Commit Graph

1957 Commits

Author SHA1 Message Date
Masahiro Yamada ba64beb174 kbuild: check the minimum assembler version in Kconfig
Documentation/process/changes.rst defines the minimum assembler version
(binutils version), but we have never checked it in the build time.

Kbuild never invokes 'as' directly because all assembly files in the
kernel tree are *.S, hence must be preprocessed. I do not expect
raw assembly source files (*.s) would be added to the kernel tree.

Therefore, we always use $(CC) as the assembler driver, and commit
aa824e0c96 ("kbuild: remove AS variable") removed 'AS'. However,
we are still interested in the version of the assembler acting behind.

As usual, the --version option prints the version string.

  $ as --version | head -n 1
  GNU assembler (GNU Binutils for Ubuntu) 2.35.1

But, we do not have $(AS). So, we can add the -Wa prefix so that
$(CC) passes --version down to the backing assembler.

  $ gcc -Wa,--version | head -n 1
  gcc: fatal error: no input files
  compilation terminated.

OK, we need to input something to satisfy gcc.

  $ gcc -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1
  GNU assembler (GNU Binutils for Ubuntu) 2.35.1

The combination of Clang and GNU assembler works in the same way:

  $ clang -no-integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1
  GNU assembler (GNU Binutils for Ubuntu) 2.35.1

Clang with the integrated assembler fails like this:

  $ clang -integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1
  clang: error: unsupported argument '--version' to option 'Wa,'

For the last case, checking the error message is fragile. If the
proposal for -Wa,--version support [1] is accepted, this may not be
even an error in the future.

One easy way is to check if -integrated-as is present in the passed
arguments. We did not pass -integrated-as to CLANG_FLAGS before, but
we can make it explicit.

Nathan pointed out -integrated-as is the default for all of the
architectures/targets that the kernel cares about, but it goes
along with "explicit is better than implicit" policy. [2]

With all this in my mind, I implemented scripts/as-version.sh to
check the assembler version in Kconfig time.

  $ scripts/as-version.sh gcc
  GNU 23501
  $ scripts/as-version.sh clang -no-integrated-as
  GNU 23501
  $ scripts/as-version.sh clang -integrated-as
  LLVM 0

[1]: https://github.com/ClangBuiltLinux/linux/issues/1320
[2]: https://lore.kernel.org/linux-kbuild/20210307044253.v3h47ucq6ng25iay@archlinux-ax161/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2021-04-25 05:14:41 +09:00
Masahiro Yamada 6e0839fda3 kbuild: replace sed with $(subst ) or $(patsubst )
For simple text replacement, it is better to use a built-in function
instead of sed if possible. You can save one process forking.

I do not mean to replace all sed invocations because GNU Make itself
does not support regular expression (unless you use guile).

I just replaced simple ones.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:14:01 +09:00
Nathan Chancellor eec08090bc Makefile: Only specify '--prefix=' when building with clang + GNU as
When building with LLVM_IAS=1, there is no point to specifying
'--prefix=' because that flag is only used to find GNU cross tools,
which will not be used indirectly when using the integrated assembler.
All of the tools are invoked directly from PATH or a full path specified
via the command line, which does not depend on the value of '--prefix='.

Sharing commands to reproduce issues becomes a little bit easier without
a '--prefix=' value because that '--prefix=' value is specific to a
user's machine due to it being an absolute path.

Some further notes from Fangrui Song:

  clang can spawn GNU as (if -f?no-integrated-as is specified) and GNU
  objcopy (-f?no-integrated-as and -gsplit-dwarf and -g[123]).
  objcopy is only used for GNU as assembled object files.
  With integrated assembler, the object file streamer creates .o and
  .dwo simultaneously.
  With GNU as, two objcopy commands are needed to extract .debug*.dwo to
  .dwo files && another command to remove .debug*.dwo sections.

A small consequence of this change (to keep things simple) is that
'--prefix=' will always be specified now, even with a native build, when
it was not before. This should not be an issue due to the way that the
Makefile searches for the prefix (based on elfedit's location). This
ends up improving the experience for host builds because PATH is better
respected and matches GCC's behavior more closely. See the below thread
for more details:

https://lore.kernel.org/r/20210205213651.GA16907@Ryzen-5-4500U.localdomain/

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:13:45 +09:00
Nathan Chancellor c91d4e47e1 Makefile: Remove '--gcc-toolchain' flag
This flag was originally added to allow clang to find the GNU cross
tools in commit 785f11aa59 ("kbuild: Add better clang cross build
support"). This flag was not enough to find the tools at times so
'--prefix' was added to the list in commit ef8c4ed9db ("kbuild: allow
to use GCC toolchain not in Clang search path") and improved upon in
commit ca9b31f6bb ("Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang
cross compilation"). Now that '--prefix' specifies a full path and
prefix, '--gcc-toolchain' serves no purpose because the kernel builds
with '-nostdinc' and '-nostdlib'.

This has been verified with self compiled LLVM 10.0.1 and LLVM 13.0.0 as
well as a distribution version of LLVM 11.1.0 without binutils in the
LLVM toolchain locations.

Link: https://reviews.llvm.org/D97902
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:12:55 +09:00
Rasmus Villemoes 0b956e2041 kbuild: apply fixdep logic to link-vmlinux.sh
The patch adding CONFIG_VMLINUX_MAP revealed a small defect in the
build system: link-vmlinux.sh takes decisions based on CONFIG_*
options, but changing one of those does not always lead to vmlinux
being linked again.

For most of the CONFIG_* knobs referenced previously, this has
probably been hidden by those knobs also affecting some object file,
hence indirectly also vmlinux.

But CONFIG_VMLINUX_MAP is only handled inside link-vmlinux.sh, and
changing CONFIG_VMLINUX_MAP=n to CONFIG_VMLINUX_MAP=y does not cause
the build system to re-link (and hence have vmlinux.map
emitted). Since that map file is mostly a debugging aid, this is
merely a nuisance which is easily worked around by just deleting
vmlinux and building again.

But one could imagine other (possibly future) CONFIG options that
actually do affect the vmlinux binary but which are not captured
through some object file dependency.

To fix this, make link-vmlinux.sh emit a .vmlinux.d file in the same
format as the dependency files generated by gcc, and apply the fixdep
logic to that. I've tested that this correctly works with both in-tree
and out-of-tree builds.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:12:32 +09:00
Masahiro Yamada 609bbb4de4 kbuild: show warning if 'make headers_check' is used
Since commit 7ecaf069da ("kbuild: move headers_check rule to
usr/include/Makefile"), 'make headers_check' is no-op.

This stub target is remaining here in case some scripts still invoke it.
In order to prompt people to remove stale code, show a noisy warning
message if used. The stub will be really removed after the Linux 5.15
release.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:11:54 +09:00
Masahiro Yamada 805b2e1d42 kbuild: include Makefile.compiler only when compiler is needed
Since commit f2f02ebd8f ("kbuild: improve cc-option to clean up all
temporary files"), running 'make kernelversion' in a read-only source
tree emits a bunch of warnings:

  mkdir: cannot create directory '.tmp_12345': Permission denied

No-build targets such as kernelversion, clean, help, etc. do not
need to evaluate $(call cc-option,) or friends. Skip Makefile.compiler
so $(call cc-option,) becomes no-op.

This not only fixes the warnings, but also runs non-build targets much
faster.

Basically, all installation targets should also be non-build targets.
Unfortunately, vdso_install requires the compiler because it builds
vdso before installation. This is a problem that must be fixed by a
separate patch.

Reported-by: Israel Tsadok <itsadok@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:09:57 +09:00
Masahiro Yamada 57fd251c78 kbuild: split cc-option and friends to scripts/Makefile.compiler
scripts/Kbuild.include is included everywhere, but macros such as
cc-option are needed by build targets only.

For example, when 'make clean' traverses the tree, it does not need
to evaluate $(call cc-option,).

Split cc-option, ld-option, etc. to scripts/Makefile.compiler, which
is only included from the top Makefile and scripts/Makefile.build.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:09:32 +09:00
Masahiro Yamada 3204a7fb98 kbuild: prefix $(srctree)/ to some included Makefiles
VPATH is used in Kbuild to make pattern rules search for prerequisites
in both $(objtree) and $(srctree). Some of *.c, *.S files are not real
sources, but generated by tools such as flex, bison, perl.

In contrast, I doubt the benefit of --include-dir=$(abs_srctree) because
it is always clear which Makefiles are real sources, and which are not.

So, my hope is to add $(srctree)/ prefix to all check-in Makefiles,
then remove --include-dir=$(abs_srctree) flag in the future.

I am touching only some Kbuild core parts for now. Treewide fixes will
be needed to achieve this goal.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-03-15 19:20:48 +09:00
Linus Torvalds 1e28eed176 Linux 5.12-rc3 2021-03-14 14:41:02 -07:00
Masahiro Yamada ce6ed1c4c9 kbuild: rebuild GCC plugins when the compiler is upgraded
Linus reported a build error due to the GCC plugin incompatibility
when the compiler is upgraded. [1]

GCC plugins are tied to a particular GCC version. So, they must be
rebuilt when the compiler is upgraded.

This seems to be a long-standing flaw since the initial support of
GCC plugins.

Extend commit 8b59cd81dc ("kbuild: ensure full rebuild when the
compiler is updated"), so that GCC plugins are covered by the
compiler upgrade detection.

[1]: https://lore.kernel.org/lkml/CAHk-=wieoN5ttOy7SnsGwZv+Fni3R6m-Ut=oxih6bbZ28G+4dw@mail.gmail.com/

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2021-03-11 14:40:50 +09:00
Masahiro Yamada 993bdde945 kbuild: add image_name to no-sync-config-targets
'make image_name' needs include/config/auto.conf to show the correct
output because KBUILD_IMAGE depends on CONFIG options, but should not
attempt to resync the configuration.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-03-10 04:17:47 +09:00
Linus Torvalds a38fd87484 Linux 5.12-rc2 2021-03-05 17:33:41 -08:00
Linus Torvalds fe07bfda2f Linux 5.12-rc1 2021-02-28 16:05:19 -08:00
Masahiro Yamada 207da4c82a kbuild: Fix <linux/version.h> for empty SUBLEVEL or PATCHLEVEL again
Commit 78d3bb4483 ("kbuild: Fix <linux/version.h> for empty SUBLEVEL
or PATCHLEVEL") fixed the build error for empty SUBLEVEL or PATCHLEVEL
by prepending a zero.

Commit 9b82f13e7e ("kbuild: clamp SUBLEVEL to 255") re-introduced
this issue.

This time, we cannot take the same approach because we have C code:

  #define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL)
  #define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)

Replace empty SUBLEVEL/PATCHLEVEL with a zero.

Fixes: 9b82f13e7e ("kbuild: clamp SUBLEVEL to 255")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-and-tested-by: Sasha Levin <sashal@kernel.org>
2021-02-28 15:23:48 +09:00
Masahiro Yamada 2214945422 kbuild: make -s option take precedence over V=1
'make -s' should be really silent. However, 'make -s V=1' prints noisy
log messages from some shell scripts.

Of course, such a combination is odd, but the build system needs to do
the right thing even if a user gives strange input.

If -s is given, KBUILD_VERBOSE should be forced to 0.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-28 15:22:02 +09:00
Linus Torvalds fe1072ff76 clang-lto fixes for v5.12-rc1
- Fix parisc build for ftrace vs mcount (Sami Tolvanen)
 - Move .thinlto-cache remove to "clean" from "distclean" (Masahiro Yamada)
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Merge tag 'clang-lto-v5.12-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO fixes from Kees Cook:
 "This gets parisc building again and moves LTO artifact caching cleanup
  from the 'distclean' build target to 'clean'.

  Summary:

   - Fix parisc build for ftrace vs mcount (Sami Tolvanen)

   - Move .thinlto-cache remove to "clean" from "distclean" (Masahiro Yamada)"

* tag 'clang-lto-v5.12-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: Move .thinlto-cache removal to 'make clean'
  parisc: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
2021-02-26 10:08:50 -08:00
Masahiro Yamada 4c7858b900 kbuild: Move .thinlto-cache removal to 'make clean'
Instead of 'make distclean', 'make clean' should remove build artifacts
unneeded by external module builds. Obviously, you do not need to keep
this directory.

Fixes: dc5723b02e ("kbuild: add support for Clang LTO")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210225193912.3303604-1-masahiroy@kernel.org
2021-02-25 12:21:06 -08:00
Linus Torvalds 6fbd6cf85a Kbuild updates for v5.12
- Fix false-positive build warnings for ARCH=ia64 builds
 
  - Optimize dictionary size for module compression with xz
 
  - Check the compiler and linker versions in Kconfig
 
  - Fix misuse of extra-y
 
  - Support DWARF v5 debug info
 
  - Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
    exceeded the limit
 
  - Add generic syscall{tbl,hdr}.sh for cleanups across arches
 
  - Minor cleanups of genksyms
 
  - Minor cleanups of Kconfig
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Merge tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Fix false-positive build warnings for ARCH=ia64 builds

 - Optimize dictionary size for module compression with xz

 - Check the compiler and linker versions in Kconfig

 - Fix misuse of extra-y

 - Support DWARF v5 debug info

 - Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
   exceeded the limit

 - Add generic syscall{tbl,hdr}.sh for cleanups across arches

 - Minor cleanups of genksyms

 - Minor cleanups of Kconfig

* tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits)
  initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD
  kbuild: remove deprecated 'always' and 'hostprogs-y/m'
  kbuild: parse C= and M= before changing the working directory
  kbuild: reuse this-makefile to define abs_srctree
  kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig
  kconfig: omit --oldaskconfig option for 'make config'
  kconfig: fix 'invalid option' for help option
  kconfig: remove dead code in conf_askvalue()
  kconfig: clean up nested if-conditionals in check_conf()
  kconfig: Remove duplicate call to sym_get_string_value()
  Makefile: Remove # characters from compiler string
  Makefile: reuse CC_VERSION_TEXT
  kbuild: check the minimum linker version in Kconfig
  kbuild: remove ld-version macro
  scripts: add generic syscallhdr.sh
  scripts: add generic syscalltbl.sh
  arch: syscalls: remove $(srctree)/ prefix from syscall tables
  arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work
  gen_compile_commands: prune some directories
  kbuild: simplify access to the kernel's version
  ...
2021-02-25 10:17:31 -08:00
Masahiro Yamada bcf637f54f kbuild: parse C= and M= before changing the working directory
If Kbuild recurses to the top Makefile (for example, 'make deb-pkg'),
C= and M= are parsed over again, needlessly.

Parse them before changing the working directory. After that,
sub_make_done is set to 1, so they are parsed just once.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-24 15:12:06 +09:00
Masahiro Yamada 30cef68d2d kbuild: reuse this-makefile to define abs_srctree
Move this-makefile up, and reuse it to define abs_srctree.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-24 15:12:06 +09:00
Nathan Chancellor c75173a269 Makefile: Remove # characters from compiler string
When using AMD's Optimizing C/C++ Compiler (AOCC), the build fails due
to a # character in the version string, which is interpreted as a
comment:

$ make CC=clang defconfig init/main.o
include/config/auto.conf.cmd:1374: *** invalid syntax in conditional. Stop.

$ sed -n 1374p include/config/auto.conf.cmd
ifneq "$(CC_VERSION_TEXT)" "AMD clang version 11.0.0 (CLANG: AOCC_2.3.0-Build#85 2020_11_10) (based on LLVM Mirror.Version.11.0.0)"

Remove all # characters in the version string so that the build does not
fail unexpectedly.

Link: https://github.com/ClangBuiltLinux/linux/issues/1298
Reported-by: Michael Fuckner <michael@fuckner.net>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-24 15:12:06 +09:00
Nick Desaulniers db07562aea Makefile: reuse CC_VERSION_TEXT
I noticed we're invoking $(CC) via $(shell) more than once to check the
version.  Let's reuse the first string captured in $CC_VERSION_TEXT.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[masahiro.yamada:
CC_VERSION_TEXT is assigned by = instead of :=, so this $(shell ) is
evaluated multiple times anyway. The number of $(CC) invocations will
be still the same. Replacing 'grep' with the built-in $(findstring )
will give real performance benefit.]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-24 15:11:17 +09:00
Linus Torvalds 414eece95b clang-lto for v5.12-rc1 (part2)
- Generate __mcount_loc in objtool (Peter Zijlstra)
 - Support running objtool against vmlinux.o (Sami Tolvanen)
 - Clang LTO enablement for x86 (Sami Tolvanen)
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Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more clang LTO updates from Kees Cook:
 "Clang LTO x86 enablement.

  Full disclosure: while this has _not_ been in linux-next (since it
  initially looked like the objtool dependencies weren't going to make
  v5.12), it has been under daily build and runtime testing by Sami for
  quite some time. These x86 portions have been discussed on lkml, with
  Peter, Josh, and others helping nail things down.

  The bulk of the changes are to get objtool working happily. The rest
  of the x86 enablement is very small.

  Summary:

   - Generate __mcount_loc in objtool (Peter Zijlstra)

   - Support running objtool against vmlinux.o (Sami Tolvanen)

   - Clang LTO enablement for x86 (Sami Tolvanen)"

Link: https://lore.kernel.org/lkml/20201013003203.4168817-26-samitolvanen@google.com/
Link: https://lore.kernel.org/lkml/cover.1611263461.git.jpoimboe@redhat.com/

* tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: lto: force rebuilds when switching CONFIG_LTO
  x86, build: allow LTO to be selected
  x86, cpu: disable LTO for cpu.c
  x86, vdso: disable LTO only for vDSO
  kbuild: lto: postpone objtool
  objtool: Split noinstr validation from --vmlinux
  x86, build: use objtool mcount
  tracing: add support for objtool mcount
  objtool: Don't autodetect vmlinux.o
  objtool: Fix __mcount_loc generation with Clang's assembler
  objtool: Add a pass for generating __mcount_loc
2021-02-23 15:13:45 -08:00
Sami Tolvanen 5e95325fbb kbuild: lto: force rebuilds when switching CONFIG_LTO
When doing non-clean builds and switching between CONFIG_LTO=n and
CONFIG_LTO=y, the build system (correctly) didn't notice that assembly
and LTO-excluded C object files were rewritten in place by objtool (to
add the .orc_unwind* sections), since their build command lines were the
same between CONFIG_LTO=y and CONFIG_LTO=n. The objtool step would fail:

vmlinux.o: warning: objtool: file already has .orc_unwind section, skipping
make: *** [Makefile:1194: vmlinux] Error 255

Avoid this by making sure the build will see a difference between an LTO
and non-LTO build (by including "-fno-lto" in KBUILD_*FLAGS). This will
get ignored when CC_FLAGS_LTO is present, and will not be included at
all when CONFIG_LTO=n.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2021-02-23 14:10:44 -08:00
Sami Tolvanen 22c8542d7b tracing: add support for objtool mcount
This change adds build support for using objtool to generate
__mcount_loc sections.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2021-02-23 12:46:57 -08:00
Linus Torvalds 79db4d2293 clang-lto series for v5.12-rc1
- Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen)
 - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)
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Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull clang LTO updates from Kees Cook:
 "Clang Link Time Optimization.

  This is built on the work done preparing for LTO by arm64 folks,
  tracing folks, etc. This includes the core changes as well as the
  remaining pieces for arm64 (LTO has been the default build method on
  Android for about 3 years now, as it is the prerequisite for the
  Control Flow Integrity protections).

  While x86 LTO enablement is done, it depends on some pending objtool
  clean-ups. It's possible that I'll send a "part 2" pull request for
  LTO that includes x86 support.

  For merge log posterity, and as detailed in commit dc5723b02e
  ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
  build:

        make LLVM=1 LLVM_IAS=1 defconfig
        scripts/config -e LTO_CLANG_THIN
        make LLVM=1 LLVM_IAS=1

  (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
  and "ARCH=arm64" to the "make" command lines.)

  Summary:

   - Clang LTO build infrastructure and arm64-specific enablement (Sami
     Tolvanen)

   - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"

* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
  arm64: allow LTO to be selected
  arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
  arm64: vdso: disable LTO
  drivers/misc/lkdtm: disable LTO for rodata.o
  efi/libstub: disable LTO
  scripts/mod: disable LTO for empty.c
  modpost: lto: strip .lto from module names
  PCI: Fix PREL32 relocations for LTO
  init: lto: fix PREL32 relocations
  init: lto: ensure initcall ordering
  kbuild: lto: add a default list of used symbols
  kbuild: lto: merge module sections
  kbuild: lto: limit inlining
  kbuild: lto: fix module versioning
  kbuild: add support for Clang LTO
  tracing: move function tracer options to Kconfig
2021-02-23 09:28:51 -08:00
Linus Torvalds a99163e9e7 Devicetree updates for v5.12:
- Sync dtc to upstream version v1.6.0-51-g183df9e9c2b9 and build
   host fdtoverlay
 
 - Add kbuild support to build DT overlays (%.dtbo)
 
 - Drop NULLifying match table in of_match_device(). In preparation for
   this, there are several driver cleanups to use
   (of_)?device_get_match_data().
 
 - Drop pointless wrappers from DT struct device API
 
 - Convert USB binding schemas to use graph schema and remove old plain
   text graph binding doc
 
 - Convert spi-nor and v3d GPU bindings to DT schema
 
 - Tree wide schema fixes for if/then schemas, array size constraints,
   and undocumented compatible strings in examples
 
 - Handle 'no-map' correctly for already reserved memblock regions
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Merge tag 'devicetree-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:

 - Sync dtc to upstream version v1.6.0-51-g183df9e9c2b9 and build host
   fdtoverlay

 - Add kbuild support to build DT overlays (%.dtbo)

 - Drop NULLifying match table in of_match_device().

   In preparation for this, there are several driver cleanups to use
   (of_)?device_get_match_data().

 - Drop pointless wrappers from DT struct device API

 - Convert USB binding schemas to use graph schema and remove old plain
   text graph binding doc

 - Convert spi-nor and v3d GPU bindings to DT schema

 - Tree wide schema fixes for if/then schemas, array size constraints,
   and undocumented compatible strings in examples

 - Handle 'no-map' correctly for already reserved memblock regions

* tag 'devicetree-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (35 commits)
  driver core: platform: Drop of_device_node_put() wrapper
  of: Remove of_dev_{get,put}()
  dt-bindings: usb: Change descibe to describe in usbmisc-imx.txt
  dt-bindings: can: rcar_canfd: Group tuples in pin control properties
  dt-bindings: power: renesas,apmu: Group tuples in cpus properties
  dt-bindings: mtd: spi-nor: Convert to DT schema format
  dt-bindings: Use portable sort for version cmp
  dt-bindings: ethernet-controller: fix fixed-link specification
  dt-bindings: irqchip: Add node name to PRUSS INTC
  dt-bindings: interconnect: Fix the expected number of cells
  dt-bindings: Fix errors in 'if' schemas
  dt-bindings: iommu: renesas,ipmmu-vmsa: Make 'power-domains' conditionally required
  dt-bindings: Fix undocumented compatible strings in examples
  kbuild: Add support to build overlays (%.dtbo)
  scripts: dtc: Remove the unused fdtdump.c file
  scripts: dtc: Build fdtoverlay tool
  scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9
  scripts: dtc: Fetch fdtoverlay.c from external DTC project
  dt-bindings: thermal: sun8i: Fix misplaced schema keyword in compatible strings
  dt-bindings: iio: dac: Fix AD5686 references
  ...
2021-02-22 10:05:12 -08:00
Linus Torvalds 51e6d17809 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:
 "Here is what we have this merge window:

   1) Support SW steering for mlx5 Connect-X6Dx, from Yevgeny Kliteynik.

   2) Add RSS multi group support to octeontx2-pf driver, from Geetha
      Sowjanya.

   3) Add support for KS8851 PHY. From Marek Vasut.

   4) Add support for GarfieldPeak bluetooth controller from Kiran K.

   5) Add support for half-duplex tcan4x5x can controllers.

   6) Add batch skb rx processing to bcrm63xx_enet, from Sieng Piaw
      Liew.

   7) Rework RX port offload infrastructure, particularly wrt, UDP
      tunneling, from Jakub Kicinski.

   8) Add BCM72116 PHY support, from Florian Fainelli.

   9) Remove Dsa specific notifiers, they are unnecessary. From Vladimir
      Oltean.

  10) Add support for picosecond rx delay in dwmac-meson8b chips. From
      Martin Blumenstingl.

  11) Support TSO on xfrm interfaces from Eyal Birger.

  12) Add support for MP_PRIO to mptcp stack, from Geliang Tang.

  13) Support BCM4908 integrated switch, from Rafał Miłecki.

  14) Support for directly accessing kernel module variables via module
      BTF info, from Andrii Naryiko.

  15) Add DASH (esktop and mobile Architecture for System Hardware)
      support to r8169 driver, from Heiner Kallweit.

  16) Add rx vlan filtering to dpaa2-eth, from Ionut-robert Aron.

  17) Add support for 100 base0x SFP devices, from Bjarni Jonasson.

  18) Support link aggregation in DSA, from Tobias Waldekranz.

  19) Support for bitwidse atomics in bpf, from Brendan Jackman.

  20) SmartEEE support in at803x driver, from Russell King.

  21) Add support for flow based tunneling to GTP, from Pravin B Shelar.

  22) Allow arbitrary number of interconnrcts in ipa, from Alex Elder.

  23) TLS RX offload for bonding, from Tariq Toukan.

  24) RX decap offklload support in mac80211, from Felix Fietkou.

  25) devlink health saupport in octeontx2-af, from George Cherian.

  26) Add TTL attr to SCM_TIMESTAMP_OPT_STATS, from Yousuk Seung

  27) Delegated actionss support in mptcp, from Paolo Abeni.

  28) Support receive timestamping when doin zerocopy tcp receive. From
      Arjun Ray.

  29) HTB offload support for mlx5, from Maxim Mikityanskiy.

  30) UDP GRO forwarding, from Maxim Mikityanskiy.

  31) TAPRIO offloading in dsa hellcreek driver, from Kurt Kanzenbach.

  32) Weighted random twos choice algorithm for ipvs, from Darby Payne.

  33) Fix netdev registration deadlock, from Johannes Berg.

  34) Various conversions to new tasklet api, from EmilRenner Berthing.

  35) Bulk skb allocations in veth, from Lorenzo Bianconi.

  36) New ethtool interface for lane setting, from Danielle Ratson.

  37) Offload failiure notifications for routes, from Amit Cohen.

  38) BCM4908 support, from Rafał Miłecki.

  39) Support several new iwlwifi chips, from Ihab Zhaika.

  40) Flow drector support for ipv6 in i40e, from Przemyslaw Patynowski.

  41) Support for mhi prrotocols, from Loic Poulain.

  42) Optimize bpf program stats.

  43) Implement RFC6056, for better port randomization, from Eric
      Dumazet.

  44) hsr tag offloading support from George McCollister.

  45) Netpoll support in qede, from Bhaskar Upadhaya.

  46) 2005/400g speed support in bonding 3ad mode, from Nikolay
      Aleksandrov.

  47) Netlink event support in mptcp, from Florian Westphal.

  48) Better skbuff caching, from Alexander Lobakin.

  49) MRP (Media Redundancy Protocol) offloading in DSA and a few
      drivers, from Horatiu Vultur.

  50) mqprio saupport in mvneta, from Maxime Chevallier.

  51) Remove of_phy_attach, no longer needed, from Florian Fainelli"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1766 commits)
  octeontx2-pf: Fix otx2_get_fecparam()
  cteontx2-pf: cn10k: Prevent harmless double shift bugs
  net: stmmac: Add PCI bus info to ethtool driver query output
  ptp: ptp_clockmatrix: clean-up - parenthesis around a == b are unnecessary
  ptp: ptp_clockmatrix: Simplify code - remove unnecessary `err` variable.
  ptp: ptp_clockmatrix: Coding style - tighten vertical spacing.
  ptp: ptp_clockmatrix: Clean-up dev_*() messages.
  ptp: ptp_clockmatrix: Remove unused header declarations.
  ptp: ptp_clockmatrix: Add alignment of 1 PPS to idtcm_perout_enable.
  ptp: ptp_clockmatrix: Add wait_for_sys_apll_dpll_lock.
  net: stmmac: dwmac-sun8i: Add a shutdown callback
  net: stmmac: dwmac-sun8i: Minor probe function cleanup
  net: stmmac: dwmac-sun8i: Use reset_control_reset
  net: stmmac: dwmac-sun8i: Remove unnecessary PHY power check
  net: stmmac: dwmac-sun8i: Return void from PHY unpower
  r8169: use macro pm_ptr
  net: mdio: Remove of_phy_attach()
  net: mscc: ocelot: select PACKING in the Kconfig
  net: re-solve some conflicts after net -> net-next merge
  net: dsa: tag_rtl4_a: Support also egress tags
  ...
2021-02-20 17:45:32 -08:00
Alexander Lobakin 2b86895205 kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
CC_FLAGS_LTO gets initialized only via +=, never with := or =.
When building with CONFIG_TRIM_UNUSED_KSYMS, Kbuild may perform
several kernel rebuilds to satisfy symbol dependencies. In this
case, value of CC_FLAGS_LTO is concatenated each time, which
triggers a full rebuild.
Initialize it with := to fix this.

Fixes: dc5723b02e ("kbuild: add support for Clang LTO")
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210121184544.659998-1-alobakin@pm.me
2021-02-17 10:10:37 -08:00
David S. Miller b8af417e4d Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2021-02-16

The following pull-request contains BPF updates for your *net-next* tree.

There's a small merge conflict between 7eeba1706e ("tcp: Add receive timestamp
support for receive zerocopy.") from net-next tree and 9cacf81f81 ("bpf: Remove
extra lock_sock for TCP_ZEROCOPY_RECEIVE") from bpf-next tree. Resolve as follows:

  [...]
                lock_sock(sk);
                err = tcp_zerocopy_receive(sk, &zc, &tss);
                err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname,
                                                          &zc, &len, err);
                release_sock(sk);
  [...]

We've added 116 non-merge commits during the last 27 day(s) which contain
a total of 156 files changed, 5662 insertions(+), 1489 deletions(-).

The main changes are:

1) Adds support of pointers to types with known size among global function
   args to overcome the limit on max # of allowed args, from Dmitrii Banshchikov.

2) Add bpf_iter for task_vma which can be used to generate information similar
   to /proc/pid/maps, from Song Liu.

3) Enable bpf_{g,s}etsockopt() from all sock_addr related program hooks. Allow
   rewriting bind user ports from BPF side below the ip_unprivileged_port_start
   range, both from Stanislav Fomichev.

4) Prevent recursion on fentry/fexit & sleepable programs and allow map-in-map
   as well as per-cpu maps for the latter, from Alexei Starovoitov.

5) Add selftest script to run BPF CI locally. Also enable BPF ringbuffer
   for sleepable programs, both from KP Singh.

6) Extend verifier to enable variable offset read/write access to the BPF
   program stack, from Andrei Matei.

7) Improve tc & XDP MTU handling and add a new bpf_check_mtu() helper to
   query device MTU from programs, from Jesper Dangaard Brouer.

8) Allow bpf_get_socket_cookie() helper also be called from [sleepable] BPF
   tracing programs, from Florent Revest.

9) Extend x86 JIT to pad JMPs with NOPs for helping image to converge when
   otherwise too many passes are required, from Gary Lin.

10) Verifier fixes on atomics with BPF_FETCH as well as function-by-function
    verification both related to zero-extension handling, from Ilya Leoshkevich.

11) Better kernel build integration of resolve_btfids tool, from Jiri Olsa.

12) Batch of AF_XDP selftest cleanups and small performance improvement
    for libbpf's xsk map redirect for newer kernels, from Björn Töpel.

13) Follow-up BPF doc and verifier improvements around atomics with
    BPF_FETCH, from Brendan Jackman.

14) Permit zero-sized data sections e.g. if ELF .rodata section contains
    read-only data from local variables, from Yonghong Song.

15) veth driver skb bulk-allocation for ndo_xdp_xmit, from Lorenzo Bianconi.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-16 13:14:06 -08:00
Sasha Levin 88a686728b kbuild: simplify access to the kernel's version
Instead of storing the version in a single integer and having various
kernel (and userspace) code how it's constructed, export individual
(major, patchlevel, sublevel) components and simplify kernel code that
uses it.

This should also make it easier on userspace.

Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-16 12:01:45 +09:00
Sasha Levin 9b82f13e7e kbuild: clamp SUBLEVEL to 255
Right now if SUBLEVEL becomes larger than 255 it will overflow into the
territory of PATCHLEVEL, causing havoc in userspace that tests for
specific kernel version.

While userspace code tests for MAJOR and PATCHLEVEL, it doesn't test
SUBLEVEL at any point as ABI changes don't happen in the context of
stable tree.

Thus, to avoid overflows, simply clamp SUBLEVEL to it's maximum value in
the context of LINUX_VERSION_CODE. This does not affect "make
kernelversion" and such.

Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-16 12:01:45 +09:00
Nick Desaulniers 98cd6f521f Kconfig: allow explicit opt in to DWARF v5
DWARF v5 is the latest standard of the DWARF debug info format. GCC 11
will change the implicit default DWARF version, if left unspecified, to
DWARF v5.

Allow users of Clang and older versions of GCC that have not changed the
implicit default DWARF version to DWARF v5 to opt in. This can help
testing consumers of DWARF debug info in preparation of v5 becoming more
widespread, as well as result in significant binary size savings of the
pre-stripped vmlinux image.

DWARF5 wins significantly in terms of size when mixed with compression
(CONFIG_DEBUG_INFO_COMPRESSED).

363M    vmlinux.clang12.dwarf5.compressed
434M    vmlinux.clang12.dwarf4.compressed
439M    vmlinux.clang12.dwarf2.compressed
457M    vmlinux.clang12.dwarf5
536M    vmlinux.clang12.dwarf4
548M    vmlinux.clang12.dwarf2

515M    vmlinux.gcc10.2.dwarf5.compressed
599M    vmlinux.gcc10.2.dwarf4.compressed
624M    vmlinux.gcc10.2.dwarf2.compressed
630M    vmlinux.gcc10.2.dwarf5
765M    vmlinux.gcc10.2.dwarf4
809M    vmlinux.gcc10.2.dwarf2

Though the quality of debug info is harder to quantify; size is not a
proxy for quality.

Jakub notes:
  One thing is GCC DWARF-5 support, that is whether the compiler will
  support -gdwarf-5 flag, and that support should be there from GCC 7
  onwards.

  All [GCC] 5.1 - 6.x did was start accepting -gdwarf-5 as experimental
  option that enabled some small DWARF subset (initially only a few
  DW_LANG_* codes newly added to DWARF5 drafts).  Only GCC 7 (released
  after DWARF 5 has been finalized) started emitting DWARF5 section
  headers and got most of the DWARF5 changes in...

  Another separate thing is whether the assembler does support
  the -gdwarf-5 option (i.e. if you can compile assembler files
  with -Wa,-gdwarf-5) ... That option is about whether the assembler
  will emit DWARF5 or DWARF2 .debug_line.  It is fine to compile C sources
  with -gdwarf-5 and use DWARF2 .debug_line for assembler files if as
  doesn't support it.

Version check GCC so that we don't need to worry about the difference in
command line args between GNU readelf and llvm-readelf/llvm-dwarfdump to
validate the DWARF Version in the assembler feature detection script.

Most issues with clang produced assembler were fixed in binutils 2.35.1,
but 2.35.2 fixed issues related to requiring the flag -Wa,-gdwarf-5
explicitly. The added shell script test checks for the latter, and is
only required when using clang without its integrated assembler, though
we use for clang regardless as we do not yet have a way to query the
assembler from Kconfig.

Disabled for now if CONFIG_DEBUG_INFO_BTF is set; pahole doesn't yet
recognize the new additions to the DWARF debug info.

This only modifies the DWARF version emitted by the compiler, not the
assembler.

The DWARF version of a binary can be validated with:
$ llvm-dwarfdump <object file> | head -n 4 | grep version
or
$ readelf --debug-dump=info <object file> 2>/dev/null | grep Version

Parts of the tree don't reuse DEBUG_CFLAGS as they should; such cleanup
is left as a follow up.

Link: http://www.dwarfstd.org/doc/DWARF5.pdf
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1922707
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Caroline Tice <cmtice@google.com>
Suggested-by: Fangrui Song <maskray@google.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v12.0.0-rc1 x86-64
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-16 12:01:45 +09:00
Nick Desaulniers a66049e2cf Kbuild: make DWARF version a choice
Adds a default CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT which allows
the implicit default version of DWARF emitted by the toolchain to
progress over time.

Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice, making it
mutually exclusive with CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT. Users
may want to select this if they are using a newer toolchain, but have
consumers of the DWARF debug info that aren't yet ready for newer DWARF
versions' debug info.

Does so in a way that's forward compatible with existing
configs, and makes adding future versions more straightforward. This
patch does not change the current behavior or selection of DWARF
version for users upgrading to kernels with this patch.

GCC since ~4.8 has defaulted to DWARF v4 implicitly, and GCC 11 has
bumped this to v5.

Remove the Kconfig help text  about DWARF v4 being larger.  It's
empirically false for the latest toolchains for x86_64 defconfig, has no
point of reference (I suspect it was DWARF v2 but that's stil
empirically false), and debug info size is not a qualatative measure.

Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Fangrui Song <maskray@google.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Suggested-by: Mark Wielaard <mark@klomp.org>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-16 12:01:45 +09:00
Masahiro Yamada 0dd77e957a kbuild: stop removing stale <linux/version.h> file
Revert commit 223c24a7db ("kbuild: Automatically remove stale
<linux/version.h> file").

It was more than 6 years ago. I do not expect anybody to start
git-bisect for such a big window.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-16 12:01:45 +09:00
Linus Torvalds f40ddce885 Linux 5.11 2021-02-14 14:32:24 -08:00
Tor Vic db4632c65e Makefile: use smaller dictionary size for xz module compression
By default, xz without parameters uses a dictionary size of 8 MB.
However, most modules are much smaller than that.
The xz manpage states that 'increasing dictionary size usually improves
compression ratio, but a dictionary bigger than the uncompressed file
is waste of memory'.
Use a dictionary size of 2 MB for module compression, resulting in
slightly higher compression speed while still maintaining a good
compression ratio.

Signed-off-by: Tor Vic <torvic9@mailbox.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-12 05:11:19 +09:00
Jiri Olsa 0e1aa629f1 kbuild: Do not clean resolve_btfids if the output does not exist
Nathan reported issue with cleaning empty build directory:

  $ make -s O=build distclean
  ../../scripts/Makefile.include:4: *** \
  O=/ho...build/tools/bpf/resolve_btfids does not exist.  Stop.

The problem that tools scripts require existing output
directory, otherwise it fails.

Adding check around the resolve_btfids clean target to
ensure the output directory is in place.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/bpf/20210211124004.1144344-1-jolsa@kernel.org
2021-02-11 11:27:58 -08:00
David S. Miller dc9d87581d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-10 13:30:12 -08:00
Jiri Olsa 50d3a3f816 kbuild: Add resolve_btfids clean to root clean target
The resolve_btfids tool is used during the kernel build,
so we should clean it on kernel's make clean.

Invoking the the resolve_btfids clean as part of root
'make clean'.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210205124020.683286-5-jolsa@kernel.org
2021-02-08 21:21:39 -08:00
Linus Torvalds 92bf22614b Linux 5.11-rc7 2021-02-07 13:57:38 -08:00
Linus Torvalds e24f9c5f6e - Remove superfluous EFI PGD range checks which lead to those assertions failing
with certain kernel configs and LLVM.
 
 - Disable setting breakpoints on facilities involved in #DB exception handling
 to avoid infinite loops.
 
 - Add extra serialization to non-serializing MSRs (IA32_TSC_DEADLINE and
 x2 APIC MSRs) to adhere to SDM's recommendation and avoid any theoretical
 issues.
 
 - Re-add the EPB MSR reading on turbostat so that it works on older
 kernels which don't have the corresponding EPB sysfs file.
 
 - Add Alder Lake to the list of CPUs which support split lock.
 
 - Fix %dr6 register handling in order to be able to set watchpoints with gdb
 again.
 
 - Disable CET instrumentation in the kernel so that gcc doesn't add
 ENDBR64 to kernel code and thus confuse tracing.
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Merge tag 'x86_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:
 "I hope this is the last batch of x86/urgent updates for this round:

   - Remove superfluous EFI PGD range checks which lead to those
     assertions failing with certain kernel configs and LLVM.

   - Disable setting breakpoints on facilities involved in #DB exception
     handling to avoid infinite loops.

   - Add extra serialization to non-serializing MSRs (IA32_TSC_DEADLINE
     and x2 APIC MSRs) to adhere to SDM's recommendation and avoid any
     theoretical issues.

   - Re-add the EPB MSR reading on turbostat so that it works on older
     kernels which don't have the corresponding EPB sysfs file.

   - Add Alder Lake to the list of CPUs which support split lock.

   - Fix %dr6 register handling in order to be able to set watchpoints
     with gdb again.

   - Disable CET instrumentation in the kernel so that gcc doesn't add
     ENDBR64 to kernel code and thus confuse tracing"

* tag 'x86_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Remove EFI PGD build time checks
  x86/debug: Prevent data breakpoints on cpu_dr7
  x86/debug: Prevent data breakpoints on __per_cpu_offset
  x86/apic: Add extra serialization for non-serializing MSRs
  tools/power/turbostat: Fallback to an MSR read for EPB
  x86/split_lock: Enable the split lock feature on another Alder Lake CPU
  x86/debug: Fix DR6 handling
  x86/build: Disable CET instrumentation in the kernel
2021-02-07 09:40:47 -08:00
Linus Torvalds 2db138bb9f Kbuild fixes for v5.11 (2nd)
- Use the 'python3' command to invoke python scripts because some
    distributions do not provide the 'python' command any more.
 
  - Clean-up and update documents
 
  - Use pkg-config to search libcrypto
 
  - Fix duplicated debug flags
 
  - Ignore some more stubs in scripts/kallsyms.c
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Merge tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Use the 'python3' command to invoke python scripts because some
   distributions do not provide the 'python' command any more.

 - Clean-up and update documents

 - Use pkg-config to search libcrypto

 - Fix duplicated debug flags

 - Ignore some more stubs in scripts/kallsyms.c

* tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kallsyms: fix nonconverging kallsyms table with lld
  kbuild: fix duplicated flags in DEBUG_CFLAGS
  scripts/clang-tools: switch explicitly to Python 3
  kbuild: remove PYTHON variable
  Documentation/llvm: Add a section about supported architectures
  Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions"
  scripts: use pkg-config to locate libcrypto
  kconfig: mconf: fix HOSTCC call
  doc: gcc-plugins: update gcc-plugins.rst
  kbuild: simplify GCC_PLUGINS enablement in dummy-tools/gcc
  Documentation/Kbuild: Remove references to gcc-plugin.sh
  scripts: switch explicitly to Python 3
2021-02-07 09:37:37 -08:00
Masahiro Yamada 315da87c0f kbuild: fix duplicated flags in DEBUG_CFLAGS
Sedat Dilek noticed duplicated flags in DEBUG_CFLAGS when building
deb-pkg with CONFIG_DEBUG_INFO. For example, 'make CC=clang bindeb-pkg'
reproduces the issue.

Kbuild recurses to the top Makefile for some targets such as package
builds.

With commit 121c5d08d5 ("kbuild: Only add -fno-var-tracking-assignments
for old GCC versions") applied, DEBUG_CFLAGS is now reset only when
CONFIG_CC_IS_GCC=y.

Fix it to reset DEBUG_CFLAGS all the time.

Fixes: 121c5d08d5 ("kbuild: Only add -fno-var-tracking-assignments for old GCC versions")
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Mark Wielaard <mark@klomp.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2021-02-05 17:53:28 +09:00
Viresh Kumar ce88c9c794 kbuild: Add support to build overlays (%.dtbo)
Add support for building DT overlays (%.dtbo). The overlay's source file
will have the usual extension, i.e. .dts, though the blob will have
.dtbo extension to distinguish it from normal blobs.

Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/434ba2467dd0cd011565625aeb3450650afe0aae.1611904394.git.viresh.kumar@linaro.org
2021-02-04 09:00:04 -06:00
Jakub Kicinski d1e1355aef Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-02 14:21:31 -08:00
Masahiro Yamada d8d2d38275 kbuild: remove PYTHON variable
Python retired in 2020, and some distributions do not provide the
'python' command any more.

As in commit 51839e29cb ("scripts: switch explicitly to Python 3"),
we need to use more specific 'python3' to invoke scripts even if they
are written in a way compatible with both Python 2 and 3.

This commit removes the variable 'PYTHON', and switches the existing
users to 'PYTHON3'.

BTW, PEP 394 (https://www.python.org/dev/peps/pep-0394/) is a helpful
material.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-01 10:37:19 +09:00
Linus Torvalds 1048ba83fb Linux 5.11-rc6 2021-01-31 13:50:09 -08:00
Josh Poimboeuf 20bf2b3787 x86/build: Disable CET instrumentation in the kernel
With retpolines disabled, some configurations of GCC, and specifically
the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation
to the kernel by default. That breaks certain tracing scenarios by
adding a superfluous ENDBR64 instruction before the fentry call, for
functions which can be called indirectly.

CET instrumentation isn't currently necessary in the kernel, as CET is
only supported in user space. Disable it unconditionally and move it
into the x86's Makefile as CET/CFI... enablement should be a per-arch
decision anyway.

 [ bp: Massage and extend commit message. ]

Fixes: 29be86d7f9 ("kbuild: add -fcf-protection=none when using retpoline flags")
Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Cc: <stable@vger.kernel.org>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble
2021-01-29 18:41:06 +01:00