linux-kernel - Re: [RFC] Notifier for Externally Mapped Memory (EMM)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080304133020.GC5301@v2.random>
Date:	Tue, 4 Mar 2008 14:30:20 +0100
From:	Andrea Arcangeli <andrea@...ranet.com>
To:	Christoph Lameter <clameter@....com>
Cc:	Jack Steiner <steiner@....com>, Nick Piggin <npiggin@...e.de>,
	akpm@...ux-foundation.org, Robin Holt <holt@....com>,
	Avi Kivity <avi@...ranet.com>, kvm-devel@...ts.sourceforge.net,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	general@...ts.openfabrics.org,
	Steve Wise <swise@...ngridcomputing.com>,
	Roland Dreier <rdreier@...co.com>,
	Kanoj Sarcar <kanojsarcar@...oo.com>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	daniel.blueman@...drics.com
Subject: Re: [RFC] Notifier for Externally Mapped Memory (EMM)

On Mon, Mar 03, 2008 at 11:31:15PM -0800, Christoph Lameter wrote:
> @@ -446,6 +450,8 @@ static int page_mkclean_one(struct page 
>  	if (address == -EFAULT)
>  		goto out;
>  
> +	/* rmap lock held */
> +	emm_notify(mm, emm_invalidate_start, address, address + PAGE_SIZE);
>  	pte = page_check_address(page, mm, address, &ptl);
>  	if (!pte)
>  		goto out;
> @@ -462,6 +468,7 @@ static int page_mkclean_one(struct page 
>  	}
>  
>  	pte_unmap_unlock(pte, ptl);
> +	emm_notify(mm, emm_invalidate_end, address, address + PAGE_SIZE);
>  out:
>  	return ret;
>  }

I could have ripped invalidate_page from my patch too, except I didn't
want to slow down those paths for the known-common-users when not even
GRU would get any benefit from two hooks when only one is needed.

When working with single pages it's more efficient and preferable to
call invalidate_page and only later release the VM reference on the
page.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/