Now that stack validation is an optional feature of objtool, add
CONFIG_OBJTOOL and replace most usages of CONFIG_STACK_VALIDATION with
it.

CONFIG_STACK_VALIDATION can now be considered to be frame-pointer
specific.  CONFIG_UNWINDER_ORC is already inherently valid for live
patching, so no need to "validate" it.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/939bf3d85604b2a126412bf11af6e3bd3b872bcb.1650300597.git.jpoimboe@redhat.com

Building 5.10-rc1 in a setgid directory failed with the following
error:

dpkg-deb: error: control directory has bad permissions 2755 (must be
>=0755 and <=0775)

When building with fakeroot, the earlier chown call would have removed
the setgid bits, but in a rootless build they remain.

Fixes: 3e8541803624 ("builddeb: Enable rootless builds")
Cc: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Sven Joachim <svenjoac@gmx.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Since commit 269a535ca931 ("modpost: generate vmlinux.symvers and
reuse it for the second modpost"), with CONFIG_MODULES disabled,
"make deb-pkg" (or "make bindeb-pkg") fails with:

  find: ‘Module.symvers’: No such file or directory

If CONFIG_MODULES is disabled, it doesn't really make sense to build
the linux-headers package.

Fixes: 269a535ca931 ("modpost: generate vmlinux.symvers and reuse it for the second modpost")
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This makes it possible to build the Debian packages without requiring
(pseudo-)root privileges, when the build drivers support this mode
of operation.

See-Also: /usr/share/doc/dpkg/rootless-builds.txt.gz
Signed-off-by: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

We should not be encoding the timestamp, otherwise we end up generating
unreproducible files that cascade into unreproducible packages.

Signed-off-by: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

There was a request to preprocess the module linker script like we
do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512)

The difference between vmlinux.lds and module.lds is that the latter
is needed for external module builds, thus must be cleaned up by
'make mrproper' instead of 'make clean'. Also, it must be created
by 'make modules_prepare'.

You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by
'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to
arch/$(SRCARCH)/include/asm/module.lds.h, which is included from
scripts/module.lds.S.

scripts/module.lds is fine because 'make clean' keeps all the
build artifacts under scripts/.

You can add arch-specific sections in <asm/module.lds.h>.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>

Deploy user-space headers (linux-libc-dev package) in a separate
function for readability.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Deploy kernel headers (linux-headers package) in a separate function
for readability.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The kernel build has already been done before builddeb is invoked.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

The commands surrounded by ( ... ) is run in a sub-shell, but you do
not have to spawn a sub-shell for every single line.

Use just one ( ... ) for creating debian/hdrsrcfiles.

For tar, use -C option instead.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>