Re: [PATCH] rust: kbuild: Don't export __pfx symbols

[Alice Ryhl]

On Tue, Mar 18, 2025 at 11:18:16PM +0000, Sami Tolvanen wrote:
> With CONFIG_PREFIX_SYMBOLS, objtool adds __pfx prefix symbols
> to claim the compiler emitted call padding bytes. When
> CONFIG_X86_KERNEL_IBT is not selected, the symbols are added to
> individual object files and for Rust objects, they end up being
> exported, resulting in warnings with CONFIG_GENDWARFKSYMS as the
> symbols have no debugging information:
> 
> warning: gendwarfksyms: symbol_print_versions: no information for symbol __pfx_rust_helper_put_task_struct
> warning: gendwarfksyms: symbol_print_versions: no information for symbol __pfx_rust_helper_task_euid
> warning: gendwarfksyms: symbol_print_versions: no information for symbol __pfx_rust_helper_readq_relaxed
> ...
> 
> Filter out the __pfx prefix from exported symbols similarly to
> the existing __cfi and __odr_asan prefixes.
> 
> Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>

Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>