Re: [PATCH 1/2] SDT markers listing by perf

From: Namhyung Kim
Date: Fri Sep 06 2013 - 02:38:03 EST


Hi Hemant,

On Wed, 04 Sep 2013 23:07:57 +0530, Hemant wrote:
> On 09/04/2013 12:12 PM, Namhyung Kim wrote:
>> On Tue, 03 Sep 2013 13:06:55 +0530, Hemant Kumar wrote:
>>> + /*
>>> + * Look for Section type = SHT_NOTE, flags = no SHF_ALLOC
>>> + * and name = .note.stapsdt
>>> + */
>>> + scn = elf_section_by_name(elf, &ehdr, &shdr, NOTE_SCN, NULL);
>>> + if (scn == NULL) {
>>> + pr_err("%s section not found!\n", NOTE_SCN);
>>> + goto out_end;
>>> + }
>>> +
>>> + if (!(shdr.sh_type == SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC))
>>> + goto out_end;
>>> +
>>> + data = elf_getdata(scn, NULL);
>>> +
>>> + /* Get the notes */
>>> + for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
>>> + &desc_off)) > 0; offset = next) {
>>> + tmp = populate_note(&elf, (const char *)((long)(data->d_buf) +
>>> + (long)desc_off),
>>> + nhdr.n_descsz, nhdr.n_type);
>> Shouldn't we check the name of note being "stapsdt" as well as version
>> (type) 3?
>
> Since, we are already fetching the section NOTE_SCN (".note.stapsdt")
> and then we check for the type being SHT_NOTE and SHF_ALLOC, is it
> required to do the same for the individual notes?

I don't know. Now it seems only includes SDT notes with name being
"stapsdt" and type being 3. But things can be changed in future..

Thanks,
Namhyung
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