kbuild: add CONFIG_HEADERS_INSTALL and loosen the dependency of samples
Commit 5318321d367c ("samples: disable CONFIG_SAMPLES for UML") used
a big hammer to fix the build errors under the samples/ directory.
Only some samples actually include uapi headers from usr/include.
Introduce CONFIG_HEADERS_INSTALL since 'depends on HEADERS_INSTALL' is
clearer than 'depends on !UML'. If this option is enabled, uapi headers
are installed before starting directory descending.
I added 'depends on HEADERS_INSTALL' to per-sample CONFIG options.
This allows UML to compile some samples.
$ make ARCH=um allmodconfig samples/
[ snip ]
CC [M] samples/configfs/configfs_sample.o
CC [M] samples/kfifo/bytestream-example.o
CC [M] samples/kfifo/dma-example.o
CC [M] samples/kfifo/inttype-example.o
CC [M] samples/kfifo/record-example.o
CC [M] samples/kobject/kobject-example.o
CC [M] samples/kobject/kset-example.o
CC [M] samples/trace_events/trace-events-sample.o
CC [M] samples/trace_printk/trace-printk.o
AR samples/vfio-mdev/built-in.a
AR samples/built-in.a
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 7cdcb96..6a6ea42 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -305,14 +305,23 @@
If unsure, say N.
-config HEADERS_CHECK
- bool "Run sanity checks on uapi headers when building 'all'"
+config HEADERS_INSTALL
+ bool "Install uapi headers to usr/include"
depends on !UML
help
- This option will extract the user-visible kernel headers when
- building the 'all' target, and will run basic sanity checks on them to
- ensure that exported files do not attempt to include files which
- were not exported, etc.
+ This option will install uapi headers (headers exported to user-space)
+ into the usr/include directory for use during the kernel build.
+ This is unneeded for building the kernel itself, but needed for some
+ user-space program samples. It is also needed by some features such
+ as uapi header sanity checks.
+
+config HEADERS_CHECK
+ bool "Run sanity checks on uapi headers when building 'all'"
+ depends on HEADERS_INSTALL
+ help
+ This option will run basic sanity checks on uapi headers when
+ building the 'all' target, for example, ensure that they do not
+ attempt to include files which were not exported, etc.
If you're making modifications to header files which are
relevant for userspace, say 'Y', and check the headers