From: Matthew Maurer <mmaurer@xxxxxxxxxx>
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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
init/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1958,7 +1958,7 @@ config RUST
depends on !MODVERSIONS
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
Patches currently in stable-queue which might be from mmaurer@xxxxxxxxxx are
queue-6.12/rust-disallow-btf-generation-with-rust-lto.patch
