Pull Kbuild updates from Masahiro Yamada:
- Remove potentially incomplete targets when Kbuid is interrupted by
SIGINT etc in case GNU Make may miss to do that when stderr is piped
to another program.
- Rewrite the single target build so it works more correctly.
- Fix rpm-pkg builds with V=1.
- List top-level subdirectories in ./Kbuild.
- Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in
kallsyms.
- Avoid two different modules in lib/zstd/ having shared code, which
potentially causes building the common code as build-in and modular
back-and-forth.
- Unify two modpost invocations to optimize the build process.
- Remove head-y syntax in favor of linker scripts for placing
particular sections in the head of vmlinux.
- Bump the minimal GNU Make version to 3.82.
- Clean up misc Makefiles and scripts.
* tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits)
docs: bump minimal GNU Make version to 3.82
ia64: simplify esi object addition in Makefile
Revert "kbuild: Check if linker supports the -X option"
kbuild: rebuild .vmlinux.export.o when its prerequisite is updated
kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o
zstd: Fixing mixed module-builtin objects
kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols
kallsyms: take the input file instead of reading stdin
kallsyms: drop duplicated ignore patterns from kallsyms.c
kbuild: reuse mksysmap output for kallsyms
mksysmap: update comment about __crc_*
kbuild: remove head-y syntax
kbuild: use obj-y instead extra-y for objects placed at the head
kbuild: hide error checker logs for V=1 builds
kbuild: re-run modpost when it is updated
kbuild: unify two modpost invocations
kbuild: move vmlinux.o rule to the top Makefile
kbuild: move .vmlinux.objs rule to Makefile.modpost
kbuild: list sub-directories in ./Kbuild
Makefile.compiler: replace cc-ifversion with compiler-specific macros
...
Pull kernel hardening updates from Kees Cook:
"Most of the collected changes here are fixes across the tree for
various hardening features (details noted below).
The most notable new feature here is the addition of the memcpy()
overflow warning (under CONFIG_FORTIFY_SOURCE), which is the next step
on the path to killing the common class of "trivially detectable"
buffer overflow conditions (i.e. on arrays with sizes known at compile
time) that have resulted in many exploitable vulnerabilities over the
years (e.g. BleedingTooth).
This feature is expected to still have some undiscovered false
positives. It's been in -next for a full development cycle and all the
reported false positives have been fixed in their respective trees.
All the known-bad code patterns we could find with Coccinelle are also
either fixed in their respective trees or in flight.
The commit message in commit 54d9469bc5 ("fortify: Add run-time WARN
for cross-field memcpy()") for the feature has extensive details, but
I'll repeat here that this is a warning _only_, and is not intended to
actually block overflows (yet). The many patches fixing array sizes
and struct members have been landing for several years now, and we're
finally able to turn this on to find any remaining stragglers.
Summary:
Various fixes across several hardening areas:
- loadpin: Fix verity target enforcement (Matthias Kaehlcke).
- zero-call-used-regs: Add missing clobbers in paravirt (Bill
Wendling).
- CFI: clean up sparc function pointer type mismatches (Bart Van
Assche).
- Clang: Adjust compiler flag detection for various Clang changes
(Sami Tolvanen, Kees Cook).
- fortify: Fix warnings in arch-specific code in sh, ARM, and xen.
Improvements to existing features:
- testing: improve overflow KUnit test, introduce fortify KUnit test,
add more coverage to LKDTM tests (Bart Van Assche, Kees Cook).
- overflow: Relax overflow type checking for wider utility.
New features:
- string: Introduce strtomem() and strtomem_pad() to fill a gap in
strncpy() replacement needs.
- um: Enable FORTIFY_SOURCE support.
- fortify: Enable run-time struct member memcpy() overflow warning"
* tag 'hardening-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (27 commits)
Makefile.extrawarn: Move -Wcast-function-type-strict to W=1
hardening: Remove Clang's enable flag for -ftrivial-auto-var-init=zero
sparc: Unbreak the build
x86/paravirt: add extra clobbers with ZERO_CALL_USED_REGS enabled
x86/paravirt: clean up typos and grammaros
fortify: Convert to struct vs member helpers
fortify: Explicitly check bounds are compile-time constants
x86/entry: Work around Clang __bdos() bug
ARM: decompressor: Include .data.rel.ro.local
fortify: Adjust KUnit test for modular build
sh: machvec: Use char[] for section boundaries
kunit/memcpy: Avoid pathological compile-time string size
lib: Improve the is_signed_type() kunit test
LoadPin: Require file with verity root digests to have a header
dm: verity-loadpin: Only trust verity targets with enforcement
LoadPin: Fix Kconfig doc about format of file with verity digests
um: Enable FORTIFY_SOURCE
lkdtm: Update tests for memcpy() run-time warnings
fortify: Add run-time WARN for cross-field memcpy()
fortify: Use SIZE_MAX instead of (size_t)-1
...
Pull kcfi updates from Kees Cook:
"This replaces the prior support for Clang's standard Control Flow
Integrity (CFI) instrumentation, which has required a lot of special
conditions (e.g. LTO) and work-arounds.
The new implementation ("Kernel CFI") is specific to C, directly
designed for the Linux kernel, and takes advantage of architectural
features like x86's IBT. This series retains arm64 support and adds
x86 support.
GCC support is expected in the future[1], and additional "generic"
architectural support is expected soon[2].
Summary:
- treewide: Remove old CFI support details
- arm64: Replace Clang CFI support with Clang KCFI support
- x86: Introduce Clang KCFI support"
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107048 [1]
Link: https://github.com/samitolvanen/llvm-project/commits/kcfi_generic [2]
* tag 'kcfi-v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
x86: Add support for CONFIG_CFI_CLANG
x86/purgatory: Disable CFI
x86: Add types to indirectly called assembly functions
x86/tools/relocs: Ignore __kcfi_typeid_ relocations
kallsyms: Drop CONFIG_CFI_CLANG workarounds
objtool: Disable CFI warnings
objtool: Preserve special st_shndx indexes in elf_update_symbol
treewide: Drop __cficanonical
treewide: Drop WARN_ON_FUNCTION_MISMATCH
treewide: Drop function_nocfi
init: Drop __nocfi from __init
arm64: Drop unneeded __nocfi attributes
arm64: Add CFI error handling
arm64: Add types to indirect called assembly functions
psci: Fix the function type for psci_initcall_t
lkdtm: Emit an indirect call for CFI tests
cfi: Add type helper macros
cfi: Switch to -fsanitize=kcfi
cfi: Drop __CFI_ADDRESSABLE
cfi: Remove CONFIG_CFI_CLANG_SHADOW
...
Pull Rust introductory support from Kees Cook:
"The tree has a recent base, but has fundamentally been in linux-next
for a year and a half[1]. It's been updated based on feedback from the
Kernel Maintainer's Summit, and to gain recent Reviewed-by: tags.
Miguel is the primary maintainer, with me helping where needed/wanted.
Our plan is for the tree to switch to the standard non-rebasing
practice once this initial infrastructure series lands.
The contents are the absolute minimum to get Rust code building in the
kernel, with many more interfaces[2] (and drivers - NVMe[3], 9p[4], M1
GPU[5]) on the way.
The initial support of Rust-for-Linux comes in roughly 4 areas:
- Kernel internals (kallsyms expansion for Rust symbols, %pA format)
- Kbuild infrastructure (Rust build rules and support scripts)
- Rust crates and bindings for initial minimum viable build
- Rust kernel documentation and samples
Rust support has been in linux-next for a year and a half now, and the
short log doesn't do justice to the number of people who have
contributed both to the Linux kernel side but also to the upstream
Rust side to support the kernel's needs. Thanks to these 173 people,
and many more, who have been involved in all kinds of ways:
Miguel Ojeda, Wedson Almeida Filho, Alex Gaynor, Boqun Feng, Gary Guo,
Björn Roy Baron, Andreas Hindborg, Adam Bratschi-Kaye, Benno Lossin,
Maciej Falkowski, Finn Behrens, Sven Van Asbroeck, Asahi Lina, FUJITA
Tomonori, John Baublitz, Wei Liu, Geoffrey Thomas, Philip Herron,
Arthur Cohen, David Faust, Antoni Boucher, Philip Li, Yujie Liu,
Jonathan Corbet, Greg Kroah-Hartman, Paul E. McKenney, Josh Triplett,
Kent Overstreet, David Gow, Alice Ryhl, Robin Randhawa, Kees Cook,
Nick Desaulniers, Matthew Wilcox, Linus Walleij, Joe Perches, Michael
Ellerman, Petr Mladek, Masahiro Yamada, Arnaldo Carvalho de Melo,
Andrii Nakryiko, Konstantin Shelekhin, Rasmus Villemoes, Konstantin
Ryabitsev, Stephen Rothwell, Andy Shevchenko, Sergey Senozhatsky, John
Paul Adrian Glaubitz, David Laight, Nathan Chancellor, Jonathan
Cameron, Daniel Latypov, Shuah Khan, Brendan Higgins, Julia Lawall,
Laurent Pinchart, Geert Uytterhoeven, Akira Yokosawa, Pavel Machek,
David S. Miller, John Hawley, James Bottomley, Arnd Bergmann,
Christian Brauner, Dan Robertson, Nicholas Piggin, Zhouyi Zhou, Elena
Zannoni, Jose E. Marchesi, Leon Romanovsky, Will Deacon, Richard
Weinberger, Randy Dunlap, Paolo Bonzini, Roland Dreier, Mark Brown,
Sasha Levin, Ted Ts'o, Steven Rostedt, Jarkko Sakkinen, Michal
Kubecek, Marco Elver, Al Viro, Keith Busch, Johannes Berg, Jan Kara,
David Sterba, Connor Kuehl, Andy Lutomirski, Andrew Lunn, Alexandre
Belloni, Peter Zijlstra, Russell King, Eric W. Biederman, Willy
Tarreau, Christoph Hellwig, Emilio Cobos Álvarez, Christian Poveda,
Mark Rousskov, John Ericson, TennyZhuang, Xuanwo, Daniel Paoliello,
Manish Goregaokar, comex, Josh Stone, Stephan Sokolow, Philipp Krones,
Guillaume Gomez, Joshua Nelson, Mats Larsen, Marc Poulhiès, Samantha
Miller, Esteban Blanc, Martin Schmidt, Martin Rodriguez Reboredo,
Daniel Xu, Viresh Kumar, Bartosz Golaszewski, Vegard Nossum, Milan
Landaverde, Dariusz Sosnowski, Yuki Okushi, Matthew Bakhtiari, Wu
XiangCheng, Tiago Lam, Boris-Chengbiao Zhou, Sumera Priyadarsini,
Viktor Garske, Niklas Mohrin, Nándor István Krácser, Morgan Bartlett,
Miguel Cano, Léo Lanteri Thauvin, Julian Merkle, Andreas Reindl,
Jiapeng Chong, Fox Chen, Douglas Su, Antonio Terceiro, SeongJae Park,
Sergio González Collado, Ngo Iok Ui (Wu Yu Wei), Joshua Abraham,
Milan, Daniel Kolsoi, ahomescu, Manas, Luis Gerhorst, Li Hongyu,
Philipp Gesang, Russell Currey, Jalil David Salamé Messina, Jon Olson,
Raghvender, Angelos, Kaviraj Kanagaraj, Paul Römer, Sladyn Nunes,
Mauro Baladés, Hsiang-Cheng Yang, Abhik Jain, Hongyu Li, Sean Nash,
Yuheng Su, Peng Hao, Anhad Singh, Roel Kluin, Sara Saa, Geert
Stappers, Garrett LeSage, IFo Hancroft, and Linus Torvalds"
Link: https://lwn.net/Articles/849849/ [1]
Link: https://github.com/Rust-for-Linux/linux/commits/rust [2]
Link: d88c3744d6 [3]
Link: 9367032607 [4]
Link: https://github.com/AsahiLinux/linux/commits/gpu/rust-wip [5]
* tag 'rust-v6.1-rc1' of https://github.com/Rust-for-Linux/linux: (27 commits)
MAINTAINERS: Rust
samples: add first Rust examples
x86: enable initial Rust support
docs: add Rust documentation
Kbuild: add Rust support
rust: add `.rustfmt.toml`
scripts: add `is_rust_module.sh`
scripts: add `rust_is_available.sh`
scripts: add `generate_rust_target.rs`
scripts: add `generate_rust_analyzer.py`
scripts: decode_stacktrace: demangle Rust symbols
scripts: checkpatch: enable language-independent checks for Rust
scripts: checkpatch: diagnose uses of `%pA` in the C side as errors
vsprintf: add new `%pA` format specifier
rust: export generated symbols
rust: add `kernel` crate
rust: add `bindings` crate
rust: add `macros` crate
rust: add `compiler_builtins` crate
rust: adapt `alloc` crate to the kernel
...
This reverts commit d79a27195a.
According to the commit description, this ld-option test was added for
the gold linker at that time.
Commit 75959d44f9 ("kbuild: Fail if gold linker is detected") gave
up the gold linker support after all.
I tested the BFD linker from binutils 2.23 and LLD from LLVM 11.0.0.
Both of them support the -X option.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When include/linux/export-internal.h is updated, .vmlinux.export.o
must be rebuilt, but it does not happen because its rule is hidden
behind scripts/link-vmlinux.sh.
Move it out of the shell script, so that Make can see the dependency
between vmlinux and .vmlinux.export.o.
Move the vmlinux rule to scripts/Makefile.vmlinux.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Do not build modules.builtin(.modinfo) as a side-effect of vmlinux.
There are no good reason to rebuild them just because any of vmlinux's
prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.
A counter approach is to control the section order by the linker script.
Actually, the code marked as __HEAD goes into the ".head.text" section,
which is placed before the normal ".text" section.
I do not know if both of them are needed. From the build system
perspective, head-y is not mandatory. If you can achieve the proper code
placement by the linker script only, it would be cleaner.
I collected the current head-y objects into head-object-list.txt. It is
a whitelist. My hope is it will be reduced in the long run.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
The objects placed at the head of vmlinux need special treatments:
- arch/$(SRCARCH)/Makefile adds them to head-y in order to place
them before other archives in the linker command line.
- arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
obj-y to avoid them going into built-in.a.
This commit gets rid of the latter.
Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.
With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.
There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.
$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].
[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Now that Clang's -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
option is no longer required, remove it from the command line. Clang 16
and later will warn when it is used, which will cause Kconfig to think
it can't use -ftrivial-auto-var-init=zero at all. Check for whether it
is required and only use it when so.
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-kbuild@vger.kernel.org
Cc: llvm@lists.linux.dev
Cc: stable@vger.kernel.org
Fixes: f02003c860 ("hardening: Avoid harmless Clang option under CONFIG_INIT_STACK_ALL_ZERO")
Signed-off-by: Kees Cook <keescook@chromium.org>
V=1 (verbose build) shows commands executed by Make, but it may cause
misunderstanding.
For example, the following command shows the outstanding error message.
$ make V=1 INSTALL_PATH=/tmp install
test -e include/generated/autoconf.h -a -e include/config/auto.conf || ( \
echo >&2; \
echo >&2 " ERROR: Kernel configuration is invalid."; \
echo >&2 " include/generated/autoconf.h or include/config/auto.conf are missing.";\
echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
echo >&2 ; \
/bin/false)
unset sub_make_done; ./scripts/install.sh
It is not an error. Make just showed the recipe lines it has executed,
but people may think that 'make install' has failed.
Likewise, the combination of V=1 and O= shows confusing
"*** The source tree is not clean, please run 'make mrproper'".
Suppress such misleading logs.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Currently, modpost is executed twice; first for vmlinux, second
for modules.
This commit merges them.
Current build flow
==================
1) build obj-y and obj-m objects
2) link vmlinux.o
3) modpost for vmlinux
4) link vmlinux
5) modpost for modules
6) link modules (*.ko)
The build steps 1) through 6) are serialized, that is, modules are
built after vmlinux. You do not get benefits of parallel builds when
scripts/link-vmlinux.sh is being run.
New build flow
==============
1) build obj-y and obj-m objects
2) link vmlinux.o
3) modpost for vmlinux and modules
4a) link vmlinux
4b) link modules (*.ko)
In the new build flow, modpost is invoked just once.
vmlinux and modules are built in parallel. One exception is
CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Move the build rules of vmlinux.o out of scripts/link-vmlinux.sh to
clearly separate 1) pre-modpost, 2) modpost, 3) post-modpost stages.
This will make further refactoring possible.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
.vmlinux.objs is used by modpost, so scripts/Makefile.modpost is
a better place to generate it.
It is used only when CONFIG_MODVERSIONS=y. It should be guarded
by "ifdef CONFIG_MODVERSIONS".
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Use the ordinary obj-y syntax to list subdirectories.
Note1:
Previously, the link order of lib-y depended on CONFIG_MODULES; lib-y
was linked before drivers-y when CONFIG_MODULES=y, otherwise after
drivers-y. This was a bug of commit 7273ad2b08 ("kbuild: link lib-y
objects to vmlinux forcibly when CONFIG_MODULES=y"), but it was not a
big deal after all. Now, all objects listed in lib-y are linked last,
irrespective of CONFIG_MODULES.
Note2:
Finally, the single target build in arch/*/lib/ works correctly. There was
a bug report about this. [1]
$ make ARCH=arm arch/arm/lib/findbit.o
CALL scripts/checksyscalls.sh
AS arch/arm/lib/findbit.o
[1]: https://lore.kernel.org/linux-kbuild/YvUQOwL6lD4%2F5%2FU6@shell.armlinux.org.uk/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
The single target build has a subtle bug for the combination for
an individual file and a subdirectory.
[1] 'make kernel/fork.i' builds only kernel/fork.i
$ make kernel/fork.i
CALL scripts/checksyscalls.sh
DESCEND objtool
CPP kernel/fork.i
[2] 'make kernel/' builds only under the kernel/ directory.
$ make kernel/
CALL scripts/checksyscalls.sh
DESCEND objtool
CC kernel/fork.o
CC kernel/exec_domain.o
[snip]
CC kernel/rseq.o
AR kernel/built-in.a
But, if you try to do [1] and [2] in a single command, you will get
only [1] with a weird log:
$ make kernel/fork.i kernel/
CALL scripts/checksyscalls.sh
DESCEND objtool
CPP kernel/fork.i
make[2]: Nothing to be done for 'kernel/'.
With 'make kernel/fork.i kernel/', you should get both [1] and [2].
Rewrite the single target build.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Now that UTS_VERSION was separated out, this header can be generated
much earlier, and probably the top Makefile is a better place to do it
than init/Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Remove the potentially invalid modules.order instead of using
the temporary file.
Also, KBUILD_MODULES is don't care for single builds. No need to
cancel it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The dependency, "modules: modules_check" is specified twice.
Commit 1a998be620 ("kbuild: check module name conflict for external
modules as well") missed to clean it up.
'PHONY += modules' also appears twice.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The AWK code was added to deduplicate modules.order in case $(obj-m)
contains the same module multiple times, but it is actually unneeded
since commit b2c8855491 ("kbuild: update modules.order only when
contained modules are updated").
The list is already deduplicated before being processed by AWK because
$^ is the deduplicated list of prerequisites.
(Please note the real-prereqs macro uses $^)
Yet, modules.order will contain duplication if two different Makefiles
build the same module:
foo/Makefile:
obj-m += bar/baz.o
foo/bar/Makefile:
obj-m += baz.o
However, the parallel builds cannot properly handle this case in the
first place. So, it is better to let it fail (as already done by
scripts/modules-check.sh).
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
It is unneeded to check the sha1sum every time.
Create the timestamp files to manage it.
Add '.' to clean-dirs because 'make clean' must visit ./Kbuild to
clean up the timestamp files.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
My future plan is to list subdirectories in ./Kbuild. When it occurs,
$(vmlinux-alldirs) will not contain all subdirectories.
Let's hard-code the directory list until I get around to implementing
a more sophisticated way for generating a source tarball.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
