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Message-ID: <2509f619-15a4-84d6-d199-12e4526bf30e@huaweicloud.com>
Date:   Tue, 20 Dec 2022 10:16:43 +0800
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Subject: Re: [RFC PATCH bpf-next 0/4] Support bpf trampoline for RV64
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To:     bpf@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org
Cc:     =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Pu Lehui <pulehui@huawei.com>
References: <20221219133736.1387008-1-pulehui@huaweicloud.com>
From:   Pu Lehui <pulehui@huaweicloud.com>
In-Reply-To: <20221219133736.1387008-1-pulehui@huaweicloud.com>
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On 2022/12/19 21:37, Pu Lehui wrote:
> BPF trampoline is the critical infrastructure of the bpf
> subsystem, acting as a mediator between kernel functions
> and BPF programs. Numerous important features, such as
> using ebpf program for zero overhead kernel introspection,
> rely on this key component. We can't wait to support bpf
> trampoline on RV64. The implementation of bpf trampoline
> was closely to x86 and arm64 for future development.
> 
> As most of riscv cpu support unaligned memory accesses,
> we temporarily use patch [1] to facilitate testing. The
> test results are as follow, and test_verifier with no
> new failure ceses.
> 
> - fexit_test:OK
> - fentry_test:OK
> - fentry_fexit:OK
> - fexit_stress:OK
> - fexit_bpf2bpf:OK
> - dummy_st_ops:OK
> - modify_return:OK
> - get_func_ip_test:OK
> - get_func_args_test:OK
> - trampoline_count:OK
> 
> [1] https://lore.kernel.org/linux-riscv/20210916130855.4054926-2-chenhuang5@huawei.com/
> 
> Pu Lehui (4):
>    bpf: Rollback to text_poke when arch not supported ftrace direct call
>    riscv, bpf: Factor out emit_call for kernel and bpf context
>    riscv, bpf: Add bpf_arch_text_poke support for RV64
>    riscv, bpf: Add bpf trampoline support for RV64
> 
>   arch/riscv/net/bpf_jit.h        |   5 +
>   arch/riscv/net/bpf_jit_comp64.c | 484 ++++++++++++++++++++++++++++++--
>   kernel/bpf/trampoline.c         |   8 +-
>   3 files changed, 472 insertions(+), 25 deletions(-)
> 

sorry, small problem of this patchset, have been resend.