Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220204185742.271030-1-song@kernel.org> <20220204185742.271030-10-song@kernel.org>
 <20220703030210.pmjft7qc2eajzi6c@alap3.anarazel.de>
In-Reply-To: <20220703030210.pmjft7qc2eajzi6c@alap3.anarazel.de>
From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date:   Sat, 2 Jul 2022 20:03:56 -0700
Message-ID: <CAADnVQJmHTTri-s7dvFbLCXKZsZXopnVNFCpkmeHPYg2h6LkZg@mail.gmail.com>
Subject: Re: [PATCH v9 bpf-next 9/9] bpf, x86_64: use bpf_jit_binary_pack_alloc
To:     Andres Freund <andres@anarazel.de>
Cc:     Song Liu <song@kernel.org>, bpf <bpf@vger.kernel.org>,
        Network Development <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Kernel Team <kernel-team@fb.com>,
        Peter Zijlstra <peterz@infradead.org>, X86 ML <x86@kernel.org>,
        Ilya Leoshkevich <iii@linux.ibm.com>,
        Song Liu <songliubraving@fb.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Sat, Jul 2, 2022 at 8:02 PM Andres Freund <andres@anarazel.de> wrote:
>
> Hi,
>
> On 2022-02-04 10:57:42 -0800, Song Liu wrote:
> > From: Song Liu <songliubraving@fb.com>
> >
> > Use bpf_jit_binary_pack_alloc in x86_64 jit. The jit engine first writes
> > the program to the rw buffer. When the jit is done, the program is copied
> > to the final location with bpf_jit_binary_pack_finalize.
> >
> > Note that we need to do bpf_tail_call_direct_fixup after finalize.
> > Therefore, the text_live = false logic in __bpf_arch_text_poke is no
> > longer needed.
>
> I think this broke bpf_jit_enable = 2.

Good. We need to remove that knob.
It's been wrong for a long time.