samples: watch_queue: build sample program for target architecture

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 should be built for
the target as well. Kbuild now supports 'userprogs' for that.

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

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/samples/Kconfig b/samples/Kconfig
index f3ac549a53b01ce145b4ffe4ea9db5cea9e858cc..0ed6e4d71d87b16d68fc217126ac1caf36ec7caa 100644 (file)
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -211,7 +211,7 @@ config SAMPLE_WATCHDOG
 
 config SAMPLE_WATCH_QUEUE
        bool "Build example /dev/watch_queue notification consumer"
-       depends on HEADERS_INSTALL
+       depends on CC_CAN_LINK && HEADERS_INSTALL
        help
          Build example userspace program to use the new mount_notify(),
          sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.

diff --git a/samples/watch_queue/Makefile b/samples/watch_queue/Makefile
index 8511fb6c53d2b72192c1dd763eca1226a2f5ca7b..792b22f593cfa7379511dc1c4306ea469b1b9f9b 100644 (file)
--- a/samples/watch_queue/Makefile
+++ b/samples/watch_queue/Makefile
@@ -1,7 +1,5 @@
-# List of programs to build
-hostprogs := watch_test
+# SPDX-License-Identifier: GPL-2.0-only
+userprogs := watch_test
+always-y := $(userprogs)
 
-# Tell kbuild to always build the programs
-always-y := $(hostprogs)
-
-HOSTCFLAGS_watch_test.o += -I$(objtree)/usr/include
+userccflags += -I usr/include