Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753279Ab3ISOzT (ORCPT ); Thu, 19 Sep 2013 10:55:19 -0400 Received: from mail.skyhub.de ([78.46.96.112]:58799 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752578Ab3ISOzN (ORCPT ); Thu, 19 Sep 2013 10:55:13 -0400 From: Borislav Petkov To: X86 ML Cc: LKML , Borislav Petkov , Matt Fleming , Matthew Garrett , "H. Peter Anvin" , James Bottomley , Vivek Goyal , Dave Young , linux-efi@vger.kernel.org Subject: [PATCH 10/11] x86, cpa: Map in an arbitrary pgd Date: Thu, 19 Sep 2013 16:54:53 +0200 Message-Id: <1379602494-26684-11-git-send-email-bp@alien8.de> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1379602494-26684-1-git-send-email-bp@alien8.de> References: <1379602494-26684-1-git-send-email-bp@alien8.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4898 Lines: 160 From: Borislav Petkov Add the ability to map pages in an arbitrary pgd. This wires in the remaining stuff so that there's a new interface with which you can map a region into an arbitrary PGD. Signed-off-by: Borislav Petkov --- arch/x86/mm/pageattr.c | 53 +++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 46 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index ca76481c09e8..991386bf3aad 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -453,7 +453,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * Check for races, another CPU might have split this page * up already: */ - tmp = lookup_address(address, &level); + tmp = _lookup_address_cpa(cpa, address, &level); if (tmp != kpte) goto out_unlock; @@ -559,7 +559,8 @@ out_unlock: } static int -__split_large_page(pte_t *kpte, unsigned long address, struct page *base) +__split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, + struct page *base) { pte_t *pbase = (pte_t *)page_address(base); unsigned long pfn, pfninc = 1; @@ -572,7 +573,7 @@ __split_large_page(pte_t *kpte, unsigned long address, struct page *base) * Check for races, another CPU might have split this page * up for us already: */ - tmp = lookup_address(address, &level); + tmp = _lookup_address_cpa(cpa, address, &level); if (tmp != kpte) { spin_unlock(&pgd_lock); return 1; @@ -648,7 +649,8 @@ __split_large_page(pte_t *kpte, unsigned long address, struct page *base) return 0; } -static int split_large_page(pte_t *kpte, unsigned long address) +static int split_large_page(struct cpa_data *cpa, pte_t *kpte, + unsigned long address) { struct page *base; @@ -660,7 +662,7 @@ static int split_large_page(pte_t *kpte, unsigned long address) if (!base) return -ENOMEM; - if (__split_large_page(kpte, address, base)) + if (__split_large_page(cpa, kpte, address, base)) __free_page(base); return 0; @@ -1041,6 +1043,9 @@ static int populate_pgd(struct cpa_data *cpa, unsigned long addr) static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr, int primary) { + if (cpa->pgd) + return populate_pgd(cpa, vaddr); + /* * Ignore all non primary paths. */ @@ -1085,7 +1090,7 @@ static int __change_page_attr(struct cpa_data *cpa, int primary) else address = *cpa->vaddr; repeat: - kpte = lookup_address(address, &level); + kpte = _lookup_address_cpa(cpa, address, &level); if (!kpte) return __cpa_process_fault(cpa, address, primary); @@ -1149,7 +1154,7 @@ repeat: /* * We have to split the large page: */ - err = split_large_page(kpte, address); + err = split_large_page(cpa, kpte, address); if (!err) { /* * Do a global flush tlb after splitting the large page @@ -1298,6 +1303,8 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, int ret, cache, checkalias; unsigned long baddr = 0; + memset(&cpa, 0, sizeof(cpa)); + /* * Check, if we are requested to change a not supported * feature: @@ -1744,6 +1751,7 @@ static int __set_pages_p(struct page *page, int numpages) { unsigned long tempaddr = (unsigned long) page_address(page); struct cpa_data cpa = { .vaddr = &tempaddr, + .pgd = 0, .numpages = numpages, .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW), .mask_clr = __pgprot(0), @@ -1762,6 +1770,7 @@ static int __set_pages_np(struct page *page, int numpages) { unsigned long tempaddr = (unsigned long) page_address(page); struct cpa_data cpa = { .vaddr = &tempaddr, + .pgd = 0, .numpages = numpages, .mask_set = __pgprot(0), .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), @@ -1822,6 +1831,36 @@ bool kernel_page_present(struct page *page) #endif /* CONFIG_DEBUG_PAGEALLOC */ +int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, + unsigned numpages, unsigned long page_flags) +{ + int retval = 0; + + struct cpa_data cpa = { + .vaddr = &address, + .pfn = pfn, + .pgd = pgd, + .numpages = numpages, + .mask_set = __pgprot(0), + .mask_clr = __pgprot(0), + .flags = 0, + }; + + if (!(__supported_pte_mask & _PAGE_NX)) + goto out; + + if (!(page_flags & _PAGE_NX)) + cpa.mask_clr = __pgprot(_PAGE_NX); + + cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags); + + retval = __change_page_attr_set_clr(&cpa, 0); + __flush_tlb_all(); + +out: + return retval; +} + /* * The testcases use internal knowledge of the implementation that shouldn't * be exposed to the rest of the kernel. 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