linux-kernel - Re: [RFC] perf record: missing buildid for callstack modules

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 7 Jan 2016 18:59:45 -0300
From:	Arnaldo Carvalho de Melo <acme@...nel.org>
To:	Stephane Eranian <eranian@...gle.com>
Cc:	LKML <linux-kernel@...r.kernel.org>, Jiri Olsa <jolsa@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	Adrian Hunter <adrian.hunter@...el.com>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>
Subject: Re: [RFC] perf record: missing buildid for callstack modules

Em Thu, Jan 07, 2016 at 01:56:14PM -0800, Stephane Eranian escreveu:
> Hi,
> 
> Whenever you do:
> 
>     $ perf record -g -a sleep 10
> 
> Perf will collect the callstack for each sample. At the end of the
> run, perf record
> adds the buildid for all dso with at least one sample. But when it does this, it
> only looks at the sampled IP and ignore the modules traversed by the callstack.
> That means that, it is not possible to uniquely identify the modules executed,
> unless they had at least one IP sample captured. But this is not
> always the case.
> 
> How about providing an option to perf record to force collecting
> buildid for all IPs
> captured in the callstack? I understand that would cost more at the end of the
> collection, but this would be beneficial to several monitoring scenarios.

I agree, would consider applying a patch that provides the option but
does not do this by default.

- Arnaldo