1 #ifndef _ASM_X86_PKEYS_H 2 #define _ASM_X86_PKEYS_H 3 4 #define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1) 5 6 extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 7 unsigned long init_val); 8 9 /* 10 * Try to dedicate one of the protection keys to be used as an 11 * execute-only protection key. 12 */ 13 extern int __execute_only_pkey(struct mm_struct *mm); 14 static inline int execute_only_pkey(struct mm_struct *mm) 15 { 16 if (!boot_cpu_has(X86_FEATURE_OSPKE)) 17 return 0; 18 19 return __execute_only_pkey(mm); 20 } 21 22 extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, 23 int prot, int pkey); 24 static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, 25 int prot, int pkey) 26 { 27 if (!boot_cpu_has(X86_FEATURE_OSPKE)) 28 return 0; 29 30 return __arch_override_mprotect_pkey(vma, prot, pkey); 31 } 32 33 extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 34 unsigned long init_val); 35 36 #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3) 37 38 #define mm_pkey_allocation_map(mm) (mm->context.pkey_allocation_map) 39 #define mm_set_pkey_allocated(mm, pkey) do { \ 40 mm_pkey_allocation_map(mm) |= (1U << pkey); \ 41 } while (0) 42 #define mm_set_pkey_free(mm, pkey) do { \ 43 mm_pkey_allocation_map(mm) &= ~(1U << pkey); \ 44 } while (0) 45 46 static inline 47 bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey) 48 { 49 return mm_pkey_allocation_map(mm) & (1U << pkey); 50 } 51 52 /* 53 * Returns a positive, 4-bit key on success, or -1 on failure. 54 */ 55 static inline 56 int mm_pkey_alloc(struct mm_struct *mm) 57 { 58 /* 59 * Note: this is the one and only place we make sure 60 * that the pkey is valid as far as the hardware is 61 * concerned. The rest of the kernel trusts that 62 * only good, valid pkeys come out of here. 63 */ 64 u16 all_pkeys_mask = ((1U << arch_max_pkey()) - 1); 65 int ret; 66 67 /* 68 * Are we out of pkeys? We must handle this specially 69 * because ffz() behavior is undefined if there are no 70 * zeros. 71 */ 72 if (mm_pkey_allocation_map(mm) == all_pkeys_mask) 73 return -1; 74 75 ret = ffz(mm_pkey_allocation_map(mm)); 76 77 mm_set_pkey_allocated(mm, ret); 78 79 return ret; 80 } 81 82 static inline 83 int mm_pkey_free(struct mm_struct *mm, int pkey) 84 { 85 /* 86 * pkey 0 is special, always allocated and can never 87 * be freed. 88 */ 89 if (!pkey) 90 return -EINVAL; 91 if (!mm_pkey_is_allocated(mm, pkey)) 92 return -EINVAL; 93 94 mm_set_pkey_free(mm, pkey); 95 96 return 0; 97 } 98 99 extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 100 unsigned long init_val); 101 extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 102 unsigned long init_val); 103 extern void copy_init_pkru_to_fpregs(void); 104 105 #endif /*_ASM_X86_PKEYS_H */ 106