linux-kernel - Re: [PATCH v3 2/6] mm/migrate: correct failure handling if !hugepage_migration

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]

Date:	Fri, 13 Dec 2013 17:05:37 -0500
From:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Mel Gorman <mgorman@...e.de>, Rik van Riel <riel@...hat.com>,
	Rafael Aquini <aquini@...hat.com>,
	Christoph Lameter <cl@...ux.com>,
	Joonsoo Kim <js1304@...il.com>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, Vlastimil Babka <vbabka@...e.cz>,
	Zhang Yanfei <zhangyanfei@...fujitsu.com>,
	Wanpeng Li <liwanp@...ux.vnet.ibm.com>
Subject: Re: [PATCH v3 2/6] mm/migrate: correct failure handling if
 !hugepage_migration_support()

On Fri, Dec 13, 2013 at 03:53:27PM +0900, Joonsoo Kim wrote:
> We should remove the page from the list if we fail with ENOSYS,
> since migrate_pages() consider error cases except -ENOMEM and -EAGAIN
> as permanent failure and it assumes that the page would be removed from
> the list. Without this patch, we could overcount number of failure.
> 
> In addition, we should put back the new hugepage if
> !hugepage_migration_support(). If not, we would leak hugepage memory.
> 
> Acked-by: Christoph Lameter <cl@...ux.com>
> Reviewed-by: Wanpeng Li <liwanp@...ux.vnet.ibm.com>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>

Reviewed-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com>

Thanks,
Naoya Horiguchi

> diff --git a/mm/migrate.c b/mm/migrate.c
> index c6ac87a..b1cfd01 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1011,7 +1011,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
>  {
>  	int rc = 0;
>  	int *result = NULL;
> -	struct page *new_hpage = get_new_page(hpage, private, &result);
> +	struct page *new_hpage;
>  	struct anon_vma *anon_vma = NULL;
>  
>  	/*
> @@ -1021,9 +1021,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
>  	 * tables or check whether the hugepage is pmd-based or not before
>  	 * kicking migration.
>  	 */
> -	if (!hugepage_migration_support(page_hstate(hpage)))
> +	if (!hugepage_migration_support(page_hstate(hpage))) {
> +		putback_active_hugepage(hpage);
>  		return -ENOSYS;
> +	}
>  
> +	new_hpage = get_new_page(hpage, private, &result);
>  	if (!new_hpage)
>  		return -ENOMEM;
>  
> -- 
> 1.7.9.5
> 
--
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/