From b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 27 Apr 2024 23:55:02 +0900
Subject: kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
---
 arch/arm64/kernel/vdso/Makefile | 2 +-
 arch/arm64/kvm/Makefile         | 4 ++--
 arch/arm64/kvm/hyp/Makefile     | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

(limited to 'arch/arm64')

diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 8818287f1095..53e86d3bc159 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -68,7 +68,7 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
 # Generate VDSO offsets using helper script
-gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh
+gen-vdsosym := $(src)/gen_vdso_offsets.sh
 quiet_cmd_vdsosym = VDSOSYM $@
       cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
 
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index c0c050e53157..ab474d444cef 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -3,7 +3,7 @@
 # Makefile for Kernel-based Virtual Machine module
 #
 
-ccflags-y += -I $(srctree)/$(src)
+ccflags-y += -I $(src)
 
 include $(srctree)/virt/kvm/Makefile.kvm
 
@@ -30,7 +30,7 @@ define rule_gen_hyp_constants
 	$(call filechk,offsets,__HYP_CONSTANTS_H__)
 endef
 
-CFLAGS_hyp-constants.o = -I $(srctree)/$(src)/hyp/include
+CFLAGS_hyp-constants.o = -I $(src)/hyp/include
 $(obj)/hyp-constants.s: $(src)/hyp/hyp-constants.c FORCE
 	$(call if_changed_dep,cc_s_c)
 
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index a38dea6186c9..d61e44642f98 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -3,7 +3,7 @@
 # Makefile for Kernel-based Virtual Machine module, HYP part
 #
 
-incdir := $(srctree)/$(src)/include
+incdir := $(src)/include
 subdir-asflags-y := -I$(incdir)
 subdir-ccflags-y := -I$(incdir)
 
-- 
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