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


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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