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Received: from [223.233.77.29] (helo=localhost.localdomain) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1tsxZr-008TWs-PU; Fri, 14 Mar 2025 06:27:29 +0100 From: Bhupesh To: akpm@linux-foundation.org Cc: bhupesh@igalia.com, kernel-dev@igalia.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, oliver.sang@intel.com, lkp@intel.com, laoar.shao@gmail.com, pmladek@suse.com, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, arnaldo.melo@gmail.com, alexei.starovoitov@gmail.com, andrii.nakryiko@gmail.com, mirq-linux@rere.qmqm.pl, peterz@infradead.org, willy@infradead.org, david@redhat.com, viro@zeniv.linux.org.uk, keescook@chromium.org, ebiederm@xmission.com, brauner@kernel.org, jack@suse.cz, mingo@redhat.com, juri.lelli@redhat.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com Subject: [PATCH RFC 0/2] Dynamically allocate memory to store task's full name Date: Fri, 14 Mar 2025 10:57:13 +0530 Message-Id: <20250314052715.610377-1-bhupesh@igalia.com> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Queue-Id: 28F3920003 X-Stat-Signature: yg6du65cndok3kmngogz7ocsseejhtn8 X-Rspamd-Server: rspam06 X-HE-Tag: 1741930062-320656 X-HE-Meta: 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 Z/4tjbxj WBoUoNGQKgjpZnVrzjujdO+sXgFU3M8H1YSSqZgF314kET0vAbBWfj6bt8F7vO4BPaKvX6+jBLI5cBzJNRyjeNKCzqneL4R5soCCz4+q8vSNW9JfFMz1//poa7U4cTogItMNhA477vwe2qeU0KDIQqr/qNTGC7SackRBJnMHBDo29mv1s5PAaTaICH4OOsgerO3oCXFXrWtfT2qsm6XoRo6TdV0RbdnRys61P43NQRt102QaXj9zp+0516WMEEgAn4x0AXMypLEUf/W0im5WUYzV9tKCujAKphe7g X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: While working with user-space debugging tools which work especially on linux gaming platforms, I found that the task name is truncated due to the limitation of TASK_COMM_LEN. For example, currently running 'ps', the task->comm value of a long task name is truncated due to the limitation of TASK_COMM_LEN. create_very_lon This leads to the names passed from userland via pthread_setname_np() being truncated. Now, during debug tracing, seeing truncated names is not very useful, especially on gaming platforms where the number of tasks running can be very hight. For example for debug applications invoking 'pthread_getname_np()' to debug task names. This RFC aims to start a conversation and improve the initial RFC patchset to avoid such buffer overflows by introducing a new dynamically allocated pointer to store task's full name, which shouldn't introduce too much overhead as it is in the non-critical path. After this change, the full name of these (otherwise truncated) tasks will be shown in 'ps'. For example: create_very_long_name_user_space_script.sh Bhupesh (2): exec: Dynamically allocate memory to store task's full name fs/proc: Pass 'task->full_name' via 'proc_task_name()' fs/exec.c | 21 ++++++++++++++++++--- fs/proc/array.c | 2 +- include/linux/sched.h | 9 +++++++++ 3 files changed, 28 insertions(+), 4 deletions(-) -- 2.38.1