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Date:   Tue, 10 Dec 2019 11:30:17 -0500
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Daniel Borkmann <daniel@iogearbox.net>,
        X86 ML <x86@kernel.org>,
        Network Development <netdev@vger.kernel.org>,
        bpf <bpf@vger.kernel.org>, Kernel Team <kernel-team@fb.com>
Subject: Re: [PATCH bpf 1/3] ftrace: Fix function_graph tracer interaction
 with BPF trampoline
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References: <20191209000114.1876138-1-ast@kernel.org>
        <20191209000114.1876138-2-ast@kernel.org>
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On Tue, 10 Dec 2019 08:19:42 -0800
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:

> On Sun, Dec 8, 2019 at 4:03 PM Alexei Starovoitov <ast@kernel.org> wrote:
> >
> > Depending on type of BPF programs served by BPF trampoline it can call original
> > function. In such case the trampoline will skip one stack frame while
> > returning. That will confuse function_graph tracer and will cause crashes with
> > bad RIP. Teach graph tracer to skip functions that have BPF trampoline attached.
> >
> > Signed-off-by: Alexei Starovoitov <ast@kernel.org>  
> 
> Steven, please take a look.

I'll try to get to it today or tomorrow. I have some other work to get
done that my job requires I do ;-)

-- Steve