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Date: Tue, 6 Jun 2017 13:03:59 +0200
From: Jiri Olsa <jolsa@redhat.com>
To: David Carrillo-Cisneros <davidcc@google.com>
Cc: linux-kernel@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Andi Kleen <ak@linux.intel.com>, Simon Que <sque@chromium.org>,
        Wang Nan <wangnan0@huawei.com>, Jiri Olsa <jolsa@kernel.org>,
        He Kuang <hekuang@huawei.com>, Masami Hiramatsu <mhiramat@kernel.org>,
        David Ahern <dsa@cumulusnetworks.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Stephane Eranian <eranian@google.com>, Paul Turner <pjt@google.com>
Subject: Re: [PATCH v2 13/13] perf tools: add feature header record to
 pipe-mode
Message-ID: <20170606110359.GA5061@krava>
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 <CALcN6mhWWDbnGkDP5unmbB3GPi8+LRoKW8DFAse-KMUy85Fpew@mail.gmail.com>
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On Tue, Jun 06, 2017 at 12:57:53AM +0000, David Carrillo-Cisneros wrote:
> On Thu, May 25, 2017 at 1:09 AM Jiri Olsa <jolsa@redhat.com> wrote:
> 
> > On Tue, May 23, 2017 at 12:48:53AM -0700, David Carrillo-Cisneros wrote:
> >
> > SNIP
> >
> > > +     for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
> > > +             if (!feat_ops[feat].has_record) {
> > > +                     pr_debug("No record header feature for header
> > :%d\n", feat);
> > > +                     continue;
> > > +             }
> > > +
> > > +             fdd.offset = sizeof(*fe);
> > > +
> > > +             ret = feat_ops[feat].write(&fdd, evlist);
> > > +             if (ret || fdd.offset <= (ssize_t)sizeof(*fe)) {
> > > +                     pr_debug("Error writing feature\n");
> > > +                     continue;
> > > +             }
> > > +
> > > +             /* fdd.buf may have changed due to realloc in do_write() */
> > > +             fe = fdd.buf;
> > > +             memset(fe, 0, sizeof(*fe));
> >
> > no need to wipe it out if you set all the members just below
> > (apart from header.misc, which is not used)
> >
> 
> what if that changes one day? isn't it better to zero to avoid hard to find
> bugs?

ok

jirka