From 02057967b5d3b77ed47f06ee8fe98e2687fdf18b Mon Sep 17 00:00:00 2001 From: David Rientjes <rientjes@google.com> Date: Tue, 14 Apr 2015 15:48:24 -0700 Subject: mm, hugetlb: abort __get_user_pages if current has been oom killed If __get_user_pages() is faulting a significant number of hugetlb pages, usually as the result of mmap(MAP_LOCKED), it can potentially allocate a very large amount of memory. If the process has been oom killed, this will cause a lot of memory to potentially deplete memory reserves. In the same way that commit 4779280d1ea4 ("mm: make get_user_pages() interruptible") aborted for pending SIGKILLs when faulting non-hugetlb memory, based on the premise of commit 462e00cc7151 ("oom: stop allocating user memory if TIF_MEMDIE is set"), hugetlb page faults now terminate when the process has been oom killed. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Greg Thelen <gthelen@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- mm/hugetlb.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'mm') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index caad3c5a926f..8874c8ad55aa 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3277,6 +3277,15 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, int absent; struct page *page; + /* + * If we have a pending SIGKILL, don't keep faulting pages and + * potentially allocating memory. + */ + if (unlikely(fatal_signal_pending(current))) { + remainder = 0; + break; + } + /* * Some archs (sparc64, sh*) have multiple pte_ts to * each hugepage. We have to make sure we get the -- cgit v1.2.3-58-ga151