From mboxrd@z Thu Jan 1 00:00:00 1970 From: mgross Subject: Re: [patch] pm_qos update fixing mmotm 2010-05-11 -dies in pm_qos_update_request() Date: Sat, 15 May 2010 14:42:56 -0700 Message-ID: <20100515214256.GA3506@thegnar.org> References: <20100515021922.GA5041@thegnar.org> <201005152138.47178.rjw@sisk.pl> Reply-To: markgross@thegnar.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: markgross@thegnar.org, Valdis.Kletnieks@vt.eu, mgross@linux.intel.com, akpm@linux-foundation.org, davem@davemloft.net, linux-kernel@vger.kernel.org, e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, linux-pm@lists.linux-foundation.org To: "Rafael J. Wysocki" Return-path: Content-Disposition: inline In-Reply-To: <201005152138.47178.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sat, May 15, 2010 at 09:38:47PM +0200, Rafael J. Wysocki wrote: > On Saturday 15 May 2010, mgross wrote: > > I apologize for the goofy email address. > > > > The following is a fix for the crash reported by Valdis. > > > > The problem was that the original pm_qos silently fails when a request > > update is passed to a parameter that has not been added to the list > > yet. It seems that the e1000e is doing this. This update restores this > > behavior. > > > > I need to think about how to better handle such abuse, but for now this > > restores the original behavior. > > Can you please post a signed-off incremental patch against > > git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6.git for-llinus > > that contains your original PM QOS update? > > Thanks, > Rafael > No problem: Signed-off-by: markgross --mgross >>From 487b8dcaeb66d3c226d4c06c1bd99689f93024be Mon Sep 17 00:00:00 2001 From: mgross Date: Sat, 15 May 2010 14:30:15 -0700 Subject: [PATCH] Gard against pm_qos users calling API before registering a proper request. This update handles a use case where pm_qos update requests need to silently fail if the update is being sent to a handle that is null. The problem was that the original pm_qos silently fails when a request update is passed to a parameter that has not been added to the list yet. This update restores that behavior. Signed-off-by: markgross --- kernel/pm_qos_params.c | 26 ++++++++++++++------------ 1 files changed, 14 insertions(+), 12 deletions(-) diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index a1aea04..f42d3f7 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -252,19 +252,21 @@ void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, int pending_update = 0; s32 temp; - spin_lock_irqsave(&pm_qos_lock, flags); - if (new_value == PM_QOS_DEFAULT_VALUE) - temp = pm_qos_array[pm_qos_req->pm_qos_class]->default_value; - else - temp = new_value; - - if (temp != pm_qos_req->value) { - pending_update = 1; - pm_qos_req->value = temp; + if (pm_qos_req) { /*guard against callers passing in null */ + spin_lock_irqsave(&pm_qos_lock, flags); + if (new_value == PM_QOS_DEFAULT_VALUE) + temp = pm_qos_array[pm_qos_req->pm_qos_class]->default_value; + else + temp = new_value; + + if (temp != pm_qos_req->value) { + pending_update = 1; + pm_qos_req->value = temp; + } + spin_unlock_irqrestore(&pm_qos_lock, flags); + if (pending_update) + update_target(pm_qos_req->pm_qos_class); } - spin_unlock_irqrestore(&pm_qos_lock, flags); - if (pending_update) - update_target(pm_qos_req->pm_qos_class); } EXPORT_SYMBOL_GPL(pm_qos_update_request); -- 1.6.3.3