From: Jiri Slaby <jslaby@suse.cz>
To: Vasily Averin <vvs@virtuozzo.com>,
Matthew Wilcox <willy@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, Waiman Long <longman@redhat.com>,
Andreas Schwab <schwab@suse.de>
Subject: Re: [PATCH] ipc/util.c: sysvipc_find_ipc() incorrectly updates position index
Date: Tue, 12 May 2020 11:21:59 +0200 [thread overview]
Message-ID: <eb1efdee-6d9c-2f03-fb88-ffec0db61037@suse.cz> (raw)
In-Reply-To: <c89b587a-b570-2a11-3001-d1c8444f3a2f@virtuozzo.com>
On 08. 05. 20, 12:01, Vasily Averin wrote:
> On 5/8/20 9:07 AM, Vasily Averin wrote:
>> On 5/8/20 6:36 AM, Matthew Wilcox wrote:
>>> On Thu, May 07, 2020 at 05:02:42PM -0700, Andrew Morton wrote:
>>>> Here's how I resolved things. Please check?
>>>>
>>>> static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
>>>> loff_t *new_pos)
>>>> {
>>>> unsigned long index = pos;
>>>> struct kern_ipc_perm *ipc;
>>>>
>>>> rcu_read_lock();
>>>> ipc = xa_find(&ids->ipcs, &index, ULONG_MAX, XA_PRESENT);
>>>> if (ipc)
>>>> ipc_lock_object(ipc);
>>>> else
>>>> rcu_read_unlock();
>>>> *new_pos = pos + 1;
>>>> return ipc;
>>>> }
>>>
>>> Surely that should be '*new_pos = index + 1'? Or did I misunderstand
>>> the reasoning behind the other patch?
>>
>> I'm not sure however it looks like xa_find() can return index < pos
> it seems, I was wrong here.
> So I'm agree with Matthew, '*new_pos = index + 1' should be used.
Any progress on this? 5.7-rc*, 5.4.40, and 5.6.12 are still affected.
Wouldn't it be better to rebase (apply the originally submitted patch)
before the XA rewrite and push that one to Linus?
thanks,
--
js
suse labs
next prev parent reply other threads:[~2020-05-12 9:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-24 7:03 [PATCH 7/7] sysvipc_find_ipc should increase position index Vasily Averin
2020-01-24 16:26 ` Waiman Long
2020-02-25 6:35 ` Vasily Averin
2020-05-05 16:13 ` Andreas Schwab
2020-05-06 5:03 ` Vasily Averin
2020-05-06 6:25 ` [PATCH] ipc/util.c: sysvipc_find_ipc() incorrectly updates " Vasily Averin
2020-05-06 15:59 ` Waiman Long
2020-05-07 12:29 ` Vasily Averin
2020-05-08 0:02 ` Andrew Morton
2020-05-08 3:36 ` Matthew Wilcox
2020-05-08 6:07 ` Vasily Averin
2020-05-08 10:01 ` Vasily Averin
2020-05-12 9:21 ` Jiri Slaby [this message]
2020-05-12 15:45 ` Vasily Averin
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