From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f182.google.com (mail-ig0-f182.google.com [209.85.213.182]) by kanga.kvack.org (Postfix) with ESMTP id 6E7C26B0038 for ; Thu, 25 Jun 2015 21:36:43 -0400 (EDT) Received: by igblr2 with SMTP id lr2so4268579igb.0 for ; Thu, 25 Jun 2015 18:36:43 -0700 (PDT) Received: from mail-ig0-x234.google.com (mail-ig0-x234.google.com. [2607:f8b0:4001:c05::234]) by mx.google.com with ESMTPS id xd13si21101435icb.36.2015.06.25.18.36.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jun 2015 18:36:42 -0700 (PDT) Received: by igcsj18 with SMTP id sj18so21879891igc.1 for ; Thu, 25 Jun 2015 18:36:42 -0700 (PDT) From: Nicholas Krause Subject: [PATCH] mm: Add error check after call to rmap_walk in the function page_referenced Date: Thu, 25 Jun 2015 21:36:37 -0400 Message-Id: <1435282597-21728-1-git-send-email-xerofoify@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: mhocko@suse.cz, riel@redhat.com, kirill.shutemov@linux.intel.com, hannes@cmpxchg.org, dave@stgolabs.net, koct9i@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org This adds a return check after the call to the function rmap_walk in the function page_referenced as this function call can fail and thus should signal callers of page_referenced if this happens by returning the SWAP macro return value as returned by rmap_walk here. In addition also check if have locked the page pointer as passed to this particular and unlock it with unlock_page if this page is locked before returning our SWAP marco return code from rmap_walk. Signed-off-by: Nicholas Krause --- mm/rmap.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/mm/rmap.c b/mm/rmap.c index 171b687..e4df848 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -814,7 +814,9 @@ static bool invalid_page_referenced_vma(struct vm_area_struct *vma, void *arg) * @vm_flags: collect encountered vma->vm_flags who actually referenced the page * * Quick test_and_clear_referenced for all mappings to a page, - * returns the number of ptes which referenced the page. + * returns the number of ptes which referenced the page.On + * error returns either zero or the error code returned from + * the failed call to rmap_walk. */ int page_referenced(struct page *page, int is_locked, @@ -855,7 +857,13 @@ int page_referenced(struct page *page, rwc.invalid_vma = invalid_page_referenced_vma; } + ret = rmap_walk(page, &rwc); + if (!ret) { + if (we_locked) + unlock_page(page); + return ret; + } *vm_flags = pra.vm_flags; if (we_locked) -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org