From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1496C87FD2 for ; Mon, 11 Aug 2025 15:09:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 463738E006D; Mon, 11 Aug 2025 11:09:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 43A778E0060; Mon, 11 Aug 2025 11:09:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 377BA8E006D; Mon, 11 Aug 2025 11:09:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 25E1C8E0060 for ; Mon, 11 Aug 2025 11:09:05 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id CF78C1DB09C for ; Mon, 11 Aug 2025 15:09:04 +0000 (UTC) X-FDA: 83764809408.08.B2904D5 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) by imf14.hostedemail.com (Postfix) with ESMTP id 7E307100009 for ; Mon, 11 Aug 2025 15:09:02 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=OSkIOWZQ; dmarc=pass (policy=none) header.from=intel.com; spf=pass (imf14.hostedemail.com: domain of andriy.shevchenko@intel.com designates 192.198.163.19 as permitted sender) smtp.mailfrom=andriy.shevchenko@intel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1754924942; a=rsa-sha256; cv=none; b=FxpqehGRpUCMlFQGUlLy8AXtV6JRHCOTrGAxTVjskyXyhiSLOPeHeV5VbvEzC8ZnOuMami bdfREupmOUDErKbF+L+pzYqaFXcr/GZEMr52pKh9PCHjtCxLr9NmNyHPW//6GPffl8g7KN u2O6zTZ1wamGABmHax97YOblE7sUj6s= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=OSkIOWZQ; dmarc=pass (policy=none) header.from=intel.com; spf=pass (imf14.hostedemail.com: domain of andriy.shevchenko@intel.com designates 192.198.163.19 as permitted sender) smtp.mailfrom=andriy.shevchenko@intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1754924942; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=z5BfcxOGfskLNbpbMbwX4KjsPVWAUvhOCnh1KC1IjLE=; b=vYWA7bToe0iSbGXcy/SQFQZ5Ji2DdkPx9Vzk+HZb8522e5iudFujaRRVmBwOp6cmj56O6L 2sN5Nj3gC+kT9XMIYyz1kq2KoOcARq+jYPC7euouNq3JzmmPK7kFUUoE/NTcVeQ7W3aMcn xAl0woxE25yDbCD2M0jacrFofaPs5CQ= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1754924942; x=1786460942; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=Fos2Bc+psd2wDnxAA9C+5WvzOAyECbjI1HOkUcLQeFQ=; b=OSkIOWZQdF4WtXR4yJZiaP3h23HctK9rnOKF1o7Qb3VJCkjDNp/sVvlh 0/5dws5yWSHVGIlTmDvk9g+G0tIVp0+7DW8vhnG1euLCaeveL/HavAhA5 rAWmFjC/varyuoQ+1WIuxEw2pZKeeQZXWOKVjkULo5DoNDAgjEJyjLcwW 1f56TEmT8wZ1OGAhBYt2i4sfmimZDpjKGT+KqDXv3Wn2rICJZyJj8XOJq UMKkIWh3SzlN3plekBzSoBNO9L3BgnG+s0jr4Xc6F/ElYXZXbHEfPltiW bykYBad6lQosEIFYLL0+hazpPvwJcBqzsVVVn3Z3evaFfs0qezrr0hLuI w==; X-CSE-ConnectionGUID: kn4RblLMSwmhcqFA//JYBA== X-CSE-MsgGUID: jgcNLGY1Rsa+gh0afWk/iA== X-IronPort-AV: E=McAfee;i="6800,10657,11518"; a="56209119" X-IronPort-AV: E=Sophos;i="6.17,278,1747724400"; d="scan'208";a="56209119" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Aug 2025 08:09:01 -0700 X-CSE-ConnectionGUID: 6HXLT3G1QeCd5htSdOz7vw== X-CSE-MsgGUID: viOw19WfRZm7kbZL2ZA/7A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.17,278,1747724400"; d="scan'208";a="165831059" Received: from black.igk.intel.com ([10.91.253.5]) by fmviesa006.fm.intel.com with ESMTP; 11 Aug 2025 08:08:54 -0700 Received: by black.igk.intel.com (Postfix, from userid 1003) id D6F1B94; Mon, 11 Aug 2025 17:08:52 +0200 (CEST) Date: Mon, 11 Aug 2025 17:08:52 +0200 From: Andy Shevchenko To: Bhupesh Cc: akpm@linux-foundation.org, 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, linux-trace-kernel@vger.kernel.org, kees@kernel.org, torvalds@linux-foundation.org Subject: Re: [PATCH v7 4/4] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Message-ID: References: <20250811064609.918593-1-bhupesh@igalia.com> <20250811064609.918593-5-bhupesh@igalia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250811064609.918593-5-bhupesh@igalia.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 7E307100009 X-Stat-Signature: pef1oquemw9t1s4hbjxr1ouq8donc6ws X-Rspam-User: X-HE-Tag: 1754924942-911860 X-HE-Meta: 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 f5CNHu1A QUiyTdXbCekr924bSdO1ztp1zovFibS7C4bOx/vr60Drww3lhorLDFu2YP77yNF26rPvOinDNweD1+GdgxhFCclU10jSDOINKMGeCWrWlqR6CsZRXuoOiJKGeOR5u7JAfCh4Wvz9i02UfuJrgCPgf6TuUmK71rgHi/EfFypRQqY62Mu2or1HDzSHl2mgAmAFJhGHg6daHcLUuhdIdcHdsbDdXO01Si2BGkLvuEDfxREhdgYmIbj0VkQYX2EgGPw+mVMAWKp/r9ACOpM79F6TOxnws1rCCpRuiw2GAXYq96M/gkkrq8q9f4vziE/Kn64tPbEPptcjrVQKt/uPwKxGrD+o/sqawH4XiK/tqBQSIRIfnVjPDYQlldViBiiNj7VodXlZd+/OdRIhCLbzdWpJKQfAg2ME4u5skEfM+77auLTjghT8= 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: On Mon, Aug 11, 2025 at 12:16:09PM +0530, Bhupesh wrote: > As Linus mentioned in [1], currently we have several memcpy() use-cases > which use 'current->comm' to copy the task name over to local copies. > For an example: > > ... > char comm[TASK_COMM_LEN]; > memcpy(comm, current->comm, TASK_COMM_LEN); > ... > > These should be rather calling a wrappper like "get_task_array()", > which is implemented as: > > static __always_inline void > __cstr_array_copy(char *dst, > const char *src, __kernel_size_t size) > { > memcpy(dst, src, size); > dst[size] = 0; > } > > #define get_task_array(dst,src) \ > __cstr_array_copy(dst, src, __must_be_array(dst)) > > The relevant 'memcpy()' users were identified using the following search > pattern: > $ git grep 'memcpy.*->comm\>' > [1]. https://lore.kernel.org/all/CAHk-=wi5c=_-FBGo_88CowJd_F-Gi6Ud9d=TALm65ReN7YjrMw@mail.gmail.com/ > > Signed-off-by: Bhupesh Same suggestion, make it a Link tag. -- With Best Regards, Andy Shevchenko