Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933261AbaJCXqQ (ORCPT ); Fri, 3 Oct 2014 19:46:16 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46282 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757260AbaJCWDb (ORCPT ); Fri, 3 Oct 2014 18:03:31 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Feiner , Cyrill Gorcunov , Pavel Emelyanov , Jamie Liu , Hugh Dickins , Andrew Morton , Linus Torvalds Subject: [PATCH 3.16 280/357] mm: softdirty: keep bit when zapping file pte Date: Fri, 3 Oct 2014 14:31:06 -0700 Message-Id: <20141003212941.902530190@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141003212933.458851516@linuxfoundation.org> References: <20141003212933.458851516@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Feiner commit dbab31aa2ceec2d201966fa0b552f151310ba5f4 upstream. This fixes the same bug as b43790eedd31 ("mm: softdirty: don't forget to save file map softdiry bit on unmap") and 9aed8614af5a ("mm/memory.c: don't forget to set softdirty on file mapped fault") where the return value of pte_*mksoft_dirty was being ignored. To be sure that no other pte/pmd "mk" function return values were being ignored, I annotated the functions in arch/x86/include/asm/pgtable.h with __must_check and rebuilt. The userspace effect of this bug is that the softdirty mark might be lost if a file mapped pte get zapped. Signed-off-by: Peter Feiner Acked-by: Cyrill Gorcunov Cc: Pavel Emelyanov Cc: Jamie Liu Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory.c +++ b/mm/memory.c @@ -1125,7 +1125,7 @@ again: addr) != page->index) { pte_t ptfile = pgoff_to_pte(page->index); if (pte_soft_dirty(ptent)) - pte_file_mksoft_dirty(ptfile); + ptfile = pte_file_mksoft_dirty(ptfile); set_pte_at(mm, addr, pte, ptfile); } if (PageAnon(page)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/