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([2620:10d:c090:500::2:8a9]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-30297bbc9a3sm718642eec.31.2026.05.13.15.33.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 May 2026 15:33:47 -0700 (PDT) Message-ID: <2ec40641b6d0313674557a682984d7ea9cdf24a4.camel@gmail.com> Subject: Re: [PATCH RESEND bpf-next v10 4/8] bpf: refactor __bpf_list_add to take insertion point via **prev_ptr From: Eduard Zingerman To: Kaitao cheng , ast@kernel.org, corbet@lwn.net, martin.lau@linux.dev, daniel@iogearbox.net, andrii@kernel.org, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, shuah@kernel.org, chengkaitao@kylinos.cn, skhan@linuxfoundation.org, memxor@gmail.com Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, vmalik@redhat.com, linux-kselftest@vger.kernel.org Date: Wed, 13 May 2026 15:33:44 -0700 In-Reply-To: <20260512055919.95716-5-kaitao.cheng@linux.dev> References: <20260512055919.95716-1-kaitao.cheng@linux.dev> <20260512055919.95716-5-kaitao.cheng@linux.dev> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.3 (3.58.3-1.fc43) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Tue, 2026-05-12 at 13:59 +0800, Kaitao cheng wrote: > From: Kaitao Cheng >=20 > Refactor __bpf_list_add to accept (node, head, struct list_head **prev_pt= r, > ..) instead of (node, head, bool tail, ..). Load prev from *prev_ptr afte= r > INIT_LIST_HEAD(h), so we never dereference an uninitialized h->prev when > head was 0-initialized (e.g. push_back passes &h->prev). >=20 > When prev is not the list head, validate that prev is in the list via > its owner. >=20 > Prepares for bpf_list_add(head, new, prev, ..) to insert after a given > list node. >=20 > Signed-off-by: Kaitao Cheng > --- Reviewed-by: Eduard Zingerman [...]