From: Jisheng Zhang <[email protected]>
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 $(src)/
Fixes: c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+")
Signed-off-by: Jisheng Zhang <[email protected]>
---
arch/riscv/kernel/vdso/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 71a315e73cbe..7b9f505ba82f 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -23,7 +23,7 @@ ifneq ($(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
@@ -42,7 +42,7 @@ $(obj)/vdso.o: $(obj)/vdso.so
# link rule for the .so file, .lds has to be first
SYSCFLAGS_vdso.so.dbg = $(c_flags)
-$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
+$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
-Wl,--build-id=sha1 -Wl,--hash-style=both
--
2.31.0
On Fri, 02 Apr 2021 06:29:08 PDT (-0700), [email protected] wrote:
> From: Jisheng Zhang <[email protected]>
>
> 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 $(src)/
>
> Fixes: c2c81bb2f691 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+")
> Signed-off-by: Jisheng Zhang <[email protected]>
> ---
> arch/riscv/kernel/vdso/Makefile | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
> index 71a315e73cbe..7b9f505ba82f 100644
> --- a/arch/riscv/kernel/vdso/Makefile
> +++ b/arch/riscv/kernel/vdso/Makefile
> @@ -23,7 +23,7 @@ ifneq ($(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
> @@ -42,7 +42,7 @@ $(obj)/vdso.o: $(obj)/vdso.so
>
> # link rule for the .so file, .lds has to be first
> SYSCFLAGS_vdso.so.dbg = $(c_flags)
> -$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
> +$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
> $(call if_changed,vdsold)
> SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
> -Wl,--build-id=sha1 -Wl,--hash-style=both
Thanks, this is on for-next.