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 /* 50 * "Allocated" pkeys are those that have been returned 51 * from pkey_alloc(). pkey 0 is special, and never 52 * returned from pkey_alloc(). 53 */ 54 if (pkey <= 0) 55 return false; 56 if (pkey >= arch_max_pkey()) 57 return false; 58 return mm_pkey_allocation_map(mm) & (1U << pkey); 59 } 60 61 /* 62 * Returns a positive, 4-bit key on success, or -1 on failure. 63 */ 64 static inline 65 int mm_pkey_alloc(struct mm_struct *mm) 66 { 67 /* 68 * Note: this is the one and only place we make sure 69 * that the pkey is valid as far as the hardware is 70 * concerned. The rest of the kernel trusts that 71 * only good, valid pkeys come out of here. 72 */ 73 u16 all_pkeys_mask = ((1U << arch_max_pkey()) - 1); 74 int ret; 75 76 /* 77 * Are we out of pkeys? We must handle this specially 78 * because ffz() behavior is undefined if there are no 79 * zeros. 80 */ 81 if (mm_pkey_allocation_map(mm) == all_pkeys_mask) 82 return -1; 83 84 ret = ffz(mm_pkey_allocation_map(mm)); 85 86 mm_set_pkey_allocated(mm, ret); 87 88 return ret; 89 } 90 91 static inline 92 int mm_pkey_free(struct mm_struct *mm, int pkey) 93 { 94 if (!mm_pkey_is_allocated(mm, pkey)) 95 return -EINVAL; 96 97 mm_set_pkey_free(mm, pkey); 98 99 return 0; 100 } 101 102 extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 103 unsigned long init_val); 104 extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 105 unsigned long init_val); 106 extern void copy_init_pkru_to_fpregs(void); 107 108 #endif /*_ASM_X86_PKEYS_H */ 109