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/mfd/act8945a.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 drivers/mfd/act8945a.c (limited to 'drivers/mfd/act8945a.c') diff --git a/drivers/mfd/act8945a.c b/drivers/mfd/act8945a.c new file mode 100644 index 000000000..cafefb445 --- /dev/null +++ b/drivers/mfd/act8945a.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * MFD driver for Active-semi ACT8945a PMIC + * + * Copyright (C) 2015 Atmel Corporation. + * + * Author: Wenyou Yang + */ + +#include +#include +#include +#include +#include + +static const struct mfd_cell act8945a_devs[] = { + { + .name = "act8945a-regulator", + }, + { + .name = "act8945a-charger", + .of_compatible = "active-semi,act8945a-charger", + }, +}; + +static const struct regmap_config act8945a_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int act8945a_i2c_probe(struct i2c_client *i2c) +{ + int ret; + struct regmap *regmap; + + regmap = devm_regmap_init_i2c(i2c, &act8945a_regmap_config); + if (IS_ERR(regmap)) { + ret = PTR_ERR(regmap); + dev_err(&i2c->dev, "regmap init failed: %d\n", ret); + return ret; + } + + i2c_set_clientdata(i2c, regmap); + + ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_NONE, + act8945a_devs, ARRAY_SIZE(act8945a_devs), + NULL, 0, NULL); + if (ret) { + dev_err(&i2c->dev, "Failed to add sub devices\n"); + return ret; + } + + return 0; +} + +static const struct i2c_device_id act8945a_i2c_id[] = { + { "act8945a" }, + {} +}; +MODULE_DEVICE_TABLE(i2c, act8945a_i2c_id); + +static const struct of_device_id act8945a_of_match[] = { + { .compatible = "active-semi,act8945a", }, + {}, +}; +MODULE_DEVICE_TABLE(of, act8945a_of_match); + +static struct i2c_driver act8945a_i2c_driver = { + .driver = { + .name = "act8945a", + .of_match_table = act8945a_of_match, + }, + .probe = act8945a_i2c_probe, + .id_table = act8945a_i2c_id, +}; + +static int __init act8945a_i2c_init(void) +{ + return i2c_add_driver(&act8945a_i2c_driver); +} +subsys_initcall(act8945a_i2c_init); + +static void __exit act8945a_i2c_exit(void) +{ + i2c_del_driver(&act8945a_i2c_driver); +} +module_exit(act8945a_i2c_exit); + +MODULE_DESCRIPTION("ACT8945A PMIC multi-function driver"); +MODULE_AUTHOR("Wenyou Yang "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1