Pull Kbuild fixes from Masahiro Yamada:

 - fix O= building on dash

 - remove unused dependency in Makefile

 - fix default of a choice in Kconfig

 - fix typos and documentation style

 - fix command options unrecognized by sparse

* tag 'kbuild-fixes-v4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: clang: fix build failures with sparse check
  kbuild doc: a bundle of fixes on makefiles.txt
  Makefile: kselftest: fix grammar typo
  kbuild: Fix optimization level choice default
  kbuild: drop unused symverfile in Makefile.modpost
  kbuild: revert $(realpath ...) to $(shell cd ... && /bin/pwd)

We should avoid using the space character when passing arguments to
clang, because static code analysis check tool such as sparse may
misinterpret the arguments followed by spaces as build targets hence
cause the build to fail.

Signed-off-by: David Lin <dtwlin@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Pull objtool fix from Ingo Molnar:
 "A single objtool fix: avoid silently broken ORC debuginfo builds and
  error out instead"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Upgrade libelf-devel warning to error for CONFIG_ORC_UNWINDER

Correct typo in kselftest help text.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

I thought commit 8e9b46679923 ("kbuild: use $(abspath ...) instead of
$(shell cd ... && /bin/pwd)") was a safe conversion, but it changed
the behavior.

$(abspath ...) / $(realpath ...) does not expand shell special
characters, such as '~'.

Here is a simple Makefile example:

  ---------------->8----------------
  $(info /bin/pwd: $(shell cd ~/; /bin/pwd))
  $(info abspath: $(abspath ~/))
  $(info realpath: $(realpath ~/))
  all:
          @:
  ---------------->8----------------

  $ make
  /bin/pwd: /home/masahiro
  abspath: /home/masahiro/workspace/~
  realpath:

This can be a real problem if 'make O=~/foo' is invoked from another
Makefile or primitive shell like dash.

This commit partially reverts 8e9b46679923.

Fixes: 8e9b46679923 ("kbuild: use $(abspath ...) instead of $(shell cd ... && /bin/pwd)")
Reported-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Julien Grall <julien.grall@arm.com>

With CONFIG_ORC_UNWINDER, if the user doesn't have libelf-devel
installed, and they don't see the make warning, their ORC unwinder will
be silently broken.  Upgrade the warning to an error.

Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d9dfc39fb8240998820f9efb233d283a1ee96084.1507079417.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>