Re: [PATCH 01/17] kallsyms: support big kernel symbols (2-byte lengths)

Matthew Wilcox
2021-07-04T21:05:39Z

On Sun, Jul 04, 2021 at 10:27:40PM +0200, ojeda@kernel.org wrote:
> From: Miguel Ojeda <ojeda@kernel.org>
>
> Rust symbols can become quite long due to namespacing introduced
> by modules, types, traits, generics, etc.
>
> Increasing to 255 is not enough in some cases, and therefore
> we need to introduce 2-byte lengths to the symbol table. We call
> these "big" symbols.
>
> In order to avoid increasing all lengths to 2 bytes (since most
> of them only require 1 byte, including many Rust ones), we use
> length zero to mark "big" symbols in the table.

What happened to my suggestion from last time of encoding symbols < 128
as 0-127 and symbols larger than that as (data[0] - 128) * 256 +
data[1]) ?