From: Greg KH <gregkh@linuxfoundation.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: Yunsheng Lin <linyunsheng@huawei.com>,
rafael@kernel.org, linux-kernel@vger.kernel.org,
peterz@infradead.org, mingo@kernel.org, linuxarm@huawei.com
Subject: Re: [PATCH] driver core: ensure a device has valid node id in device_add()
Date: Tue, 10 Sep 2019 12:12:52 +0100 [thread overview]
Message-ID: <20190910111252.GA8970@kroah.com> (raw)
In-Reply-To: <20190910110451.GP2063@dhcp22.suse.cz>
On Tue, Sep 10, 2019 at 01:04:51PM +0200, Michal Hocko wrote:
> On Tue 10-09-19 18:58:05, Yunsheng Lin wrote:
> > On 2019/9/10 17:31, Greg KH wrote:
> > > On Tue, Sep 10, 2019 at 02:43:32PM +0800, Yunsheng Lin wrote:
> > >> On 2019/9/9 17:53, Greg KH wrote:
> > >>> On Mon, Sep 09, 2019 at 02:04:23PM +0800, Yunsheng Lin wrote:
> > >>>> Currently a device does not belong to any of the numa nodes
> > >>>> (dev->numa_node is NUMA_NO_NODE) when the node id is neither
> > >>>> specified by fw nor by virtual device layer and the device has
> > >>>> no parent device.
> > >>>
> > >>> Is this really a problem?
> > >>
> > >> Not really.
> > >> Someone need to guess the node id when it is not specified, right?
> > >
> > > No, why? Guessing guarantees you will get it wrong on some systems.
> > >
> > > Are you seeing real problems because the id is not being set? What
> > > problem is this fixing that you can actually observe?
> >
> > When passing the return value of dev_to_node() to cpumask_of_node()
> > without checking the node id if the node id is not valid, there is
> > global-out-of-bounds detected by KASAN as below:
>
> OK, I seem to remember this being brought up already. And now when I
> think about it, we really want to make cpumask_of_node NUMA_NO_NODE
> aware. That means using the same trick the allocator does for this
> special case.
That seems reasonable to me, and much more "obvious" as to what is going
on.
thanks,
greg k-h
next prev parent reply other threads:[~2019-09-10 11:12 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 6:04 [PATCH] driver core: ensure a device has valid node id in device_add() Yunsheng Lin
2019-09-09 9:53 ` Greg KH
2019-09-10 6:43 ` Yunsheng Lin
2019-09-10 7:13 ` Michal Hocko
2019-09-10 9:31 ` Greg KH
2019-09-10 10:58 ` Yunsheng Lin
2019-09-10 11:04 ` Michal Hocko
2019-09-10 11:12 ` Greg KH [this message]
2019-09-10 12:47 ` Yunsheng Lin
2019-09-10 12:53 ` Michal Hocko
2019-09-11 5:33 ` Michal Hocko
2019-09-11 6:15 ` Yunsheng Lin
2019-09-11 6:49 ` Michal Hocko
2019-09-11 7:22 ` Yunsheng Lin
2019-09-11 7:34 ` Michal Hocko
2019-09-11 11:03 ` Yunsheng Lin
2019-09-11 11:41 ` Yunsheng Lin
2019-09-11 12:02 ` Michal Hocko
2019-09-23 15:09 ` Peter Zijlstra
2019-09-09 18:50 ` Michal Hocko
2019-09-10 7:08 ` Yunsheng Lin
2019-09-10 7:24 ` Michal Hocko
2019-09-10 10:40 ` Yunsheng Lin
2019-09-10 11:01 ` Michal Hocko
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