Re: [PATCH bpf-next v2 5/6] bpf, arm64: bpf trampoline for arm64

From: KP Singh <kpsingh@kernel.org>
To: Xu Kuohai <xukuohai@huawei.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
	bpf <bpf@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	open list <linux-kernel@vger.kernel.org>,
	Networking <netdev@vger.kernel.org>,
	"open list:KERNEL SELFTEST FRAMEWORK" 
	<linux-kselftest@vger.kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@redhat.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexei Starovoitov <ast@kernel.org>,
	Zi Shen Lim <zlim.lnx@gmail.com>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	"David S . Miller" <davem@davemloft.net>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	David Ahern <dsahern@kernel.org>,
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	Borislav Petkov <bp@alien8.de>,
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	hpa@zytor.com, Shuah Khan <shuah@kernel.org>,
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	Steven Price <steven.price@arm.com>,
	Marc Zyngier <maz@kernel.org>, Mark Brown <broonie@kernel.org>,
	Kumar Kartikeya Dwivedi <memxor@gmail.com>,
	Delyan Kratunov <delyank@fb.com>
Subject: Re: [PATCH bpf-next v2 5/6] bpf, arm64: bpf trampoline for arm64
Date: Wed, 20 Apr 2022 13:42:54 +0200	[thread overview]
Message-ID: <CACYkzJ6QZek1VV-QgO52Kp9X4cCJnXaD7QJFkMtMLtzDTzDDsA@mail.gmail.com> (raw)
In-Reply-To: <82e7faec-7f0c-573f-4945-de7072744dcb@huawei.com>

On Wed, Apr 20, 2022 at 9:44 AM Xu Kuohai <xukuohai@huawei.com> wrote:
>
> On 4/16/2022 9:57 AM, Xu Kuohai wrote:
> > On 4/16/2022 1:12 AM, Andrii Nakryiko wrote:
> >> On Thu, Apr 14, 2022 at 9:10 AM Xu Kuohai <xukuohai@huawei.com> wrote:
> >>>
> >>> Add bpf trampoline support for arm64. Most of the logic is the same as
> >>> x86.
> >>>
> >>> fentry before bpf trampoline hooked:
> >>>  mov x9, x30
> >>>  nop
> >>>
> >>> fentry after bpf trampoline hooked:
> >>>  mov x9, x30
> >>>  bl  <bpf_trampoline>
> >>>
> >>> Tested on qemu, result:
> >>>  #55 fentry_fexit:OK
> >>>  #56 fentry_test:OK
> >>>  #58 fexit_sleep:OK
> >>>  #59 fexit_stress:OK
> >>>  #60 fexit_test:OK
> >>>  #67 get_func_args_test:OK
> >>>  #68 get_func_ip_test:OK
> >>>  #101 modify_return:OK
> >>>
> >>> Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
> >>> Acked-by: Song Liu <songliubraving@fb.com>
> >>> ---
> >>
> >> Can you please also take a look at [0], which is an ongoing work to
> >> add support for BPF cookie to BPF trampoline-based BPF programs. It's
> >> very close to being done, so it would be good if you can implement
> >> that at the same time.
> >
> > OK, I'll take a look and try to implemnt it.
>
> already implemented, but there are some conflicts between these two
> series, will send v3 after trampoline cookie are merged.

Awesome work, Thanks for doing this!