From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752025AbcGAANO (ORCPT ); Thu, 30 Jun 2016 20:13:14 -0400 Received: from mga04.intel.com ([192.55.52.120]:50021 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbcGAANM (ORCPT ); Thu, 30 Jun 2016 20:13:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,554,1459839600"; d="scan'208";a="838365145" Subject: [PATCH 4/6] mm: move flush in madvise_free_pte_range() To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-mm@kvack.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, bp@alien8.de, ak@linux.intel.com, mhocko@suse.com, Dave Hansen , dave.hansen@linux.intel.com, minchan@kernel.org From: Dave Hansen Date: Thu, 30 Jun 2016 17:12:15 -0700 References: <20160701001209.7DA24D1C@viggo.jf.intel.com> In-Reply-To: <20160701001209.7DA24D1C@viggo.jf.intel.com> Message-Id: <20160701001215.C0689717@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen I think this code is OK and does not *need* to be patched. We are just rewriting the PTE without the Accessed and Dirty bits. The hardware could come along and set them at any time with or without the erratum that this series addresses But this does make the ptep_get_and_clear_full() and tlb_remove_tlb_entry() calls here more consistent with the other places they are used together and look *obviously* the same between call-sites. Signed-off-by: Dave Hansen Cc: Minchan Kim --- b/mm/madvise.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN mm/madvise.c~knl-leak-40-madvise_free_pte_range-move-flush mm/madvise.c --- a/mm/madvise.c~knl-leak-40-madvise_free_pte_range-move-flush 2016-06-30 17:10:42.557246755 -0700 +++ b/mm/madvise.c 2016-06-30 17:10:42.561246936 -0700 @@ -369,13 +369,13 @@ static int madvise_free_pte_range(pmd_t */ ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); + tlb_remove_tlb_entry(tlb, pte, addr); ptent = pte_mkold(ptent); ptent = pte_mkclean(ptent); set_pte_at(mm, addr, pte, ptent); if (PageActive(page)) deactivate_page(page); - tlb_remove_tlb_entry(tlb, pte, addr); } } out: _