From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Helge Deller Subject: [PATCH 4.14 012/222] parisc: Fix map_pages() to not overwrite existing pte entries Date: Sun, 11 Nov 2018 14:21:49 -0800 Message-Id: <20181111221649.149203301@linuxfoundation.org> In-Reply-To: <20181111221647.665769131@linuxfoundation.org> References: <20181111221647.665769131@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Helge Deller commit 3c229b3f2dd8133f61bb81d3cb018be92f4bba39 upstream. Fix a long-existing small nasty bug in the map_pages() implementation which leads to overwriting already written pte entries with zero, *if* map_pages() is called a second time with an end address which isn't aligned on a pmd boundry. This happens for example if we want to remap only the text segment read/write in order to run alternative patching on the code. Exiting the loop when we reach the end address fixes this. Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- arch/parisc/mm/init.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/arch/parisc/mm/init.c +++ b/arch/parisc/mm/init.c @@ -495,12 +495,8 @@ static void __init map_pages(unsigned lo pte = pte_mkhuge(pte); } - if (address >= end_paddr) { - if (force) - break; - else - pte_val(pte) = 0; - } + if (address >= end_paddr) + break; set_pte(pg_table, pte);