diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-06-10 05:30:17 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-06-10 05:30:17 -0300 |
commit | d635711daa98be86d4c7fd01499c34f566b54ccb (patch) | |
tree | aa5cc3760a27c3d57146498cb82fa549547de06c /arch/x86/include/asm/mmu_context.h | |
parent | c91265cd0efb83778f015b4d4b1129bd2cfd075e (diff) |
Linux-libre 4.6.2-gnu
Diffstat (limited to 'arch/x86/include/asm/mmu_context.h')
-rw-r--r-- | arch/x86/include/asm/mmu_context.h | 85 |
1 files changed, 80 insertions, 5 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index bfd9b2a35..84280029c 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -52,15 +52,15 @@ struct ldt_struct { /* * Used for LDT copy/destruction. */ -int init_new_context(struct task_struct *tsk, struct mm_struct *mm); -void destroy_context(struct mm_struct *mm); +int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm); +void destroy_context_ldt(struct mm_struct *mm); #else /* CONFIG_MODIFY_LDT_SYSCALL */ -static inline int init_new_context(struct task_struct *tsk, - struct mm_struct *mm) +static inline int init_new_context_ldt(struct task_struct *tsk, + struct mm_struct *mm) { return 0; } -static inline void destroy_context(struct mm_struct *mm) {} +static inline void destroy_context_ldt(struct mm_struct *mm) {} #endif static inline void load_mm_ldt(struct mm_struct *mm) @@ -104,6 +104,17 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) #endif } +static inline int init_new_context(struct task_struct *tsk, + struct mm_struct *mm) +{ + init_new_context_ldt(tsk, mm); + return 0; +} +static inline void destroy_context(struct mm_struct *mm) +{ + destroy_context_ldt(mm); +} + static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { @@ -275,4 +286,68 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma, mpx_notify_unmap(mm, vma, start, end); } +static inline int vma_pkey(struct vm_area_struct *vma) +{ + u16 pkey = 0; +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS + unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 | + VM_PKEY_BIT2 | VM_PKEY_BIT3; + pkey = (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; +#endif + return pkey; +} + +static inline bool __pkru_allows_pkey(u16 pkey, bool write) +{ + u32 pkru = read_pkru(); + + if (!__pkru_allows_read(pkru, pkey)) + return false; + if (write && !__pkru_allows_write(pkru, pkey)) + return false; + + return true; +} + +/* + * We only want to enforce protection keys on the current process + * because we effectively have no access to PKRU for other + * processes or any way to tell *which * PKRU in a threaded + * process we could use. + * + * So do not enforce things if the VMA is not from the current + * mm, or if we are in a kernel thread. + */ +static inline bool vma_is_foreign(struct vm_area_struct *vma) +{ + if (!current->mm) + return true; + /* + * Should PKRU be enforced on the access to this VMA? If + * the VMA is from another process, then PKRU has no + * relevance and should not be enforced. + */ + if (current->mm != vma->vm_mm) + return true; + + return false; +} + +static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, + bool write, bool execute, bool foreign) +{ + /* pkeys never affect instruction fetches */ + if (execute) + return true; + /* allow access if the VMA is not one from this process */ + if (foreign || vma_is_foreign(vma)) + return true; + return __pkru_allows_pkey(vma_pkey(vma), write); +} + +static inline bool arch_pte_access_permitted(pte_t pte, bool write) +{ + return __pkru_allows_pkey(pte_flags_pkey(pte_flags(pte)), write); +} + #endif /* _ASM_X86_MMU_CONTEXT_H */ |