linux-kernel - Re: [PATCH 2/5] perf tool: Initialize events IDs in a single function

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:	Sat, 19 Nov 2011 20:36:21 -0500
From:	Jiri Olsa <jolsa@...hat.com>
To:	Arnaldo Carvalho de Melo <acme@...hat.com>
Cc:	a.p.zijlstra@...llo.nl, mingo@...e.hu, paulus@...ba.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/5] perf tool: Initialize events IDs in a single function

On Fri, Nov 18, 2011 at 12:22:55PM -0200, Arnaldo Carvalho de Melo wrote:
> Em Fri, Nov 18, 2011 at 02:46:42PM +0100, Jiri Olsa escreveu:
> > Currently events' IDs initialization is scattered among the
> > code. Adding function 'perf_evlist__init_ids' to allocate
> > and retrive events' IDs in one place.
> 
> I'm ok with this one, will merge it in my perf/core branch together with
> a fix for a bug I noticed in the original code and that remains with
> your changes: consider what happens if we do a second perf_evlist__mmap,
> we will call perf_evlist__id_add_fd again and thus bump evsel->ids++
> over nr_threads * nr_cpus, overflowing it.

is there a valid scenario for this function to be called more than once?
I'd think that just ensuring this is called once is enough

jirka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/