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Wed, 16 Apr 2025 10:36:33 -0700 (PDT) Received: from ezingerman-mba ([2620:10d:c090:500::4:24a]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4796edc1af2sm110366571cf.69.2025.04.16.10.36.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Apr 2025 10:36:33 -0700 (PDT) From: Eduard Zingerman To: Kumar Kartikeya Dwivedi Cc: bpf@vger.kernel.org, Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Emil Tsalapatis , Barret Rhoden , kkd@meta.com, kernel-team@meta.com Subject: Re: [RFC PATCH bpf-next/net v1 06/13] bpf: Introduce bpf_dynptr_from_mem_slice In-Reply-To: <20250414161443.1146103-7-memxor@gmail.com> (Kumar Kartikeya Dwivedi's message of "Mon, 14 Apr 2025 09:14:36 -0700") References: <20250414161443.1146103-1-memxor@gmail.com> <20250414161443.1146103-7-memxor@gmail.com> Date: Wed, 16 Apr 2025 10:36:27 -0700 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Kumar Kartikeya Dwivedi writes: > Add a new bpf_dynptr_from_mem_slice kfunc to create a dynptr from a > PTR_TO_BTF_ID exposing a variable-length slice of memory, represented by > the new bpf_mem_slice type. This slice is read-only, for a read-write > slice we can expose a distinct type in the future. > > We rely on the previous commits ensuring source objects underpinning > dynptr memory are tracked correctly for invalidation to ensure when a > PTR_TO_BTF_ID holding a memory slice goes away, it's corresponding > dynptrs get invalidated. > > Signed-off-by: Kumar Kartikeya Dwivedi If I remove KF_TRUSTED_ARGS flag from the function nothing fails. But that's because with current interface slices will always have a ref_obj_id, right? And pointers with ref_obj_id are always trusted. Acked-by: Eduard Zingerman [...]