[PATCH 12/16] samples: pidfd: build sample program for target architecture

[Masahiro Yamada]

This userspace program includes UAPI headers exported to usr/include/.
'make headers' always works for the target architecture (i.e. the same
architecture as the kernel), so the sample program must be built for
the target as well. Kbuild now supports the 'userprogs' syntax to
describe it cleanly.

I also guarded the CONFIG option by 'depends on CC_CAN_LINK' because
$(CC) may not necessarily provide libc.

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

 samples/Kconfig        | 2 +-
 samples/pidfd/Makefile | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/samples/Kconfig b/samples/Kconfig
index b8beb6fd75b4..b8113555aa6c 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -122,7 +122,7 @@ config SAMPLE_HIDRAW
 
 config SAMPLE_PIDFD
 	bool "pidfd sample"
-	depends on HEADERS_INSTALL
+	depends on CC_CAN_LINK && HEADERS_INSTALL
 
 config SAMPLE_SECCOMP
 	bool "Build seccomp sample code"
diff --git a/samples/pidfd/Makefile b/samples/pidfd/Makefile
index ee2979849d92..0191902647ca 100644
--- a/samples/pidfd/Makefile
+++ b/samples/pidfd/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-hostprogs := pidfd-metadata
-always-y := $(hostprogs)
-HOSTCFLAGS_pidfd-metadata.o += -I$(objtree)/usr/include
-all: pidfd-metadata
+usertprogs := pidfd-metadata
+always-y := $(userprogs)
+
+user-ccflags += -I usr/include
-- 
2.25.1