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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 /net/dsa/conduit.h | |
| 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 'net/dsa/conduit.h')
| -rw-r--r-- | net/dsa/conduit.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/net/dsa/conduit.h b/net/dsa/conduit.h new file mode 100644 index 000000000..31f8834f5 --- /dev/null +++ b/net/dsa/conduit.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#ifndef __DSA_CONDUIT_H +#define __DSA_CONDUIT_H + +struct dsa_port; +struct net_device; +struct netdev_lag_upper_info; +struct netlink_ext_ack; + +int dsa_conduit_setup(struct net_device *dev, struct dsa_port *cpu_dp); +void dsa_conduit_teardown(struct net_device *dev); +int dsa_conduit_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp, + struct netdev_lag_upper_info *uinfo, + struct netlink_ext_ack *extack); +void dsa_conduit_lag_teardown(struct net_device *lag_dev, + struct dsa_port *cpu_dp); +int __dsa_conduit_hwtstamp_validate(struct net_device *dev, + const struct kernel_hwtstamp_config *config, + struct netlink_ext_ack *extack); + +#endif |