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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 378E2C433EF for ; Thu, 6 Jan 2022 22:18:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245032AbiAFWRv (ORCPT ); Thu, 6 Jan 2022 17:17:51 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:49744 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244435AbiAFWRs (ORCPT ); Thu, 6 Jan 2022 17:17:48 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3A7BB61E4C; Thu, 6 Jan 2022 22:17:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18A9FC36AE5; Thu, 6 Jan 2022 22:17:46 +0000 (UTC) Date: Thu, 6 Jan 2022 17:17:45 -0500 From: Steven Rostedt To: Beau Belgrave Cc: mhiramat@kernel.org, linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 08/12] user_events: Optimize writing events by only copying data once Message-ID: <20220106171745.1496c723@gandalf.local.home> In-Reply-To: <20211216173511.10390-9-beaub@linux.microsoft.com> References: <20211216173511.10390-1-beaub@linux.microsoft.com> <20211216173511.10390-9-beaub@linux.microsoft.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 16 Dec 2021 09:35:07 -0800 Beau Belgrave wrote: > @@ -1018,16 +1081,11 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i) > if (likely(atomic_read(&tp->key.enabled) > 0)) { > struct tracepoint_func *probe_func_ptr; > user_event_func_t probe_func; > + struct iov_iter copy; > void *tpdata; > - void *kdata; > - u32 datalen; > - > - kdata = kmalloc(i->count, GFP_KERNEL); > > - if (unlikely(!kdata)) > - return -ENOMEM; > - > - datalen = copy_from_iter(kdata, i->count, i); > + if (unlikely(iov_iter_fault_in_readable(i, i->count))) Can you rebase on my tree: ftrace/core ? That's because upstream now has: a6294593e8a12 ("iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable") And it looks like you need to call fault_in_iov_iter_readable(). -- Steve > + return -EFAULT; > > rcu_read_lock_sched(); >