From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: [PATCH v10 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Date: Wed, 29 Apr 2020 15:07:20 -0700 Message-ID: <20200429220732.31602-15-yu-cheng.yu@intel.com> References: <20200429220732.31602-1-yu-cheng.yu@intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from mga09.intel.com ([134.134.136.24]:61300 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727902AbgD2WIs (ORCPT ); Wed, 29 Apr 2020 18:08:48 -0400 In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit Cc: Yu-cheng Yu Shadow stack memory is writable, but its VMA has VM_SHSTK instead of VM_WRITE. Update maybe_mkwrite() to include the shadow stack. Signed-off-by: Yu-cheng Yu --- arch/x86/Kconfig | 4 ++++ arch/x86/mm/pgtable.c | 18 ++++++++++++++++++ include/asm-generic/pgtable.h | 24 ++++++++++++++++++++++++ include/linux/mm.h | 2 ++ mm/huge_memory.c | 2 ++ 5 files changed, 50 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c98f82fffe85..ac07e1f6a2bc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1955,6 +1955,9 @@ config AS_HAS_SHADOW_STACK config X86_INTEL_CET def_bool n +config ARCH_MAYBE_MKWRITE + def_bool n + config ARCH_HAS_SHADOW_STACK def_bool n @@ -1965,6 +1968,7 @@ config X86_INTEL_SHADOW_STACK_USER depends on AS_HAS_SHADOW_STACK select ARCH_USES_HIGH_VMA_FLAGS select X86_INTEL_CET + select ARCH_MAYBE_MKWRITE select ARCH_HAS_SHADOW_STACK help Shadow Stacks provides protection against program stack diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 7bd2c3a52297..aa4d396ff98d 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -603,6 +603,24 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, } #endif +#ifdef CONFIG_ARCH_MAYBE_MKWRITE +pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_SHSTK)) + pte = pte_mkwrite_shstk(pte); + return pte; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_SHSTK)) + pmd = pmd_mkwrite_shstk(pmd); + return pmd; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif /* CONFIG_ARCH_MAYBE_MKWRITE */ + /** * reserve_top_address - reserves a hole in the top of kernel address space * @reserve - size of hole to reserve diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 329b8c8ca703..2c3875724809 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1191,6 +1191,30 @@ static inline bool arch_has_pfn_modify_check(void) } #endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */ +#ifdef CONFIG_MMU +#ifdef CONFIG_ARCH_MAYBE_MKWRITE +pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#else /* !CONFIG_ARCH_MAYBE_MKWRITE */ +static inline pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + return pte; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + return pmd; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#endif /* CONFIG_ARCH_MAYBE_MKWRITE */ +#endif /* CONFIG_MMU */ + /* * Architecture PAGE_KERNEL_* fallbacks * diff --git a/include/linux/mm.h b/include/linux/mm.h index 54bb4cd9fee8..f0669e3cdd37 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -944,6 +944,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pte = pte_mkwrite(pte); + else + pte = arch_maybe_mkwrite(pte, vma); return pte; } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 6ecd1045113b..608746bb9d19 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -485,6 +485,8 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pmd = pmd_mkwrite(pmd); + else + pmd = arch_maybe_pmd_mkwrite(pmd, vma); return pmd; } -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Yu-cheng Yu Subject: [PATCH v10 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Date: Wed, 29 Apr 2020 15:07:20 -0700 Message-ID: <20200429220732.31602-15-yu-cheng.yu@intel.com> In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com> References: <20200429220732.31602-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang Cc: Yu-cheng Yu List-ID: Message-ID: <20200429220720.MVA8TGwU7FoGwOudjj--AakHOBHUmbiUO4FIvxXVLJw@z> Shadow stack memory is writable, but its VMA has VM_SHSTK instead of VM_WRITE. Update maybe_mkwrite() to include the shadow stack. Signed-off-by: Yu-cheng Yu --- arch/x86/Kconfig | 4 ++++ arch/x86/mm/pgtable.c | 18 ++++++++++++++++++ include/asm-generic/pgtable.h | 24 ++++++++++++++++++++++++ include/linux/mm.h | 2 ++ mm/huge_memory.c | 2 ++ 5 files changed, 50 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c98f82fffe85..ac07e1f6a2bc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1955,6 +1955,9 @@ config AS_HAS_SHADOW_STACK config X86_INTEL_CET def_bool n +config ARCH_MAYBE_MKWRITE + def_bool n + config ARCH_HAS_SHADOW_STACK def_bool n @@ -1965,6 +1968,7 @@ config X86_INTEL_SHADOW_STACK_USER depends on AS_HAS_SHADOW_STACK select ARCH_USES_HIGH_VMA_FLAGS select X86_INTEL_CET + select ARCH_MAYBE_MKWRITE select ARCH_HAS_SHADOW_STACK help Shadow Stacks provides protection against program stack diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 7bd2c3a52297..aa4d396ff98d 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -603,6 +603,24 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, } #endif +#ifdef CONFIG_ARCH_MAYBE_MKWRITE +pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_SHSTK)) + pte = pte_mkwrite_shstk(pte); + return pte; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + if (likely(vma->vm_flags & VM_SHSTK)) + pmd = pmd_mkwrite_shstk(pmd); + return pmd; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#endif /* CONFIG_ARCH_MAYBE_MKWRITE */ + /** * reserve_top_address - reserves a hole in the top of kernel address space * @reserve - size of hole to reserve diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 329b8c8ca703..2c3875724809 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1191,6 +1191,30 @@ static inline bool arch_has_pfn_modify_check(void) } #endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */ +#ifdef CONFIG_MMU +#ifdef CONFIG_ARCH_MAYBE_MKWRITE +pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma); + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#else /* !CONFIG_ARCH_MAYBE_MKWRITE */ +static inline pte_t arch_maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + return pte; +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static inline pmd_t arch_maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) +{ + return pmd; +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#endif /* CONFIG_ARCH_MAYBE_MKWRITE */ +#endif /* CONFIG_MMU */ + /* * Architecture PAGE_KERNEL_* fallbacks * diff --git a/include/linux/mm.h b/include/linux/mm.h index 54bb4cd9fee8..f0669e3cdd37 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -944,6 +944,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pte = pte_mkwrite(pte); + else + pte = arch_maybe_mkwrite(pte, vma); return pte; } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 6ecd1045113b..608746bb9d19 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -485,6 +485,8 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) pmd = pmd_mkwrite(pmd); + else + pmd = arch_maybe_pmd_mkwrite(pmd, vma); return pmd; } -- 2.21.0