Pull Kbuild updates from Masahiro Yamada:
- Enable -Wenum-conversion warning option
- Refactor the rpm-pkg target
- Fix scripts/setlocalversion to consider annotated tags for rt-kernel
- Add a jump key feature for the search menu of 'make nconfig'
- Support Qt6 for 'make xconfig'
- Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow,
and -Wrestrict warnings for W=1 builds
- Replace <asm/export.h> with <linux/export.h> for alpha, ia64, and
sparc
- Support DEB_BUILD_OPTIONS=parallel=N for the debian source package
- Refactor scripts/Makefile.modinst and fix some modules_sign issues
- Add a new Kconfig env variable to warn symbols that are not defined
anywhere
- Show help messages of config fragments in 'make help'
* tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (62 commits)
kconfig: fix possible buffer overflow
kbuild: Show marked Kconfig fragments in "help"
kconfig: add warn-unknown-symbols sanity check
kbuild: dummy-tools: make MPROFILE_KERNEL checks work on BE
Documentation/llvm: refresh docs
modpost: Skip .llvm.call-graph-profile section check
kbuild: support modules_sign for external modules as well
kbuild: support 'make modules_sign' with CONFIG_MODULE_SIG_ALL=n
kbuild: move more module installation code to scripts/Makefile.modinst
kbuild: reduce the number of mkdir calls during modules_install
kbuild: remove $(MODLIB)/source symlink
kbuild: move depmod rule to scripts/Makefile.modinst
kbuild: add modules_sign to no-{compiler,sync-config}-targets
kbuild: do not run depmod for 'make modules_sign'
kbuild: deb-pkg: support DEB_BUILD_OPTIONS=parallel=N in debian/rules
alpha: remove <asm/export.h>
alpha: replace #include <asm/export.h> with #include <linux/export.h>
ia64: remove <asm/export.h>
ia64: replace #include <asm/export.h> with #include <linux/export.h>
sparc: remove <asm/export.h>
...
Currently the Kconfig fragments in kernel/configs and arch/*/configs
that aren't used internally aren't discoverable through "make help",
which consists of hard-coded lists of config fragments. Instead, list
all the fragment targets that have a "# Help: " comment prefix so the
targets can be generated dynamically.
Add logic to the Makefile to search for and display the fragment and
comment. Add comments to fragments that are intended to be direct targets.
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The modules_sign target is currently only available for in-tree modules,
but it actually works for external modules as well.
Move the modules_sign rule to the common part.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Move more relevant code to scripts/Makefile.modinst.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Pull rust updates from Miguel Ojeda:
"In terms of lines, most changes this time are on the pinned-init API
and infrastructure. While we have a Rust version upgrade, and thus a
bunch of changes from the vendored 'alloc' crate as usual, this time
those do not account for many lines.
Toolchain and infrastructure:
- Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
smaller jump compared to the last time.
This version allows us to remove the '__rust_*' allocator functions
-- the compiler now generates them as expected, thus now our
'KernelAllocator' is used.
It also introduces the 'offset_of!' macro in the standard library
(as an unstable feature) which we will need soon. So far, we were
using a declarative macro as a prerequisite in some not-yet-landed
patch series, which did not support sub-fields (i.e. nested
structs):
#[repr(C)]
struct S {
a: u16,
b: (u8, u8),
}
assert_eq!(offset_of!(S, b.1), 3);
- Upgrade to bindgen 0.65.1. This is the first time we upgrade its
version.
Given it is a fairly big jump, it comes with a fair number of
improvements/changes that affect us, such as a fix needed to
support LLVM 16 as well as proper support for '__noreturn' C
functions, which are now mapped to return the '!' type in Rust:
void __noreturn f(void); // C
pub fn f() -> !; // Rust
- 'scripts/rust_is_available.sh' improvements and fixes.
This series takes care of all the issues known so far and adds a
few new checks to cover for even more cases, plus adds some more
help texts. All this together will hopefully make problematic
setups easier to identify and to be solved by users building the
kernel.
In addition, it adds a test suite which covers all branches of the
shell script, as well as tests for the issues found so far.
- Support rust-analyzer for out-of-tree modules too.
- Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.
- Drop 'scripts/is_rust_module.sh' since it is not needed anymore.
Macros crate:
- New 'paste!' proc macro.
This macro is a more flexible version of 'concat_idents!': it
allows the resulting identifier to be used to declare new items and
it allows to transform the identifiers before concatenating them,
e.g.
let x_1 = 42;
paste!(let [<x _2>] = [<x _1>];);
assert!(x_1 == x_2);
The macro is then used for several of the pinned-init API changes
in this pull.
Pinned-init API:
- Make '#[pin_data]' compatible with conditional compilation of
fields, allowing to write code like:
#[pin_data]
pub struct Foo {
#[cfg(CONFIG_BAR)]
a: Bar,
#[cfg(not(CONFIG_BAR))]
a: Baz,
}
- New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait,
which allows 'unsafe' implementations for structs where every field
implements the 'Zeroable' trait, e.g.:
#[derive(Zeroable)]
pub struct DriverData {
id: i64,
buf_ptr: *mut u8,
len: usize,
}
- Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for
zeroing all other fields, e.g.:
pin_init!(Buf {
buf: [1; 64],
..Zeroable::zeroed()
});
- New '{,pin_}init_array_from_fn()' functions to create array
initializers given a generator function, e.g.:
let b: Box<[usize; 1_000]> = Box::init::<Error>(
init_array_from_fn(|i| i)
).unwrap();
assert_eq!(b.len(), 1_000);
assert_eq!(b[123], 123);
- New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
execute a closure on the value directly after initialization, e.g.:
let foo = init!(Foo {
buf <- init::zeroed()
}).chain(|foo| {
foo.setup();
Ok(())
});
- Support arbitrary paths in init macros, instead of just identifiers
and generic types.
- Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
'Opaque<T>' types.
- Make initializer values inaccessible after initialization.
- Make guards in the init macros hygienic.
'allocator' module:
- Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
misaligned allocations when the Rust 1.71.1 upgrade is applied
later in this pull.
The equivalent fix for the previous compiler version (where
'KernelAllocator' is not yet used) was merged into 6.5 already,
which added the 'krealloc_aligned()' function used here.
- Implement 'KernelAllocator::{realloc, alloc_zeroed}' for
performance, using 'krealloc_aligned()' too, which forwards the
call to the C API.
'types' module:
- Make 'Opaque' be '!Unpin', removing the need to add a
'PhantomPinned' field to Rust structs that contain C structs which
must not be moved.
- Make 'Opaque' use 'UnsafeCell' as the outer type, rather than
inner.
Documentation:
- Suggest obtaining the source code of the Rust's 'core' library
using the tarball instead of the repository.
MAINTAINERS:
- Andreas and Alice, from Samsung and Google respectively, are
joining as reviewers of the "RUST" entry.
As well as a few other minor changes and cleanups"
* tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits)
rust: init: update expanded macro explanation
rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`
rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`
rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
rust: init: add support for arbitrary paths in init macros
rust: init: add functions to create array initializers
rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields
rust: init: make initializer values inaccessible after initializing
rust: init: wrap type checking struct initializers in a closure
rust: init: make guards in the init macros hygienic
rust: add derive macro for `Zeroable`
rust: init: make `#[pin_data]` compatible with conditional compilation of fields
rust: init: consolidate init macros
docs: rust: clarify what 'rustup override' does
docs: rust: update instructions for obtaining 'core' source
docs: rust: add command line to rust-analyzer section
scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`
rust: bindgen: upgrade to 0.65.1
rust: enable `no_mangle_with_rust_abi` Clippy lint
rust: upgrade to Rust 1.71.1
...
depmod is a part of the module installation.
scripts/Makefile.modinst is a better place to run it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Like modules_install, modules_sign should avoid the syncconfig.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Commit 961ab4a3cd ("kbuild: merge scripts/Makefile.modsign to
scripts/Makefile.modinst") started to run depmod at the end of
'make modules_sign'.
Move the depmod rule to scripts/Makefile.modinst and run it only when
$(modules_sign_only) is empty.
Fixes: 961ab4a3cd ("kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
This is a remnant of commit 5e9e95cc91 ("kbuild: implement
CONFIG_TRIM_UNUSED_KSYMS without recursion").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Warning options are enabled and disabled in inconsistent ways and
inconsistent locations. Start rearranging those by moving all options
into Makefile.extrawarn.
This should not change any behavior, but makes sure we can group them
in a way that ensures that each warning that got temporarily disabled
is turned back on at an appropriate W=1 level later on.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Introduced in Rust 1.69.0 [1], this lint prevents forgetting to set
the C ABI when using `#[no_mangle]` (or thinking it is implied).
For instance, it would have prevented the issue [2] fixed by commit
c682e4c37d ("rust: kernel: Mark rust_fmt_argument as extern "C"").
error: `#[no_mangle]` set on a function with the default (`Rust`) ABI
--> rust/kernel/print.rs:21:1
|
21 | / unsafe fn rust_fmt_argument(
22 | | buf: *mut c_char,
23 | | end: *mut c_char,
24 | | ptr: *const c_void,
25 | | ) -> *mut c_char {
| |________________^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#no_mangle_with_rust_abi
= note: requested on the command line with `-D clippy::no-mangle-with-rust-abi`
help: set an ABI
|
21 | unsafe extern "C" fn rust_fmt_argument(
| ++++++++++
help: or explicitly set the default
|
21 | unsafe extern "Rust" fn rust_fmt_argument(
| +++++++++++++
Thus enable it.
In rare cases, we may need to use the Rust ABI even with `#[no_mangle]`
(e.g. one case, before 1.71.0, would have been the `__rust_*`
functions). In those cases, we would need to `#[allow(...)]` the lint,
since using `extern "Rust"` explicitly (as the compiler suggests)
currently gets overwritten by `rustfmt` [3].
Link: https://github.com/rust-lang/rust-clippy/issues/10347 [1]
Link: https://github.com/Rust-for-Linux/linux/pull/967 [2]
Link: https://github.com/rust-lang/rustfmt/issues/5701 [3]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230729220317.416771-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Adds support for out-of-tree rust modules to use the `rust-analyzer`
make target to generate the rust-project.json file.
The change involves adding an optional parameter `external_src` to the
`generate_rust_analyzer.py` which expects the path to the out-of-tree
module's source directory. When this parameter is passed, I have chosen
not to add the non-core modules (samples and drivers) into the result
since these are not expected to be used in third party modules. Related
changes are also made to the Makefile and rust/Makefile allowing the
`rust-analyzer` target to be used for out-of-tree modules as well.
Link: https://github.com/Rust-for-Linux/linux/pull/914
Link: https://github.com/Rust-for-Linux/rust-out-of-tree-module/pull/2
Signed-off-by: Vinay Varma <varmavinaym@gmail.com>
Link: https://lore.kernel.org/r/20230411091714.130525-1-varmavinaym@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Now kernel.spec and binkernel.spec have the exactly same contents.
Use kernel.spec for binrpm-pkg as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
There are some cases where we want to run a command with the same
environment variables as Kbuild uses. For example, 'make coccicheck'
invokes scripts/coccicheck from the top Makefile so that the script can
reference to ${LINUXINCLUDE}, ${KBUILD_EXTMOD}, etc. The top Makefile
defines several phony targets that run a script.
We do it also for an internally used script, which results in a somewhat
complex call graph.
One example:
debian/rules binary-arch
-> make intdeb-pkg
-> scripts/package/builddeb
It is also tedious to add a dedicated target like 'intdeb-pkg' for each
use case.
Add a generic target 'run-command' to run an arbitrary command in an
environment with all Kbuild variables set.
The usage is:
$ make run-command KBUILD_RUN_COMMAND=<command>
The concept is similar to:
$ dpkg-architecture -c <command>
This executes <command> in an environment which has all DEB_* variables
defined.
Convert the existing 'make intdeb-pkg'.
Another possible usage is to interrogate a Make variable.
$ make run-command KBUILD_RUN_COMMAND='echo $(KBUILD_CFLAGS)'
might be useful to see KBUILD_CFLAGS set by the top Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This diagnostic checks whether there is a type mismatch when
converting enums (assign an enum of type A to an enum of type B, for
example) and it caught a legit issue recently. The reason it didn't show
is because that warning is enabled only with -Wextra with GCC. Clang,
however, enables it by default.
GCC folks were considering enabling it by default but it was too noisy
back then:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78736
Now that due to clang all those warnings have been fixed, enable it with
GCC too.
allmodconfig tests done with: x86, arm{,64}, powerpc{,64}, riscv
crossbuilds.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull Kbuild fixes from Masahiro Yamada:
- Fix stale help text in gconfig
- Support *.S files in compile_commands.json
- Flatten KBUILD_CFLAGS
- Fix external module builds with Rust so that temporary files are
created in the modules directories instead of the kernel tree
* tag 'kbuild-fixes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: rust: avoid creating temporary files
kbuild: flatten KBUILD_CFLAGS
gen_compile_commands: add assembly files to compilation database
kconfig: gconfig: correct program name in help text
kconfig: gconfig: drop the Show Debug Info help text
Make it slightly easier to see which compiler options are added and
removed (and not worry about column limit too!).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull scope-based resource management infrastructure from Peter Zijlstra:
"These are the first few patches in the Scope-based Resource Management
series that introduce the infrastructure but not any conversions as of
yet.
Adding the infrastructure now allows multiple people to start using
them.
Of note is that Sparse will need some work since it doesn't yet
understand this attribute and might have decl-after-stmt issues"
* tag 'core_guards_for_6.5_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue:
kbuild: Drop -Wdeclaration-after-statement
locking: Introduce __cleanup() based infrastructure
apparmor: Free up __cleanup() name
dmaengine: ioat: Free up __cleanup() name
Pull Kbuild updates from Masahiro Yamada:
- Remove the deprecated rule to build *.dtbo from *.dts
- Refactor section mismatch detection in modpost
- Fix bogus ARM section mismatch detections
- Fix error of 'make gtags' with O= option
- Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
with the latest LLVM version
- Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed
- Ignore more compiler-generated symbols for kallsyms
- Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles
- Enable more kernel-doc warnings with W=2
- Refactor <linux/export.h> by generating KSYMTAB data by modpost
- Deprecate <asm/export.h> and <asm-generic/export.h>
- Remove the EXPORT_DATA_SYMBOL macro
- Move the check for static EXPORT_SYMBOL back to modpost, which makes
the build faster
- Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm
- Warn missing MODULE_DESCRIPTION when building modules with W=1
- Make 'make clean' robust against too long argument error
- Exclude more objects from GCOV to fix CFI failures with GCOV
- Allow 'make modules_install' to install modules.builtin and
modules.builtin.modinfo even when CONFIG_MODULES is disabled
- Include modules.builtin and modules.builtin.modinfo in the
linux-image Debian package even when CONFIG_MODULES is disabled
- Revive "Entering directory" logging for the latest Make version
* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
modpost: define more R_ARM_* for old distributions
kbuild: revive "Entering directory" for Make >= 4.4.1
kbuild: set correct abs_srctree and abs_objtree for package builds
scripts/mksysmap: Ignore prefixed KCFI symbols
kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
kbuild: builddeb: always make modules_install, to install modules.builtin*
modpost: continue even with unknown relocation type
modpost: factor out Elf_Sym pointer calculation to section_rel()
modpost: factor out inst location calculation to section_rel()
kbuild: Disable GCOV for *.mod.o
kbuild: Fix CFI failures with GCOV
kbuild: make clean rule robust against too long argument error
script: modpost: emit a warning when the description is missing
kbuild: make modules_install copy modules.builtin(.modinfo)
linux/export.h: rename 'sec' argument to 'license'
modpost: show offset from symbol for section mismatch warnings
modpost: merge two similar section mismatch warnings
kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
modpost: use null string instead of NULL pointer for default namespace
modpost: squash sym_update_namespace() into sym_add_exported()
...
Pull hardening updates from Kees Cook:
"There are three areas of note:
A bunch of strlcpy()->strscpy() conversions ended up living in my tree
since they were either Acked by maintainers for me to carry, or got
ignored for multiple weeks (and were trivial changes).
The compiler option '-fstrict-flex-arrays=3' has been enabled
globally, and has been in -next for the entire devel cycle. This
changes compiler diagnostics (though mainly just -Warray-bounds which
is disabled) and potential UBSAN_BOUNDS and FORTIFY _warning_
coverage. In other words, there are no new restrictions, just
potentially new warnings. Any new FORTIFY warnings we've seen have
been fixed (usually in their respective subsystem trees). For more
details, see commit df8fc4e934.
The under-development compiler attribute __counted_by has been added
so that we can start annotating flexible array members with their
associated structure member that tracks the count of flexible array
elements at run-time. It is possible (likely?) that the exact syntax
of the attribute will change before it is finalized, but GCC and Clang
are working together to sort it out. Any changes can be made to the
macro while we continue to add annotations.
As an example of that last case, I have a treewide commit waiting with
such annotations found via Coccinelle:
https://git.kernel.org/linus/adc5b3cb48a049563dc673f348eab7b6beba8a9b
Also see commit dd06e72e68 for more details.
Summary:
- Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko)
- Convert strreplace() to return string start (Andy Shevchenko)
- Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook)
- Add missing function prototypes seen with W=1 (Arnd Bergmann)
- Fix strscpy() kerndoc typo (Arne Welzel)
- Replace strlcpy() with strscpy() across many subsystems which were
either Acked by respective maintainers or were trivial changes that
went ignored for multiple weeks (Azeem Shaikh)
- Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers)
- Add KUnit tests for strcat()-family
- Enable KUnit tests of FORTIFY wrappers under UML
- Add more complete FORTIFY protections for strlcat()
- Add missed disabling of FORTIFY for all arch purgatories.
- Enable -fstrict-flex-arrays=3 globally
- Tightening UBSAN_BOUNDS when using GCC
- Improve checkpatch to check for strcpy, strncpy, and fake flex
arrays
- Improve use of const variables in FORTIFY
- Add requested struct_size_t() helper for types not pointers
- Add __counted_by macro for annotating flexible array size members"
* tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (54 commits)
netfilter: ipset: Replace strlcpy with strscpy
uml: Replace strlcpy with strscpy
um: Use HOST_DIR for mrproper
kallsyms: Replace all non-returning strlcpy with strscpy
sh: Replace all non-returning strlcpy with strscpy
of/flattree: Replace all non-returning strlcpy with strscpy
sparc64: Replace all non-returning strlcpy with strscpy
Hexagon: Replace all non-returning strlcpy with strscpy
kobject: Use return value of strreplace()
lib/string_helpers: Change returned value of the strreplace()
jbd2: Avoid printing outside the boundary of the buffer
checkpatch: Check for 0-length and 1-element arrays
riscv/purgatory: Do not use fortified string functions
s390/purgatory: Do not use fortified string functions
x86/purgatory: Do not use fortified string functions
acpi: Replace struct acpi_table_slit 1-element array with flex-array
clocksource: Replace all non-returning strlcpy with strscpy
string: use __builtin_memcpy() in strlcpy/strlcat
staging: most: Replace all non-returning strlcpy with strscpy
drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy
...
With commit 9da0763bdd ("kbuild: Use relative path when building in
a subdir of the source tree"), compiler messages in out-of-tree builds
include relative paths, which are relative to the build directory, not
the directory where make was started.
To help IDEs/editors find the source files, Kbuild lets GNU Make print
"Entering directory ..." when it changes the working directory. It has
been working fine for a long time, but David reported it is broken with
the latest GNU Make.
The behavior was changed by GNU Make commit 8f9e7722ff0f ("[SV 63537]
Fix setting -w in makefiles"). Previously, setting --no-print-directory
to MAKEFLAGS only affected child makes, but it is now interpreted in
the current make as soon as it is set.
[test code]
$ cat /tmp/Makefile
ifneq ($(SUBMAKE),1)
MAKEFLAGS += --no-print-directory
all: ; $(MAKE) SUBMAKE=1
else
all: ; :
endif
[before 8f9e7722ff0f]
$ make -C /tmp
make: Entering directory '/tmp'
make SUBMAKE=1
:
make: Leaving directory '/tmp'
[after 8f9e7722ff0f]
$ make -C /tmp
make SUBMAKE=1
:
Previously, the effect of --no-print-directory was delayed until Kbuild
started the directory descending, but it is no longer true with GNU Make
4.4.1.
This commit adds one more recursion to cater to GNU Make >= 4.4.1.
When Kbuild needs to change the working directory, __submake will be
executed twice.
__submake without --no-print-directory --> show "Entering directory ..."
__submake with --no-print-directory --> parse the rest of Makefile
We end up with one more recursion than needed for GNU Make < 4.4.1, but
I do not want to complicate the version check.
Reported-by: David Howells <dhowells@redhat.com>
Closes: https://lore.kernel.org/all/2427604.1686237298@warthog.procyon.org.uk/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <n.schier@avm.de>
When you run 'make rpm-pkg', the rpmbuild tool builds the kernel in
rpmbuild/BUILD, but $(abs_srctree) and $(abs_objtree) point to the
directory path where make was started, not the kernel is actually
being built. The same applies to 'make snap-pkg'. Fix it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Josh Triplett reports that initramfs-tools needs modules.builtin and
modules.builtin.modinfo to create a working initramfs for a non-modular
kernel.
If this is a general tooling issue not limited to Debian, I think it
makes sense to change modules_install.
This commit changes the targets as follows when CONFIG_MODULES=n.
In-tree builds:
make modules -> no-op
make modules_install -> install modules.builtin(.modinfo)
External module builds:
make modules -> show error message like before
make modules_install -> show error message like before
Link: https://lore.kernel.org/lkml/36a4014c73a52af27d930d3ca31d362b60f4461c.1686356364.git.josh@joshtriplett.org/
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Josh Triplett <josh@joshtriplett.org>
When CONFIG_TRIM_UNUSED_KSYMS is enabled, Kbuild recursively traverses
the directory tree to determine which EXPORT_SYMBOL to trim. If an
EXPORT_SYMBOL turns out to be unused by anyone, Kbuild begins the
second traverse, where some source files are recompiled with their
EXPORT_SYMBOL() tuned into a no-op.
Linus stated negative opinions about this slowness in commits:
- 5cf0fd591f ("Kbuild: disable TRIM_UNUSED_KSYMS option")
- a555bdd0c5 ("Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding")
We can do this better now. The final data structures of EXPORT_SYMBOL
are generated by the modpost stage, so modpost can selectively emit
KSYMTAB entries that are really used by modules.
Commit f73edc8951 ("kbuild: unify two modpost invocations") is another
ground-work to do this in a one-pass algorithm. With the list of modules,
modpost sets sym->used if it is used by a module. modpost emits KSYMTAB
only for symbols with sym->used==true.
BTW, Nicolas explained why the trimming was implemented with recursion:
https://lore.kernel.org/all/2o2rpn97-79nq-p7s2-nq5-8p83391473r@syhkavp.arg/
Actually, we never achieved that level of optimization where the chain
reaction of trimming comes into play because:
- CONFIG_LTO_CLANG cannot remove any unused symbols
- CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is enabled only for vmlinux,
but not modules
If deeper trimming is required, we need to revisit this, but I guess
that is unlikely to happen.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
