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Date: Mon, 7 Dec 2015 19:24:06 -0800
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        syzkaller <syzkaller@googlegroups.com>,
        Kostya Serebryany <kcc@google.com>,
        Alexander Potapenko <glider@google.com>,
        Eric Dumazet <edumazet@google.com>,
        Sasha Levin <sasha.levin@oracle.com>
Subject: Re: use-after-free in __perf_install_in_context
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On Mon, Dec 07, 2015 at 05:09:21PM +0100, Dmitry Vyukov wrote:
> > So it would be _awesome_ if we could somehow extend this callchain to
> > include the site that calls call_rcu().
> 
> We have a patch for KASAN in works that adds so-called stack depot
> which allows to map a stack trace onto uint32 id. Then we can plumb

I was hacking something similar to categorize stack traces with u32 id.
How are you planning to limit the number of such stack traces ?
and what is the interface for user space to get stack trace from an id?