Re: [PATCH 0/3] Fix kallsyms with CONFIG_LTO_CLANG

Song Liu
2024-07-30T05:37:04Z

On Mon, Jul 29, 2024 at 5:54 PM Song Liu <song@kernel.org> wrote:
>
> With CONFIG_LTO_CLANG, the compiler/linker adds .llvm.<hash> suffix to
> local symbols to avoid duplications. Existing scripts/kallsyms sorts
> symbols without .llvm.<hash> suffix. However, this causes quite some
> issues later on. Some users of kallsyms, such as livepatch, have to match
> symbols exactly; while other users, such as kprobe, would match symbols
> without the suffix.
>
> Address this by sorting full symbols (with .llvm.<hash>) at build time, and
> split kallsyms APIs to explicitly match full symbols or without suffix.
> Specifically, exiting APIs will match symbols exactly. Two new APIs are
> added to match symbols with suffix. Use the new APIs in tracing/kprobes.

Forgot to mention: This is to follow up the discussions in this thread:

https://lore.kernel.org/live-patching/20240605032120.3179157-1-song@kernel.org/T/#u

Thanks,
Song