Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755709AbdIGRhl (ORCPT ); Thu, 7 Sep 2017 13:37:41 -0400 Received: from mail-io0-f173.google.com ([209.85.223.173]:38882 "EHLO mail-io0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755646AbdIGRhQ (ORCPT ); Thu, 7 Sep 2017 13:37:16 -0400 X-Google-Smtp-Source: ADKCNb4Al3+ec69tCfL8dYXUht+PmbbGu2pr6LgoKWYY7bBdNaGNuRRfvJP0/o6Cfxo73x1vA9Oz+g== From: Tycho Andersen To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto , Juerg Haefliger , Tycho Andersen , linux-arm-kernel@lists.infradead.org, x86@kernel.org Subject: [PATCH v6 10/11] mm: add a user_virt_to_phys symbol Date: Thu, 7 Sep 2017 11:36:08 -0600 Message-Id: <20170907173609.22696-11-tycho@docker.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170907173609.22696-1-tycho@docker.com> References: <20170907173609.22696-1-tycho@docker.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4589 Lines: 172 We need someting like this for testing XPFO. Since it's architecture specific, putting it in the test code is slightly awkward, so let's make it an arch-specific symbol and export it for use in LKDTM. v6: * add a definition of user_virt_to_phys in the !CONFIG_XPFO case CC: linux-arm-kernel@lists.infradead.org CC: x86@kernel.org Signed-off-by: Tycho Andersen Tested-by: Marco Benatto --- arch/arm64/mm/xpfo.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++ arch/x86/mm/xpfo.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/xpfo.h | 5 +++++ 3 files changed, 113 insertions(+) diff --git a/arch/arm64/mm/xpfo.c b/arch/arm64/mm/xpfo.c index 342a9ccb93c1..94a667d94e15 100644 --- a/arch/arm64/mm/xpfo.c +++ b/arch/arm64/mm/xpfo.c @@ -74,3 +74,54 @@ void xpfo_dma_map_unmap_area(bool map, const void *addr, size_t size, xpfo_temp_unmap(addr, size, mapping, sizeof(mapping[0]) * num_pages); } + +/* Convert a user space virtual address to a physical address. + * Shamelessly copied from slow_virt_to_phys() and lookup_address() in + * arch/x86/mm/pageattr.c + */ +phys_addr_t user_virt_to_phys(unsigned long addr) +{ + phys_addr_t phys_addr; + unsigned long offset; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset(current->mm, addr); + if (pgd_none(*pgd)) + return 0; + + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) + return 0; + + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) + return 0; + + if (pud_sect(*pud) || !pud_present(*pud)) { + phys_addr = (unsigned long)pud_pfn(*pud) << PAGE_SHIFT; + offset = addr & ~PUD_MASK; + goto out; + } + + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) + return 0; + + if (pmd_sect(*pmd) || !pmd_present(*pmd)) { + phys_addr = (unsigned long)pmd_pfn(*pmd) << PAGE_SHIFT; + offset = addr & ~PMD_MASK; + goto out; + } + + pte = pte_offset_kernel(pmd, addr); + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; + offset = addr & ~PAGE_MASK; + +out: + return (phys_addr_t)(phys_addr | offset); +} +EXPORT_SYMBOL(user_virt_to_phys); diff --git a/arch/x86/mm/xpfo.c b/arch/x86/mm/xpfo.c index 6794d6724ab5..d24cf2c600e8 100644 --- a/arch/x86/mm/xpfo.c +++ b/arch/x86/mm/xpfo.c @@ -112,3 +112,60 @@ inline void xpfo_flush_kernel_tlb(struct page *page, int order) flush_tlb_kernel_range(kaddr, kaddr + (1 << order) * size); } + +/* Convert a user space virtual address to a physical address. + * Shamelessly copied from slow_virt_to_phys() and lookup_address() in + * arch/x86/mm/pageattr.c + */ +phys_addr_t user_virt_to_phys(unsigned long addr) +{ + phys_addr_t phys_addr; + unsigned long offset; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pgd = pgd_offset(current->mm, addr); + if (pgd_none(*pgd)) + return 0; + + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) + return 0; + + if (p4d_large(*p4d) || !p4d_present(*p4d)) { + phys_addr = (unsigned long)p4d_pfn(*p4d) << PAGE_SHIFT; + offset = addr & ~P4D_MASK; + goto out; + } + + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) + return 0; + + if (pud_large(*pud) || !pud_present(*pud)) { + phys_addr = (unsigned long)pud_pfn(*pud) << PAGE_SHIFT; + offset = addr & ~PUD_MASK; + goto out; + } + + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) + return 0; + + if (pmd_large(*pmd) || !pmd_present(*pmd)) { + phys_addr = (unsigned long)pmd_pfn(*pmd) << PAGE_SHIFT; + offset = addr & ~PMD_MASK; + goto out; + } + + pte = pte_offset_kernel(pmd, addr); + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; + offset = addr & ~PAGE_MASK; + +out: + return (phys_addr_t)(phys_addr | offset); +} +EXPORT_SYMBOL(user_virt_to_phys); diff --git a/include/linux/xpfo.h b/include/linux/xpfo.h index 1693af1a0293..be72da5fba26 100644 --- a/include/linux/xpfo.h +++ b/include/linux/xpfo.h @@ -19,6 +19,7 @@ #ifdef CONFIG_XPFO #include +#include extern struct page_ext_operations page_xpfo_ops; @@ -45,6 +46,8 @@ void xpfo_temp_unmap(const void *addr, size_t size, void **mapping, bool xpfo_enabled(void); +phys_addr_t user_virt_to_phys(unsigned long addr); + #else /* !CONFIG_XPFO */ static inline void xpfo_kmap(void *kaddr, struct page *page) { } @@ -69,6 +72,8 @@ static inline void xpfo_temp_unmap(const void *addr, size_t size, static inline bool xpfo_enabled(void) { return false; } +static inline phys_addr_t user_virt_to_phys(unsigned long addr) { return 0; } + #endif /* CONFIG_XPFO */ #endif /* _LINUX_XPFO_H */ -- 2.11.0