From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B5674B04AE; Thu, 27 Aug 2026 18:23:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787855039; cv=none; b=svBxPwPTykk4MFMPOJKZLHu/mWq1yVQWmXxesMFFbPMQIOUKACJCOdEpaaNjw3sAHMtyHIoYYyn8/PxucSkYroTGJlbBjxhgi33lY8JXjhXOWi8K9Kn28vqNzAfwzi9AYtwneFegaSAmrFpU9eYFRWGPk9YLIH1nYWq8WpI1Jho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787855039; c=relaxed/simple; bh=G/uPqElZfueOSCnwwOaTro8vtp2fBdZhLXQL2QOHKHw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=MjO/qFTAtx6a82RWG4vha4tMt30UfIoO29eqU/PvQXA5I2p9Iw7Zk4LVX/OKjoyMbUb9ugBdqbokuUdG7nl+yZO5ZraimHWS32HrbFY+4EsahCh+XaHTWOSMKUzV+E1/W0ApJc1GLTq5LKof0HOeMTPW85K/A2zeaas3v7SdsF4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=rQUtyokI; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="rQUtyokI" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:Message-Id:Content-Transfer-Encoding:Content-Type: MIME-Version:Subject:Date:From:From:Reply-To; bh=HO/5xE4JJZ1CCxn8HlprPB8vAIdq2WQK98oz1e8eTqk=; b=rQUtyokI1+jdIsJPy83y+Fg5Yl Ykdlki6QcbiItfEuyFBe3MFOrNjpg8SmMHtqy4n3rHT/GB4Uf7zlPQQR9G8V2QeLoyzLECF2IpJJ5 TAaVZHOwz/Qd4UaT2u8Aeu6HxDfwc75H7UoQvHAhGlYsrdRPSIW1puQRu4jtrPBRwMT08rrdVUJ6D TUA5o5K55J2OqHiH/yl37NoHMarjazIsWehaEVEWW1UOC7aRIAZqA2M+V0ErctgEAGXtGq1JpIvSd 84AxqBF9/cOrr/+t4sTQyffhDB9N/s4TH+T72yXmv+Oe2hTrJfPfe9BDjLxGEuMamETTdAPBgdPhU aukUHCsw==; Received: from [187.57.78.212] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wzelM-00AOUg-Bn; Thu, 27 Aug 2026 20:23:44 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= Date: Thu, 27 Aug 2026 15:23:04 -0300 Subject: [PATCH v5 5/6] prctl: Add support for long user thread names Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260827-tonyk-long_name-v5-5-5fa843782a00@igalia.com> References: <20260827-tonyk-long_name-v5-0-5fa843782a00@igalia.com> In-Reply-To: <20260827-tonyk-long_name-v5-0-5fa843782a00@igalia.com> To: Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Christian Brauner , Kees Cook , Shuah Khan , willy@infradead.org, mathieu.desnoyers@efficios.com, David Laight , Linus Torvalds , akpm@linux-foundation.org, Yafang Shao , andrii.nakryiko@gmail.com, arnaldo.melo@gmail.com, Petr Mladek Cc: linux-kernel@vger.kernel.org, kernel-dev@igalia.com, linux-mm@kvack.org, linux-api@vger.kernel.org, linux-trace-kernel@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Almeida?= X-Mailer: b4 0.15.2 Add support for getting and setting long user thread names with PR_{SET,GET}_EXT_NAME. Signed-off-by: André Almeida --- include/linux/sched.h | 2 +- include/uapi/linux/prctl.h | 3 +++ kernel/sys.c | 15 ++++++++++++++- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index c41d61e9babf..4f2cd802f172 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2032,7 +2032,7 @@ extern void kick_process(struct task_struct *tsk); extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); #define set_task_comm(tsk, from) ({ \ - BUILD_BUG_ON(sizeof(from) != TASK_COMM_LEN); \ + BUILD_BUG_ON(sizeof(from) < TASK_COMM_LEN); \ __set_task_comm(tsk, from, false); \ }) diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index b6ec6f693719..a07f8edadd65 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -56,6 +56,9 @@ #define PR_SET_NAME 15 /* Set process name */ #define PR_GET_NAME 16 /* Get process name */ +#define PR_SET_EXT_NAME 17 /* Set extended process name */ +#define PR_GET_EXT_NAME 18 /* Get extended process name */ + /* Get/set process endian */ #define PR_GET_ENDIAN 19 #define PR_SET_ENDIAN 20 diff --git a/kernel/sys.c b/kernel/sys.c index 5ebd3c1dfddf..4caf6ef836f1 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2535,7 +2535,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, unsigned long, arg4, unsigned long, arg5) { struct task_struct *me = current; - unsigned char comm[TASK_COMM_LEN]; + unsigned char comm[TASK_COMM_EXT_LEN]; long error; error = security_task_prctl(option, arg2, arg3, arg4, arg5); @@ -2613,6 +2613,19 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, if (copy_to_user((char __user *)arg2, comm, TASK_COMM_LEN)) return -EFAULT; break; + case PR_SET_EXT_NAME: + comm[TASK_COMM_EXT_LEN - 1] = 0; + if (strncpy_from_user(comm, (char __user *)arg2, + TASK_COMM_EXT_LEN - 1) < 0) + return -EFAULT; + set_task_comm(me, comm); + proc_comm_connector(me); + break; + case PR_GET_EXT_NAME: + strscpy_pad(comm, me->comm, TASK_COMM_EXT_LEN); + if (copy_to_user((char __user *)arg2, comm, TASK_COMM_EXT_LEN)) + return -EFAULT; + break; case PR_GET_ENDIAN: error = GET_ENDIAN(me, arg2); break; -- 2.55.0