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([2620:10d:c090:500::6:82c0]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-29246ffef8esm112694575ad.51.2025.10.21.08.57.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Oct 2025 08:57:49 -0700 (PDT) Message-ID: Subject: Re: [PATCH v3 bpf] bpf: liveness: clarify get_outer_instance() handling in propagate_to_outer_instance() From: Eduard Zingerman To: Shardul Bankar , bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , open list Date: Tue, 21 Oct 2025 08:57:47 -0700 In-Reply-To: <20251021080849.860072-1-shardulsb08@gmail.com> References: <20251021080849.860072-1-shardulsb08@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Tue, 2025-10-21 at 13:38 +0530, Shardul Bankar wrote: > propagate_to_outer_instance() calls get_outer_instance() and uses the > returned pointer to reset and commit stack write marks. Under normal > conditions, update_instance() guarantees that an outer instance exists, > so get_outer_instance() cannot return an ERR_PTR. >=20 > However, explicitly checking for IS_ERR(outer_instance) makes this code > more robust and self-documenting. It reduces cognitive load when reading > the control flow and silences potential false-positive reports from > static analysis or automated tooling. >=20 > No functional change intended. >=20 > Reported-by: kernel-patches-review-bot (https://github.com/kernel-patches= /bpf/pull/10006#issuecomment-3409419240) > Suggested-by: Eduard Zingerman > Signed-off-by: Shardul Bankar > --- Acked-by: Eduard Zingerman