commit a75bb4eb9e565b9f5115e2e8c07377ce32cbe69a upstream.

The clang option -Oz enables *aggressive* optimization for size,
which doesn't necessarily result in smaller images, but can have
negative impact on performance. Switch back to the less aggressive
-Os.

This reverts commit 6748cb3c.
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit ad15006cc78459d059af56729c4d9bed7c7fd860 upstream.

This causes an issue when trying to build with `make LD=ld.lld` if
ld.lld and the rest of your cross tools aren't in the same directory
(ex. /usr/local/bin) (as is the case for Android's build system), as the
GCC_TOOLCHAIN_DIR then gets set based on `which $(LD)` which will point
where LLVM tools are, not GCC/binutils tools are located.

Instead, select the GCC_TOOLCHAIN_DIR based on another tool provided by
binutils for which LLVM does not provide a substitute for, such as
elfedit.

Fixes: 785f11aa ("kbuild: Add better clang cross build support")
Link: https://github.com/ClangBuiltLinux/linux/issues/341Suggested-by: NNathan Chancellor <natechancellor@gmail.com>
Reviewed-by: NNathan Chancellor <natechancellor@gmail.com>
Tested-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 9390dff66a52d1a60c6e517d8fa6cdbdffc83cb1 ]

If include/config/auto.conf.cmd is lost for some reasons, it is not
self-healing, so the top Makefile misses to run syncconfig.
Move include/config/auto.conf.cmd to the target side.

I used a pattern rule instead of a normal rule here although it is
a bit gross.

If the rule were written with a normal rule like this,

  include/config/auto.conf \
  include/config/auto.conf.cmd \
  include/config/tristate.conf: $(KCONFIG_CONFIG)
          $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig

... syncconfig would be executed per target.

Using a pattern rule makes sure that syncconfig is executed just once
because Make assumes the recipe will create all of the targets.

Here is a quote from the GNU Make manual [1]:

"Pattern rules may have more than one target. Unlike normal rules,
this does not act as many different rules with the same prerequisites
and recipe. If a pattern rule has multiple targets, make knows that
the rule's recipe is responsible for making all of the targets. The
recipe is executed only once to make all the targets. When searching
for a pattern rule to match a target, the target patterns of a rule
other than the one that matches the target in need of a rule are
incidental: make worries only about giving a recipe and prerequisites
to the file presently in question. However, when this file's recipe is
run, the other targets are marked as having been updated themselves."

[1]: https://www.gnu.org/software/make/manual/html_node/Pattern-Intro.htmlSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 056d28d135bca0b1d0908990338e00e9dadaf057 upstream.

If it is not in the default location, compilation fails at several points.
Signed-off-by: NRolf Eike Beer <eb@emlix.com>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/91a25e992566a7968fedc89ec80e7f4c83ad0548.1553622500.git.jpoimboe@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3bd9805090af843b25f97ffe5049f20ade1d86d6 upstream.

The powerpc makefile will use these in it's boot wrapper.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 238bcbc4e07fad2fff99c5b157d0c37ccd4d093c upstream.

Collect basic Clang options such as --target, --prefix, --gcc-toolchain,
-no-integrated-as into a single variable CLANG_FLAGS so that it can be
easily reused in other parts of Makefile.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Acked-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit dbe27a002ef8573168cb64e181458ea23a74e2b6 upstream.

We are still a way off the Clang's integrated assembler support for
the kernel. Hence, -no-integrated-as is mandatory to build the kernel
with Clang. If you had an ancient version of Clang that does not
recognize this option, you would not be able to compile the kernel
anyway.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ef7cfd00b2caf6edeb7f169682b64be2d0a798cf ]

For the same reason as commit 25896d073d8a ("x86/build: Fix compiler
support check for CONFIG_RETPOLINE"), you cannot put this $(error ...)
into the parse stage of the top Makefile.

Perhaps I'd propose a more sophisticated solution later, but this is
the best I can do for now.

Link: https://lkml.org/lkml/2017/12/25/211Reported-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Reported-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
Reported-by: NQian Cai <cai@lca.pw>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NQian Cai <cai@lca.pw>
Signed-off-by: NSasha Levin <sashal@kernel.org>