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From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Leon Hwang" <leon.hwang@linux.dev>, <bpf@vger.kernel.org>
Cc: "Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Eduard Zingerman" <eddyz87@gmail.com>,
	"Kumar Kartikeya Dwivedi" <memxor@gmail.com>,
	"Martin KaFai Lau" <martin.lau@linux.dev>,
	"Song Liu" <song@kernel.org>,
	"Yonghong Song" <yonghong.song@linux.dev>,
	"Jiri Olsa" <jolsa@kernel.org>,
	"Emil Tsalapatis" <emil@etsalapatis.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Shuah Khan" <shuah@kernel.org>,
	"Puranjay Mohan" <puranjay@kernel.org>,
	"Anton Protopopov" <a.s.protopopov@gmail.com>,
	<linux-kernel@vger.kernel.org>, <linux-kselftest@vger.kernel.org>
Subject: Re: [RFC PATCH bpf 0/6] bpf: Disallow interpreter fallback for interpreter-unsupported insns
Date: Tue, 30 Jun 2026 22:50:43 -0700	[thread overview]
Message-ID: <DJN001X0S57Y.18CKUS4NDDQT1@gmail.com> (raw)
In-Reply-To: <18678d0c-f878-4d7b-bf7e-ffca4967dec5@linux.dev>

On Tue Jun 30, 2026 at 7:59 PM PDT, Leon Hwang wrote:
> On 1/7/26 07:12, Alexei Starovoitov wrote:
>> On Fri Jun 26, 2026 at 8:43 AM PDT, Leon Hwang wrote:
> [...]
>> 
>> I don't think we need such fallback in patch [3].
>
> Do you mean we can add the internal BPF_ADDR_PERCPU insn support to the
> interpreter?

No. See why CONFIG_BPF_JIT_ALWAYS_ON was introduced.
The interpreter is a security hole.
It has to be _compiled out_ of the kernel.
Hence all patches that improve fallback to interpreter are misguided.
The interpreter has to be removed completely... sooner or later.

  parent reply	other threads:[~2026-07-01  5:50 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-26 15:43 [RFC PATCH bpf 0/6] bpf: Disallow interpreter fallback for interpreter-unsupported insns Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 1/6] bpf: Disallow interpreter fallback for user BPF_ADDR_SPACE_CAST insn Leon Hwang
2026-06-30 14:29   ` KaFai Wan
2026-06-30 14:36     ` Leon Hwang
2026-07-01  1:26       ` Tiezhu Yang
2026-07-01  6:21         ` Leon Hwang
2026-07-01  6:49           ` Tiezhu Yang
2026-07-01  7:02             ` Leon Hwang
2026-07-01  7:29               ` Tiezhu Yang
2026-07-01  8:04                 ` Leon Huang Fu
2026-07-01  9:07                   ` Tiezhu Yang
2026-07-01 18:47                     ` Alexei Starovoitov
2026-06-26 15:43 ` [RFC PATCH bpf 2/6] bpf: Disallow interpreter fallback for arena insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 3/6] bpf: Disallow interpreter fallback for BPF_MOV64_PERCPU_REG insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 4/6] bpf: Disallow interpreter fallback for internal BPF_PROBE_ATOMIC insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 5/6] bpf: Disallow interpreter fallback for gotox insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 6/6] lib/test_bpf: Add interpreter-fallback tests Leon Hwang
2026-06-26 16:11 ` [RFC PATCH bpf 0/6] bpf: Disallow interpreter fallback for interpreter-unsupported insns Leon Hwang
2026-06-30 23:12 ` Alexei Starovoitov
2026-07-01  2:59   ` Leon Hwang
2026-07-01  3:05     ` Leon Hwang
2026-07-01  5:50     ` Alexei Starovoitov [this message]
2026-07-01  6:20       ` Leon Hwang

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