Pull Rust fixes from Miguel Ojeda: - Soundness: make internal functions generated by the 'module!' macro inaccessible, do not implement 'Zeroable' for 'Infallible' and require 'Send' for the 'Module' trait. - Build: avoid errors with "empty" files and workaround 'rustdoc' ICE. - Kconfig: depend on '!CFI_CLANG' and avoid selecting 'CONSTRUCTORS'. - Code docs: remove non-existing key from 'module!' macro example. - Docs: trivial rendering fix in arch table. * tag 'rust-fixes-6.9' of https://github.com/Rust-for-Linux/linux: rust: remove `params` from `module` macro example kbuild: rust: force `alloc` extern to allow "empty" Rust files kbuild: rust: remove unneeded `@rustc_cfg` to avoid ICE rust: kernel: require `Send` for `Module` implementations rust: phy: implement `Send` for `Registration` rust: make mutually exclusive with CFI_CLANG rust: macros: fix soundness issue in `module!` macro rust: init: remove impl Zeroable for Infallible docs: rust: fix improper rendering in Arch Support page rust: don't select CONSTRUCTORS
If one attempts to build an essentially empty file somewhere in the
kernel tree, it leads to a build error because the compiler does not
recognize the `new_uninit` unstable feature:
error[E0635]: unknown feature `new_uninit`
--> <crate attribute>:1:9
|
1 | feature(new_uninit)
| ^^^^^^^^^^
The reason is that we pass `-Zcrate-attr='feature(new_uninit)'` (together
with `-Zallow-features=new_uninit`) to let non-`rust/` code use that
unstable feature.
However, the compiler only recognizes the feature if the `alloc` crate
is resolved (the feature is an `alloc` one). `--extern alloc`, which we
pass, is not enough to resolve the crate.
Introducing a reference like `use alloc;` or `extern crate alloc;`
solves the issue, thus this is not seen in normal files. For instance,
`use`ing the `kernel` prelude introduces such a reference, since `alloc`
is used inside.
While normal use of the build system is not impacted by this, it can still
be fairly confusing for kernel developers [1], thus use the unstable
`force` option of `--extern` [2] (added in Rust 1.71 [3]) to force the
compiler to resolve `alloc`.
This new unstable feature is only needed meanwhile we use the other
unstable feature, since then we will not need `-Zcrate-attr`.
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Daniel Almeida <daniel.almeida@collabora.com>
Reported-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/x/near/424096982 [1]
Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
Link: https://github.com/rust-lang/rust/issues/111302 [2]
Link: https://github.com/rust-lang/rust/pull/109421 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240422090644.525520-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull hardening fixes from Kees Cook: - gcc-plugins/stackleak: Avoid .head.text section (Ard Biesheuvel) - ubsan: fix unused variable warning in test module (Arnd Bergmann) - Improve entropy diffusion in randomize_kstack * tag 'hardening-v6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randomize_kstack: Improve entropy diffusion ubsan: fix unused variable warning in test module gcc-plugins/stackleak: Avoid .head.text section
The .head.text section carries the startup code that runs with the MMU
off or with a translation of memory that deviates from the ordinary one.
So avoid instrumentation with the stackleak plugin, which already avoids
.init.text and .noinstr.text entirely.
Fixes: 48204aba801f1b51 ("x86/sme: Move early SME kernel encryption handling into .head.text")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202403221630.2692c998-oliver.sang@intel.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240328064256.2358634-2-ardb+git@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Pull documentation fixes from Jonathan Corbet: "Four small documentation fixes" * tag 'docs-6.9-fixes' of git://git.lwn.net/linux: docs: zswap: fix shell command format tracing: Fix documentation on tp_printk cmdline option docs: Fix bitfield handling in kernel-doc Documentation: dev-tools: Add link to RV docs
Pull Kbuild fixes from Masahiro Yamada: - Deduplicate Kconfig entries for CONFIG_CXL_PMU - Fix unselectable choice entry in MIPS Kconfig, and forbid this structure - Remove unused include/asm-generic/export.h - Fix a NULL pointer dereference bug in modpost - Enable -Woverride-init warning consistently with W=1 - Drop KCSAN flags from *.mod.c files * tag 'kbuild-fixes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: Fix typo HEIGTH to HEIGHT Documentation/llvm: Note s390 LLVM=1 support with LLVM 18.1.0 and newer kbuild: Disable KCSAN for autogenerated *.mod.c intermediaries kbuild: make -Woverride-init warnings more consistent modpost: do not make find_tosym() return NULL export.h: remove include/asm-generic/export.h kconfig: do not reparent the menu inside a choice block MIPS: move unselectable FIT_IMAGE_FDT_EPM5 out of the "System type" choice cxl: remove CONFIG_CXL_PMU entry in drivers/cxl/Kconfig
Fixed a typo in some variables where height was misspelled as heigth. Signed-off-by: Isak Ellmer <isak01@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When KCSAN and CONSTRUCTORS are enabled, one can trigger the
"Unpatched return thunk in use. This should not happen!"
catch-all warning.
Usually, when objtool runs on the .o objects, it does generate a section
.return_sites which contains all offsets in the objects to the return
thunks of the functions present there. Those return thunks then get
patched at runtime by the alternatives.
KCSAN and CONSTRUCTORS add this to the object file's .text.startup
section:
-------------------
Disassembly of section .text.startup:
...
0000000000000010 <_sub_I_00099_0>:
10: f3 0f 1e fa endbr64
14: e8 00 00 00 00 call 19 <_sub_I_00099_0+0x9>
15: R_X86_64_PLT32 __tsan_init-0x4
19: e9 00 00 00 00 jmp 1e <__UNIQUE_ID___addressable_cryptd_alloc_aead349+0x6>
1a: R_X86_64_PLT32 __x86_return_thunk-0x4
-------------------
which, if it is built as a module goes through the intermediary stage of
creating a <module>.mod.c file which, when translated, receives a second
constructor:
-------------------
Disassembly of section .text.startup:
0000000000000010 <_sub_I_00099_0>:
10: f3 0f 1e fa endbr64
14: e8 00 00 00 00 call 19 <_sub_I_00099_0+0x9>
15: R_X86_64_PLT32 __tsan_init-0x4
19: e9 00 00 00 00 jmp 1e <_sub_I_00099_0+0xe>
1a: R_X86_64_PLT32 __x86_return_thunk-0x4
...
0000000000000030 <_sub_I_00099_0>:
30: f3 0f 1e fa endbr64
34: e8 00 00 00 00 call 39 <_sub_I_00099_0+0x9>
35: R_X86_64_PLT32 __tsan_init-0x4
39: e9 00 00 00 00 jmp 3e <__ksymtab_cryptd_alloc_ahash+0x2>
3a: R_X86_64_PLT32 __x86_return_thunk-0x4
-------------------
in the .ko file.
Objtool has run already so that second constructor's return thunk cannot
be added to the .return_sites section and thus the return thunk remains
unpatched and the warning rightfully fires.
Drop KCSAN flags from the mod.c generation stage as those constructors
do not contain data races one would be interested about.
Debugged together with David Kaplan <David.Kaplan@amd.com> and Nikolay
Borisov <nik.borisov@suse.com>.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Closes: https://lore.kernel.org/r/0851a207-7143-417e-be31-8bf2b3afb57d@molgen.mpg.de
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> # Dell XPS 13
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The -Woverride-init warn about code that may be intentional or not,
but the inintentional ones tend to be real bugs, so there is a bit of
disagreement on whether this warning option should be enabled by default
and we have multiple settings in scripts/Makefile.extrawarn as well as
individual subsystems.
Older versions of clang only supported -Wno-initializer-overrides with
the same meaning as gcc's -Woverride-init, though all supported versions
now work with both. Because of this difference, an earlier cleanup of
mine accidentally turned the clang warning off for W=1 builds and only
left it on for W=2, while it's still enabled for gcc with W=1.
There is also one driver that only turns the warning off for newer
versions of gcc but not other compilers, and some but not all the
Makefiles still use a cc-disable-warning conditional that is no
longer needed with supported compilers here.
Address all of the above by removing the special cases for clang
and always turning the warning off unconditionally where it got
in the way, using the syntax that is supported by both compilers.
Fixes: 2cd3271b7a31 ("kbuild: avoid duplicate warning options")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
kernel-doc doesn't handle bitfields that are specified with symbolic name, e.g. u32 cs_index_mask : SPI_CS_CNT_MAX This results in the following warnings when running `make htmldocs`: include/linux/spi/spi.h:246: warning: Function parameter or struct member 'cs_index_mask:SPI_CS_CNT_MAX' not described in 'spi_device' include/linux/spi/spi.h:246: warning: Excess struct member 'cs_index_mask' description in 'spi_device' Update the regexp for bitfields to accept all word chars, not just digits. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240326173825.99190-1-donald.hunter@gmail.com