From: Andrew Morton <akpm@linux-foundation.org>
To: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
David Rientjes <rientjes@google.com>,
Yaowei Bai <baiyaowei@cmss.chinamobile.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Dan Williams <dan.j.williams@intel.com>,
Xishi Qiu <qiuxishi@huawei.com>,
David Vrabel <david.vrabel@citrix.com>,
Chen Yucong <slaoub@gmail.com>, Andrew Banman <abanman@sgi.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RESEND PATCH v2] memory-hotplug: fix store_mem_state() return value
Date: Wed, 31 Aug 2016 13:25:57 -0700 [thread overview]
Message-ID: <20160831132557.c5cf0985e3da5f2850a10b1d@linux-foundation.org> (raw)
In-Reply-To: <1472658241-32748-1-git-send-email-arbab@linux.vnet.ibm.com>
On Wed, 31 Aug 2016 10:44:01 -0500 Reza Arbab <arbab@linux.vnet.ibm.com> wrote:
> Attempting to online memory which is already online will cause this:
>
> 1. store_mem_state() called with buf="online"
> 2. device_online() returns 1 because device is already online
> 3. store_mem_state() returns 1
> 4. calling code interprets this as 1-byte buffer read
> 5. store_mem_state() called again with buf="nline"
> 6. store_mem_state() returns -EINVAL
>
> Example:
>
> $ cat /sys/devices/system/memory/memory0/state
> online
> $ echo online > /sys/devices/system/memory/memory0/state
> -bash: echo: write error: Invalid argument
>
> Fix the return value of store_mem_state() so this doesn't happen.
So.. what *does* happen after the patch? Is some sort of failure still
reported? Or am I correct in believing that the operation will appear
to have succeeded? If so, is that desirable?
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next prev parent reply other threads:[~2016-08-31 20:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20160831150105.GB26702@kroah.com>
2016-08-31 15:44 ` [RESEND PATCH v2] memory-hotplug: fix store_mem_state() return value Reza Arbab
2016-08-31 20:25 ` Andrew Morton [this message]
2016-08-31 21:06 ` David Rientjes
2016-08-31 23:38 ` Reza Arbab
2016-09-01 0:03 ` David Rientjes
2016-09-01 0:17 ` Reza Arbab
2016-09-01 0:28 ` David Rientjes
2016-09-01 1:57 ` Reza Arbab
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