From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Subject: [PATCH v2] x86/power/64: Support unaligned addresses for temporary mapping Date: Wed, 3 Aug 2016 11:23:08 -0700 Message-ID: <20160803182308.19227-1-yinghai@kernel.org> References: <1470071280-78706-1-git-send-email-thgarnie@google.com> <1470071280-78706-2-git-send-email-thgarnie@google.com> Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:20919 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751460AbcHCS0a (ORCPT ); Wed, 3 Aug 2016 14:26:30 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Kees Cook , "Rafael J . Wysocki" , Pavel Machek Cc: the arch/x86 maintainers , Linux Kernel Mailing List , Linux PM list , kernel-hardening@lists.openwall.com, Thomas Garnier , Yinghai Lu From: Thomas Garnier Correctly setup the temporary mapping for hibernation. Previous implementation assumed the offset between KVA and PA was aligned on the PGD level. With KASLR memory randomization enabled, the offset is randomized on the PUD level. This change supports unaligned up to PMD. Signed-off-by: Thomas Garnier [yinghai: change loop to virtual address] Signed-off-by: Yinghai Lu --- arch/x86/mm/ident_map.c | 54 ++++++++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 22 deletions(-) Index: linux-2.6/arch/x86/mm/ident_map.c =================================================================== --- linux-2.6.orig/arch/x86/mm/ident_map.c +++ linux-2.6/arch/x86/mm/ident_map.c @@ -3,40 +3,47 @@ * included by both the compressed kernel and the regular kernel. */ -static void ident_pmd_init(unsigned long pmd_flag, pmd_t *pmd_page, +static void ident_pmd_init(struct x86_mapping_info *info, 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); + unsigned long off = info->kernel_mapping ? __PAGE_OFFSET : 0; + unsigned long vaddr = addr + off; + unsigned long vend = end + off; + + vaddr &= PMD_MASK; + for (; vaddr < vend; vaddr += PMD_SIZE) { + pmd_t *pmd = pmd_page + pmd_index(vaddr); if (!pmd_present(*pmd)) - set_pmd(pmd, __pmd(addr | pmd_flag)); + set_pmd(pmd, __pmd((vaddr - off) | info->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; + unsigned long off = info->kernel_mapping ? __PAGE_OFFSET : 0; + unsigned long vaddr = addr + off; + unsigned long vend = end + off; + unsigned long vnext; - for (; addr < end; addr = next) { - pud_t *pud = pud_page + pud_index(addr); + for (; vaddr < vend; vaddr = vnext) { + pud_t *pud = pud_page + pud_index(vaddr); pmd_t *pmd; - next = (addr & PUD_MASK) + PUD_SIZE; - if (next > end) - next = end; + vnext = (vaddr & PUD_MASK) + PUD_SIZE; + if (vnext > vend) + vnext = vend; if (pud_present(*pud)) { pmd = pmd_offset(pud, 0); - ident_pmd_init(info->pmd_flag, pmd, addr, next); + ident_pmd_init(info, pmd, vaddr - off, vnext - off); continue; } pmd = (pmd_t *)info->alloc_pgt_page(info->context); if (!pmd) return -ENOMEM; - ident_pmd_init(info->pmd_flag, pmd, addr, next); + ident_pmd_init(info, pmd, vaddr - off, vnext - off); set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); } @@ -46,21 +53,24 @@ static int ident_pud_init(struct x86_map 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; + unsigned long off = info->kernel_mapping ? __PAGE_OFFSET : 0; + unsigned long vaddr = addr + off; + unsigned long vend = end + off; + unsigned long vnext; - for (; addr < end; addr = next) { - pgd_t *pgd = pgd_page + pgd_index(addr) + off; + for (; vaddr < vend; vaddr = vnext) { + pgd_t *pgd = pgd_page + pgd_index(vaddr); pud_t *pud; - next = (addr & PGDIR_MASK) + PGDIR_SIZE; - if (next > end) - next = end; + vnext = (vaddr & PGDIR_MASK) + PGDIR_SIZE; + if (vnext > vend) + vnext = vend; if (pgd_present(*pgd)) { pud = pud_offset(pgd, 0); - result = ident_pud_init(info, pud, addr, next); + result = ident_pud_init(info, pud, vaddr - off, + vnext - off); if (result) return result; continue; @@ -69,7 +79,7 @@ int kernel_ident_mapping_init(struct x86 pud = (pud_t *)info->alloc_pgt_page(info->context); if (!pud) return -ENOMEM; - result = ident_pud_init(info, pud, addr, next); + result = ident_pud_init(info, pud, vaddr - off, vnext - off); if (result) return result; set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));