On Mon 21-11-11 14:18:29, Linus Torvalds wrote: > On Mon, Nov 21, 2011 at 1:49 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > > > Subject : hugetlb oops on 3.1.0-rc8-devel > > Submitter : Andy Lutomirski <luto@xxxxxxxxxxxxxx> > > Date : 2011-11-01 22:20 > > Message-ID : CALCETrW1mpVCz2tO5roaz1r6vnno+srHR-dHA6_pkRi2qiCfdw@xxxxxxxxxxxxxx > > References : http://marc.info/?l=linux-kernel&m=132018604426692&w=2 > > Despite the subject line, that's not an oops, it's a BUG_ON(). > > And it *should* be fixed by commit ea4039a34c4c ("hugetlb: release > pages in the error path of hugetlb_cow()") although I don't think Andy > ever confirmed that (since it was hard to trigger). AFAICS the issue has been introduced by 0fe6e20b (hugetlb, rmap: add reverse mapping for hugepage) in 2.6.36-rc1 so this is a stable material. I do not see the patch in any stable branch so here we go. The patch is on top of 3.0.y branch and it applies as is to 3.1.y as well. --- >From fdaa4aaa008cce149a5fd60934112acd8988e0b6 Mon Sep 17 00:00:00 2001 From: Hillf Danton <dhillf@xxxxxxxxx> Date: Tue, 15 Nov 2011 14:36:12 -0800 Subject: [PATCH] hugetlb: release pages in the error path of hugetlb_cow() commit ea4039a34c4c206d015d34a49d0b00868e37db1d upstream. If we fail to prepare an anon_vma, the {new, old}_page should be released, or they will leak. Signed-off-by: Hillf Danton <dhillf@xxxxxxxxx> Reviewed-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <jweiner@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index bfcf153..2b57cd9 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2415,6 +2415,8 @@ retry_avoidcopy: * anon_vma prepared. */ if (unlikely(anon_vma_prepare(vma))) { + page_cache_release(new_page); + page_cache_release(old_page); /* Caller expects lock to be held */ spin_lock(&mm->page_table_lock); return VM_FAULT_OOM; -- 1.7.7.3 -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
