From: Leo Yan <leo.yan@linaro.org>
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Andi Kleen <ak@linux.intel.com>,
"David S. Miller" <davem@davemloft.net>,
Davidlohr Bueso <dave@stgolabs.net>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Jin Yao <yao.jin@linux.intel.com>,
Song Liu <songliubraving@fb.com>,
Alexios Zavras <alexios.zavras@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Changbin Du <changbin.du@intel.com>,
Eric Saint-Etienne <eric.saint.etienne@oracle.com>,
Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
Thomas Richter <tmricht@linux.ibm.com>,
Alexey Budankov <alexey.budankov@linux.intel.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v1 10/11] perf intel-pt: Smatch: Fix potential NULL pointer dereference
Date: Wed, 3 Jul 2019 16:16:57 +0800 [thread overview]
Message-ID: <20190703081657.GD6852@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <b65cf4c6-3484-85c8-d191-35021ed6ed3e@intel.com>
On Wed, Jul 03, 2019 at 08:19:19AM +0300, Adrian Hunter wrote:
> On 3/07/19 4:35 AM, Leo Yan wrote:
> > Hi Adrian,
> >
> > On Tue, Jul 02, 2019 at 02:07:40PM +0300, Adrian Hunter wrote:
> >> On 2/07/19 1:34 PM, Leo Yan wrote:
> >>> Based on the following report from Smatch, fix the potential
> >>> NULL pointer dereference check.
> >>
> >> It never is NULL. Remove the NULL test if you want:
> >>
> >> - if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
> >> + if (session->itrace_synth_opts->set) {
> >>
> >> But blindly making changes like below is questionable.
> >
> > Thanks for suggestions.
> >
> > I checked report and script commands, as you said, both command will
> > always set session->itrace_synth_opts. For these two commands, we can
> > safely remove the NULL test.
> >
> > Because perf tool contains many sub commands, so I don't have much
> > confidence it's very safe to remove the NULL test for all cases; e.g.
> > there have cases which will process aux trace buffer but without
> > itrace options; for this case, session->itrace_synth_opts might be NULL.
> >
> > For either way (remove NULL test or keep NULL test), I don't want to
> > introduce regression and extra efforts by my patch. So want to double
> > confirm with you for this :)
>
> Yes, intel_pt_process_auxtrace_info() only gets called if a tool sets up the
> tools->auxtrace_info() callback. The tools that do that also set
> session->itrace_synth_opts.
Yes.
I also checked the another case for 'perf inject', just as you said,
it sets both inject->tool.auxtrace_info and session->itrace_synth_opts
if we use 'itrace' option. So it's safe to remove the NULL test for
session->itrace_synth_opts.
Will follow your suggestion for new patches. Thanks a lot for
confirmation and suggestions.
Thanks,
Leo Yan
next prev parent reply other threads:[~2019-07-03 8:17 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-02 10:34 [PATCH v1 00/11] perf: Fix errors detected by Smatch Leo Yan
2019-07-02 10:34 ` [PATCH v1 01/11] perf report: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-02 10:34 ` [PATCH v1 02/11] perf stat: Smatch: Fix use-after-freed pointer Leo Yan
2019-07-03 18:18 ` Arnaldo Carvalho de Melo
2019-07-13 10:53 ` [tip:perf/urgent] perf stat: Fix use-after-freed pointer detected by the smatch tool tip-bot for Leo Yan
2019-07-02 10:34 ` [PATCH v1 03/11] perf top: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-03 18:30 ` Arnaldo Carvalho de Melo
2019-07-13 10:53 ` [tip:perf/urgent] perf top: Fix potential NULL pointer dereference detected by the smatch tool tip-bot for Leo Yan
2019-07-02 10:34 ` [PATCH v1 04/11] perf annotate: Smatch: Fix dereferencing freed memory Leo Yan
2019-07-03 18:43 ` Arnaldo Carvalho de Melo
2019-07-13 10:54 ` [tip:perf/urgent] perf annotate: Fix dereferencing freed memory found by the smatch tool tip-bot for Leo Yan
2019-07-02 10:34 ` [PATCH v1 05/11] perf trace: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-03 18:46 ` Arnaldo Carvalho de Melo
2019-07-13 10:55 ` [tip:perf/urgent] perf trace: Fix potential NULL pointer dereference found by the smatch tool tip-bot for Leo Yan
2019-07-02 10:34 ` [PATCH v1 06/11] perf hists: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-02 11:07 ` Jiri Olsa
2019-07-02 10:34 ` [PATCH v1 07/11] perf map: " Leo Yan
2019-07-13 10:55 ` [tip:perf/urgent] perf map: Fix potential NULL pointer dereference found by smatch tool tip-bot for Leo Yan
2019-07-02 10:34 ` [PATCH v1 08/11] perf session: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-03 19:01 ` Arnaldo Carvalho de Melo
2019-07-13 10:57 ` [tip:perf/urgent] perf session: Fix potential NULL pointer dereference found by the smatch tool tip-bot for Leo Yan
2019-07-02 10:34 ` [PATCH v1 09/11] perf intel-bts: Smatch: Fix potential NULL pointer dereference Leo Yan
2019-07-02 10:34 ` [PATCH v1 10/11] perf intel-pt: " Leo Yan
2019-07-02 11:07 ` Adrian Hunter
2019-07-03 1:35 ` Leo Yan
2019-07-03 5:19 ` Adrian Hunter
2019-07-03 8:16 ` Leo Yan [this message]
2019-07-03 10:00 ` Daniel Thompson
2019-07-03 10:28 ` Leo Yan
2019-07-02 10:34 ` [PATCH v1 11/11] perf cs-etm: " Leo Yan
2019-07-02 17:03 ` Mathieu Poirier
2019-07-03 8:22 ` Leo Yan
2019-07-02 11:07 ` [PATCH v1 00/11] perf: Fix errors detected by Smatch Jiri Olsa
2019-07-03 1:48 ` Leo Yan
2019-07-03 18:18 ` Arnaldo Carvalho de Melo
2019-07-04 7:29 ` Leo Yan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190703081657.GD6852@leoy-ThinkPad-X240s \
--to=leo.yan@linaro.org \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=ak@linux.intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=alexey.budankov@linux.intel.com \
--cc=alexios.zavras@intel.com \
--cc=changbin.du@intel.com \
--cc=dave@stgolabs.net \
--cc=davem@davemloft.net \
--cc=eric.saint.etienne@oracle.com \
--cc=jolsa@redhat.com \
--cc=khlebnikov@yandex-team.ru \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=mathieu.poirier@linaro.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=songliubraving@fb.com \
--cc=suzuki.poulose@arm.com \
--cc=tglx@linutronix.de \
--cc=tmricht@linux.ibm.com \
--cc=yao.jin@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).