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/ntb/Kconfig | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 drivers/ntb/Kconfig (limited to 'drivers/ntb/Kconfig') diff --git a/drivers/ntb/Kconfig b/drivers/ntb/Kconfig new file mode 100644 index 000000000..df16c755b --- /dev/null +++ b/drivers/ntb/Kconfig @@ -0,0 +1,40 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig NTB + tristate "Non-Transparent Bridge support" + depends on PCI + help + The PCI-E Non-transparent bridge hardware is a point-to-point PCI-E bus + connecting 2 systems. When configured, writes to the device's PCI + mapped memory will be mirrored to a buffer on the remote system. The + ntb Linux driver uses this point-to-point communication as a method to + transfer data from one system to the other. + + If unsure, say N. + +if NTB + +config NTB_MSI + bool "MSI Interrupt Support" + depends on PCI_MSI + help + Support using MSI interrupt forwarding instead of (or in addition to) + hardware doorbells. MSI interrupts typically offer lower latency + than doorbells and more MSI interrupts can be made available to + clients. However this requires an extra memory window and support + in the hardware driver for creating the MSI interrupts. + + If unsure, say N. +source "drivers/ntb/hw/Kconfig" + +source "drivers/ntb/test/Kconfig" + +config NTB_TRANSPORT + tristate "NTB Transport Client" + help + This is a transport driver that enables connected systems to exchange + messages over the ntb hardware. The transport exposes a queue pair api + to client drivers. + + If unsure, say N. + +endif # NTB -- cgit v1.3.1