
Fix this build bug by adding vdso-syms.S to $(targets)
At the same time, there are two trivial clean up modifications:
- the vdso-dummy.o is not needed any more after so remove it.
- vdso.lds is a generated file, so it should be prefixed with $(obj)/ instead of $(src)/
Fixes: c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+") Cc: stable@vger.kernel.org Signed-off-by: Jisheng Zhang jszhang@kernel.org Signed-off-by: Palmer Dabbelt palmerdabbelt@google.com
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile index ca2b40dfd24b..24d936c147cd 100644 --- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -23,7 +23,7 @@ ifneq ($(c-gettimeofday-y),) endif
# Build rules -targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o +targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-syms.S obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
obj-y += vdso.o vdso-syms.o @@ -41,7 +41,7 @@ KASAN_SANITIZE := n $(obj)/vdso.o: $(obj)/vdso.so
# link rule for the .so file, .lds has to be first -$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE +$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE $(call if_changed,vdsold) LDFLAGS_vdso.so.dbg = -shared -s -soname=linux-vdso.so.1 \ --build-id=sha1 --hash-style=both --eh-frame-hdr