Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752930AbcDNWci (ORCPT ); Thu, 14 Apr 2016 18:32:38 -0400 Received: from mail-pf0-f177.google.com ([209.85.192.177]:36617 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558AbcDNW3c (ORCPT ); Thu, 14 Apr 2016 18:29:32 -0400 From: Kees Cook To: Ingo Molnar Cc: Kees Cook , Yinghai Lu , Baoquan He , Ard Biesheuvel , Matt Redfearn , x86@kernel.org, "H. Peter Anvin" , Ingo Molnar , Borislav Petkov , Vivek Goyal , Andy Lutomirski , lasse.collin@tukaani.org, Andrew Morton , Dave Young , kernel-hardening@lists.openwall.com, LKML Subject: [PATCH v5 11/21] x86, boot: Split out kernel_ident_mapping_init Date: Thu, 14 Apr 2016 15:29:04 -0700 Message-Id: <1460672954-32567-12-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.6.3 In-Reply-To: <1460672954-32567-1-git-send-email-keescook@chromium.org> References: <1460672954-32567-1-git-send-email-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5928 Lines: 211 From: Yinghai Lu In order to support on-demand page table creation when moving the kernel for KASLR, we need to use kernel_ident_mapping_init in the decompression code. This splits it out into its own file for use outside of init_64.c. Additionally, checking for __pa/__va defines is added since they need to be overridden in the decompression code. Reviewed-by: Kees Cook Signed-off-by: Yinghai Lu [kees: rewrote changelog] Signed-off-by: Kees Cook --- arch/x86/include/asm/page.h | 5 +++ arch/x86/mm/ident_map.c | 74 +++++++++++++++++++++++++++++++++++++++++++++ arch/x86/mm/init_64.c | 74 +-------------------------------------------- 3 files changed, 80 insertions(+), 73 deletions(-) create mode 100644 arch/x86/mm/ident_map.c diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index 802dde30c928..cf8f619b305f 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -37,7 +37,10 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr) #define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#ifndef __pa #define __pa(x) __phys_addr((unsigned long)(x)) +#endif + #define __pa_nodebug(x) __phys_addr_nodebug((unsigned long)(x)) /* __pa_symbol should be used for C visible symbols. This seems to be the official gcc blessed way to do such arithmetic. */ @@ -51,7 +54,9 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, #define __pa_symbol(x) \ __phys_addr_symbol(__phys_reloc_hide((unsigned long)(x))) +#ifndef __va #define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET)) +#endif #define __boot_va(x) __va(x) #define __boot_pa(x) __pa(x) diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c new file mode 100644 index 000000000000..751ca920773a --- /dev/null +++ b/arch/x86/mm/ident_map.c @@ -0,0 +1,74 @@ + +static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page, + unsigned long addr, unsigned long end) +{ + addr &= PMD_MASK; + for (; addr < end; addr += PMD_SIZE) { + pmd_t *pmd = pmd_page + pmd_index(addr); + + if (!pmd_present(*pmd)) + set_pmd(pmd, __pmd(addr | pmd_flag)); + } +} +static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page, + unsigned long addr, unsigned long end) +{ + unsigned long next; + + for (; addr < end; addr = next) { + pud_t *pud = pud_page + pud_index(addr); + pmd_t *pmd; + + next = (addr & PUD_MASK) + PUD_SIZE; + if (next > end) + next = end; + + if (pud_present(*pud)) { + pmd = pmd_offset(pud, 0); + ident_pmd_init(info->pmd_flag, pmd, addr, next); + continue; + } + pmd = (pmd_t *)info->alloc_pgt_page(info->context); + if (!pmd) + return -ENOMEM; + ident_pmd_init(info->pmd_flag, pmd, addr, next); + set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); + } + + return 0; +} + +int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, + unsigned long addr, unsigned long end) +{ + unsigned long next; + int result; + int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0; + + for (; addr < end; addr = next) { + pgd_t *pgd = pgd_page + pgd_index(addr) + off; + pud_t *pud; + + next = (addr & PGDIR_MASK) + PGDIR_SIZE; + if (next > end) + next = end; + + if (pgd_present(*pgd)) { + pud = pud_offset(pgd, 0); + result = ident_pud_init(info, pud, addr, next); + if (result) + return result; + continue; + } + + pud = (pud_t *)info->alloc_pgt_page(info->context); + if (!pud) + return -ENOMEM; + result = ident_pud_init(info, pud, addr, next); + if (result) + return result; + set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); + } + + return 0; +} diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 214afda97911..65cfbeefbec4 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -58,79 +58,7 @@ #include "mm_internal.h" -static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page, - unsigned long addr, unsigned long end) -{ - addr &= PMD_MASK; - for (; addr < end; addr += PMD_SIZE) { - pmd_t *pmd = pmd_page + pmd_index(addr); - - if (!pmd_present(*pmd)) - set_pmd(pmd, __pmd(addr | pmd_flag)); - } -} -static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page, - unsigned long addr, unsigned long end) -{ - unsigned long next; - - for (; addr < end; addr = next) { - pud_t *pud = pud_page + pud_index(addr); - pmd_t *pmd; - - next = (addr & PUD_MASK) + PUD_SIZE; - if (next > end) - next = end; - - if (pud_present(*pud)) { - pmd = pmd_offset(pud, 0); - ident_pmd_init(info->pmd_flag, pmd, addr, next); - continue; - } - pmd = (pmd_t *)info->alloc_pgt_page(info->context); - if (!pmd) - return -ENOMEM; - ident_pmd_init(info->pmd_flag, pmd, addr, next); - set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); - } - - return 0; -} - -int kernel_ident_mapping_init(struct x86_mapping_info *info, pgd_t *pgd_page, - unsigned long addr, unsigned long end) -{ - unsigned long next; - int result; - int off = info->kernel_mapping ? pgd_index(__PAGE_OFFSET) : 0; - - for (; addr < end; addr = next) { - pgd_t *pgd = pgd_page + pgd_index(addr) + off; - pud_t *pud; - - next = (addr & PGDIR_MASK) + PGDIR_SIZE; - if (next > end) - next = end; - - if (pgd_present(*pgd)) { - pud = pud_offset(pgd, 0); - result = ident_pud_init(info, pud, addr, next); - if (result) - return result; - continue; - } - - pud = (pud_t *)info->alloc_pgt_page(info->context); - if (!pud) - return -ENOMEM; - result = ident_pud_init(info, pud, addr, next); - if (result) - return result; - set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE)); - } - - return 0; -} +#include "ident_map.c" /* * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the -- 2.6.3