From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757957AbcGKGl7 (ORCPT ); Mon, 11 Jul 2016 02:41:59 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:33651 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757934AbcGKGl4 (ORCPT ); Mon, 11 Jul 2016 02:41:56 -0400 From: zhongjiang To: CC: , Subject: [PATCH 2/2] kexec: add a pmd huge entry condition during the page table Date: Mon, 11 Jul 2016 14:36:01 +0800 Message-ID: <1468218961-11018-2-git-send-email-zhongjiang@huawei.com> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1468218961-11018-1-git-send-email-zhongjiang@huawei.com> References: <1468218961-11018-1-git-send-email-zhongjiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.102.37] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A090202.57833FB1.004E,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 010855f8ff20a6a1b60e35f807d5bc7d Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: zhong jiang when image is loaded into kernel, we need set up page table for it. and all valid pfn also set up new mapping. it will set up a pmd huge entry if pud_present is true. relocate_kernel points to code segment can locate in the pmd huge entry in init_transtion_pgtable. therefore, we need to take the situation into account. Signed-off-by: zhong jiang --- arch/x86/kernel/machine_kexec_64.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 5a294e4..c33e344 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -34,6 +35,17 @@ static struct kexec_file_ops *kexec_file_loaders[] = { }; #endif +static void split_pmd(pmd_t *pmd, pte_t *pte) +{ + unsigned long pfn = pmd_pfn(*pmd); + int i = 0; + + do { + set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); + pfn++; + } while (pte++, i++, i < PTRS_PER_PTE); +} + static void free_transition_pgtable(struct kimage *image) { free_page((unsigned long)image->arch.pud); @@ -68,15 +80,19 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); } pmd = pmd_offset(pud, vaddr); - if (!pmd_present(*pmd)) { + if (!pmd_present(*pmd) || pmd_huge(*pmd)) { pte = (pte_t *)get_zeroed_page(GFP_KERNEL); if (!pte) goto err; image->arch.pte = pte; - set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); + if (pmd_huge(*pmd)) + split_pmd(pmd, pte); + else + set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); } pte = pte_offset_kernel(pmd, vaddr); set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC)); + return 0; err: free_transition_pgtable(image); -- 1.8.3.1