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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 30 Aug 2018 22:14:01 +0000 From: Pasha Tatashin <Pavel.Tatashin@...rosoft.com> To: David Hildenbrand <david@...hat.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> CC: "linux-mm@...ck.org" <linux-mm@...ck.org>, Andrew Morton <akpm@...ux-foundation.org>, Michal Hocko <mhocko@...e.com>, Vlastimil Babka <vbabka@...e.cz>, Stephen Rothwell <sfr@...b.auug.org.au>, Pavel Tatashin <pasha.tatashin@...cle.com>, Kemi Wang <kemi.wang@...el.com>, David Rientjes <rientjes@...gle.com>, Jia He <jia.he@...-semitech.com>, Oscar Salvador <osalvador@...e.de>, Petr Tesarik <ptesarik@...e.com>, Andrey Ryabinin <aryabinin@...tuozzo.com>, Dan Williams <dan.j.williams@...el.com>, Mathieu Malaterre <malat@...ian.org>, Baoquan He <bhe@...hat.com>, Wei Yang <richard.weiyang@...il.com>, Ross Zwisler <zwisler@...nel.org>, "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com> Subject: Re: [PATCH v1 2/5] mm/memory_hotplug: enforce section alignment when onlining/offlining Hi David, I am not sure this is needed, because we already have a stricter checker: check_hotplug_memory_range() You could call it from online_pages(), if you think there is a reason to do it, but other than that it is done from add_memory_resource() and from remove_memory(). Thank you, Pavel On 8/16/18 6:06 AM, David Hildenbrand wrote: > onlining/offlining code works on whole sections, so let's enforce that. > Existing code only allows to add memory in memory block size. And only > whole memory blocks can be onlined/offlined. Memory blocks are always > aligned to sections, so this should not break anything. > > online_pages/offline_pages will implicitly mark whole sections > online/offline, so the code really can only handle such granularities. > > (especially offlining code cannot deal with pageblock_nr_pages but > theoretically only MAX_ORDER-1) > > Signed-off-by: David Hildenbrand <david@...hat.com> > --- > mm/memory_hotplug.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 090cf474de87..30d2fa42b0bb 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -897,6 +897,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ > struct memory_notify arg; > struct memory_block *mem; > > + if (!IS_ALIGNED(pfn, PAGES_PER_SECTION)) > + return -EINVAL; > + if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) > + return -EINVAL; > + > /* > * We can't use pfn_to_nid() because nid might be stored in struct page > * which is not yet initialized. Instead, we find nid from memory block. > @@ -1600,10 +1605,9 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) > struct zone *zone; > struct memory_notify arg; > > - /* at least, alignment against pageblock is necessary */ > - if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) > + if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) > return -EINVAL; > - if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) > + if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) > return -EINVAL; > /* This makes hotplug much easier...and readable. > we assume this for now. .*/ >
Powered by blists - more mailing lists