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From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Alexei Starovoitov <ast@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Steven Rostedt <rostedt@goodmis.org>, 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
Date: Tue, 10 Dec 2019 08:19:42 -0800	[thread overview]
Message-ID: <CAADnVQJVabzj-aytRnZrFCwRJAf+g_wZ-zWiO7D0bUm7UVpDQw@mail.gmail.com> (raw)
In-Reply-To: <20191209000114.1876138-2-ast@kernel.org>

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.

  reply	other threads:[~2019-12-10 16:19 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-09  0:01 [PATCH bpf 0/3] bpf: Make BPF trampoline friendly to ftrace Alexei Starovoitov
2019-12-09  0:01 ` [PATCH bpf 1/3] ftrace: Fix function_graph tracer interaction with BPF trampoline Alexei Starovoitov
2019-12-10 16:19   ` Alexei Starovoitov [this message]
2019-12-10 16:30     ` Steven Rostedt
2019-12-10 23:35   ` Steven Rostedt
2019-12-10 23:49     ` Alexei Starovoitov
2019-12-09  0:01 ` [PATCH bpf 2/3] bpf: Make BPF trampoline use register_ftrace_direct() API Alexei Starovoitov
2019-12-09  0:01 ` [PATCH bpf 3/3] selftests/bpf: test function_graph tracer and bpf trampoline together Alexei Starovoitov
2019-12-09 18:42 ` [PATCH bpf 0/3] bpf: Make BPF trampoline friendly to ftrace Martin Lau

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