commit d5028ba8

 upstream.

Disable retpoline validation in objtool if your compiler sucks, and otherwise
select the validation stuff for CONFIG_RETPOLINE=y (most builds would already
have it set due to ORC).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit cfe17c9b upstream.

Geert reported commit ae6b289a ("kbuild: Set KBUILD_CFLAGS before
incl. arch Makefile") broke cross-compilation using a cross-compiler
that supports less compiler options than the host compiler.

For example,

  cc1: error: unrecognized command line option "-Wno-unused-but-set-variable"

This problem happens on architectures that setup CROSS_COMPILE in their
arch/*/Makefile.

Move the cc-option and cc-disable-warning back to the original position,
but keep the Clang target options untouched.

Fixes: ae6b289a

 ("kbuild: Set KBUILD_CFLAGS before incl. arch Makefile")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ae6b289a

 upstream.

Set the clang KBUILD_CFLAGS up before including arch/ Makefiles,
so that ld-options (etc.) can work correctly.

This fixes errors with clang such as ld-options trying to CC
against your host architecture, but LD trying to link against
your target architecture.
Signed-off-by: Chris Fries <cfries@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2c1f4f12

 upstream.

The top Makefile is divided into some sections such as mixed targets,
config targets, build targets, etc.

When we build mixed targets, Kbuild just invokes submake to process
them one by one.  In this case, compiler-related variables like CC,
KBUILD_CFLAGS, etc. are unneeded.

Check what kind of targets we are building first, and parse variables
for building only when necessary.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ba634ece

 upstream.

The first "_all" occurrence around line 120 is only visible when
KBUILD_SRC is unset.

If O=... is specified, the working directory is relocated, then the
only second occurrence around line 193 is visible, that is not set
to PHONY.

Move the first one to an always visible place.  This clarifies "_all"
is our default target and it is always set to PHONY.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0e410e15 upstream.

With KASAN enabled the kernel has two different memset() functions, one
with KASAN checks (memset) and one without (__memset).  KASAN uses some
macro tricks to use the proper version where required.  For example
memset() calls in mm/slub.c are without KASAN checks, since they operate
on poisoned slab object metadata.

The issue is that clang emits memset() calls even when there is no
memset() in the source code.  They get linked with improper memset()
implementation and the kernel fails to boot due to a huge amount of KASAN
reports during early boot stages.

The solution is to add -fno-builtin flag for files with KASAN_SANITIZE :=
n marker.

Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3ce120b1

 upstream.

It appears that hardened gentoo enables "-fstack-check" by default for
gcc.

That doesn't work _at_all_ for the kernel, because the kernel stack
doesn't act like a user stack at all: it's much smaller, and it doesn't
auto-expand on use.  So the extra "probe one page below the stack" code
generated by -fstack-check just breaks the kernel in horrible ways,
causing infinite double faults etc.

[ I have to say, that the particular code gcc generates looks very
  stupid even for user space where it works, but that's a separate
  issue.  ]
Reported-and-tested-by: Alexander Tsoy <alexander@tsoy.me>
Reported-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 11af8474

 upstream.

Rename the unwinder config options from:

  CONFIG_ORC_UNWINDER
  CONFIG_FRAME_POINTER_UNWINDER
  CONFIG_GUESS_UNWINDER

to:

  CONFIG_UNWINDER_ORC
  CONFIG_UNWINDER_FRAME_POINTER
  CONFIG_UNWINDER_GUESS

... in order to give them a more logical config namespace.
Suggested-by: Ingo Molnar <mingo@kernel.org>
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/73972fc7e2762e91912c6b9584582703d6f1b8cc.1507924831.git.jpoimboe@redhat.com

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 433dc2eb

 ]

Some $(call cc-option,...) are invoked very early, even before
KBUILD_CFLAGS, etc. are initialized.

The returned string from $(call cc-option,...) depends on
KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS.

Since they are exported, they are not empty when the top Makefile
is recursively invoked.

The recursion occurs in several places.  For example, the top
Makefile invokes itself for silentoldconfig.  "make tinyconfig",
"make rpm-pkg" are the cases, too.

In those cases, the second call of cc-option from the same line
runs a different shell command due to non-pristine KBUILD_CFLAGS.

To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS
must be initialized before any call of cc-option.  This avoids
garbage data in the .cache.mk file.

Move all calls of cc-option below the config targets because target
compiler flags are unnecessary for Kconfig.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>