From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751706Ab2LaRwl (ORCPT ); Mon, 31 Dec 2012 12:52:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:62108 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751637Ab2LaRwf (ORCPT ); Mon, 31 Dec 2012 12:52:35 -0500 Date: Mon, 31 Dec 2012 18:52:20 +0100 From: Oleg Nesterov To: Ingo Molnar , Peter Zijlstra , Srikar Dronamraju Cc: Ananth N Mavinakayanahalli , Anton Arapov , Frank Eigler , Josh Stone , "Suzuki K. Poulose" , linux-kernel@vger.kernel.org Subject: [PATCH 3/7] uprobes: Turn add_utask() into get_utask() Message-ID: <20121231175220.GA32098@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121231175150.GA32066@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rename add_utask() into get_utask() and change it to allocate on demand to simplify the caller. Like get_xol_area() it will have more users. Signed-off-by: Oleg Nesterov --- kernel/events/uprobes.c | 27 +++++++++------------------ 1 files changed, 9 insertions(+), 18 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index ef81162..b09b3ba 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1290,23 +1290,18 @@ void uprobe_copy_process(struct task_struct *t) } /* - * Allocate a uprobe_task object for the task. - * Called when the thread hits a breakpoint for the first time. + * Allocate a uprobe_task object for the task if if necessary. + * Called when the thread hits a breakpoint. * * Returns: * - pointer to new uprobe_task on success * - NULL otherwise */ -static struct uprobe_task *add_utask(void) +static struct uprobe_task *get_utask(void) { - struct uprobe_task *utask; - - utask = kzalloc(sizeof *utask, GFP_KERNEL); - if (unlikely(!utask)) - return NULL; - - current->utask = utask; - return utask; + if (!current->utask) + current->utask = kzalloc(sizeof(struct uprobe_task), GFP_KERNEL); + return current->utask; } /* Prepare to single-step probed instruction out of line. */ @@ -1505,13 +1500,9 @@ static void handle_swbp(struct pt_regs *regs) if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags))) goto out; - utask = current->utask; - if (!utask) { - utask = add_utask(); - /* Cannot allocate; re-execute the instruction. */ - if (!utask) - goto out; - } + utask = get_utask(); + if (!utask) + goto out; /* re-execute the instruction. */ handler_chain(uprobe, regs); if (can_skip_sstep(uprobe, regs)) -- 1.5.5.1