Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
* MAINTAINERS: add CLANG/LLVM BUILD SUPPORT info
commit 8708e13c6a0600625eea3aebd027c0715a5d2bb2 upstream.
Add keyword support so that our mailing list gets cc'ed for clang/llvm
patches. We're pretty active on our mailing list so far as code review.
There are numerous Googlers like myself that are paid to support
building the Linux kernel with Clang and LLVM.
Link: http://lkml.kernel.org/r/20190620001907.255803-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Joe Perches <joe@perches.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>
* Documentation/llvm: add documentation on building w/ Clang/LLVM
commit fcf1b6a35c16ac500fa908a4022238e5d666eabf upstream.
added to kbuild documentation. Provides more official info on building
kernels with Clang and LLVM than our wiki.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nd: hunk against Documentation/kbuild/index.rst dropped due to not backporting
commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Documentation/llvm: fix the name of llvm-size
commit 0f44fbc162b737ff6251ae248184390ae2279fee upstream.
The tool is called llvm-size, not llvm-objsize.
Fixes: fcf1b6a35c16 ("Documentation/llvm: add documentation on building w/ Clang/LLVM")
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: mark prepare0 as PHONY to fix external module build
[ Upstream commit e00d8880481497474792d28c14479a9fb6752046 ]
Commit c3ff2a5193fa ("powerpc/32: add stack protector support")
caused kernel panic on PowerPC when an external module is used with
CONFIG_STACKPROTECTOR because the 'prepare' target was not executed
for the external module build.
Commit e07db28eea38 ("kbuild: fix single target build for external
module") turned it into a build error because the 'prepare' target is
now executed but the 'prepare0' target is missing for the external
module build.
External module on arm/arm64 with CONFIG_STACKPROTECTOR_PER_TASK is
also broken in the same way.
Move 'PHONY += prepare0' to the common place. GNU Make is fine with
missing rule for phony targets. I also removed the comment which is
wrong irrespective of this commit.
I minimize the change so it can be easily backported to 4.20.x
To fix v4.20, please backport e07db28eea38 ("kbuild: fix single target
build for external module"), and then this commit.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201891
Fixes: e07db28eea38 ("kbuild: fix single target build for external module")
Fixes: c3ff2a5193fa ("powerpc/32: add stack protector support")
Fixes: 189af4657186 ("ARM: smp: add support for per-task stack canaries")
Fixes: 0a1213fa7432 ("arm64: enable per-task stack canaries")
Cc: linux-stable <stable@vger.kernel.org> # v4.20
Reported-by: Samuel Holland <samuel@sholland.org>
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Sasha Levin <sashal@kernel.org>
* Makefile: remove CCACHE for now
* kbuild: add OBJSIZE variable for the size tool
commit 7bac98707f65b93bf994ef4e99b1eb9e7dbb9c32 upstream.
Define and export OBJSIZE variable for "size" tool from binutils to be
used in architecture specific Makefiles (naming the variable just "SIZE"
would be too risky). In particular this tool is useful to perform checks
that early boot code is not using bss section (which might have not been
zeroed yet or intersects with initrd or other files boot loader might
have put right after the linux kernel).
Link: http://lkml.kernel.org/r/patch-1.thread-2257a1.git-188f5a3d81d5.your-ad-here.call-01565088755-ext-5120@work.hours
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/boot: kbuild: allow readelf executable to be specified
commit eefb8c124fd969e9a174ff2bedff86aa305a7438 upstream.
Introduce a new READELF variable to top-level Makefile, so the name of
readelf binary can be specified.
Before this change the name of the binary was hardcoded to
"$(CROSS_COMPILE)readelf" which might not be present for every
toolchain.
This allows to build with LLVM Object Reader by using make parameter
READELF=llvm-readelf.
Link: https://github.com/ClangBuiltLinux/linux/issues/771
Signed-off-by: Dmitry Golovin <dima@golovin.in>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: wan: wanxl: use allow to pass CROSS_COMPILE_M68k for rebuilding firmware
commit 63b903dfebdea92aa92ad337d8451a6fbfeabf9d upstream.
As far as I understood from the Kconfig help text, this build rule is
used to rebuild the driver firmware, which runs on an old m68k-based
chip. So, you need m68k tools for the firmware rebuild.
wanxl.c is a PCI driver, but CONFIG_M68K does not select CONFIG_HAVE_PCI.
So, you cannot enable CONFIG_WANXL_BUILD_FIRMWARE for ARCH=m68k. In other
words, ifeq ($(ARCH),m68k) is false here.
I am keeping the dead code for now, but rebuilding the firmware requires
'as68k' and 'ld68k', which I do not have in hand.
Instead, the kernel.org m68k GCC [1] successfully built it.
Allowing a user to pass in CROSS_COMPILE_M68K= is handier.
[1] https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/9.2.0/x86_64-gcc-9.2.0-nolibc-m68k-linux.tar.xz
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: wan: wanxl: use $(M68KCC) instead of $(M68KAS) for rebuilding firmware
commit 734f3719d3438f9cc181d674c33ca9762e9148a1 upstream.
The firmware source, wanxlfw.S, is currently compiled by the combo of
$(CPP) and $(M68KAS). This is not what we usually do for compiling *.S
files. In fact, this Makefile is the only user of $(AS) in the kernel
build.
Instead of combining $(CPP) and (AS) from different tool sets, using
$(M68KCC) as an assembler driver is simpler, and saner.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: remove AS variable
commit aa824e0c962b532d5073cbb41b2efcd6f5e72bae upstream.
As commit 5ef872636ca7 ("kbuild: get rid of misleading $(AS) from
documents") noted, we rarely use $(AS) directly in the kernel build.
Now that the only/last user of $(AS) in drivers/net/wan/Makefile was
converted to $(CC), $(AS) is no longer used in the build process.
You can still pass in AS=clang, which is just a switch to turn on
the LLVM integrated assembler.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: replace AS=clang with LLVM_IAS=1
commit 7e20e47c70f810d678d02941fa3c671209c4ca97 upstream.
The 'AS' variable is unused for building the kernel. Only the remaining
usage is to turn on the integrated assembler. A boolean flag is a better
fit for this purpose.
AS=clang was added for experts. So, I replaced it with LLVM_IAS=1,
breaking the backward compatibility.
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
commit a0d1c951ef08ed24f35129267e3595d86f57f5d3 upstream.
As Documentation/kbuild/llvm.rst implies, building the kernel with a
full set of LLVM tools gets very verbose and unwieldy.
Provide a single switch LLVM=1 to use Clang and LLVM tools instead
of GCC and Binutils. You can pass it from the command line or as an
environment variable.
Please note LLVM=1 does not turn on the integrated assembler. You need
to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the
integrated assembler, I think we can make it default.
We discussed what we need, and we agreed to go with a simple boolean
flag that switches both target and host tools:
https://lkml.org/lkml/2020/3/28/494
https://lkml.org/lkml/2020/4/3/43
Some items discussed, but not adopted:
- LLVM_DIR
When multiple versions of LLVM are installed, I just thought supporting
LLVM_DIR=/path/to/my/llvm/bin/ might be useful.
CC = $(LLVM_DIR)clang
LD = $(LLVM_DIR)ld.lld
...
However, we can handle this by modifying PATH. So, we decided to not do
this.
- LLVM_SUFFIX
Some distributions (e.g. Debian) package specific versions of LLVM with
naming conventions that use the version as a suffix.
CC = clang$(LLVM_SUFFIX)
LD = ld.lld(LLVM_SUFFIX)
...
will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc.,
but the suffixed versions in /usr/bin/ are symlinks to binaries in
/usr/lib/llvm-#/bin/, so this can also be handled by PATH.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
[nd: hunk against Documentation/kbuild/kbuild.rst dropped due to not backporting
commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* FROMLIST: Kbuild: do not emit debug info for assembly with LLVM_IAS=1
Clang's integrated assembler produces the warning for assembly files:
warning: DWARF2 only supports one section per compilation unit
If -Wa,-gdwarf-* is unspecified, then debug info is not emitted for
assembly sources (it is still emitted for C sources). This will be
re-enabled for newer DWARF versions in a follow up patch.
Enables defconfig+CONFIG_DEBUG_INFO to build cleanly with
LLVM=1 LLVM_IAS=1 for x86_64 and arm64.
Reported-by: Dmitry Golovin <dima@golovin.in>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Dmitry Golovin <dima@golovin.in>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/716
Bug: 141693040
Link: https://lore.kernel.org/lkml/20201109183528.1391885-1-ndesaulniers@google.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: I55c8ad79dfeaae478c8de52d484e76fb2e37c194
* x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
commit 4d6ffa27b8e5116c0abb318790fd01d4e12d75e6 upstream.
Commit
393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions")
added .weak directives to arch/x86/lib/mem*_64.S instead of changing the
existing ENTRY macros to WEAK. This can lead to the assembly snippet
.weak memcpy
...
.globl memcpy
which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy
with LLVM's integrated assembler before LLVM 12. LLVM 12 (since
https://reviews.llvm.org/D90108) will error on such an overridden symbol
binding.
Commit
ef1e03152cb0 ("x86/asm: Make some functions local")
changed ENTRY in arch/x86/lib/memcpy_64.S to SYM_FUNC_START_LOCAL, which
was ineffective due to the preceding .weak directive.
Use the appropriate SYM_FUNC_START_WEAK instead.
Fixes: 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions")
Fixes: ef1e03152cb0 ("x86/asm: Make some functions local")
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103012358.168682-1-maskray@google.com
[nd: backport due to missing
commit e9b9d020c487 ("x86/asm: Annotate aliases")
commit ffedeeb780dc ("linkage: Introduce new macros for assembler symbols")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* arm64: lse: fix LSE atomics with LLVM's integrated assembler
commit e0d5896bd356cd577f9710a02d7a474cdf58426b upstream.
Unlike gcc, clang considers each inline assembly block to be independent
and therefore, when using the integrated assembler for inline assembly,
any preambles that enable features must be repeated in each block.
This change defines __LSE_PREAMBLE and adds it to each inline assembly
block that has LSE instructions, which allows them to be compiled also
with clang's assembler.
Link: https://github.com/ClangBuiltLinux/linux/issues/671
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Andrew Murray <andrew.murray@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
[nd: backport adjusted due to missing:
commit addfc38672c7 ("arm64: atomics: avoid out-of-line ll/sc atomics")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Makefile: Move -Wno-unused-but-set-variable out of GCC only block
commit 885480b084696331bea61a4f7eba10652999a9c1 upstream.
Currently, -Wunused-but-set-variable is only supported by GCC so it is
disabled unconditionally in a GCC only block (it is enabled with W=1).
clang currently has its implementation for this warning in review so
preemptively move this statement out of the GCC only block and wrap it
with cc-disable-warning so that both compilers function the same.
Cc: stable@vger.kernel.org
Link: https://reviews.llvm.org/D100581
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nc: Backport, workaround lack of e2079e93f562 in older branches]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fortify: Explicitly disable Clang support
commit a52f8a59aef46b59753e583bf4b28fccb069ce64 upstream.
Clang has never correctly compiled the FORTIFY_SOURCE defenses due to
a couple bugs:
Eliding inlines with matching __builtin_* names
https://bugs.llvm.org/show_bug.cgi?id=50322
Incorrect __builtin_constant_p() of some globals
https://bugs.llvm.org/show_bug.cgi?id=41459
In the process of making improvements to the FORTIFY_SOURCE defenses, the
first (silent) bug (coincidentally) becomes worked around, but exposes
the latter which breaks the build. As such, Clang must not be used with
CONFIG_FORTIFY_SOURCE until at least latter bug is fixed (in Clang 13),
and the fortify routines have been rearranged.
Update the Kconfig to reflect the reality of the current situation.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOd=A+ueGV2ihdy5GtgR2fQbcXjjAtVxv3=cPjffpebZB7A@mail.gmail.com
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Makefile.debug: re-enable debug info for .S files
This is _not_ an upstream commit and just for 4.19.y only. It is based
on commit 32ef9e5054ec0321b9336058c58ec749e9c6b0fe upstream.
Alexey reported that the fraction of unknown filename instances in
kallsyms grew from ~0.3% to ~10% recently; Bill and Greg tracked it down
to assembler defined symbols, which regressed as a result of:
commit b8a9092330da ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
In that commit, I allude to restoring debug info for assembler defined
symbols in a follow up patch, but it seems I forgot to do so in
commit a66049e2cf0e ("Kbuild: make DWARF version a choice")
Fixes: b8a9092330da ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* perf llvm: Return -ENOMEM when asprintf() fails
[ Upstream commit c435c166dcf526ac827bc964d82cc0d5e7a1fd0b ]
Zhihao sent a patch but it made llvm__compile_bpf() return what
asprintf() returns on error, which is just -1, but since this function
returns -errno, fix it by returning -ENOMEM for this case instead.
Fixes: cb76371441d098 ("perf llvm: Allow passing options to llc ...")
Fixes: 5eab5a7ee032ac ("perf llvm: Display eBPF compiling command ...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210609115945.2193194-1-chengzhihao1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
* perf llvm: Fix inadvertent file creation
[ Upstream commit 9f19aab47ced012eddef1e2bc96007efc7713b61 ]
The LLVM template is first echo-ed into command_out and then
command_out executed. The echo surrounds the template with double
quotes, however, the template itself may contain quotes. This is
generally innocuous but in tools/perf/tests/bpf-script-test-prologue.c
we see:
...
SEC("func=null_lseek file->f_mode offset orig")
...
where the first double quote ends the double quote of the echo, then
the > redirects output into a file called f_mode.
To avoid this inadvertent behavior substitute redirects and similar
characters to be ASCII control codes, then substitute the output in
the echo back again.
Fixes: 5eab5a7ee032acaa ("perf llvm: Display eBPF compiling command in debug output")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: llvm@lists.linux.dev
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230105082609.344538-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
* BACKPORT: arm64: Fix minor issues with the dcache_by_line_op macro
[ Upstream commit 33309ecda0070506c49182530abe7728850ebe78 ]
The dcache_by_line_op macro suffers from a couple of small problems:
First, the GAS directives that are currently being used rely on
assembler behavior that is not documented, and probably not guaranteed
to produce the correct behavior going forward. As a result, we end up
with some undefined symbols in cache.o:
$ nm arch/arm64/mm/cache.o
...
U civac
...
U cvac
U cvap
U cvau
This is due to the fact that the comparisons used to select the
operation type in the dcache_by_line_op macro are comparing symbols
not strings, and even though it seems that GAS is doing the right
thing here (undefined symbols by the same name are equal to each
other), it seems unwise to rely on this.
Second, when patching in a DC CVAP instruction on CPUs that support it,
the fallback path consists of a DC CVAU instruction which may be
affected by CPU errata that require ARM64_WORKAROUND_CLEAN_CACHE.
Solve these issues by unrolling the various maintenance routines and
using the conditional directives that are documented as operating on
strings. To avoid the complexity of nested alternatives, we move the
DC CVAP patching to __clean_dcache_area_pop, falling back to a branch
to __clean_dcache_area_poc if DCPOP is not supported by the CPU.
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Change-Id: I006dd10a0f3706b9302832d04c65262861239709
* BACKPORT: crypto: arm64/aes-modes - get rid of literal load of addend vector
commit ed6ed11830a9ded520db31a6e2b69b6b0a1eb0e2 upstream.
Replace the literal load of the addend vector with a sequence that
performs each add individually. This sequence is only 2 instructions
longer than the original, and 2% faster on Cortex-A53.
This is an improvement by itself, but also works around a Clang issue,
whose integrated assembler does not implement the GNU ARM asm syntax
completely, and does not support the =literal notation for FP registers
(more info at https://bugs.llvm.org/show_bug.cgi?id=38642)
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: Ic8f7adcd28bd2da57b465a8e11e9d55b5669a539
* crypto: arm64/aes-ce-cipher - match round key endianness with generic code
In order to be able to reuse the generic AES code as a fallback for
situations where the NEON may not be used, update the key handling
to match the byte order of the generic code: it stores round keys
as sequences of 32-bit quantities rather than streams of bytes, and
so our code needs to be updated to reflect that.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Change-Id: Ia5d6a7464a33240cafc544e79becd47018ecb703
* BACKPORT: crypto: arm64/aes-ce-cipher - move assembler code to .S file
commit 019cd46984d04703a39924178f503a98436ac0d7 upstream.
Most crypto drivers involving kernel mode NEON take care to put the code
that actually touches the NEON register file in a separate compilation
unit, to prevent the compiler from reordering code that preserves or
restores the NEON context with code that may corrupt it. This is
necessary because we currently have no way to express the restrictions
imposed upon use of the NEON in kernel mode in a way that the compiler
understands.
However, in the case of aes-ce-cipher, it did not seem unreasonable to
deviate from this rule, given how it does not seem possible for the
compiler to reorder cross object function calls with asm blocks whose
in- and output constraints reflect that it reads from and writes to
memory.
Now that LTO is being proposed for the arm64 kernel, it is time to
revisit this. The link time optimization may replace the function
calls to kernel_neon_begin() and kernel_neon_end() with instantiations
of the IR that make up its implementation, allowing further reordering
with the asm block.
So let's clean this up, and move the asm() blocks into a separate .S
file.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-By: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Matthias Kaehlcke <mka@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ bgcngm: Backported to 4.9 ]
Signed-off-by: Bruno Martins <bgcngm@gmail.com>
Change-Id: I7b271d83a3d5baf81aa5fca69cd4f2817945a477
* FROMLIST: Makefile: lld: tell clang to use lld
This is needed because clang doesn't select which linker to use based on
$LD but rather -fuse-ld=lld. This is problematic especially for
cc-ldoption, which checks for linker flag support via invoking the
compiler, rather than the linker.
(am from https://lkml.org/lkml/2019/2/11/1947)
Link: https://github.com/ClangBuiltLinux/linux/issues/342
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>
Bug: 63740206
Change-Id: I3edf2f0f6c0bac842bef22194bd48a993fc0e3c0
Signed-off-by: Yousef Algadri <yusufgadrie@gmail.com>
Signed-off-by: Raphiel Rollerscaperers <rapherion@raphielgang.org>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* arm64: add endianness option to LDFLAGS instead of LD
With the recent syntax extension, Kconfig is now able to evaluate the
compiler / toolchain capability.
However, accumulating flags to 'LD' is not compatible with the way
it works; 'LD' must be passed to Kconfig to call $(ld-option,...)
from Kconfig files. If you tweak 'LD' in arch Makefile depending on
CONFIG_CPU_BIG_ENDIAN, this would end up with circular dependency
between Makefile and Kconfig.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Change-Id: I8a7654684975d45e979917e3b1c4b6249dec02ec
* arm64: build with baremetal linker target instead of Linux when available
Not all toolchains have the baremetal elf targets, RedHat/Fedora ones
in particular. So, probe for whether it's available and use the previous
(linux) targets if it isn't.
Reported-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Kocialkowski <contact@paulk.fr>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Change-Id: Icf5462a8318b347cf11559c1654886c48c7a62b5
* FROMLIST: Makefile: lld: set -O2 linker flag when linking with LLD
For arm64:
0.34% size improvement with lld -O2 over lld for vmlinux.
3.3% size improvement with lld -O2 over lld for Image.lz4-dtb.
(am from https://lkml.org/lkml/2019/2/11/1949)
Change-Id: Ibdc7ecc9861562305b49456d6d37274ce8075e22
Link: https://github.com/ClangBuiltLinux/linux/issues/343
Suggested-by: Rui Ueyama <ruiu@google.com>
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>
Bug: 63740206
Signed-off-by: Yousef Algadri <yusufgadrie@gmail.com>
Signed-off-by: Raphiel Rollerscaperers <rapherion@raphielgang.org>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* kbuild: clear LDFLAGS in the top Makefile
The kernel needs to be compiled as a LP64 binary for ARM64, even when
using a compiler that defaults to code-generation for the ILP32 ABI.
Consequently, we need to explicitly pass '-mabi=lp64' (supported on
gcc-4.9 and newer).
Signed-off-by: Andrew Pinski <Andrew.Pinski@caviumnetworks.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Reviewed-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Change-Id: Ife00e01e3e3a6d85841b88c2f1a042617bd61500
* BACKPORT: arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S
commit ec9d78070de986ecf581ea204fd322af4d2477ec upstream.
Commit 39d114ddc682 ("arm64: add KASAN support") added .weak directives to
arch/arm64/lib/mem*.S instead of changing the existing SYM_FUNC_START_PI
macros. This can lead to the assembly snippet `.weak memcpy ... .globl
memcpy` which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL
memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since
https://reviews.llvm.org/D90108) will error on such an overridden symbol
binding.
Use the appropriate SYM_FUNC_START_WEAK_PI instead.
Fixes: 39d114ddc682 ("arm64: add KASAN support")
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201029181951.1866093-1-maskray@google.com
Signed-off-by: Will Deacon <will@kernel.org>
[nd: backport to adjust for missing:
commit 3ac0f4526dfb ("arm64: lib: Use modern annotations for assembly functions")
commit 35e61c77ef38 ("arm64: asm: Add new-style position independent function annotations")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: Ibebbfa15f3337b5a2ac88ba683c5e429758d7a98
* arm64: relocatable: fix inconsistencies in linker script and options
readelf complains about the section layout of vmlinux when building
with CONFIG_RELOCATABLE=y (for KASLR):
readelf: Warning: [21]: Link field (0) should index a symtab section.
readelf: Warning: [21]: Info field (0) should index a relocatable section.
Also, it seems that our use of '-pie -shared' is contradictory, and
thus ambiguous. In general, the way KASLR is wired up at the moment
is highly tailored to how ld.bfd happens to implement (and conflate)
PIE executables and shared libraries, so given the current effort to
support other toolchains, let's fix some of these issues as well.
- Drop the -pie linker argument and just leave -shared. In ld.bfd,
the differences between them are unclear (except for the ELF type
of the produced image [0]) but lld chokes on seeing both at the
same time.
- Rename the .rela output section to .rela.dyn, as is customary for
shared libraries and PIE executables, so that it is not misidentified
by readelf as a static relocation section (producing the warnings
above).
- Pass the -z notext and -z norelro options to explicitly instruct the
linker to permit text relocations, and to omit the RELRO program
header (which requires a certain section layout that we don't adhere
to in the kernel). These are the defaults for current versions of
ld.bfd.
- Discard .eh_frame and .gnu.hash sections to avoid them from being
emitted between .head.text and .text, screwing up the section layout.
These changes only affect the ELF image, and produce the same binary
image.
[0] b9dce7f1ba01 ("arm64: kernel: force ET_DYN ELF type for ...")
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Smith <peter.smith@linaro.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
* Makefile: Enable MLGO for register allocation
This enables Machine Learning Guided Optimizations (MLGO) for register
allocation. MLGO supported toolchain needed for that feature.
* kbuild: Add support for LLVM's Polly optimizer
This adds support for compiling the kernel with optimizations offered
by LLVM's polyhedral loop optimizer known as Polly, which can improve
performance by improving cache locality in loops. Note that LLVM is not
compiled with Polly by default -- it must be enabled explicitly.
Signed-off-by: halibw <bymark256@gmail.com>
* Makefile: llvm / poly optimize flags
* Makefile: Exynos9810 mtunes
* defconfig: set pstore compression to LZO-RLE
This is optimized for zeroed memory also uses less cpu and fast
* MAINTAINERS: add CLANG/LLVM BUILD SUPPORT info
commit 8708e13c6a0600625eea3aebd027c0715a5d2bb2 upstream.
Add keyword support so that our mailing list gets cc'ed for clang/llvm
patches. We're pretty active on our mailing list so far as code review.
There are numerous Googlers like myself that are paid to support
building the Linux kernel with Clang and LLVM.
Link: http://lkml.kernel.org/r/20190620001907.255803-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Joe Perches <joe@perches.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>
* Documentation/llvm: add documentation on building w/ Clang/LLVM
commit fcf1b6a35c16ac500fa908a4022238e5d666eabf upstream.
added to kbuild documentation. Provides more official info on building
kernels with Clang and LLVM than our wiki.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nd: hunk against Documentation/kbuild/index.rst dropped due to not backporting
commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Documentation/llvm: fix the name of llvm-size
commit 0f44fbc162b737ff6251ae248184390ae2279fee upstream.
The tool is called llvm-size, not llvm-objsize.
Fixes: fcf1b6a35c16 ("Documentation/llvm: add documentation on building w/ Clang/LLVM")
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: add OBJSIZE variable for the size tool
commit 7bac98707f65b93bf994ef4e99b1eb9e7dbb9c32 upstream.
Define and export OBJSIZE variable for "size" tool from binutils to be
used in architecture specific Makefiles (naming the variable just "SIZE"
would be too risky). In particular this tool is useful to perform checks
that early boot code is not using bss section (which might have not been
zeroed yet or intersects with initrd or other files boot loader might
have put right after the linux kernel).
Link: http://lkml.kernel.org/r/patch-1.thread-2257a1.git-188f5a3d81d5.your-ad-here.call-01565088755-ext-5120@work.hours
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/boot: kbuild: allow readelf executable to be specified
commit eefb8c124fd969e9a174ff2bedff86aa305a7438 upstream.
Introduce a new READELF variable to top-level Makefile, so the name of
readelf binary can be specified.
Before this change the name of the binary was hardcoded to
"$(CROSS_COMPILE)readelf" which might not be present for every
toolchain.
This allows to build with LLVM Object Reader by using make parameter
READELF=llvm-readelf.
Link: https://github.com/ClangBuiltLinux/linux/issues/771
Signed-off-by: Dmitry Golovin <dima@golovin.in>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: wan: wanxl: use allow to pass CROSS_COMPILE_M68k for rebuilding firmware
commit 63b903dfebdea92aa92ad337d8451a6fbfeabf9d upstream.
As far as I understood from the Kconfig help text, this build rule is
used to rebuild the driver firmware, which runs on an old m68k-based
chip. So, you need m68k tools for the firmware rebuild.
wanxl.c is a PCI driver, but CONFIG_M68K does not select CONFIG_HAVE_PCI.
So, you cannot enable CONFIG_WANXL_BUILD_FIRMWARE for ARCH=m68k. In other
words, ifeq ($(ARCH),m68k) is false here.
I am keeping the dead code for now, but rebuilding the firmware requires
'as68k' and 'ld68k', which I do not have in hand.
Instead, the kernel.org m68k GCC [1] successfully built it.
Allowing a user to pass in CROSS_COMPILE_M68K= is handier.
[1] https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/9.2.0/x86_64-gcc-9.2.0-nolibc-m68k-linux.tar.xz
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: wan: wanxl: use $(M68KCC) instead of $(M68KAS) for rebuilding firmware
commit 734f3719d3438f9cc181d674c33ca9762e9148a1 upstream.
The firmware source, wanxlfw.S, is currently compiled by the combo of
$(CPP) and $(M68KAS). This is not what we usually do for compiling *.S
files. In fact, this Makefile is the only user of $(AS) in the kernel
build.
Instead of combining $(CPP) and (AS) from different tool sets, using
$(M68KCC) as an assembler driver is simpler, and saner.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: remove AS variable
commit aa824e0c962b532d5073cbb41b2efcd6f5e72bae upstream.
As commit 5ef872636ca7 ("kbuild: get rid of misleading $(AS) from
documents") noted, we rarely use $(AS) directly in the kernel build.
Now that the only/last user of $(AS) in drivers/net/wan/Makefile was
converted to $(CC), $(AS) is no longer used in the build process.
You can still pass in AS=clang, which is just a switch to turn on
the LLVM integrated assembler.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: replace AS=clang with LLVM_IAS=1
commit 7e20e47c70f810d678d02941fa3c671209c4ca97 upstream.
The 'AS' variable is unused for building the kernel. Only the remaining
usage is to turn on the integrated assembler. A boolean flag is a better
fit for this purpose.
AS=clang was added for experts. So, I replaced it with LLVM_IAS=1,
breaking the backward compatibility.
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
commit a0d1c951ef08ed24f35129267e3595d86f57f5d3 upstream.
As Documentation/kbuild/llvm.rst implies, building the kernel with a
full set of LLVM tools gets very verbose and unwieldy.
Provide a single switch LLVM=1 to use Clang and LLVM tools instead
of GCC and Binutils. You can pass it from the command line or as an
environment variable.
Please note LLVM=1 does not turn on the integrated assembler. You need
to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the
integrated assembler, I think we can make it default.
We discussed what we need, and we agreed to go with a simple boolean
flag that switches both target and host tools:
https://lkml.org/lkml/2020/3/28/494
https://lkml.org/lkml/2020/4/3/43
Some items discussed, but not adopted:
- LLVM_DIR
When multiple versions of LLVM are installed, I just thought supporting
LLVM_DIR=/path/to/my/llvm/bin/ might be useful.
CC = $(LLVM_DIR)clang
LD = $(LLVM_DIR)ld.lld
...
However, we can handle this by modifying PATH. So, we decided to not do
this.
- LLVM_SUFFIX
Some distributions (e.g. Debian) package specific versions of LLVM with
naming conventions that use the version as a suffix.
CC = clang$(LLVM_SUFFIX)
LD = ld.lld(LLVM_SUFFIX)
...
will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc.,
but the suffixed versions in /usr/bin/ are symlinks to binaries in
/usr/lib/llvm-#/bin/, so this can also be handled by PATH.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[nd: conflict in exported vars list from not backporting commit
e83b9f55448a ("kbuild: add ability to generate BTF type info for vmlinux")]
[nd: hunk against Documentation/kbuild/kbuild.rst dropped due to not backporting
commit cd238effefa2 ("docs: kbuild: convert docs to ReST and rename to *.rst")]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* FROMLIST: Kbuild: do not emit debug info for assembly with LLVM_IAS=1
Clang's integrated assembler produces the warning for assembly files:
warning: DWARF2 only supports one section per compilation unit
If -Wa,-gdwarf-* is unspecified, then debug info is not emitted for
assembly sources (it is still emitted for C sources). This will be
re-enabled for newer DWARF versions in a follow up patch.
Enables defconfig+CONFIG_DEBUG_INFO to build cleanly with
LLVM=1 LLVM_IAS=1 for x86_64 and arm64.
Reported-by: Dmitry Golovin <dima@golovin.in>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Dmitry Golovin <dima@golovin.in>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/716
Bug: 141693040
Link: https://lore.kernel.org/lkml/20201109183528.1391885-1-ndesaulniers@google.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: I55c8ad79dfeaae478c8de52d484e76fb2e37c194
* Makefile: Move -Wno-unused-but-set-variable out of GCC only block
commit 885480b084696331bea61a4f7eba10652999a9c1 upstream.
Currently, -Wunused-but-set-variable is only supported by GCC so it is
disabled unconditionally in a GCC only block (it is enabled with W=1).
clang currently has its implementation for this warning in review so
preemptively move this statement out of the GCC only block and wrap it
with cc-disable-warning so that both compilers function the same.
Cc: stable@vger.kernel.org
Link: https://reviews.llvm.org/D100581
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[nc: Backport, workaround lack of e2079e93f562 in older branches]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Makefile.debug: re-enable debug info for .S files
This is _not_ an upstream commit and just for 4.19.y only. It is based
on commit 32ef9e5054ec0321b9336058c58ec749e9c6b0fe upstream.
Alexey reported that the fraction of unknown filename instances in
kallsyms grew from ~0.3% to ~10% recently; Bill and Greg tracked it down
to assembler defined symbols, which regressed as a result of:
commit b8a9092330da ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
In that commit, I allude to restoring debug info for assembler defined
symbols in a follow up patch, but it seems I forgot to do so in
commit a66049e2cf0e ("Kbuild: make DWARF version a choice")
Fixes: b8a9092330da ("Kbuild: do not emit debug info for assembly with LLVM_IAS=1")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* perf llvm: Return -ENOMEM when asprintf() fails
[ Upstream commit c435c166dcf526ac827bc964d82cc0d5e7a1fd0b ]
Zhihao sent a patch but it made llvm__compile_bpf() return what
asprintf() returns on error, which is just -1, but since this function
returns -errno, fix it by returning -ENOMEM for this case instead.
Fixes: cb76371441d098 ("perf llvm: Allow passing options to llc ...")
Fixes: 5eab5a7ee032ac ("perf llvm: Display eBPF compiling command ...")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20210609115945.2193194-1-chengzhihao1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
* perf llvm: Fix inadvertent file creation
[ Upstream commit 9f19aab47ced012eddef1e2bc96007efc7713b61 ]
The LLVM template is first echo-ed into command_out and then
command_out executed. The echo surrounds the template with double
quotes, however, the template itself may contain quotes. This is
generally innocuous but in tools/perf/tests/bpf-script-test-prologue.c
we see:
...
SEC("func=null_lseek file->f_mode offset orig")
...
where the first double quote ends the double quote of the echo, then
the > redirects output into a file called f_mode.
To avoid this inadvertent behavior substitute redirects and similar
characters to be ASCII control codes, then substitute the output in
the echo back again.
Fixes: 5eab5a7ee032acaa ("perf llvm: Display eBPF compiling command in debug output")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: llvm@lists.linux.dev
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230105082609.344538-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
* arm64: add endianness option to LDFLAGS instead of LD
With the recent syntax extension, Kconfig is now able to evaluate the
compiler / toolchain capability.
However, accumulating flags to 'LD' is not compatible with the way
it works; 'LD' must be passed to Kconfig to call $(ld-option,...)
from Kconfig files. If you tweak 'LD' in arch Makefile depending on
CONFIG_CPU_BIG_ENDIAN, this would end up with circular dependency
between Makefile and Kconfig.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Change-Id: I8a7654684975d45e979917e3b1c4b6249dec02ec
* arm64: build with baremetal linker target instead of Linux when available
Not all toolchains have the baremetal elf targets, RedHat/Fedora ones
in particular. So, probe for whether it's available and use the previous
(linux) targets if it isn't.
Reported-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Kocialkowski <contact@paulk.fr>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Change-Id: Icf5462a8318b347cf11559c1654886c48c7a62b5
* FROMLIST: Makefile: lld: set -O2 linker flag when linking with LLD
For arm64:
0.34% size improvement with lld -O2 over lld for vmlinux.
3.3% size improvement with lld -O2 over lld for Image.lz4-dtb.
(am from https://lkml.org/lkml/2019/2/11/1949)
Change-Id: Ibdc7ecc9861562305b49456d6d37274ce8075e22
Link: https://github.com/ClangBuiltLinux/linux/issues/343
Suggested-by: Rui Ueyama <ruiu@google.com>
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>
Bug: 63740206
Signed-off-by: Yousef Algadri <yusufgadrie@gmail.com>
Signed-off-by: Raphiel Rollerscaperers <rapherion@raphielgang.org>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* Makefile: Enable MLGO for register allocation
This enables Machine Learning Guided Optimizations (MLGO) for register
allocation. MLGO supported toolchain needed for that feature.
* kbuild: Add support for LLVM's Polly optimizer
This adds support for compiling the kernel with optimizations offered
by LLVM's polyhedral loop optimizer known as Polly, which can improve
performance by improving cache locality in loops. Note that LLVM is not
compiled with Polly by default -- it must be enabled explicitly.
Signed-off-by: halibw <bymark256@gmail.com>
* Makefile: Make CROSS_COMPILE optional
Since our tree now supports LLVM_IAS there is no need for CROSS_COMPILE and gnu assembler, which was the only reason we needed gcc
this makes the kernel compatible with latest aosp clang and simplifies the toolchain setup.
-----------------------------------------------------------------------------------------
Before:
make LLVM=1 LLVM__IAS=1 CROSS_COMPILE=aarch-linux-gnu CROSS_COMPILE_ARM32=arm-linux-gnueabi CLANG_TRIPLE=aarch-linux-gnu**
After:
make LLVM=1
-----------------------------------------------------------------------------------------
Moved Stuff to scripts/Makefile.clang , we do not modify the 4.14 too much to make it upstream friendly.
Kanged Commits:
GrapheneOS/kernel_gs@f0a6553
GrapheneOS/kernel_gs@26a2046
GrapheneOS/kernel_gs@37b9bb0
GrapheneOS/kernel_gs@3a260e9
GrapheneOS/kernel_gs@79bd0fe
Signed-off-by: ghazzor <kartikhis8o@gmail.com>
* Makefile: llvm / poly optimize flags
* FROMLIST: Makefile: lld: set -O2 linker flag when linking with LLD
For arm64:
0.34% size improvement with lld -O2 over lld for vmlinux.
3.3% size improvement with lld -O2 over lld for Image.lz4-dtb.
(am from https://lkml.org/lkml/2019/2/11/1949)
Change-Id: Ibdc7ecc9861562305b49456d6d37274ce8075e22
Link: https://github.com/ClangBuiltLinux/linux/issues/343
Suggested-by: Rui Ueyama <ruiu@google.com>
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>
Bug: 63740206
Signed-off-by: Yousef Algadri <yusufgadrie@gmail.com>
Signed-off-by: Raphiel Rollerscaperers <rapherion@raphielgang.org>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* kbuild: allow lld to be used with CONFIG_LTO_CLANG
Bug: 63740206
Bug: 117299373
Change-Id: Ic9c8ca03fd082a8404905718f5312a3f497efa5a
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Yousef Algadri <yusufgadrie@gmail.com>
Signed-off-by: Raphiel Rollerscaperers <rapherion@raphielgang.org>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* Makefile: Globally disable compound-token-split-by-space warnings for Clang
Signed-off-by: Adam W. Willis <return.of.octobot@gmail.com>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* ANDROID: kbuild: limit LTO inlining
This change limits function inlining across translation unit
boundaries in order to reduce the binary size with LTO.
The -import-instr-limit flag defines a size limit, as the number
of LLVM IR instructions, for importing functions from other TUs.
The default value is 100, and decreasing it to 5 reduces the size
of a stripped arm64 defconfig vmlinux by 11%.
Bug: 145297228
Bug: 140525226
Change-Id: Iaf366f843582972a5dfadc4695abb8f9c59882af
Suggested-by: George Burgess IV <gbiv@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
(cherry picked from commit 2ee80bf76d779d4ee3ef386774522208979d48ae)
Signed-off-by: Kyle Lin <kylelin@google.com>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* ANDROID: kbuild: merge module sections with LTO
LLD always splits sections with LTO, which increases module sizes. This
change adds a linker script that merges the split sections in the final
module.
Bug: 145297228
Bug: 140525226
Change-Id: I247e8bd029bd0f98a4fa1cd4db7f6398467b8e55
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
(cherry picked from commit 6cea04778e129512a395b5043864f79bd970c750)
Signed-off-by: Kyle Lin <kylelin@google.com>
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* ANDROID: kbuild: fix module linker script flags for LTO
KBUILD_LDS_MODULE didn't exist in 4.19, it was added in upstream commit
10df06385582 ("kbuild: rebuild modules when module linker scripts are
updated"), which means the module-lto.lds linker script is not actually
passed to the linker. Append the flags directly to KBUILD_LDFLAGS_MODULE
instead.
Bug: 151700304
Fixes: 6cea04778e12 ("ANDROID: kbuild: merge module sections with LTO")
Change-Id: I600db54d2ff9cd4e287913e8ddd463a20741a4a3
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
(cherry picked from commit 68fc81859b56f7e0dfb9e14021ace5c090eeec87)
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* Makefile: Set --lto-O3 LLD linker flag when building with clang LTO
Signed-off-by: kdrag0n <dragon@khronodragon.com>
Change-Id: I87faddd3bb5ca6e132ff3831bfddd2a0b4511fb9
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
* Revert "kbuild: disable clang's default use of -fmerge-all-constants"
This reverts commit 87e0d4f0f37fb0c8c4aeeac46fff5e957738df79.
-fno-merge-all-constants has been the default since clang-6; the minimum
supported version of clang in the kernel is clang-10 (10.0.1).
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200902225911.209899-3-ndesaulniers@google.com
Link: https://reviews.llvm.org/rL329300.
Link: https://github.com/ClangBuiltLinux/linux/issues/9
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Makefile: evaluate LDFLAGS_BUILD_ID only once
Evaluate LDFLAGS_BUILD_ID (which involves invoking the compiler) only
once instead of over and over.
This provides a ~20% reduction in null build time with x86 allnoconfig:
$ make allnoconfig && make -j8
$ perf stat -r5 -e sched:sched_process_exec make -j8
- 2 119 sched:sched_process_exec
+ 1 878 sched:sched_process_exec
- 1,238817018 seconds time elapsed
+ 0,971020553 seconds time elapsed
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: test --build-id linker flag by ld-option instead of cc-ldoption
'--build-id' is passed to $(LD), so it should be tested by 'ld-option'.
This seems a kind of misconversion when ld-option was renamed to
cc-ldoption.
Commit f86fd3066052 ("kbuild: rename ld-option to cc-ldoption") renamed
all instances of 'ld-option' to 'cc-ldoption'.
Then, commit 691ef3e7fdc1 ("kbuild: introduce ld-option") re-added
'ld-option' as a new implementation.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: Remove -Wno-format-invalid-specifier from clang block
Turning on -Wformat does not reveal any instances of this warning across
several different builds so remove this line to keep the number of
disabled warnings as slim as possible.
This has been disabled since commit 61163efae020 ("kbuild: LLVMLinux:
Add Kbuild support for building kernel with Clang"), which does not
explain exactly why it was turned off but since it was so long ago in
terms of both the kernel and LLVM so it is possible that some bug got
fixed along the way.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
* ANDROID: scripts/Kbuild: avoid <<< for dash shell
The build server seems to be using dash shell, which doesn't support
<<<. Avoid invoking the shell entirely to figure out which linker we're
using, so that we don't have bugs and build failures on the server that
aren't reproducible locally.
Bug: 117299373
Change-Id: I0cd9940c2fa07a6bb4573ec8b1edcd21fd1f3a4d
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Rapherion Rollerscaperers <rapherion@raphielgang.org>
* ANDROID: modpost: filter function/data section ldflags
The previous addition of -plugin-opt=-function-sections and
-plugin-opt=-data-sections to LDFLAGS when performing LTO with gold was
causing kernel modules to have individual sections for functions and
data. This means that rather than having multiple symbols in the
standard .text, .bss, and .data sections, there were now tens of
thousands of sections, each with one symbol. This was problematic for
third party tools used for parsing ramdumps that expect to find symbols
in the standard object layout.
This patch filters out these flags from LDFLAGS when constructing
modules.
Modules are linked in two phases with LTO.
1. produces <module>.lto.o
2. produces <module>.ko
We must not use these flags during BOTH links otherwise these objects
will have individual function and data sections. Running `readelf -S`
on the above two files should show a number of sections in the order of
tens (vs. tens of thousands) for the tooling to work properly.
A more robust solution may be to look into is fixing the tooling to work
with function and data section object layouts, but this should fix the
tooling to work with the previous object layout for now.
Bug: 116819139
Bug: 119467548
Bug: 120503084
Change-Id: I2a388f42d5e460654de9cbd0b37dae4463bbb73e
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Rapherion Rollerscaperers <rapherion@raphielgang.org>
* Fix build break for Argument list too long
Reduce the number of files listed in the for loop statement
in function update_lto_symversions to prevent error "Argument
list too long" when building kernel in local workstation.
Bug: 138277477
Test: Build pass
Change-Id: I5218c60e6728f2425f3faa7f795c7782c5f817ad
Signed-off-by: Hsiu-Chang Chen <hsiuchangchen@google.com>
* kbuild: rename LDFLAGS to KBUILD_LDFLAGS
Commit a0f97e06a43c ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.
Commit 222d394d30e7 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.
Commit 06c5040cdb13 ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.
For some reason, LDFLAGS was not renamed.
Using a well-known variable like LDFLAGS may result in accidental
override of the variable.
Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.
I did not touch Makefiles under tools/ since the tools build system
is a different world.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
* Revert "Makefile: Set --lto-O3 LLD linker flag when building with clang LTO"
This reverts commit afc9e253de92ac70bb8d4ffcc161126aa9c3d03b.
It's not time to use the lto-O3 LLD linker flag
...
aarch64-none-linux-gnu-ld: unrecognized option '--lto-O3'
...
* Makefile: evaluate LDFLAGS_BUILD_ID only once
Evaluate LDFLAGS_BUILD_ID (which involves invoking the compiler) only
once instead of over and over.
This provides a ~20% reduction in null build time with x86 allnoconfig:
$ make allnoconfig && make -j8
$ perf stat -r5 -e sched:sched_process_exec make -j8
- 2 119 sched:sched_process_exec
+ 1 878 sched:sched_process_exec
- 1,238817018 seconds time elapsed
+ 0,971020553 seconds time elapsed
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
* kbuild: test --build-id linker flag by ld-option instead of cc-ldoption
'--build-id' is passed to $(LD), so it should be tested by 'ld-option'.
This seems a kind of misconversion when ld-option was renamed to
cc-ldoption.
Commit f86fd3066052 ("kbuild: rename ld-option to cc-ldoption") renamed
all instances of 'ld-option' to 'cc-ldoption'.
Then, commit 691ef3e7fdc1 ("kbuild: introduce ld-option") re-added
'ld-opt…- Loading branch information
48 people
authored
Sep 30, 2024
1 parent
aff028e
commit 3f3ed6b