From: Rik van Riel <riel@redhat.com>
To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH] [BUGFIX] rmap: remove anon_vma check in page_address_in_vma()
Date: Fri, 23 Apr 2010 09:52:09 -0400 [thread overview]
Message-ID: <4BD1A609.4040401@redhat.com> (raw)
In-Reply-To: <20100423020827.GB7383@spritzerA.linux.bs1.fc.nec.co.jp>
On 04/22/2010 10:08 PM, Naoya Horiguchi wrote:
> Currently page_address_in_vma() compares vma->anon_vma and page_anon_vma(page)
> for parameter check, but in 2.6.34 a vma can have multiple anon_vmas with
> anon_vma_chain, so current check does not work. (For anonymous page shared by
> multiple processes, some verified (page,vma) pairs return -EFAULT wrongly.)
>
> We can go to checking all anon_vmas in the "same_vma" chain, but it needs
> to meet lock requirement. Instead, we can remove anon_vma check safely
> because page_address_in_vma() assumes that page and vma are already checked
> to belong to the identical process.
>
> Signed-off-by: Naoya Horiguchi<n-horiguchi@ah.jp.nec.com>
> Cc: Andrew Morton<akpm@linux-foundation.org>
> Cc: Rik van Riel<riel@redhat.com>
> Cc: Andi Kleen<andi@firstfloor.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
WARNING: multiple messages have this Message-ID (diff)
From: Rik van Riel <riel@redhat.com>
To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH] [BUGFIX] rmap: remove anon_vma check in page_address_in_vma()
Date: Fri, 23 Apr 2010 09:52:09 -0400 [thread overview]
Message-ID: <4BD1A609.4040401@redhat.com> (raw)
In-Reply-To: <20100423020827.GB7383@spritzerA.linux.bs1.fc.nec.co.jp>
On 04/22/2010 10:08 PM, Naoya Horiguchi wrote:
> Currently page_address_in_vma() compares vma->anon_vma and page_anon_vma(page)
> for parameter check, but in 2.6.34 a vma can have multiple anon_vmas with
> anon_vma_chain, so current check does not work. (For anonymous page shared by
> multiple processes, some verified (page,vma) pairs return -EFAULT wrongly.)
>
> We can go to checking all anon_vmas in the "same_vma" chain, but it needs
> to meet lock requirement. Instead, we can remove anon_vma check safely
> because page_address_in_vma() assumes that page and vma are already checked
> to belong to the identical process.
>
> Signed-off-by: Naoya Horiguchi<n-horiguchi@ah.jp.nec.com>
> Cc: Andrew Morton<akpm@linux-foundation.org>
> Cc: Rik van Riel<riel@redhat.com>
> Cc: Andi Kleen<andi@firstfloor.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
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next prev parent reply other threads:[~2010-04-23 13:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-22 5:42 [BUG] rmap: fix page_address_in_vma() to walk through anon_vma_chain Naoya Horiguchi
2010-04-22 5:42 ` Naoya Horiguchi
2010-04-22 6:03 ` Naoya Horiguchi
2010-04-22 6:03 ` Naoya Horiguchi
2010-04-22 15:17 ` Rik van Riel
2010-04-22 15:17 ` Rik van Riel
2010-04-23 2:06 ` Naoya Horiguchi
2010-04-23 2:06 ` Naoya Horiguchi
2010-04-23 2:08 ` [PATCH] [BUGFIX] rmap: remove anon_vma check in page_address_in_vma() Naoya Horiguchi
2010-04-23 2:08 ` Naoya Horiguchi
2010-04-23 13:52 ` Rik van Riel [this message]
2010-04-23 13:52 ` Rik van Riel
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