Two consecutive "make" on an already compiled kernel tree will show
different behavior:
$ make
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
DESCEND objtool
CHK include/generated/compile.h
VDSOCHK arch/x86/entry/vdso/vdso64.so.dbg
VDSOCHK arch/x86/entry/vdso/vdso32.so.dbg
Kernel: arch/x86/boot/bzImage is ready (#3)
Building modules, stage 2.
MODPOST 12 modules
$ make
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
DESCEND objtool
CHK include/generated/compile.h
VDSO arch/x86/entry/vdso/vdso64.so.dbg
OBJCOPY arch/x86/entry/vdso/vdso64.so
VDSO2C arch/x86/entry/vdso/vdso-image-64.c
CC arch/x86/entry/vdso/vdso-image-64.o
VDSO arch/x86/entry/vdso/vdso32.so.dbg
OBJCOPY arch/x86/entry/vdso/vdso32.so
VDSO2C arch/x86/entry/vdso/vdso-image-32.c
CC arch/x86/entry/vdso/vdso-image-32.o
AR arch/x86/entry/vdso/built-in.a
AR arch/x86/entry/built-in.a
AR arch/x86/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
<snip>
This is causing "LD vmlinux" once every two times even without any
modifications. This is the same bug fixed in commit 92a4728608a8
("x86/boot: Fix if_changed build flip/flop bug"). We cannot use two
"if_changed" in one target. Fix this build bug by merging two commands
into one function.
Signed-off-by: Naohiro Aota <[email protected]>
---
arch/arm64/kernel/vdso/Makefile | 6 ++++--
arch/x86/entry/vdso/Makefile | 12 ++++++------
2 files changed, 10 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 4ab863045188..068c614b1231 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -57,8 +57,7 @@ $(obj)/vdso.o : $(obj)/vdso.so
# Link rule for the .so file, .lds has to be first
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
- $(call if_changed,ld)
- $(call if_changed,vdso_check)
+ $(call if_changed,ld_and_vdso_check)
# Strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
@@ -77,6 +76,9 @@ include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
quiet_cmd_vdsocc = VDSOCC $@
cmd_vdsocc = $(CC) $(a_flags) $(c_flags) -c -o $@ $<
+quiet_cmd_ld_and_vdso_check = LD $@
+ cmd_ld_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
+
# Install commands for the unstripped file
quiet_cmd_vdso_install = INSTALL $@
cmd_vdso_install = cp $(obj)/[email protected] $(MODLIB)/vdso/$@
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 39106111be86..34773395139a 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -56,8 +56,7 @@ VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
-z max-page-size=4096
$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
- $(call if_changed,vdso)
- $(call if_changed,vdso_check)
+ $(call if_changed,vdso_and_check)
HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
hostprogs-y += vdso2c
@@ -127,8 +126,7 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
- $(call if_changed,vdso)
- $(call if_changed,vdso_check)
+ $(call if_changed,vdso_and_check)
CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
@@ -167,8 +165,7 @@ $(obj)/vdso32.so.dbg: FORCE \
$(obj)/vdso32/note.o \
$(obj)/vdso32/system_call.o \
$(obj)/vdso32/sigreturn.o
- $(call if_changed,vdso)
- $(call if_changed,vdso_check)
+ $(call if_changed,vdso_and_check)
#
# The DSO images are built using a special linker script.
@@ -184,6 +181,9 @@ VDSO_LDFLAGS = -shared $(call ld-option, --hash-style=both) \
-Bsymbolic
GCOV_PROFILE := n
+quiet_cmd_vdso_and_check = VDSO $@
+ cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
+
#
# Install the unstripped copies of vdso*.so. If our toolchain supports
# build-id, install .build-id links as well.
--
2.22.0
On Fri, Jul 12, 2019 at 2:46 PM Naohiro Aota <[email protected]> wrote:
>
> Two consecutive "make" on an already compiled kernel tree will show
> different behavior:
>
> $ make
> CALL scripts/checksyscalls.sh
> CALL scripts/atomic/check-atomics.sh
> DESCEND objtool
> CHK include/generated/compile.h
> VDSOCHK arch/x86/entry/vdso/vdso64.so.dbg
> VDSOCHK arch/x86/entry/vdso/vdso32.so.dbg
> Kernel: arch/x86/boot/bzImage is ready (#3)
> Building modules, stage 2.
> MODPOST 12 modules
>
> $ make
> CALL scripts/checksyscalls.sh
> CALL scripts/atomic/check-atomics.sh
> DESCEND objtool
> CHK include/generated/compile.h
> VDSO arch/x86/entry/vdso/vdso64.so.dbg
> OBJCOPY arch/x86/entry/vdso/vdso64.so
> VDSO2C arch/x86/entry/vdso/vdso-image-64.c
> CC arch/x86/entry/vdso/vdso-image-64.o
> VDSO arch/x86/entry/vdso/vdso32.so.dbg
> OBJCOPY arch/x86/entry/vdso/vdso32.so
> VDSO2C arch/x86/entry/vdso/vdso-image-32.c
> CC arch/x86/entry/vdso/vdso-image-32.o
> AR arch/x86/entry/vdso/built-in.a
> AR arch/x86/entry/built-in.a
> AR arch/x86/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
> <snip>
>
> This is causing "LD vmlinux" once every two times even without any
> modifications. This is the same bug fixed in commit 92a4728608a8
> ("x86/boot: Fix if_changed build flip/flop bug"). We cannot use two
> "if_changed" in one target. Fix this build bug by merging two commands
> into one function.
>
> Signed-off-by: Naohiro Aota <[email protected]>
The code looks OK, but you should split this
into two patches, for arm64 and x86,
and then add Fixes: for each of them.
--
Best Regards
Masahiro Yamada
On Fri, Jul 12, 2019 at 03:24:01PM +0900, Masahiro Yamada wrote:
>On Fri, Jul 12, 2019 at 2:46 PM Naohiro Aota <[email protected]> wrote:
>>
>> Two consecutive "make" on an already compiled kernel tree will show
>> different behavior:
>>
>> $ make
>> CALL scripts/checksyscalls.sh
>> CALL scripts/atomic/check-atomics.sh
>> DESCEND objtool
>> CHK include/generated/compile.h
>> VDSOCHK arch/x86/entry/vdso/vdso64.so.dbg
>> VDSOCHK arch/x86/entry/vdso/vdso32.so.dbg
>> Kernel: arch/x86/boot/bzImage is ready (#3)
>> Building modules, stage 2.
>> MODPOST 12 modules
>>
>> $ make
>> CALL scripts/checksyscalls.sh
>> CALL scripts/atomic/check-atomics.sh
>> DESCEND objtool
>> CHK include/generated/compile.h
>> VDSO arch/x86/entry/vdso/vdso64.so.dbg
>> OBJCOPY arch/x86/entry/vdso/vdso64.so
>> VDSO2C arch/x86/entry/vdso/vdso-image-64.c
>> CC arch/x86/entry/vdso/vdso-image-64.o
>> VDSO arch/x86/entry/vdso/vdso32.so.dbg
>> OBJCOPY arch/x86/entry/vdso/vdso32.so
>> VDSO2C arch/x86/entry/vdso/vdso-image-32.c
>> CC arch/x86/entry/vdso/vdso-image-32.o
>> AR arch/x86/entry/vdso/built-in.a
>> AR arch/x86/entry/built-in.a
>> AR arch/x86/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
>> <snip>
>>
>> This is causing "LD vmlinux" once every two times even without any
>> modifications. This is the same bug fixed in commit 92a4728608a8
>> ("x86/boot: Fix if_changed build flip/flop bug"). We cannot use two
>> "if_changed" in one target. Fix this build bug by merging two commands
>> into one function.
>>
>> Signed-off-by: Naohiro Aota <[email protected]>
>
>
>The code looks OK, but you should split this
>into two patches, for arm64 and x86,
>and then add Fixes: for each of them.
Thanks, I'll split and add the tags.
>
>
>--
>Best Regards
>Masahiro Yamada