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 --- net/can/Kconfig | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 net/can/Kconfig (limited to 'net/can/Kconfig') diff --git a/net/can/Kconfig b/net/can/Kconfig new file mode 100644 index 000000000..abbb4be7a --- /dev/null +++ b/net/can/Kconfig @@ -0,0 +1,73 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Controller Area Network (CAN) network layer core configuration +# + +menuconfig CAN + tristate "CAN bus subsystem support" + select SKB_EXTENSIONS + help + Controller Area Network (CAN) is a slow (up to 1Mbit/s) serial + communications protocol. Development of the CAN bus started in + 1983 at Robert Bosch GmbH, and the protocol was officially + released in 1986. The CAN bus was originally mainly for automotive, + but is now widely used in marine (NMEA2000), industrial, and medical + applications. More information on the CAN network protocol family + PF_CAN is contained in . + + If you want CAN support you should say Y here and also to the + specific driver for your controller(s) under the Network device + support section. + +if CAN + +config CAN_RAW + tristate "Raw CAN Protocol (raw access with CAN-ID filtering)" + default y + help + The raw CAN protocol option offers access to the CAN bus via + the BSD socket API. You probably want to use the raw socket in + most cases where no higher level protocol is being used. The raw + socket has several filter options e.g. ID masking / error frames. + To receive/send raw CAN messages, use AF_CAN with protocol CAN_RAW. + +config CAN_BCM + tristate "Broadcast Manager CAN Protocol (with content filtering)" + default y + help + The Broadcast Manager offers content filtering, timeout monitoring, + sending of RTR frames, and cyclic CAN messages without permanent user + interaction. The BCM can be 'programmed' via the BSD socket API and + informs you on demand e.g. only on content updates / timeouts. + You probably want to use the bcm socket in most cases where cyclic + CAN messages are used on the bus (e.g. in automotive environments). + To use the Broadcast Manager, use AF_CAN with protocol CAN_BCM. + +config CAN_GW + tristate "CAN Gateway/Router (with netlink configuration)" + default y + help + The CAN Gateway/Router is used to route (and modify) CAN frames. + It is based on the PF_CAN core infrastructure for msg filtering and + msg sending and can optionally modify routed CAN frames on the fly. + CAN frames can be routed between CAN network interfaces (one hop). + They can be modified with AND/OR/XOR/SET operations as configured + by the netlink configuration interface known e.g. from iptables. + +source "net/can/j1939/Kconfig" + +config CAN_ISOTP + tristate "ISO 15765-2 CAN transport protocol" + help + CAN Transport Protocols offer support for segmented Point-to-Point + communication between CAN nodes via two defined CAN Identifiers. + This protocol driver implements segmented data transfers for CAN CC + (aka Classical CAN, CAN 2.0B) and CAN FD frame types which were + introduced with ISO 15765-2:2016. + As CAN frames can only transport a small amount of data bytes + (max. 8 bytes for CAN CC and max. 64 bytes for CAN FD) this + segmentation is needed to transport longer Protocol Data Units (PDU) + as needed e.g. for vehicle diagnosis (UDS, ISO 14229) or IP-over-CAN + traffic. + +endif -- cgit v1.3.1