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Date:   Tue, 4 Feb 2020 20:26:57 +0100
From:   Jiri Olsa <jolsa@redhat.com>
To:     Marek Majkowski <marek@cloudflare.com>
Cc:     Ivan Babrou <ivan@cloudflare.com>,
        kernel-team <kernel-team@cloudflare.com>,
        Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Namhyung Kim <namhyung@kernel.org>, sashal@kernel.org,
        Kenton Varda <kenton@cloudflare.com>
Subject: Re: perf not picking up symbols for namespaced processes
Message-ID: <20200204192657.GB1554679@krava>
References: <CABWYdi1ZKR=jmKnjoJTik08Q9uJBvyZ4W0C29iPiUJ5ef1obvw@mail.gmail.com>
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On Tue, Feb 04, 2020 at 03:09:48PM +0000, Marek Majkowski wrote:
> On Fri, Dec 6, 2019 at 2:17 AM Ivan Babrou <ivan@cloudflare.com> wrote:
> >
> > I'm not very good at this, but the following works for me. If you this
> > is in general vicinity of what you expected, I can email patch
> > properly.
> >
> 
> Thanks for the patch, I can confirm it works. I had this problem today
> when playing
> with gvisor. Gvisor is starting up in a fresh mount namespace and perf fails
> to read the symbols. Stracing perf shows:
> 
> 11913 openat(AT_FDCWD, "/proc/9512/ns/mnt", O_RDONLY) = 197
> 11913 setns(197, CLONE_NEWNS) = 0
> 11913 stat("/home/marek/bin/runsc-debug", 0x7fffffff8480) = -1 ENOENT
> (No such file or directory)
> 11913 setns(196, CLONE_NEWNS) = 0
> 
> Which of course makes no sense - the runsc-debug binary does not exist in the
> empty mount namespace of the restricted runsc process.

hi,
could you guys please share more details on what you run exactly,
and perhaps that change you mentioned?

thanks,
jirka