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: Sat, 25 May 2019 11:28:51 -0700 From: Andrew Morton <akpm@...ux-foundation.org> To: zhong jiang <zhongjiang@...wei.com> Cc: <osalvador@...e.de>, <khandual@...ux.vnet.ibm.com>, <mhocko@...e.com>, <mgorman@...hsingularity.net>, <aarcange@...hat.com>, <rcampbell@...dia.com>, <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>, Vlastimil Babka <vbabka@...e.cz> Subject: Re: [PATCH] mm/mempolicy: Fix an incorrect rebind node in mpol_rebind_nodemask (Cc Vlastimil) On Sat, 25 May 2019 15:07:23 +0800 zhong jiang <zhongjiang@...wei.com> wrote: > We bind an different node to different vma, Unluckily, > it will bind different vma to same node by checking the /proc/pid/numa_maps. > Commit 213980c0f23b ("mm, mempolicy: simplify rebinding mempolicies when updating cpusets") > has introduced the issue. when we change memory policy by seting cpuset.mems, > A process will rebind the specified policy more than one times. > if the cpuset_mems_allowed is not equal to user specified nodes. hence the issue will trigger. > Maybe result in the out of memory which allocating memory from same node. > > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -345,7 +345,7 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes) > else { > nodes_remap(tmp, pol->v.nodes,pol->w.cpuset_mems_allowed, > *nodes); > - pol->w.cpuset_mems_allowed = tmp; > + pol->w.cpuset_mems_allowed = *nodes; > } > > if (nodes_empty(tmp)) hm, I'm not surprised the code broke. What the heck is going on in there? It used to have a perfunctory comment, but Vlastimil deleted it. Could someone please propose a comment for the above code block explaining why we're doing what we do?
Powered by blists - more mailing lists