Re: [PATCH v3 bpf-next 02/10] bpftool: Dump the kernel symbol's module name

[Quentin Monnet <quentin@isovalent.com>]

2023-06-12 15:16 UTC+0000 ~ Yafang Shao <laoar.shao@gmail.com>
> If the kernel symbol is in a module, we will dump the module name as
> well.
> 
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---
>  tools/bpf/bpftool/xlated_dumper.c | 6 +++++-
>  tools/bpf/bpftool/xlated_dumper.h | 2 ++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c
> index da608e1..dd917f3 100644
> --- a/tools/bpf/bpftool/xlated_dumper.c
> +++ b/tools/bpf/bpftool/xlated_dumper.c
> @@ -46,7 +46,11 @@ void kernel_syms_load(struct dump_data *dd)
>  		}
>  		dd->sym_mapping = tmp;
>  		sym = &dd->sym_mapping[dd->sym_count];
> -		if (sscanf(buff, "%p %*c %s", &address, sym->name) != 2)
> +
> +		/* module is optional */
> +		sym->module[0] = '\0';
> +		if (sscanf(buff, "%p %*c %s %s", &address, sym->name,
> +		    sym->module) < 2)
>  			continue;
>  		sym->address = (unsigned long)address;
>  		if (!strcmp(sym->name, "__bpf_call_base")) {
> diff --git a/tools/bpf/bpftool/xlated_dumper.h b/tools/bpf/bpftool/xlated_dumper.h
> index 9a94637..5df8025 100644
> --- a/tools/bpf/bpftool/xlated_dumper.h
> +++ b/tools/bpf/bpftool/xlated_dumper.h
> @@ -5,12 +5,14 @@
>  #define __BPF_TOOL_XLATED_DUMPER_H
>  
>  #define SYM_MAX_NAME	256
> +#define MODULE_NAME_LEN	64
>  
>  struct bpf_prog_linfo;
>  
>  struct kernel_sym {
>  	unsigned long address;
>  	char name[SYM_MAX_NAME];
> +	char module[MODULE_NAME_LEN];

Nit: MODULE_MAX_NAME would be more consistent and would make more sense
to me? And it would avoid confusion with MODULE_NAME_LEN from kernel,
which doesn't have the same value.

>  };
>  
>  struct dump_data {