From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966593AbcHBNSu (ORCPT ); Tue, 2 Aug 2016 09:18:50 -0400 Received: from mail.kernel.org ([198.145.29.136]:39110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966477AbcHBNRL (ORCPT ); Tue, 2 Aug 2016 09:17:11 -0400 Date: Tue, 2 Aug 2016 22:17:05 +0900 From: Masami Hiramatsu To: Tomoki Sekiyama Cc: linux-kernel@vger.kernel.org, ltc-kernel@rdgml.intra.hitachi.co.jp, masumi.moritani.ju@hitachi.com, Jiri Olsa , David Ahern , Namhyung Kim , Peter Zijlstra , Masami Hiramatsu Subject: Re: [PATCH 1/2 v4] perf sched: fix wrong conversion of task state Message-Id: <20160802221705.dd12eec42d636965a110fd9f@kernel.org> In-Reply-To: <1470025826-8813-1-git-send-email-tomoki.sekiyama.qu@hitachi.com> References: <1470025826-8813-1-git-send-email-tomoki.sekiyama.qu@hitachi.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 1 Aug 2016 13:30:25 +0900 Tomoki Sekiyama wrote: > Currently sched_out_state() converts the prev_state u64 bitmask to a char > using the bitmask as an index, which may cause invalid memory access. > This fixes the issue by using the __ffs() returned value as an index. OK, looks good to me:) Acked-by: Masami Hiramatsu Thanks! > > Signed-off-by: Tomoki Sekiyama > Fixes: cdce9d738b91e ("perf sched: Add sched latency profiling") > Cc: Jiri Olsa > Cc: David Ahern > Cc: Namhyung Kim > Cc: Peter Zijlstra > Cc: Masami Hiramatsu > --- > Changes from v3: > Added Fixes: > Split the patch into 2 pieces. > > tools/perf/builtin-sched.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c > index 0dfe8df..ce9bef6 100644 > --- a/tools/perf/builtin-sched.c > +++ b/tools/perf/builtin-sched.c > @@ -897,9 +897,10 @@ static int thread_atoms_insert(struct perf_sched *sched, struct thread *thread) > > static char sched_out_state(u64 prev_state) > { > - const char *str = TASK_STATE_TO_CHAR_STR; > + const char str[] = TASK_STATE_TO_CHAR_STR; > + unsigned int bit = prev_state ? __ffs(prev_state) + 1 : 0; > > - return str[prev_state]; > + return bit < ARRAY_SIZE(str) - 1 ? str[bit] : '?'; > } > > static int > -- > 2.7.4 > -- Masami Hiramatsu