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
| ||
|
Date: Wed, 31 Jul 2013 11:27:51 +0900 From: Joonsoo Kim <iamjoonsoo.kim@....com> To: Hillf Danton <dhillf@...il.com> Cc: Andrew Morton <akpm@...ux-foundation.org>, Rik van Riel <riel@...hat.com>, Mel Gorman <mgorman@...e.de>, Michal Hocko <mhocko@...e.cz>, "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>, Hugh Dickins <hughd@...gle.com>, Davidlohr Bueso <davidlohr.bueso@...com>, David Gibson <david@...son.dropbear.id.au>, linux-mm@...ck.org, linux-kernel@...r.kernel.org, Wanpeng Li <liwanp@...ux.vnet.ibm.com>, Naoya Horiguchi <n-horiguchi@...jp.nec.com> Subject: Re: [PATCH 01/18] mm, hugetlb: protect reserved pages when softofflining requests the pages On Mon, Jul 29, 2013 at 03:24:46PM +0800, Hillf Danton wrote: > On Mon, Jul 29, 2013 at 1:31 PM, Joonsoo Kim <iamjoonsoo.kim@....com> wrote: > > alloc_huge_page_node() use dequeue_huge_page_node() without > > any validation check, so it can steal reserved page unconditionally. > > Well, why is it illegal to use reserved page here? Hello, Hillf. If we use reserved page here, other processes which are promised to use enough hugepages cannot get enough hugepages and can die. This is unexpected result to them. Thanks. > > > To fix it, check the number of free_huge_page in alloc_huge_page_node(). > > > > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com> > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 6782b41..d971233 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -935,10 +935,11 @@ static struct page *alloc_buddy_huge_page(struct hstate *h, int nid) > > */ > > struct page *alloc_huge_page_node(struct hstate *h, int nid) > > { > > - struct page *page; > > + struct page *page = NULL; > > > > spin_lock(&hugetlb_lock); > > - page = dequeue_huge_page_node(h, nid); > > + if (h->free_huge_pages - h->resv_huge_pages > 0) > > + page = dequeue_huge_page_node(h, nid); > > spin_unlock(&hugetlb_lock); > > > > if (!page) > > -- > > 1.7.9.5 > > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@...ck.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a> -- 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/
Powered by blists - more mailing lists