From patchwork Wed Jun 22 00:46:59 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9191593 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 374916075A for ; Wed, 22 Jun 2016 00:47:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 266362837F for ; Wed, 22 Jun 2016 00:47:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 19FA32838C; Wed, 22 Jun 2016 00:47:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 8F9B72837F for ; Wed, 22 Jun 2016 00:47:41 +0000 (UTC) Received: (qmail 24010 invoked by uid 550); 22 Jun 2016 00:47:29 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 23893 invoked from network); 22 Jun 2016 00:47:26 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=s9h6rgEaYNKnycKj7B4qTh/T5Na8eEx5yBMR78fym+c=; b=fvPOykDuEE2/U9MrA/oklVRTGrmenpBO2KW/nuFFccv8CmEiv1qGL5uCcNpS85KVw3 ffe2xPVKBZXSla+6Bm/poRtAwBKa/AOKZaHhCukPWZmHNSXIV/alIbv4vCSROBMyD8VO iGtYXY3uEn79eIpipcm+b4FREuTeqzFstXSYk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=s9h6rgEaYNKnycKj7B4qTh/T5Na8eEx5yBMR78fym+c=; b=EaYDuY3BsV9hz5M/jSR1Ur9d2ifjhDuEtnuF2mhVQq18hNrHriciG/k4y4YpwXpSsr sKm4gZbly5JY6UbjyG8BOpOLBsNsKMfePei3d6CX1bsKh7I5Dlep2Xg88/e5z4w66gb5 iEoBQd3KkBcYv+J134QW1Pk0VRG1ASM/tCUpg+4YqHxYOOjohnrpOyP1QDrp5wA5Lt8d gQuZzpQ7SrI0PGd5KWOLdyd6NI3sxgG7tpccJ/TAF02qipSln6iWpr/ZNv2pj4HezaUA vOi3SUigDCSUpwkrBs3V3NaHbvf+uEm61VHkG+mQ6/P7rjoG+FigJc8vuIQqtrSzsWaK 9adQ== X-Gm-Message-State: ALyK8tK5Y7ug3STa03i3857VXs6880ySOvKP/jPBck9gZLJDhmOd8CUZ94YCt8cGJ2Lzsdej X-Received: by 10.66.151.140 with SMTP id uq12mr18698746pab.10.1466556434780; Tue, 21 Jun 2016 17:47:14 -0700 (PDT) From: Kees Cook To: Ingo Molnar Cc: Kees Cook , Thomas Garnier , Andy Lutomirski , x86@kernel.org, Borislav Petkov , Baoquan He , Yinghai Lu , Juergen Gross , Matt Fleming , Toshi Kani , Andrew Morton , Dan Williams , "Kirill A. Shutemov" , Dave Hansen , Xiao Guangrong , Martin Schwidefsky , "Aneesh Kumar K.V" , Alexander Kuleshov , Alexander Popov , Dave Young , Joerg Roedel , Lv Zheng , Mark Salter , Dmitry Vyukov , Stephen Smalley , Boris Ostrovsky , Christian Borntraeger , Jan Beulich , linux-kernel@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com Date: Tue, 21 Jun 2016 17:46:59 -0700 Message-Id: <1466556426-32664-3-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1466556426-32664-1-git-send-email-keescook@chromium.org> References: <1466556426-32664-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH v7 2/9] x86/mm: Update physical mapping variable names (x86_64) X-Virus-Scanned: ClamAV using ClamSMTP From: Thomas Garnier Change the variable names on kernel_physical_mapping_init and related functions to correctly reflect physical and virtual memory addresses. Also add comments on each function to describe usage and alignment constraints. Signed-off-by: Thomas Garnier Signed-off-by: Kees Cook --- arch/x86/mm/init_64.c | 162 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 96 insertions(+), 66 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index bce2e5d9edd4..6714712bd5da 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -328,22 +328,30 @@ void __init cleanup_highmap(void) } } +/* + * Create PTE level page table mapping for physical addresses. + * It returns the last physical address mapped. + */ static unsigned long __meminit -phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, +phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end, pgprot_t prot) { - unsigned long pages = 0, next; - unsigned long last_map_addr = end; + unsigned long pages = 0, paddr_next; + unsigned long paddr_last = paddr_end; + pte_t *pte; int i; - pte_t *pte = pte_page + pte_index(addr); + pte = pte_page + pte_index(paddr); + i = pte_index(paddr); - for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) { - next = (addr & PAGE_MASK) + PAGE_SIZE; - if (addr >= end) { + for (; i < PTRS_PER_PTE; i++, paddr = paddr_next, pte++) { + paddr_next = (paddr & PAGE_MASK) + PAGE_SIZE; + if (paddr >= paddr_end) { if (!after_bootmem && - !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) && - !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN)) + !e820_any_mapped(paddr & PAGE_MASK, paddr_next, + E820_RAM) && + !e820_any_mapped(paddr & PAGE_MASK, paddr_next, + E820_RESERVED_KERN)) set_pte(pte, __pte(0)); continue; } @@ -361,37 +369,44 @@ phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, } if (0) - printk(" pte=%p addr=%lx pte=%016lx\n", - pte, addr, pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL).pte); + pr_info(" pte=%p addr=%lx pte=%016lx\n", pte, paddr, + pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL).pte); pages++; - set_pte(pte, pfn_pte(addr >> PAGE_SHIFT, prot)); - last_map_addr = (addr & PAGE_MASK) + PAGE_SIZE; + set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot)); + paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE; } update_page_count(PG_LEVEL_4K, pages); - return last_map_addr; + return paddr_last; } +/* + * Create PMD level page table mapping for physical addresses. The virtual + * and physical address have to be aligned at this level. + * It returns the last physical address mapped. + */ static unsigned long __meminit -phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, +phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end, unsigned long page_size_mask, pgprot_t prot) { - unsigned long pages = 0, next; - unsigned long last_map_addr = end; + unsigned long pages = 0, paddr_next; + unsigned long paddr_last = paddr_end; - int i = pmd_index(address); + int i = pmd_index(paddr); - for (; i < PTRS_PER_PMD; i++, address = next) { - pmd_t *pmd = pmd_page + pmd_index(address); + for (; i < PTRS_PER_PMD; i++, paddr = paddr_next) { + pmd_t *pmd = pmd_page + pmd_index(paddr); pte_t *pte; pgprot_t new_prot = prot; - next = (address & PMD_MASK) + PMD_SIZE; - if (address >= end) { + paddr_next = (paddr & PMD_MASK) + PMD_SIZE; + if (paddr >= paddr_end) { if (!after_bootmem && - !e820_any_mapped(address & PMD_MASK, next, E820_RAM) && - !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN)) + !e820_any_mapped(paddr & PMD_MASK, paddr_next, + E820_RAM) && + !e820_any_mapped(paddr & PMD_MASK, paddr_next, + E820_RESERVED_KERN)) set_pmd(pmd, __pmd(0)); continue; } @@ -400,8 +415,8 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, if (!pmd_large(*pmd)) { spin_lock(&init_mm.page_table_lock); pte = (pte_t *)pmd_page_vaddr(*pmd); - last_map_addr = phys_pte_init(pte, address, - end, prot); + paddr_last = phys_pte_init(pte, paddr, + paddr_end, prot); spin_unlock(&init_mm.page_table_lock); continue; } @@ -420,7 +435,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, if (page_size_mask & (1 << PG_LEVEL_2M)) { if (!after_bootmem) pages++; - last_map_addr = next; + paddr_last = paddr_next; continue; } new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd)); @@ -430,42 +445,49 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, pages++; spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pmd, - pfn_pte((address & PMD_MASK) >> PAGE_SHIFT, + pfn_pte((paddr & PMD_MASK) >> PAGE_SHIFT, __pgprot(pgprot_val(prot) | _PAGE_PSE))); spin_unlock(&init_mm.page_table_lock); - last_map_addr = next; + paddr_last = paddr_next; continue; } pte = alloc_low_page(); - last_map_addr = phys_pte_init(pte, address, end, new_prot); + paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot); spin_lock(&init_mm.page_table_lock); pmd_populate_kernel(&init_mm, pmd, pte); spin_unlock(&init_mm.page_table_lock); } update_page_count(PG_LEVEL_2M, pages); - return last_map_addr; + return paddr_last; } +/* + * Create PUD level page table mapping for physical addresses. The virtual + * and physical address have to be aligned at this level. + * It returns the last physical address mapped. + */ static unsigned long __meminit -phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, - unsigned long page_size_mask) +phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end, + unsigned long page_size_mask) { - unsigned long pages = 0, next; - unsigned long last_map_addr = end; - int i = pud_index(addr); + unsigned long pages = 0, paddr_next; + unsigned long paddr_last = paddr_end; + int i = pud_index(paddr); - for (; i < PTRS_PER_PUD; i++, addr = next) { - pud_t *pud = pud_page + pud_index(addr); + for (; i < PTRS_PER_PUD; i++, paddr = paddr_next) { + pud_t *pud = pud_page + pud_index(paddr); pmd_t *pmd; pgprot_t prot = PAGE_KERNEL; - next = (addr & PUD_MASK) + PUD_SIZE; - if (addr >= end) { + paddr_next = (paddr & PUD_MASK) + PUD_SIZE; + if (paddr >= paddr_end) { if (!after_bootmem && - !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) && - !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN)) + !e820_any_mapped(paddr & PUD_MASK, paddr_next, + E820_RAM) && + !e820_any_mapped(paddr & PUD_MASK, paddr_next, + E820_RESERVED_KERN)) set_pud(pud, __pud(0)); continue; } @@ -473,8 +495,10 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, if (pud_val(*pud)) { if (!pud_large(*pud)) { pmd = pmd_offset(pud, 0); - last_map_addr = phys_pmd_init(pmd, addr, end, - page_size_mask, prot); + paddr_last = phys_pmd_init(pmd, paddr, + paddr_end, + page_size_mask, + prot); __flush_tlb_all(); continue; } @@ -493,7 +517,7 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, if (page_size_mask & (1 << PG_LEVEL_1G)) { if (!after_bootmem) pages++; - last_map_addr = next; + paddr_last = paddr_next; continue; } prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud)); @@ -503,16 +527,16 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, pages++; spin_lock(&init_mm.page_table_lock); set_pte((pte_t *)pud, - pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT, + pfn_pte((paddr & PUD_MASK) >> PAGE_SHIFT, PAGE_KERNEL_LARGE)); spin_unlock(&init_mm.page_table_lock); - last_map_addr = next; + paddr_last = paddr_next; continue; } pmd = alloc_low_page(); - last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask, - prot); + paddr_last = phys_pmd_init(pmd, paddr, paddr_end, + page_size_mask, prot); spin_lock(&init_mm.page_table_lock); pud_populate(&init_mm, pud, pmd); @@ -522,38 +546,44 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, update_page_count(PG_LEVEL_1G, pages); - return last_map_addr; + return paddr_last; } +/* + * Create page table mapping for the physical memory for specific physical + * addresses. The virtual and physical addresses have to be aligned on PUD level + * down. It returns the last physical address mapped. + */ unsigned long __meminit -kernel_physical_mapping_init(unsigned long start, - unsigned long end, +kernel_physical_mapping_init(unsigned long paddr_start, + unsigned long paddr_end, unsigned long page_size_mask) { bool pgd_changed = false; - unsigned long next, last_map_addr = end; - unsigned long addr; + unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last; - start = (unsigned long)__va(start); - end = (unsigned long)__va(end); - addr = start; + paddr_last = paddr_end; + vaddr = (unsigned long)__va(paddr_start); + vaddr_end = (unsigned long)__va(paddr_end); + vaddr_start = vaddr; - for (; start < end; start = next) { - pgd_t *pgd = pgd_offset_k(start); + for (; vaddr < vaddr_end; vaddr = vaddr_next) { + pgd_t *pgd = pgd_offset_k(vaddr); pud_t *pud; - next = (start & PGDIR_MASK) + PGDIR_SIZE; + vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE; if (pgd_val(*pgd)) { pud = (pud_t *)pgd_page_vaddr(*pgd); - last_map_addr = phys_pud_init(pud, __pa(start), - __pa(end), page_size_mask); + paddr_last = phys_pud_init(pud, __pa(vaddr), + __pa(vaddr_end), + page_size_mask); continue; } pud = alloc_low_page(); - last_map_addr = phys_pud_init(pud, __pa(start), __pa(end), - page_size_mask); + paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end), + page_size_mask); spin_lock(&init_mm.page_table_lock); pgd_populate(&init_mm, pgd, pud); @@ -562,11 +592,11 @@ kernel_physical_mapping_init(unsigned long start, } if (pgd_changed) - sync_global_pgds(addr, end - 1, 0); + sync_global_pgds(vaddr_start, vaddr_end - 1, 0); __flush_tlb_all(); - return last_map_addr; + return paddr_last; } #ifndef CONFIG_NUMA