commit 6f303d60534c46aa1a239f29c321f95c83dda748 upstream.
We already did this for clang, but now gcc has that warning too. Yes,
yes, the address may be unaligned. And that's kind of the point.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 6748cb3c299de1ffbe56733647b01dbcc398c419.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Sasha 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: 785f11aa595b ("kbuild: Add better clang cross build support")
Link: https://github.com/ClangBuiltLinux/linux/issues/341
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 217c3e0196758662aa0429863b09d1c13da1c5d6 upstream.
They are too noisy
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9f3f1fd299768782465cb32cdf0dd4528d11f26b upstream.
cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines
whether an option is supported or not. This is fine for options used to
build the kernel itself, however some components like the x86 boot code
use a different set of flags.
Add the new macro __cc-option which is a more generic version of
cc-option with additional parameters. One parameter is the compiler
with which the check should be performed, the other the compiler options
to be used instead KBUILD_C*FLAGS.
Refactor cc-option and hostcc-option to use __cc-option and move
hostcc-option to scripts/Kbuild.include.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Fix conflicts due to lack of CC_OPTION_CFLAGS and hostcc-option
wasn't added until v4.8 so no point including it in this tree]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef8c4ed9db80261f397f0c0bf723684601ae3b52 upstream.
When using a GCC cross toolchain which is not in a compiled in
Clang search path, Clang reverts to the system assembler and
linker. This leads to assembler or linker errors, depending on
which tool is first used for a given architecture.
It seems that Clang is not searching $PATH for a matching
assembler or linker.
Make sure that Clang picks up the correct assembler or linker by
passing the cross compilers bin directory as search path.
This allows to use Clang provided by distributions with GCC
toolchains not in /usr/bin.
Link: https://github.com/ClangBuiltLinux/linux/issues/78
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-and-tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Adjust context]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0f0e8de334c54c38818a4a5390a39aa09deff5bf upstream.
In order to make sure compiler flag detection for ARM works
correctly the no-integrated-as flags need to be set before
including the arch specific Makefile.
Fixes: cfe17c9bbe6a ("kbuild: move cc-option and cc-disable-warning after incl. arch Makefile")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Adjust context]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0a5f41767444cc3b4fc5573921ab914b4f78baaa upstream.
Currently, GCC disables -Wunused-const-variable, but not
-Wunused-variable, so warns unused variables if they are
non-constant.
While, Clang does not warn unused variables at all regardless of
the const qualifier because -Wno-unused-const-variable is implied
by the stronger option -Wno-unused-variable.
Disable -Wunused-const-variable instead of -Wunused-variable so that
GCC and Clang work in the same way.
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit df16aaac26e92e97ab7234d3f93c953466adc4b5 upstream.
When compiling with `make CC=clang HOSTCC=clang`, I was seeing warnings
that clang did not recognize -fno-delete-null-pointer-checks for HOSTCC
targets. These were added in commit 61163efae0 ("kbuild: LLVMLinux:
Add Kbuild support for building kernel with Clang").
Clang does not support -fno-delete-null-pointer-checks, so adding it to
HOSTCFLAGS if HOSTCC is clang does not make sense.
It's not clear why the other warnings were disabled, and just for
HOSTCFLAGS, but I can remove them, add -Werror to HOSTCFLAGS and compile
with clang just fine.
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Adjust context]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bb3f38c3c5b759163e09b9152629cc789731de47 upstream.
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>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cfe17c9bbe6a673fdafdab179c32b355ed447f66 upstream.
Geert reported commit ae6b289a3789 ("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: ae6b289a3789 ("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>
[nc: Adjust context]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ae6b289a37890909fea0e4a1666e19377fa0ed2c 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>
[nc: Adjust context]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bfb38988c51e440fd7062ddf3157f7d8b1dd5d70 upstream.
clang generates plenty of these warnings in different parts of the code,
to an extent that the warnings are little more than noise. Disable the
'address-of-packed-member' warning.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 433db3e260bc8134d4a46ddf20b3668937e12556 upstream.
Add rules to kbuild in order to generate LLVM assembly files with the .ll
extension when using clang.
# from c code
make CC=clang kernel/pid.ll
Signed-off-by: Vinícius Tinti <viniciustinti@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Fix conflicts due to lack of commit 6b90bd4ba40b3 in linux-4.4.y]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a0ae981eba8f07dbc74bce38fd3a462b69a5bc8e upstream.
Since commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to
cc-option to support clang"), cc-option and friends work nicely
for clang.
However, -Wno-unknown-warning-option makes clang happy with any
unknown warning options even if -Werror is specified.
Once -Wno-unknown-warning-option is added, any succeeding call of
cc-disable-warning is evaluated positive, then unknown warning
options are accepted. This should be dropped.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a37c45cd82e62a361706b9688a984a3a63957321 upstream.
The Linux Kernel relies on GCC's acceptance of inline assembly as an
opaque object which will not have any validation performed on the content.
The current behaviour in LLVM is to perform validation of the contents by
means of parsing the input if the MC layer can handle it.
Disable clangs integrated assembler and use the GNU assembler instead.
Wording-mostly-from: Saleem Abdulrasool <compnerd@compnerd.org>
Signed-off-by: Michael Davidson <md@google.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
