Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Song Liu]

> On Mar 4, 2019, at 5:53 AM, Jiri Olsa <jo...@redhat.com> wrote:
> 
> On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:
> 
> SNIP
> 
>> +    fflush(s);
>> +    do {
>> +            const struct bpf_line_info *linfo = NULL;
>> +            struct disasm_line *dl;
>> +            size_t prev_buf_size;
>> +            const char *srcline;
>> +            u64 addr;
>> +
>> +            addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
>> +            count = disassemble(pc, &info);
>> +
>> +            if (prog_linfo)
>> +                    linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
>> +                                                            addr, sub_id,
>> +                                                            nr_skip);
>> +
>> +            if (linfo && btf) {
>> +                    srcline = btf__name_by_offset(btf, linfo->line_off);
>> +                    nr_skip++;
>> +            } else
>> +                    srcline = NULL;
>> +
>> +            fprintf(s, "\n");
>> +            prev_buf_size = buf_size;
>> +            fflush(s);
>> +
>> +            if (!opts->hide_src_code && srcline) {
>> +                    args->offset = -1;
> 
> why's the offset not needed in here?

This is the source code line. Based on my understanding of annotation
code, we put -1 for source code line. Did I misunderstand something?

Thanks,
Song

> 
> jirka
> 
>> +                    args->line = strdup(srcline);
>> +                    args->line_nr = 0;
>> +                    args->ms.sym  = sym;
>> +                    dl = disasm_line__new(args);
>> +                    if (dl) {
>> +                            annotation_line__add(&dl->al,
>> +                                                 &notes->src->source);
>> +                    }
>> +            }
> 
> SNIP