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| author | Miguel Ojeda <ojeda@kernel.org> | 2026-08-16 15:32:33 +0200 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2026-08-23 21:27:17 +0200 |
| commit | 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 (patch) | |
| tree | 93a1ed1d337bc53adf1e572c2586d347703b286e /Documentation/ABI/testing/sysfs-class-led-trigger-oneshot | |
| download | linux-stable-5febf432df1cfa5b25d99b54c32103fafbdd0eb9.tar.gz linux-stable-5febf432df1cfa5b25d99b54c32103fafbdd0eb9.zip | |
kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted
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 <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-led-trigger-oneshot')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led-trigger-oneshot | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-oneshot b/Documentation/ABI/testing/sysfs-class-led-trigger-oneshot new file mode 100644 index 000000000..378a3a4df --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-oneshot @@ -0,0 +1,36 @@ +What: /sys/class/leds/<led>/delay_on +Date: Jun 2012 +KernelVersion: 3.6 +Contact: linux-leds@vger.kernel.org +Description: + Specifies for how many milliseconds the LED has to stay at + LED_FULL brightness after it has been armed. + Defaults to 100 ms. + +What: /sys/class/leds/<led>/delay_off +Date: Jun 2012 +KernelVersion: 3.6 +Contact: linux-leds@vger.kernel.org +Description: + Specifies for how many milliseconds the LED has to stay at + LED_OFF brightness after it has been armed. + Defaults to 100 ms. + +What: /sys/class/leds/<led>/invert +Date: Jun 2012 +KernelVersion: 3.6 +Contact: linux-leds@vger.kernel.org +Description: + Reverse the blink logic. If set to 0 (default) blink on for + delay_on ms, then blink off for delay_off ms, leaving the LED + normally off. If set to 1, blink off for delay_off ms, then + blink on for delay_on ms, leaving the LED normally on. + Setting this value also immediately changes the LED state. + +What: /sys/class/leds/<led>/shot +Date: Jun 2012 +KernelVersion: 3.6 +Contact: linux-leds@vger.kernel.org +Description: + Write any non-empty string to signal an events, this starts a + blink sequence if not already running. |