Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

Pull misc kbuild updates from Michal Marek:
 "This is the non-critical part of kbuild for 3.17-rc1:

   - make help hint to use make -s with make kernelrelease et al.
   - moved a kbuild document to Documentation/kbuild where it belongs
   - four new Coccinelle scripts, one dropped and one fixed
   - new make kselftest target to run various tests on the kernel"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: kselftest - new make target to build and run kernel selftests
  Coccinelle: Script to replace if and BUG with BUG_ON
  Coccinelle: Script to detect incorrect argument to sizeof
  Coccinelle: Script to use ARRAY_SIZE instead of division of two sizeofs
  Coccinelle: Script to detect cast after memory allocation
  coccinelle/null: solve parse error
  Documentation: headers_install.txt is part of kbuild
  kbuild: make -s should be used with kernelrelease/kernelversion/image_name

2 files changed, 49 insertions, 0 deletions

diff --git a/Documentation/kbuild/00-INDEX b/Documentation/kbuild/00-INDEX
index e8d2b6d83a3d..8c5e6aa78004 100644
--- a/Documentation/kbuild/00-INDEX
+++ b/Documentation/kbuild/00-INDEX
@@ -1,5 +1,7 @@
 00-INDEX
         - this file: info on the kernel build process
+headers_install.txt
+        - how to export Linux headers for use by userspace
 kbuild.txt
         - developer information on kbuild
 kconfig.txt
diff --git a/Documentation/kbuild/headers_install.txt b/Documentation/kbuild/headers_install.txt
new file mode 100644
index 000000000000..951eb9f1e040
--- /dev/null
+++ b/Documentation/kbuild/headers_install.txt
@@ -0,0 +1,47 @@
+Exporting kernel headers for use by userspace
+=============================================
+
+The "make headers_install" command exports the kernel's header files in a
+form suitable for use by userspace programs.
+
+The linux kernel's exported header files describe the API for user space
+programs attempting to use kernel services.  These kernel header files are
+used by the system's C library (such as glibc or uClibc) to define available
+system calls, as well as constants and structures to be used with these
+system calls.  The C library's header files include the kernel header files
+from the "linux" subdirectory.  The system's libc headers are usually
+installed at the default location /usr/include and the kernel headers in
+subdirectories under that (most notably /usr/include/linux and
+/usr/include/asm).
+
+Kernel headers are backwards compatible, but not forwards compatible.  This
+means that a program built against a C library using older kernel headers
+should run on a newer kernel (although it may not have access to new
+features), but a program built against newer kernel headers may not work on an
+older kernel.
+
+The "make headers_install" command can be run in the top level directory of the
+kernel source code (or using a standard out-of-tree build).  It takes two
+optional arguments:
+
+  make headers_install ARCH=i386 INSTALL_HDR_PATH=/usr/include
+
+ARCH indicates which architecture to produce headers for, and defaults to the
+current architecture.  The linux/asm directory of the exported kernel headers
+is platform-specific, to see a complete list of supported architectures use
+the command:
+
+  ls -d include/asm-* | sed 's/.*-//'
+
+INSTALL_HDR_PATH indicates where to install the headers.  It defaults to
+"./usr/include".
+
+The command "make headers_install_all" exports headers for all architectures
+simultaneously.  (This is mostly of interest to distribution maintainers,
+who create an architecture-independent tarball from the resulting include
+directory.)  You also can use HDR_ARCH_LIST to specify list of architectures.
+Remember to provide the appropriate linux/asm directory via "mv" or "ln -s"
+before building a C library with headers exported this way.
+
+The kernel header export infrastructure is maintained by David Woodhouse
+<dwmw2@infradead.org>.