Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932725AbbKCVsm (ORCPT ); Tue, 3 Nov 2015 16:48:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41825 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754871AbbKCVsl (ORCPT ); Tue, 3 Nov 2015 16:48:41 -0500 From: Laura Abbott To: Catalin Marinas , Will Deacon Cc: Laura Abbott , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Kees Cook , Xishi Qiu , Ard Biesheuvel , Mark Rutland Subject: [PATCH 1/2] arm64: Get existing page protections in split_pmd Date: Tue, 3 Nov 2015 13:48:34 -0800 Message-Id: <1446587315-18145-2-git-send-email-labbott@fedoraproject.org> In-Reply-To: <1446587315-18145-1-git-send-email-labbott@fedoraproject.org> References: <1446587315-18145-1-git-send-email-labbott@fedoraproject.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1256 Lines: 41 Rather than always putting the least restrictived permissions (PAGE_KERNEL_EXEC) when spliting a pmd into pages, use the existing permissions from the pmd for the page. Signed-off-by: Laura Abbott --- arch/arm64/mm/mmu.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 9211b85..ff41efa 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -75,14 +75,13 @@ static void __init *early_alloc(unsigned long sz) static void split_pmd(pmd_t *pmd, pte_t *pte) { unsigned long pfn = pmd_pfn(*pmd); + unsigned long addr = pfn << PAGE_SHIFT; + pgprot_t prot = __pgprot(pmd_val(*pmd) ^ addr) | PTE_TYPE_PAGE; + int i = 0; do { - /* - * Need to have the least restrictive permissions available - * permissions will be fixed up later - */ - set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); + set_pte(pte, pfn_pte(pfn, prot)); pfn++; } while (pte++, i++, i < PTRS_PER_PTE); } -- 2.4.3 -- 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/