Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752001AbbKKB5s (ORCPT ); Tue, 10 Nov 2015 20:57:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38794 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751807AbbKKB5q (ORCPT ); Tue, 10 Nov 2015 20:57:46 -0500 From: Laura Abbott To: Catalin Marinas , Will Deacon , Ard Biesheuvel , Zhong Jiang Cc: Laura Abbott , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Kees Cook , Xishi Qiu , Mark Rutland Subject: [PATCHv2 1/2] arm64: Get existing page protections in split_pmd Date: Tue, 10 Nov 2015 17:57:36 -0800 Message-Id: <1447207057-11323-2-git-send-email-labbott@fedoraproject.org> In-Reply-To: <1447207057-11323-1-git-send-email-labbott@fedoraproject.org> References: <1447207057-11323-1-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: 1517 Lines: 47 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 --- v2: Typo and typechecking fixed I chose not to add the Reviewed-by from Ard here because of the addition of the contiguous bit in split_pmd. Not sure if I should be explicitly carrying it over. --- arch/arm64/mm/mmu.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index c2fa6b5..496c3fd 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -76,15 +76,13 @@ 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. Default the new page - * range as contiguous ptes. - */ - set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC_CONT)); + set_pte(pte, pfn_pte(pfn, prot)); pfn++; } while (pte++, i++, i < PTRS_PER_PTE); } -- 2.5.0 -- 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/