From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Olsa Subject: Re: [PATCH] perf/report: Report OOM in perf report status line Date: Fri, 26 Apr 2019 16:44:06 +0200 Message-ID: <20190426144406.GD12922@krava> References: <20190423105303.61683-1-tmricht@linux.ibm.com> <20190426140907.GB22086@kernel.org> <20190426141032.GA23426@kernel.org> <20190426141607.GB23426@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20190426141607.GB23426@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Arnaldo Carvalho de Melo Cc: Thomas Richter , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com List-Id: linux-perf-users.vger.kernel.org On Fri, Apr 26, 2019 at 11:16:07AM -0300, Arnaldo Carvalho de Melo wrote: SNIP > > util/session.c: In function ‘perf_session__process_events’: > > util/session.c:1936:7: error: ‘skip’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > err = skip; > > ~~~~^~~~~~ > > util/session.c:1874:6: note: ‘skip’ was declared here > > s64 skip; > > ^~~~ > > cc1: all warnings being treated as errors > > mv: cannot stat '/tmp/build/perf/util/.session.o.tmp': No such file or directory > > make[4]: *** [/home/acme/git/perf/tools/build/Makefile.build:96: /tmp/build/perf/util/session.o] Error 1 > > make[3]: *** [/home/acme/git/perf/tools/build/Makefile.build:139: util] Error 2 > > make[2]: *** [Makefile.perf:559: /tmp/build/perf/perf-in.o] Error 2 > > make[1]: *** [Makefile.perf:215: sub-make] Error 2 > > make: *** [Makefile:110: install-bin] Error 2 > > make: Leaving directory '/home/acme/git/perf/tools/perf' > > So, here is your patch: > > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index b17f1c9bc965..e89716175588 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1930,10 +1930,10 @@ reader__process_events(struct reader *rd, struct perf_session *session, > > if (size < sizeof(struct perf_event_header) || > (skip = rd->process(session, event, file_pos)) < 0) { > - pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n", > + pr_err("%#" PRIx64 " [%#x]: failed to process type: %d [%s]\n", > file_offset + head, event->header.size, > - event->header.type); > - err = -EINVAL; > + event->header.type, strerror(-skip)); > + err = skip; > goto out; > } > > [acme@quaco perf]$ > > What happens if (size < sizeof(struct perf_event_header)) is true? size > will have an undefined value, so the right thing is to have this patch > on top of yours, so that err get, as before, set to -EINVAL when the > size is less than the perf_event_header sizeof: I'd think you need to squash your change with the original patch for the bisecting sake, right? > > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c > index e89716175588..bad5f87ae001 100644 > --- a/tools/perf/util/session.c > +++ b/tools/perf/util/session.c > @@ -1928,6 +1928,8 @@ reader__process_events(struct reader *rd, struct perf_session *session, > > size = event->header.size; > > + skip = -EINVAL; > + > if (size < sizeof(struct perf_event_header) || > (skip = rd->process(session, event, file_pos)) < 0) { > pr_err("%#" PRIx64 " [%#x]: failed to process type: %d [%s]\n", > > --- > > With two Reviewed-by tags, I jumped to quickly at applying, please > compile test next time guys ;-) :-) ugh.. need to slow down, this is happening too often now :-\ jirka