From: Vince Weaver <vincent.weaver@maine.edu>
To: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc: linux-kernel@vger.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>
Subject: Re: perf: perf report stuck in an infinite loop
Date: Mon, 29 Jul 2019 11:03:26 -0400 (EDT) [thread overview]
Message-ID: <alpine.DEB.2.21.1907291102500.31029@macbook-air> (raw)
In-Reply-To: <20190726211415.GE24867@kernel.org>
On Fri, 26 Jul 2019, Arnaldo Carvalho de Melo wrote:
> Em Fri, Jul 26, 2019 at 04:46:51PM -0400, Vince Weaver escreveu:
> >
> > Currently the perf_data_fuzzer causes perf report to get stuck in an
> > infinite loop.
> >
> > >From what I can tell, the issue happens in reader__process_events()
> > when an event is mapped using mmap(), but when it goes to process the
> > event finds out the internal event header has the size (invalidly) set to
> > something much larger than the mmap buffer size. This means
> > fetch_mmaped_event() fails, which gotos remap: which tries again with
> > the exact same mmap size, and this will loop forever.
> >
> > I haven't been able to puzzle out how to fix this, but maybe you have a
> > better feel for what's going on here.
>
> Perhaps the patch below?
yes, with the patch you provided I can no longer trigger the infinite
loop.
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
next prev parent reply other threads:[~2019-07-29 15:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-26 20:46 perf: perf report stuck in an infinite loop Vince Weaver
2019-07-26 21:14 ` Arnaldo Carvalho de Melo
2019-07-29 15:03 ` Vince Weaver [this message]
2019-08-15 9:16 ` [tip:perf/core] perf session: Avoid infinite loop when seeing invalid header.size tip-bot for Arnaldo Carvalho de Melo
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=alpine.DEB.2.21.1907291102500.31029@macbook-air \
--to=vincent.weaver@maine.edu \
--cc=alexander.shishkin@linux.intel.com \
--cc=arnaldo.melo@gmail.com \
--cc=jolsa@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
/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).