Linux 6.9-rc4

Linux 6.9-rc3

Linux 6.9-rc2

Linux 6.9-rc1

Linux 6.8

kbuild: unexport abs_srctree and abs_objtree

Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory")
exported abs_srctree and abs_objtree to avoid recomputation after the
sub-make.

kbuild: unexport abs_srctree and abs_objtree

Commit 25b146c5b8ce ("kbuild: allow Kbuild to start from any directory")
exported abs_srctree and abs_objtree to avoid recomputation after the
sub-make. However, this approach turned out to be fragile.

Commit 5fa94ceb793e ("kbuild: set correct abs_srctree and abs_objtree
for package builds") moved them above "ifneq ($(sub_make_done),1)",
eliminating the need for exporting them.

These are only needed in the top Makefile. If an absolute path is
required in sub-directories, you can use $(abspath ) or $(realpath )
as needed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

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kbuild: fix inconsistent indentation in top Makefile

Commit 3b9ab248bc45 ("kbuild: use 4-space indentation when followed
by conditionals") introduced inconsistent indentation because it
deliberately

kbuild: fix inconsistent indentation in top Makefile

Commit 3b9ab248bc45 ("kbuild: use 4-space indentation when followed
by conditionals") introduced inconsistent indentation because it
deliberately touched only the conditional directives to minimize the
change set.

This commit reformats some blocks in the top Makefile so they are
consistently indented with 4 spaces.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>

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Linux 6.8-rc7

kbuild: mark `rustc` (and others) invocations as recursive

`rustc` (like Cargo) may take advantage of the jobserver at any time
(e.g. for backend parallelism, or eventually frontend too). In the ker

kbuild: mark `rustc` (and others) invocations as recursive

`rustc` (like Cargo) may take advantage of the jobserver at any time
(e.g. for backend parallelism, or eventually frontend too). In the kernel,
we call `rustc` with `-Ccodegen-units=1` (and `-Zthreads` is 1 so far),
so we do not expect parallelism. However, in the upcoming Rust 1.76.0, a
warning is emitted by `rustc` [1] when it cannot connect to the jobserver
it was passed (in many cases, but not all: compiling and `--print sysroot`
do, but `--version` does not). And given GNU Make always passes
the jobserver in the environment variable (even when a line is deemed
non-recursive), `rustc` will end up complaining about it (in particular
in Make 4.3 where there is only the simple pipe jobserver style).

One solution is to remove the jobserver from `MAKEFLAGS`. However, we
can mark the lines with calls to `rustc` (and Cargo) as recursive, which
looks simpler. This is being documented as a recommendation in `rustc`
[2] and allows us to be ready for the time we may use parallelism inside
`rustc` (potentially now, if a user passes `-Zthreads`). Thus do so.

Similarly, do the same for `rustdoc` and `cargo` calls.

Finally, there is one case that the solution does not cover, which is the
`$(shell ...)` call we have. Thus, for that one, set an empty `MAKEFLAGS`
environment variable.

Link: https://github.com/rust-lang/rust/issues/120515 [1]
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://github.com/rust-lang/rust/pull/121564 [2]
Link: https://lore.kernel.org/r/20240217002638.57373-1-ojeda@kernel.org
[ Reworded to add link to PR documenting the recommendation. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

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Linux 6.8-rc6

kbuild: Use -fmin-function-alignment when available

GCC recently added option -fmin-function-alignment, which should appear
in GCC 14. Unlike -falign-functions, this option causes all functions to
b

kbuild: Use -fmin-function-alignment when available

GCC recently added option -fmin-function-alignment, which should appear
in GCC 14. Unlike -falign-functions, this option causes all functions to
be aligned at the specified value, including the cold ones.

In particular, when an arm64 kernel is built with
DYNAMIC_FTRACE_WITH_CALL_OPS=y, the 8-byte function alignment is
required for correct functionality. This was done by -falign-functions=8
and having workarounds in the kernel to force the compiler to follow
this alignment. The new -fmin-function-alignment option directly
guarantees it.

Detect availability of -fmin-function-alignment and use it instead of
-falign-functions when present. Introduce CC_HAS_SANE_FUNCTION_ALIGNMENT
and enable __cold to work as expected when it is set.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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Makefile: drop warn-stack-size plugin opt

Now that the minimum supported version of LLVM for building the kernel has
been bumped to 13.0.1, the inner ifeq statement is always false, as the
build wil

Makefile: drop warn-stack-size plugin opt

Now that the minimum supported version of LLVM for building the kernel has
been bumped to 13.0.1, the inner ifeq statement is always false, as the
build will fail during the configuration stage for older LLVM versions.

This effectively reverts commit 24845dcb170e ("Makefile: LTO: have linker
check -Wframe-larger-than") and its follow up fix, commit 0236526d76b8
("Makefile: lto: Pass -warn-stack-size only on LLD < 13.0.0").

Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-2-f5ff9bda41c5@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Conor Dooley <conor@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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kbuild: simplify dtbs_install by reading the list of compiled DTBs

Retrieve the list of *.dtb(o) files from arch/*/boot/dts/dtbs-list
instead of traversing the directory tree again.

Please note tha

kbuild: simplify dtbs_install by reading the list of compiled DTBs

Retrieve the list of *.dtb(o) files from arch/*/boot/dts/dtbs-list
instead of traversing the directory tree again.

Please note that 'make dtbs_install' installs *.dtb(o) files directly
added to dtb-y because scripts/Makefile.dtbinst installs $(dtb-y)
without expanding the -dtbs suffix.

This commit preserves this behavior.

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

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kbuild: create a list of all built DTB files

It is useful to have a list of all *.dtb and *.dtbo files generated
from the current build.

With this commit, 'make dtbs' creates arch/*/boot/dts/dtbs-l

kbuild: create a list of all built DTB files

It is useful to have a list of all *.dtb and *.dtbo files generated
from the current build.

With this commit, 'make dtbs' creates arch/*/boot/dts/dtbs-list, which
lists the dtb(o) files created in the current build. It maintains the
order of the dtb-y additions in Makefiles although the order is not
important for DTBs. It is a (good) side effect through the reuse of the
modules.order rule.

Please note this list only includes the files directly added to dtb-y.

For example, consider this case:

foo-dtbs := foo_base.dtb foo_overlay.dtbo
dtb-y := foo.dtb

In this example, the list will include foo.dtb, but not foo_base.dtb
or foo_overlay.dtbo.

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

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Linux 6.8-rc5

kbuild: use 4-space indentation when followed by conditionals

GNU Make manual [1] clearly forbids a tab at the beginning of the
conditional directive line:
"Extra spaces are allowed and ignored at

kbuild: use 4-space indentation when followed by conditionals

GNU Make manual [1] clearly forbids a tab at the beginning of the
conditional directive line:
"Extra spaces are allowed and ignored at the beginning of the
conditional directive line, but a tab is not allowed."

This will not work for the next release of GNU Make, hence commit
82175d1f9430 ("kbuild: Replace tabs with spaces when followed by
conditionals") replaced the inappropriate tabs with 8 spaces.

However, the 8-space indentation cannot be visually distinguished.
Linus suggested 2-4 spaces for those nested if-statements. [2]

This commit redoes the replacement with 4 spaces.

[1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax
[2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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Linux 6.8-rc4

rust: Refactor the build target to allow the use of builtin targets

Eventually we want all architectures to be using the target as defined
by rustc. However currently some architectures can't do tha

rust: Refactor the build target to allow the use of builtin targets

Eventually we want all architectures to be using the target as defined
by rustc. However currently some architectures can't do that and are
using the target.json specification. This puts in place the foundation
to allow the use of the builtin target definition or a target.json
specification.

Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231020155056.3495121-2-Jamie.Cunliffe@arm.com
[catalin.marinas@arm.com: squashed loongarch ifneq fix from WANG Rui]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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Linux 6.8-rc3

kbuild: Replace tabs with spaces when followed by conditionals

This is needed for the future (post make-4.4.1) versions of gnu make.

Starting from https://git.savannah.gnu.org/cgit/make.git/commit/

kbuild: Replace tabs with spaces when followed by conditionals

This is needed for the future (post make-4.4.1) versions of gnu make.

Starting from https://git.savannah.gnu.org/cgit/make.git/commit/?id=07fcee35f058a876447c8a021f9eb1943f902534
gnu make won't allow conditionals to follow recipe prefix.

For example there is a tab followed by ifeq on line 324 in the root Makefile.
With the new make this conditional causes the following

$ make cpu.o
/home/dgoncharov/src/linux-kbuild/Makefile:2063: *** missing 'endif'. Stop.
make: *** [Makefile:240: __sub-make] Error 2

This patch replaces tabs followed by conditionals with 8 spaces.

See https://savannah.gnu.org/bugs/?64185 and
https://savannah.gnu.org/bugs/?64259 for details.

Signed-off-by: Dmitry Goncharov <dgoncharov@users.sf.net>
Reported-by: Martin Dorey <martin.dorey@hitachivantara.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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kbuild: fix W= flags in the help message

W=c and W=e are supported.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Linux 6.8-rc2

init: Kconfig: Disable -Wstringop-overflow for GCC-11

-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we int

init: Kconfig: Disable -Wstringop-overflow for GCC-11

-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW.

The compiler option related to string operation overflow is now managed
under configuration CC_STRINGOP_OVERFLOW. This option is enabled by
default for all other versions of GCC that support it.

Link: https://lore.kernel.org/lkml/b3c99290-40bc-426f-b3d2-1aa903f95c4e@embeddedor.com/
Link: https://lore.kernel.org/lkml/20231128091351.2bfb38dd@canb.auug.org.au/
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/linux-hardening/ZWj1+jkweEDWbmAR@work/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

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Makefile: Enable -Wstringop-overflow globally

It seems that we have finished addressing all the remaining
issues regarding -Wstringop-overflow. So, we are now in good
shape to enable this compiler o

Makefile: Enable -Wstringop-overflow globally

It seems that we have finished addressing all the remaining
issues regarding -Wstringop-overflow. So, we are now in good
shape to enable this compiler option globally.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

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Linux 6.8-rc1