On Mon, 29 Jul 2024 17:54:33 -0700
Song Liu <s...@kernel.org> wrote:

> Use the new kallsyms APIs that matches symbols name with .llvm.<hash>
> suffix. This allows userspace tools to get kprobes on the expected
> function name, while the actual symbol has a .llvm.<hash> suffix.
> 

_kprobe_addr@kernel/kprobes.c may also fail with this change.

Thanks,

> This only effects kernel compared with CONFIG_LTO_CLANG.
> 
> Signed-off-by: Song Liu <s...@kernel.org>
> ---
>  kernel/trace/trace_kprobe.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 61a6da808203..c319382c1a09 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -202,7 +202,8 @@ unsigned long trace_kprobe_address(struct trace_kprobe 
> *tk)
>  
>       if (tk->symbol) {
>               addr = (unsigned long)
> -                     kallsyms_lookup_name(trace_kprobe_symbol(tk));
> +                     kallsyms_lookup_name_or_prefix(trace_kprobe_symbol(tk));
> +
>               if (addr)
>                       addr += tk->rp.kp.offset;
>       } else {
> @@ -766,8 +767,13 @@ static unsigned int number_of_same_symbols(const char 
> *mod, const char *func_nam
>  {
>       struct sym_count_ctx ctx = { .count = 0, .name = func_name };
>  
> -     if (!mod)
> +     if (!mod) {
>               kallsyms_on_each_match_symbol(count_symbols, func_name, 
> &ctx.count);
> +             if (IS_ENABLED(CONFIG_LTO_CLANG) && !ctx.count) {
> +                     kallsyms_on_each_match_symbol_or_prefix(
> +                             count_symbols, func_name, &ctx.count);
> +             }
> +     }
>  
>       module_kallsyms_on_each_symbol(mod, count_mod_symbols, &ctx);
>  
> -- 
> 2.43.0
> 


-- 
Masami Hiramatsu (Google) <mhira...@kernel.org>

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