[PATCH v2] kbuild: make samples really depend on headers_install

[Masahiro Yamada]

Kernel headers must be installed into $(objtree)/usr/include to avoid
the build failure of samples.

Commit ddea05fa148b ("kbuild: make samples depend on headers_install")
addressed this, but "samples/" is only used for the single target build.

"make samples/" properly installs kernel headers, but it does not work
for general building because a phony target "sample" (no trailing slash)
is used.

Reported-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2:
  - Correct commit log (backslash -> slash)
  - Fix a typo

 Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 7a3c454..1e47d13 100644
--- a/Makefile
+++ b/Makefile
@@ -1009,9 +1009,10 @@ ifdef CONFIG_GDB_SCRIPTS
 endif
 	+$(call if_changed,link-vmlinux)
 
-# Build samples along the rest of the kernel
+# Build samples along the rest of the kernel. This needs headers_install.
 ifdef CONFIG_SAMPLES
 vmlinux-dirs += samples
+samples: headers_install
 endif
 
 # The actual objects are generated when descending,
-- 
2.7.4