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/input/misc/retu-pwrbutton.c | 92 +++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 drivers/input/misc/retu-pwrbutton.c (limited to 'drivers/input/misc/retu-pwrbutton.c') diff --git a/drivers/input/misc/retu-pwrbutton.c b/drivers/input/misc/retu-pwrbutton.c new file mode 100644 index 000000000..64023ac08 --- /dev/null +++ b/drivers/input/misc/retu-pwrbutton.c @@ -0,0 +1,92 @@ +/* + * Retu power button driver. + * + * Copyright (C) 2004-2010 Nokia Corporation + * + * Original code written by Ari Saastamoinen, Juha Yrjölä and Felipe Balbi. + * Rewritten by Aaro Koskinen. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file "COPYING" in the main directory of this + * archive for more details. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define RETU_STATUS_PWRONX (1 << 5) + +static irqreturn_t retu_pwrbutton_irq(int irq, void *_pwr) +{ + struct input_dev *idev = _pwr; + struct retu_dev *rdev = input_get_drvdata(idev); + bool state; + + state = !(retu_read(rdev, RETU_REG_STATUS) & RETU_STATUS_PWRONX); + input_report_key(idev, KEY_POWER, state); + input_sync(idev); + + return IRQ_HANDLED; +} + +static int retu_pwrbutton_probe(struct platform_device *pdev) +{ + struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); + struct input_dev *idev; + int irq; + int error; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + idev = devm_input_allocate_device(&pdev->dev); + if (!idev) + return -ENOMEM; + + idev->name = "retu-pwrbutton"; + idev->dev.parent = &pdev->dev; + + input_set_capability(idev, EV_KEY, KEY_POWER); + input_set_drvdata(idev, rdev); + + error = devm_request_threaded_irq(&pdev->dev, irq, + NULL, retu_pwrbutton_irq, + IRQF_ONESHOT, + "retu-pwrbutton", idev); + if (error) + return error; + + error = input_register_device(idev); + if (error) + return error; + + return 0; +} + +static struct platform_driver retu_pwrbutton_driver = { + .probe = retu_pwrbutton_probe, + .driver = { + .name = "retu-pwrbutton", + }, +}; +module_platform_driver(retu_pwrbutton_driver); + +MODULE_ALIAS("platform:retu-pwrbutton"); +MODULE_DESCRIPTION("Retu Power Button"); +MODULE_AUTHOR("Ari Saastamoinen"); +MODULE_AUTHOR("Felipe Balbi"); +MODULE_AUTHOR("Aaro Koskinen "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1