From: Eduard Zingerman <eddyz87@gmail.com>
To: Zesen Liu <ftyghome@gmail.com>,
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 <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@fomichev.me>,
Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
Matt Bobrowski <mattbobrowski@google.com>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>, Daniel Xu <dxu@dxuuu.xyz>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, netdev@vger.kernel.org,
Shuran Liu <electronlsr@gmail.com>,
Peili Gao <gplhust955@gmail.com>,
Haoran Ni <haoran.ni.cs@gmail.com>
Subject: Re: [PATCH bpf RESEND v2 2/2] bpf: Require ARG_PTR_TO_MEM with memory flag
Date: Mon, 19 Jan 2026 12:25:08 -0800 [thread overview]
Message-ID: <600177c05c552f470cc5e25c7dba6990d96790e9.camel@gmail.com> (raw)
In-Reply-To: <20260118-helper_proto-v2-2-ab3a1337e755@gmail.com>
On Sun, 2026-01-18 at 16:16 +0800, Zesen Liu wrote:
> Add check to ensure that ARG_PTR_TO_MEM is used with either MEM_WRITE or
> MEM_RDONLY.
>
> Using ARG_PTR_TO_MEM alone without tags does not make sense because:
>
> - If the helper does not change the argument, missing MEM_RDONLY causes the
> verifier to incorrectly reject a read-only buffer.
> - If the helper does change the argument, missing MEM_WRITE causes the
> verifier to incorrectly assume the memory is unchanged, leading to errors
> in code optimization.
>
> Co-developed-by: Shuran Liu <electronlsr@gmail.com>
> Signed-off-by: Shuran Liu <electronlsr@gmail.com>
> Co-developed-by: Peili Gao <gplhust955@gmail.com>
> Signed-off-by: Peili Gao <gplhust955@gmail.com>
> Co-developed-by: Haoran Ni <haoran.ni.cs@gmail.com>
> Signed-off-by: Haoran Ni <haoran.ni.cs@gmail.com>
> Signed-off-by: Zesen Liu <ftyghome@gmail.com>
> ---
Note: this patch no longer applies properly because of the change in
the check_func_proto() signature.
[...]
next prev parent reply other threads:[~2026-01-19 20:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-18 8:16 [PATCH bpf RESEND v2 0/2] bpf: Fix memory access flags in helper prototypes Zesen Liu
2026-01-18 8:16 ` [PATCH bpf RESEND v2 1/2] " Zesen Liu
2026-01-19 20:24 ` Eduard Zingerman
2026-01-20 3:39 ` Zesen Liu
2026-01-20 17:54 ` Eduard Zingerman
2026-01-18 8:16 ` [PATCH bpf RESEND v2 2/2] bpf: Require ARG_PTR_TO_MEM with memory flag Zesen Liu
2026-01-19 20:25 ` Eduard Zingerman [this message]
2026-01-20 8:11 ` Zesen Liu
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