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([2604:3d08:9880:5900:ad05:9ec6:fc65:cf63]) by smtp.gmail.com with ESMTPSA id l10-20020a170903120a00b001e789aff266sm2097537plh.118.2024.04.18.16.57.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Apr 2024 16:57:59 -0700 (PDT) Message-ID: Subject: Re: [PATCH bpf-next v2 2/5] bpf/verifier: improve XOR and OR range computation From: Eduard Zingerman To: Cupertino Miranda , bpf@vger.kernel.org Cc: Yonghong Song , Alexei Starovoitov , David Faust , Elena Zannoni Date: Thu, 18 Apr 2024 16:57:58 -0700 In-Reply-To: <20240417122341.331524-3-cupertino.miranda@oracle.com> References: <20240417122341.331524-1-cupertino.miranda@oracle.com> <20240417122341.331524-3-cupertino.miranda@oracle.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4-0ubuntu2 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2024-04-17 at 13:23 +0100, Cupertino Miranda wrote: > Range for XOR and OR operators would not be attempted unless src_reg > would resolve to a single value, i.e. a known constant value. > This condition is unnecessary, and the following XOR/OR operator > handling could compute a possible better range. >=20 > Signed-off-by: Cupertino Miranda Cc: Yonghong Song > Cc: Alexei Starovoitov > Cc: David Faust > Cc: Jose Marchesi Cc: Elena Zannoni > --- I agree with this reasoning regarding OR/XOR processing. Acked-by: Eduard Zingerman