On 2024/8/2 11:45, Song Liu wrote: > > >> On Aug 1, 2024, at 6:18 PM, Leizhen (ThunderTown) <thunder.leizhen@xxxxxxxxxxxxxxx> wrote: >> >> On 2024/7/31 9:00, Song Liu wrote: >>> Hi Masami, >>> >>>> On Jul 30, 2024, at 6:03 AM, Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: >>>> >>>> On Mon, 29 Jul 2024 17:54:32 -0700 >>>> Song Liu <song@xxxxxxxxxx> wrote: >>>> >>>>> With CONFIG_LTO_CLANG=y, the compiler may add suffix to function names >>>>> to avoid duplication. This causes confusion with users of kallsyms. >>>>> On one hand, users like livepatch are required to match the symbols >>>>> exactly. On the other hand, users like kprobe would like to match to >>>>> original function names. >>>>> >>>>> Solve this by splitting kallsyms APIs. Specifically, existing APIs now >>>>> should match the symbols exactly. Add two APIs that matches the full >>>>> symbol, or only the part without .llvm.suffix. Specifically, the following >>>>> two APIs are added: >>>>> >>>>> 1. kallsyms_lookup_name_or_prefix() >>>>> 2. kallsyms_on_each_match_symbol_or_prefix() >>>> >>>> Since this API only removes the suffix, "match prefix" is a bit confusing. >>>> (this sounds like matching "foo" with "foo" and "foo_bar", but in reality, >>>> it only matches "foo" and "foo.llvm.*") >>>> What about the name below? >>>> >>>> kallsyms_lookup_name_without_suffix() >>>> kallsyms_on_each_match_symbol_without_suffix() >>> >>> I am open to name suggestions. I named it as xx or prefix to highlight >>> that these two APIs will try match full name first, and they only match >>> the symbol without suffix when there is no full name match. >>> >>> Maybe we can call them: >>> - kallsyms_lookup_name_or_without_suffix() >>> - kallsyms_on_each_match_symbol_or_without_suffix() >>> >>> Again, I am open to any name selections here. >> >> Only static functions have suffixes. In my opinion, explicitly marking static >> might be a little clearer. >> kallsyms_lookup_static_name() >> kallsyms_on_each_match_static_symbol() > > While these names are shorter, I think they are more confusing. Not all > folks know that only static functions can have suffixes. > > Maybe we should not hide the "try match full name first first" in the > API, and let the users handle it. Then, we can safely call the new APIs > *_without_suffix(), as Masami suggested. Yes, that would be clearer. > > If there is no objections, I will send v2 based on this direction. > > Thanks, > Song > -- Regards, Zhen Lei
