From 04d17d50e903bf8a3777afb5e1056c4c3c87b62b Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Thu, 25 Jul 2024 20:33:21 +0200 Subject: [PATCH] x86/rust: support MITIGATION_SLS Support `MITIGATION_SLS` by enabling the target features that Clang does. Without this, `objtool` would complain if enabled for Rust, e.g.: rust/core.o: warning: objtool: _R...next_up+0x44: missing int3 after ret These should be eventually enabled via `-Ctarget-feature` when `rustc` starts recognizing them (or via a new dedicated flag) [1]. Link: https://github.com/rust-lang/rust/issues/116851 [1] Reviewed-by: Gary Guo Tested-by: Alice Ryhl Tested-by: Benno Lossin Link: https://lore.kernel.org/r/20240725183325.122827-5-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- scripts/generate_rust_target.rs | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs index 836fdf622c2dea..86372077731344 100644 --- a/scripts/generate_rust_target.rs +++ b/scripts/generate_rust_target.rs @@ -173,6 +173,14 @@ fn main() { features += ",+retpoline-indirect-branches"; features += ",+retpoline-indirect-calls"; } + if cfg.has("MITIGATION_SLS") { + // The kernel uses `-mharden-sls=all`, which Clang maps to both these target features in + // `clang/lib/Driver/ToolChains/Arch/X86.cpp`. These should be eventually enabled via + // `-Ctarget-feature` when `rustc` starts recognizing them (or via a new dedicated + // flag); see https://github.com/rust-lang/rust/issues/116851. + features += ",+harden-sls-ijmp"; + features += ",+harden-sls-ret"; + } ts.push("features", features); ts.push("llvm-target", "x86_64-linux-gnu"); ts.push("target-pointer-width", "64");