[PATCH] powerpc: rebuild vdsos correctly

When using if_changed, we need to add FORCE to dependencies, otherwise
we don't get command line change checking amongst other things. This
has resulted in vdsos not being rebuilt when switching between big and
little endian.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---

There look to be some other cases in arch/powerpc/ of if_changed
being used without FORCE too, which should also be investigated.
Also, why are we using if_changed_deps?
---
 arch/powerpc/kernel/vdso32/Makefile | 8 ++++----
 arch/powerpc/kernel/vdso64/Makefile | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
index cbabd14..ae1f245 100644
--- a/arch/powerpc/kernel/vdso32/Makefile
+++ b/arch/powerpc/kernel/vdso32/Makefile

@@ -30,7 +30,7 @@ CPPFLAGS_vdso32.lds += -P -C -Upowerpc
 $(obj)/vdso32_wrapper.o : $(obj)/vdso32.so
 
 # link rule for the .so file, .lds has to be first
-$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32)
+$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) FORCE
 	$(call if_changed,vdso32ld)
 
 # strip rule for the .so file

@@ -39,14 +39,14 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
 # assembly rules for the .S files
-$(obj-vdso32): %.o: %.S
+$(obj-vdso32): %.o: %.S FORCE
 	$(call if_changed_dep,vdso32as)
 
 # actual build commands
 quiet_cmd_vdso32ld = VDSO32L $@
-      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -Wl,-T $^ -o $@
+      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
 quiet_cmd_vdso32as = VDSO32A $@
-      cmd_vdso32as = $(CROSS32CC) $(a_flags) -c -o $@ $<
+      cmd_vdso32as = $(CROSS32CC) $(a_flags) -o $@ -c $<
 
 # install commands for the unstripped file
 quiet_cmd_vdso_install = INSTALL $@

diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile
index c710802..0d5f04a 100644
--- a/arch/powerpc/kernel/vdso64/Makefile
+++ b/arch/powerpc/kernel/vdso64/Makefile

@@ -23,7 +23,7 @@ CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
 $(obj)/vdso64_wrapper.o : $(obj)/vdso64.so
 
 # link rule for the .so file, .lds has to be first
-$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64)
+$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) FORCE
 	$(call if_changed,vdso64ld)
 
 # strip rule for the .so file

@@ -32,14 +32,14 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
 # assembly rules for the .S files
-$(obj-vdso64): %.o: %.S
+$(obj-vdso64): %.o: %.S FORCE
 	$(call if_changed_dep,vdso64as)
 
 # actual build commands
 quiet_cmd_vdso64ld = VDSO64L $@
-      cmd_vdso64ld = $(CC) $(c_flags) -Wl,-T $^ -o $@
+      cmd_vdso64ld = $(CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
 quiet_cmd_vdso64as = VDSO64A $@
-      cmd_vdso64as = $(CC) $(a_flags) -c -o $@ $<
+      cmd_vdso64as = $(CC) $(a_flags) -o $@ -c $<
 
 # install commands for the unstripped file
 quiet_cmd_vdso_install = INSTALL $@

-- 
2.8.1

Nicholas Piggin [off-list ref] writes:

Are the two changes above required, they aren't obviously related.

cheers

On Tue, 09 Aug 2016 14:49:25 +1000
Michael Ellerman [off-list ref] wrote:

Nicholas Piggin [off-list ref] writes:

quoted

diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
index cbabd14..ae1f245 100644
--- a/arch/powerpc/kernel/vdso32/Makefile
+++ b/arch/powerpc/kernel/vdso32/Makefile

@@ -39,14 +39,14 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
 # assembly rules for the .S files
-$(obj-vdso32): %.o: %.S
+$(obj-vdso32): %.o: %.S FORCE
 	$(call if_changed_dep,vdso32as)
 
 # actual build commands
 quiet_cmd_vdso32ld = VDSO32L $@
-      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -Wl,-T $^ -o $@
+      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
 quiet_cmd_vdso32as = VDSO32A $@
-      cmd_vdso32as = $(CROSS32CC) $(a_flags) -c -o $@ $<
+      cmd_vdso32as = $(CROSS32CC) $(a_flags) -o $@ -c $<  

Are the two changes above required, they aren't obviously related.

The vdso32ld change is required because otherwise "FORCE" gets put on
the end of the command line. vdso32as... I think is not required. Want
a new version without it?

Nicholas Piggin [off-list ref] writes:

On Tue, 09 Aug 2016 14:49:25 +1000
Michael Ellerman [off-list ref] wrote:

quoted

Nicholas Piggin [off-list ref] writes:

quoted

diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
index cbabd14..ae1f245 100644
--- a/arch/powerpc/kernel/vdso32/Makefile
+++ b/arch/powerpc/kernel/vdso32/Makefile

@@ -39,14 +39,14 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
 # assembly rules for the .S files
-$(obj-vdso32): %.o: %.S
+$(obj-vdso32): %.o: %.S FORCE
 	$(call if_changed_dep,vdso32as)
 
 # actual build commands
 quiet_cmd_vdso32ld = VDSO32L $@
-      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -Wl,-T $^ -o $@
+      cmd_vdso32ld = $(CROSS32CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
 quiet_cmd_vdso32as = VDSO32A $@
-      cmd_vdso32as = $(CROSS32CC) $(a_flags) -c -o $@ $<
+      cmd_vdso32as = $(CROSS32CC) $(a_flags) -o $@ -c $<  

Are the two changes above required, they aren't obviously related.

The vdso32ld change is required because otherwise "FORCE" gets put on
the end of the command line. vdso32as... I think is not required. Want
a new version without it?

Yeah either without it or just explaining why it's needed in the change log.

cheers

On Mon, 2016-08-08 at 09:35:43 UTC, Nicholas Piggin wrote:

When using if_changed, we need to add FORCE to dependencies, otherwise
we don't get command line change checking amongst other things. This
has resulted in vdsos not being rebuilt when switching between big and
little endian.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/b9a4a0d02c5b8d9a1397c11d74

cheers