From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- Documentation/process/index.rst | 114 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 Documentation/process/index.rst (limited to 'Documentation/process/index.rst') diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst new file mode 100644 index 000000000..aa7c959a5 --- /dev/null +++ b/Documentation/process/index.rst @@ -0,0 +1,114 @@ +.. raw:: latex + + \renewcommand\thesection* + \renewcommand\thesubsection* + +.. _process_index: + +============================================= +Working with the kernel development community +============================================= + +So you want to be a Linux kernel developer? Welcome! While there is a lot +to be learned about the kernel in a technical sense, it is also important +to learn about how our community works. Reading these documents will make +it much easier for you to get your changes merged with a minimum of +trouble. + +An introduction to how kernel development works +----------------------------------------------- + +Read these documents first: an understanding of the material here will ease +your entry into the kernel community. + +.. toctree:: + :maxdepth: 1 + + howto + development-process + submitting-patches + submit-checklist + +Tools and technical guides for kernel developers +------------------------------------------------ + +This is a collection of material that kernel developers should be familiar +with. + +.. toctree:: + :maxdepth: 1 + + changes + programming-language + coding-style + maintainer-pgp-guide + email-clients + applying-patches + backporting + adding-syscalls + volatile-considered-harmful + botching-up-ioctls + +Policy guides and developer statements +-------------------------------------- + +These are the rules that we try to live by in the kernel community (and +beyond). + +.. toctree:: + :maxdepth: 1 + + license-rules + code-of-conduct + code-of-conduct-interpretation + contribution-maturity-model + kernel-enforcement-statement + kernel-driver-statement + stable-api-nonsense + stable-kernel-rules + management-style + researcher-guidelines + generated-content + coding-assistants + conclave + +Dealing with bugs +----------------- + +Bugs are a fact of life; it is important that we handle them properly. The +documents below provide general advice about debugging and describe our +policies around the handling of a couple of special classes of bugs: +regressions and security problems. + +.. toctree:: + :maxdepth: 1 + + debugging/index + handling-regressions + security-bugs + threat-model + cve + embargoed-hardware-issues + +Maintainer information +---------------------- + +How to find the people who will accept your patches. + +.. toctree:: + :maxdepth: 1 + + maintainer-handbooks + maintainers + +Other material +-------------- + +Here are some other guides to the community that are of interest to most +developers: + +.. toctree:: + :maxdepth: 1 + + kernel-docs + deprecated -- cgit v1.3.1