From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752904Ab2INQW7 (ORCPT ); Fri, 14 Sep 2012 12:22:59 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:49238 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750858Ab2INQW5 (ORCPT ); Fri, 14 Sep 2012 12:22:57 -0400 Date: Fri, 14 Sep 2012 21:48:48 +0530 From: Srikar Dronamraju To: Oleg Nesterov Cc: Ingo Molnar , Peter Zijlstra , Ananth N Mavinakayanahalli , Anton Arapov , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] uprobes: uprobes_treelock should not disable irqs Message-ID: <20120914161848.GC28033@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20120819164008.GA25454@redhat.com> <20120819164037.GA25480@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20120819164037.GA25480@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) x-cbid: 12091416-5140-0000-0000-000002139D80 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Oleg Nesterov [2012-08-19 18:40:37]: > Nobody plays with uprobes_tree/uprobes_treelock in interrupt context, > no need to disable irqs. > > Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju > --- > kernel/events/uprobes.c | 21 ++++++++------------- > 1 files changed, 8 insertions(+), 13 deletions(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 25c0d74..abe077e 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -413,11 +413,10 @@ static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset) > static struct uprobe *find_uprobe(struct inode *inode, loff_t offset) > { > struct uprobe *uprobe; > - unsigned long flags; > > - spin_lock_irqsave(&uprobes_treelock, flags); > + spin_lock(&uprobes_treelock); > uprobe = __find_uprobe(inode, offset); > - spin_unlock_irqrestore(&uprobes_treelock, flags); > + spin_unlock(&uprobes_treelock); > > return uprobe; > } > @@ -464,12 +463,11 @@ static struct uprobe *__insert_uprobe(struct uprobe *uprobe) > */ > static struct uprobe *insert_uprobe(struct uprobe *uprobe) > { > - unsigned long flags; > struct uprobe *u; > > - spin_lock_irqsave(&uprobes_treelock, flags); > + spin_lock(&uprobes_treelock); > u = __insert_uprobe(uprobe); > - spin_unlock_irqrestore(&uprobes_treelock, flags); > + spin_unlock(&uprobes_treelock); > > /* For now assume that the instruction need not be single-stepped */ > uprobe->flags |= UPROBE_SKIP_SSTEP; > @@ -707,11 +705,9 @@ remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vad > */ > static void delete_uprobe(struct uprobe *uprobe) > { > - unsigned long flags; > - > - spin_lock_irqsave(&uprobes_treelock, flags); > + spin_lock(&uprobes_treelock); > rb_erase(&uprobe->rb_node, &uprobes_tree); > - spin_unlock_irqrestore(&uprobes_treelock, flags); > + spin_unlock(&uprobes_treelock); > iput(uprobe->inode); > put_uprobe(uprobe); > atomic_dec(&uprobe_events); > @@ -969,7 +965,6 @@ static void build_probe_list(struct inode *inode, > struct list_head *head) > { > loff_t min, max; > - unsigned long flags; > struct rb_node *n, *t; > struct uprobe *u; > > @@ -977,7 +972,7 @@ static void build_probe_list(struct inode *inode, > min = vaddr_to_offset(vma, start); > max = min + (end - start) - 1; > > - spin_lock_irqsave(&uprobes_treelock, flags); > + spin_lock(&uprobes_treelock); > n = find_node_in_range(inode, min, max); > if (n) { > for (t = n; t; t = rb_prev(t)) { > @@ -995,7 +990,7 @@ static void build_probe_list(struct inode *inode, > atomic_inc(&u->ref); > } > } > - spin_unlock_irqrestore(&uprobes_treelock, flags); > + spin_unlock(&uprobes_treelock); > } > > /* > -- > 1.5.5.1 >