rust: Disallow BTF generation with Rust + LTO

commit 5daa0c35a1f0e7a6c3b8ba9cb721e7d1ace6e619 upstream.

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@google.com>
Cc: stable@vger.kernel.org
Fixes: c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole")
Link: https://lore.kernel.org/r/20250108-rust-btf-lto-incompat-v1-1-60243ff6d820@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Matthew Maurer 2025-01-08 23:35:08 +00:00 committed by Greg Kroah-Hartman
parent d8bc07d16b
commit 52229ebbe0

View File

@ -1925,7 +1925,7 @@ config RUST
depends on !GCC_PLUGINS
depends on !RANDSTRUCT
depends on !SHADOW_CALL_STACK
depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
help
Enables Rust support in the kernel.