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 --- drivers/of/Kconfig | 129 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 drivers/of/Kconfig (limited to 'drivers/of/Kconfig') diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig new file mode 100644 index 000000000..50697cc3b --- /dev/null +++ b/drivers/of/Kconfig @@ -0,0 +1,129 @@ +# SPDX-License-Identifier: GPL-2.0 +config DTC + bool + +config GENERIC_BUILTIN_DTB + bool + +config BUILTIN_DTB_ALL + bool + +menuconfig OF + bool "Device Tree and Open Firmware support" + help + This option enables the device tree infrastructure. + It is automatically selected by platforms that need it or can + be enabled manually for unittests, overlays or + compile-coverage. + +if OF + +config OF_UNITTEST + bool "Device Tree runtime unit tests" + depends on OF_EARLY_FLATTREE + select IRQ_DOMAIN + select OF_RESOLVE + help + This option builds in test cases for the device tree infrastructure + that are executed once at boot time, and the results dumped to the + console. + + This option should only be enabled for a development kernel. The tests + will taint the kernel with TAINT_TEST. The tests will cause ERROR and + WARNING messages to print on the console. The tests will cause stack + traces to print on the console. It is possible that the tests will + leave the devicetree in a corrupted state. + + The unittest output will be verbose. Copy the output to a file + via capturing the console output or via the dmesg command. Process + this file with scripts/dtc/of_unittest_expect to reduce the + verbosity, test whether expected output is present, and to + summarize the results. + + If unsure, say N here. This option is not safe to enable. + +config OF_KUNIT_TEST + tristate "Devicetree KUnit Test" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This option builds KUnit unit tests for device tree infrastructure. + + If unsure, say N here, but this option is safe to enable. + +config OF_ALL_DTBS + bool "Build all Device Tree Blobs" + depends on COMPILE_TEST + select DTC + help + This option builds all possible Device Tree Blobs (DTBs) for the + current architecture. + + If unsure, say N here, but this option is safe to enable. + +config OF_FLATTREE + bool + select DTC + select LIBFDT + select CRC32 + +config OF_EARLY_FLATTREE + def_bool OF && !(SPARC || ALPHA || HEXAGON || M68K || PARISC || S390) + select DMA_DECLARE_COHERENT if HAS_DMA && HAS_IOMEM + select OF_FLATTREE + +config OF_PROMTREE + bool + +config OF_KOBJ + def_bool SYSFS + +# Hardly any platforms need this. It is safe to select, but only do so if you +# need it. +config OF_DYNAMIC + bool "Support for dynamic device trees" if OF_UNITTEST + select OF_KOBJ + help + On some platforms, the device tree can be manipulated at runtime. + While this option is selected automatically on such platforms, you + can enable it manually to improve device tree unit test coverage. + +config OF_ADDRESS + def_bool y + depends on !SPARC && (HAS_IOMEM || UML) + +config OF_IRQ + def_bool y + depends on !SPARC && IRQ_DOMAIN + +config OF_RESERVED_MEM + def_bool OF_EARLY_FLATTREE + +config OF_RESOLVE + bool + +config OF_OVERLAY + bool "Device Tree overlays" + select OF_DYNAMIC + select OF_FLATTREE + select OF_RESOLVE + help + Overlays are a method to dynamically modify part of the kernel's + device tree with dynamically loaded data. + While this option is selected automatically when needed, you can + enable it manually to improve device tree unit test coverage. + +config OF_OVERLAY_KUNIT_TEST + tristate "Device Tree overlay KUnit tests" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + select DTC + help + This option builds KUnit unit tests for the device tree overlay code. + + If unsure, say N here, but this option is safe to enable. + +config OF_NUMA + bool + +endif # OF -- cgit v1.3.1