pm24.git/init, branch rust-6.12

rust: kasan: Rust does not support KHWASAN

2024-09-16T16:04:37Z

Rust does not yet have support for software tags. Prevent RUST from being selected if KASAN_SW_TAGS is enabled. Signed-off-by: Matthew Maurer Reviewed-by: Andrey Konovalov Link: https://lore.kernel.org/r/20240820194910.187826-3-mmaurer@google.com Signed-off-by: Miguel Ojeda

rust: cfi: add support for CFI_CLANG with Rust

2024-09-16T15:29:58Z

Make it possible to use the Control Flow Integrity (CFI) sanitizer when Rust is enabled. Enabling CFI with Rust requires that CFI is configured to normalize integer types so that all integer types of the same size and signedness are compatible under CFI. Rust and C use the same LLVM backend for code generation, so Rust KCFI is compatible with the KCFI used in the kernel for C. In the case of FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting the function prologue, so we set that flag for Rust as well. The flag for FineIBT requires rustc 1.80.0 or later, so include a Kconfig requirement for that. Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag is required to use Rust with CFI. Using select rather than `depends on` avoids the case where Rust is not visible in menuconfig due to CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of select is that RUST must `depends on` all of the things that CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations. Alice has been using KCFI on her phone for several months, so it is reasonably well tested on arm64. Signed-off-by: Matthew Maurer Co-developed-by: Alice Ryhl Signed-off-by: Alice Ryhl Reviewed-by: Sami Tolvanen Tested-by: Gatlin Newhouse Acked-by: Kees Cook Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20240801-kcfi-v2-2-c93caed3d121@google.com [ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent a build error on older Rust compilers. Fixed typo. - Miguel ] Signed-off-by: Miguel Ojeda

rust: support for shadow call stack sanitizer

2024-09-12T22:03:14Z

Add all of the flags that are needed to support the shadow call stack (SCS) sanitizer with Rust, and updates Kconfig to allow only configurations that work. The -Zfixed-x18 flag is required to use SCS on arm64, and requires rustc version 1.80.0 or greater. This restriction is reflected in Kconfig. When CONFIG_DYNAMIC_SCS is enabled, the build will be configured to include unwind tables in the build artifacts. Dynamic SCS uses the unwind tables at boot to find all places that need to be patched. The -Cforce-unwind-tables=y flag ensures that unwind tables are available for Rust code. In non-dynamic mode, the -Zsanitizer=shadow-call-stack flag is what enables the SCS sanitizer. Using this flag requires rustc version 1.82.0 or greater on the targets used by Rust in the kernel. This restriction is reflected in Kconfig. It is possible to avoid the requirement of rustc 1.80.0 by using -Ctarget-feature=+reserve-x18 instead of -Zfixed-x18. However, this flag emits a warning during the build, so this patch does not add support for using it and instead requires 1.80.0 or greater. The dependency is placed on `select HAVE_RUST` to avoid a situation where enabling Rust silently turns off the sanitizer. Instead, turning on the sanitizer results in Rust being disabled. We generally do not want changes to CONFIG_RUST to result in any mitigations being changed or turned off. At the time of writing, rustc 1.82.0 only exists via the nightly release channel. There is a chance that the -Zsanitizer=shadow-call-stack flag will end up needing 1.83.0 instead, but I think it is small. Reviewed-by: Sami Tolvanen Reviewed-by: Ard Biesheuvel Reviewed-by: Kees Cook Acked-by: Will Deacon Signed-off-by: Alice Ryhl Link: https://lore.kernel.org/r/20240829-shadow-call-stack-v7-1-2f62a4432abf@google.com [ Fixed indentation using spaces. - Miguel ] Signed-off-by: Miguel Ojeda

kbuild: rust: re-run Kconfig if the version text changes

2024-09-05T20:44:34Z

Re-run Kconfig if we detect the Rust compiler has changed via the version text, like it is done for C. Unlike C, and unlike `RUSTC_VERSION`, the `RUSTC_VERSION_TEXT` is kept under `depends on RUST`, since it should not be needed unless `RUST` is enabled. Reviewed-by: Nicolas Schier Tested-by: Alice Ryhl Acked-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240902165535.1101978-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda

kbuild: rust: add `CONFIG_RUSTC_VERSION`

2024-09-05T20:44:18Z

Now that we support several Rust versions, introduce `CONFIG_RUSTC_VERSION` so that it can be used in Kconfig to enable and disable configuration options based on the `rustc` version. The approach taken resembles `pahole`'s -- see commit 613fe1692377 ("kbuild: Add CONFIG_PAHOLE_VERSION"), i.e. a simple version parsing without trying to identify several kinds of compilers, since so far there is only one (`rustc`). However, unlike `pahole`'s, we also print a zero if executing failed for any reason, rather than checking if the command is found and executable (which still leaves things like a file that exists and is executable, but e.g. is built for another platform [1]). An equivalent approach to the one here was also submitted for `pahole` [2]. Link: https://lore.kernel.org/rust-for-linux/CANiq72=4vX_tJMJLE6e+bg7ZECHkS-AQpm8GBzuK75G1EB7+Nw@mail.gmail.com/ [1] Link: https://lore.kernel.org/linux-kbuild/20240728125527.690726-1-ojeda@kernel.org/ [2] Reviewed-by: Nicolas Schier Tested-by: Alice Ryhl Acked-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240902165535.1101978-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda

init/Kconfig: Only block on RANDSTRUCT for RUST

2024-08-18T21:10:53Z

When enabling Rust in the kernel, we only need to block on the RANDSTRUCT feature and GCC plugin. The rest of the GCC plugins are reasonably safe to enable. [ Originally (years ago) we only had this restriction, but we ended up restricting also the rest of the GCC plugins 1) to be on the safe side, 2) since compiler plugin support could be going away in the kernel and 3) since mixed builds are best effort so far; so I asked Neal about his experience enabling the other plugins -- Neal says: When I originally wrote this patch two years ago to get things working, Fedora used all the GCC plugins, so I was trying to get GCC + Rust to work while minimizing the delta on build differences. This was the combination that worked. We've been carrying this patch in the Asahi tree for a year now. And while Fedora does not currently have GCC plugins enabled because it caused issues with some third-party modules (I think it was the NVIDIA driver, but I'm not sure), it was around long enough for me to know with some confidence that it was fine this way. - Miguel ] Signed-off-by: Neal Gompa Link: https://lore.kernel.org/r/20240731125615.3368813-1-neal@gompa.dev Signed-off-by: Miguel Ojeda

Merge tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux

2024-08-16T18:24:06Z

Pull rust fixes from Miguel Ojeda: - Fix '-Os' Rust 1.80.0+ builds adding more intrinsics (also tweaked in upstream Rust for the upcoming 1.82.0). - Fix support for the latest version of rust-analyzer due to a change on rust-analyzer config file semantics (considered a fix since most developers use the latest version of the tool, which is the only one actually supported by upstream). I am discussing stability of the config file with upstream -- they may be able to start versioning it. - Fix GCC 14 builds due to '-fmin-function-alignment' not skipped for libclang (bindgen). - A couple Kconfig fixes around '{RUSTC,BINDGEN}_VERSION_TEXT' to suppress error messages in a foreign architecture chroot and to use a proper default format. - Clean 'rust-analyzer' target warning due to missing recursive make invocation mark. - Clean Clippy warning due to missing indentation in docs. - Clean LLVM 19 build warning due to removed 3dnow feature upstream. * tag 'rust-fixes-6.11' of https://github.com/Rust-for-Linux/linux: rust: x86: remove `-3dnow{,a}` from target features kbuild: rust-analyzer: mark `rust_is_available.sh` invocation as recursive rust: add intrinsics to fix `-Os` builds kbuild: rust: skip -fmin-function-alignment in bindgen flags rust: Support latest version of `rust-analyzer` rust: macros: indent list item in `module!`'s docs rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT

rust: SHADOW_CALL_STACK is incompatible with Rust

2024-08-01T15:15:03Z

When using the shadow call stack sanitizer, all code must be compiled with the -ffixed-x18 flag, but this flag is not currently being passed to Rust. This results in crashes that are extremely difficult to debug. To ensure that nobody else has to go through the same debugging session that I had to, prevent configurations that enable both SHADOW_CALL_STACK and RUST. It is rather common for people to backport 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64"), so I recommend applying this fix all the way back to 6.1. Cc: stable@vger.kernel.org # 6.1 and later Fixes: 724a75ac9542 ("arm64: rust: Enable Rust support for AArch64") Signed-off-by: Alice Ryhl Acked-by: Miguel Ojeda Link: https://lore.kernel.org/r/20240729-shadow-call-stack-v4-1-2a664b082ea4@google.com Signed-off-by: Catalin Marinas

rust: fix the default format for CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT

2024-07-28T22:48:26Z

Another oddity in these config entries is their default value can fall back to 'n', which is a value for bool or tristate symbols. The '|| echo n' is an incorrect workaround to avoid the syntax error. This is not a big deal, as the entry is hidden by 'depends on RUST' in situations where '$(RUSTC) --version' or '$(BINDGEN) --version' fails. Anyway, it looks odd. The default of a string type symbol should be a double-quoted string literal. Turn it into an empty string when the version command fails. Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727140302.1806011-2-masahiroy@kernel.org [ Rebased on top of v6.11-rc1. - Miguel ] Signed-off-by: Miguel Ojeda

rust: suppress error messages from CONFIG_{RUSTC,BINDGEN}_VERSION_TEXT

2024-07-28T22:48:12Z

While this is a somewhat unusual case, I encountered odd error messages when I ran Kconfig in a foreign architecture chroot. $ make allmodconfig sh: 1: rustc: not found sh: 1: bindgen: not found # # configuration written to .config # The successful execution of 'command -v rustc' does not necessarily mean that 'rustc --version' will succeed. $ sh -c 'command -v rustc' /home/masahiro/.cargo/bin/rustc $ sh -c 'rustc --version' sh: 1: rustc: not found Here, 'rustc' is built for x86, and I ran it in an arm64 system. The current code: command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version || echo n can be turned into: command -v $(RUSTC) >/dev/null 2>&1 && $(RUSTC) --version 2>/dev/null || echo n However, I did not understand the necessity of 'command -v $(RUSTC)'. I simplified it to: $(RUSTC) --version 2>/dev/null || echo n Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support") Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20240727140302.1806011-1-masahiroy@kernel.org [ Rebased on top of v6.11-rc1. - Miguel ] Signed-off-by: Miguel Ojeda