The kernel cannot currently self-parse BTF containing Rust debug
information. pahole uses the language of the CU to determine whether to
filter out debug information when generating the BTF. When LTO is
enabled, Rust code can cross CU boundaries, resulting in Rust debug
information in CUs labeled as C. This results in a system which cannot
parse its own BTF.
Signed-off-by: Matthew Maurer <mmaurer@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole")
Link: https://lore.kernel.org/r/20250108-rust-btf-lto-incompat-v1-1-60243ff6d820@xxxxxxxxxx
Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
diff --git a/init/Kconfig b/init/Kconfig
index d0d021b3fa3b..324c2886b2ea 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1973,7 +1973,7 @@ config RUST
depends on !MODVERSIONS || GENDWARFKSYMS
depends on !GCC_PLUGIN_RANDSTRUCT
depends on !RANDSTRUCT
- depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
+ depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
depends on !CFI_CLANG || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG
depends on !CALL_PADDING || RUSTC_VERSION >= 108100
