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[209.85.218.44]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a690f03320csm200138066b.184.2024.06.03.15.24.05 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 03 Jun 2024 15:24:05 -0700 (PDT) Received: by mail-ej1-f44.google.com with SMTP id a640c23a62f3a-a68ca4d6545so380647966b.0 for ; Mon, 03 Jun 2024 15:24:05 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCW/EHdkiSswK2SGqgED0dHgaSF6MtAyGPbfud4VW/Cp3VN9KXR0lhkIpfyZJcCcjKqrfY4mxtyKzrEUj9yQL1F7cxc= X-Received: by 2002:a17:906:d217:b0:a62:49ae:cd7b with SMTP id a640c23a62f3a-a69543e118emr67505166b.24.1717453445163; Mon, 03 Jun 2024 15:24:05 -0700 (PDT) MIME-Version: 1.0 References: <20240602023754.25443-1-laoar.shao@gmail.com> <20240602023754.25443-3-laoar.shao@gmail.com> <20240603172008.19ba98ff@gandalf.local.home> <20240603181943.09a539aa@gandalf.local.home> In-Reply-To: <20240603181943.09a539aa@gandalf.local.home> From: Linus Torvalds Date: Mon, 3 Jun 2024 15:23:48 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 2/6] tracing: Replace memcpy() with __get_task_comm() To: Steven Rostedt Cc: Yafang Shao , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, audit@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, bpf@vger.kernel.org, Masami Hiramatsu , Mathieu Desnoyers Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 7D6761C0018 X-Stat-Signature: dz7yp6nrpxrumk86pzf85y7y3uzikpse X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1717453448-775897 X-HE-Meta: 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 c9hbhFIw 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.002895, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 3 Jun 2024 at 15:18, Steven Rostedt wrote: > > The logic behind __string() and __assign_str() will always add a NUL > character. Ok. But then you still end up with the issue that now the profiles are different, and you have a 8-byte pointer to dynamically allocated memory instead of just the simpler comm[TASK_COMM_LEN]. Is that actually a good idea for tracing? We're trying to fix the core code to be cleaner for places that may actually *care* (like 'ps'). Would we really want to touch this part of tracing? Linus