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([2001:b07:6468:f312:7ffb:1107:73ba:dbcf]) by smtp.gmail.com with ESMTPSA id e7sm24517410wrm.6.2020.10.12.00.01.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 12 Oct 2020 00:01:58 -0700 (PDT) Subject: Re: [PATCH v3 02/16] fuzz: Add general virtual-device fuzzer To: Alexander Bulekov References: <20200921022506.873303-1-alxndr@bu.edu> <20200921022506.873303-3-alxndr@bu.edu> <63ca7622-557b-4217-f15e-ee9b024fbd77@redhat.com> <20200921143405.3taiymgzwvscxsry@mozz.bu.edu> <74511624-33ed-ff5d-62c2-f9b2b632b39a@redhat.com> <20201011153522.oyad5n47p4hphgfm@mozz.bu.edu> From: Paolo Bonzini Message-ID: <244cc05c-e063-9d25-3833-96bda5cfc2e2@redhat.com> Date: Mon, 12 Oct 2020 09:02:01 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20201011153522.oyad5n47p4hphgfm@mozz.bu.edu> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/11 23:52:29 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Thomas Huth , qemu-devel@nongnu.org, darren.kenny@oracle.com, bsd@redhat.com, stefanha@redhat.com, =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 11/10/20 17:35, Alexander Bulekov wrote: >> Instead of always looking for a separator, can you: >> >> 1) skip over it if you find it naturally at the end of a command (that >> is, "FUZZ" is like a comment command) >> >> 2) actively search for it only if you stumble upon an unrecognized command? >> > What is the end goal? Is it to be able to use the "FUZZ" bytes to fuzz > devices? Yes, possibly, and perhaps also using a shorter separator that is easier to learn. But if the dictionary is enough to work around the learning time and it's unlikely that crossover produces inputs like that, I guess it's okay to have the separator. Paolo