On Tue, Sep 27, 2022 at 03:14:36PM +0200, Miguel Ojeda wrote:

Rust symbols can become quite long due to namespacing introduced
by modules, types, traits, generics, etc. For instance,
the following code:

    pub mod my_module {
        pub struct MyType;
        pub struct MyGenericType<T>(T);

        pub trait MyTrait {
            fn my_method() -> u32;
        }

        impl MyTrait for MyGenericType<MyType> {
            fn my_method() -> u32 {
                42
            }
        }
    }

generates a symbol of length 96 when using the upcoming v0 mangling scheme:

    _RNvXNtCshGpAVYOtgW1_7example9my_moduleINtB2_13MyGenericTypeNtB2_6MyTypeENtB2_7MyTrait9my_method

At the moment, Rust symbols may reach up to 300 in length.
Setting 512 as the maximum seems like a reasonable choice to
keep some headroom.

Reviewed-by: Kees Cook <redacted>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Co-developed-by: Alex Gaynor <redacted>
Signed-off-by: Alex Gaynor <redacted>
Co-developed-by: Wedson Almeida Filho <redacted>
Signed-off-by: Wedson Almeida Filho <redacted>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boqun Feng <redacted>
Signed-off-by: Boqun Feng <redacted>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 include/linux/kallsyms.h            | 2 +-
 kernel/livepatch/core.c             | 4 ++--
 scripts/kallsyms.c                  | 4 ++--
 tools/include/linux/kallsyms.h      | 2 +-
 tools/lib/perf/include/perf/event.h | 2 +-
 tools/lib/symbol/kallsyms.h         | 2 +-
 6 files changed, 8 insertions(+), 8 deletions(-)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>