1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 266d37570SDave Hansen #ifndef _ASM_X86_PKEYS_H 366d37570SDave Hansen #define _ASM_X86_PKEYS_H 466d37570SDave Hansen 50a0b1520SDave Hansen #define ARCH_DEFAULT_PKEY 0 60a0b1520SDave Hansen 716171bffSDave Hansen /* 816171bffSDave Hansen * If more than 16 keys are ever supported, a thorough audit 916171bffSDave Hansen * will be necessary to ensure that the types that store key 1016171bffSDave Hansen * numbers and masks have sufficient capacity. 1116171bffSDave Hansen */ 12*8a1dc55aSThomas Gleixner #define arch_max_pkey() (cpu_feature_enabled(X86_FEATURE_OSPKE) ? 16 : 1) 1366d37570SDave Hansen 1484594296SDave Hansen extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 1584594296SDave Hansen unsigned long init_val); 1684594296SDave Hansen 173f36c942SMichael Ellerman static inline bool arch_pkeys_enabled(void) 183f36c942SMichael Ellerman { 19*8a1dc55aSThomas Gleixner return cpu_feature_enabled(X86_FEATURE_OSPKE); 203f36c942SMichael Ellerman } 213f36c942SMichael Ellerman 2262b5f7d0SDave Hansen /* 2362b5f7d0SDave Hansen * Try to dedicate one of the protection keys to be used as an 2462b5f7d0SDave Hansen * execute-only protection key. 2562b5f7d0SDave Hansen */ 2662b5f7d0SDave Hansen extern int __execute_only_pkey(struct mm_struct *mm); 2762b5f7d0SDave Hansen static inline int execute_only_pkey(struct mm_struct *mm) 2862b5f7d0SDave Hansen { 29*8a1dc55aSThomas Gleixner if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) 300a0b1520SDave Hansen return ARCH_DEFAULT_PKEY; 3162b5f7d0SDave Hansen 3262b5f7d0SDave Hansen return __execute_only_pkey(mm); 3362b5f7d0SDave Hansen } 3462b5f7d0SDave Hansen 3562b5f7d0SDave Hansen extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, 3662b5f7d0SDave Hansen int prot, int pkey); 3762b5f7d0SDave Hansen static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, 3862b5f7d0SDave Hansen int prot, int pkey) 3962b5f7d0SDave Hansen { 40*8a1dc55aSThomas Gleixner if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) 4162b5f7d0SDave Hansen return 0; 4262b5f7d0SDave Hansen 4362b5f7d0SDave Hansen return __arch_override_mprotect_pkey(vma, prot, pkey); 4462b5f7d0SDave Hansen } 4562b5f7d0SDave Hansen 467d06d9c9SDave Hansen extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 477d06d9c9SDave Hansen unsigned long init_val); 487d06d9c9SDave Hansen 49a8502b67SDave Hansen #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3) 50a8502b67SDave Hansen 51e8c24d3aSDave Hansen #define mm_pkey_allocation_map(mm) (mm->context.pkey_allocation_map) 52e8c24d3aSDave Hansen #define mm_set_pkey_allocated(mm, pkey) do { \ 53e8c24d3aSDave Hansen mm_pkey_allocation_map(mm) |= (1U << pkey); \ 54e8c24d3aSDave Hansen } while (0) 55e8c24d3aSDave Hansen #define mm_set_pkey_free(mm, pkey) do { \ 56e8c24d3aSDave Hansen mm_pkey_allocation_map(mm) &= ~(1U << pkey); \ 57e8c24d3aSDave Hansen } while (0) 58e8c24d3aSDave Hansen 59e8c24d3aSDave Hansen static inline 60e8c24d3aSDave Hansen bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey) 61e8c24d3aSDave Hansen { 6258ab9a08SDave Hansen /* 6358ab9a08SDave Hansen * "Allocated" pkeys are those that have been returned 642fa9d1cfSDave Hansen * from pkey_alloc() or pkey 0 which is allocated 652fa9d1cfSDave Hansen * implicitly when the mm is created. 6658ab9a08SDave Hansen */ 672fa9d1cfSDave Hansen if (pkey < 0) 6858ab9a08SDave Hansen return false; 6958ab9a08SDave Hansen if (pkey >= arch_max_pkey()) 7058ab9a08SDave Hansen return false; 710a0b1520SDave Hansen /* 720a0b1520SDave Hansen * The exec-only pkey is set in the allocation map, but 730a0b1520SDave Hansen * is not available to any of the user interfaces like 740a0b1520SDave Hansen * mprotect_pkey(). 750a0b1520SDave Hansen */ 760a0b1520SDave Hansen if (pkey == mm->context.execute_only_pkey) 770a0b1520SDave Hansen return false; 780a0b1520SDave Hansen 79e8c24d3aSDave Hansen return mm_pkey_allocation_map(mm) & (1U << pkey); 80e8c24d3aSDave Hansen } 81e8c24d3aSDave Hansen 82e8c24d3aSDave Hansen /* 83e8c24d3aSDave Hansen * Returns a positive, 4-bit key on success, or -1 on failure. 84e8c24d3aSDave Hansen */ 85e8c24d3aSDave Hansen static inline 86e8c24d3aSDave Hansen int mm_pkey_alloc(struct mm_struct *mm) 87e8c24d3aSDave Hansen { 88e8c24d3aSDave Hansen /* 89e8c24d3aSDave Hansen * Note: this is the one and only place we make sure 90e8c24d3aSDave Hansen * that the pkey is valid as far as the hardware is 91e8c24d3aSDave Hansen * concerned. The rest of the kernel trusts that 92e8c24d3aSDave Hansen * only good, valid pkeys come out of here. 93e8c24d3aSDave Hansen */ 94e8c24d3aSDave Hansen u16 all_pkeys_mask = ((1U << arch_max_pkey()) - 1); 95e8c24d3aSDave Hansen int ret; 96e8c24d3aSDave Hansen 97e8c24d3aSDave Hansen /* 98e8c24d3aSDave Hansen * Are we out of pkeys? We must handle this specially 99e8c24d3aSDave Hansen * because ffz() behavior is undefined if there are no 100e8c24d3aSDave Hansen * zeros. 101e8c24d3aSDave Hansen */ 102e8c24d3aSDave Hansen if (mm_pkey_allocation_map(mm) == all_pkeys_mask) 103e8c24d3aSDave Hansen return -1; 104e8c24d3aSDave Hansen 105e8c24d3aSDave Hansen ret = ffz(mm_pkey_allocation_map(mm)); 106e8c24d3aSDave Hansen 107e8c24d3aSDave Hansen mm_set_pkey_allocated(mm, ret); 108e8c24d3aSDave Hansen 109e8c24d3aSDave Hansen return ret; 110e8c24d3aSDave Hansen } 111e8c24d3aSDave Hansen 112e8c24d3aSDave Hansen static inline 113e8c24d3aSDave Hansen int mm_pkey_free(struct mm_struct *mm, int pkey) 114e8c24d3aSDave Hansen { 115e8c24d3aSDave Hansen if (!mm_pkey_is_allocated(mm, pkey)) 116e8c24d3aSDave Hansen return -EINVAL; 117e8c24d3aSDave Hansen 118e8c24d3aSDave Hansen mm_set_pkey_free(mm, pkey); 119e8c24d3aSDave Hansen 120e8c24d3aSDave Hansen return 0; 121e8c24d3aSDave Hansen } 122e8c24d3aSDave Hansen 123e8c24d3aSDave Hansen extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 124e8c24d3aSDave Hansen unsigned long init_val); 125e8c24d3aSDave Hansen extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 126e8c24d3aSDave Hansen unsigned long init_val); 127acd547b2SDave Hansen extern void copy_init_pkru_to_fpregs(void); 128e8c24d3aSDave Hansen 129555934a7SMichael Ellerman static inline int vma_pkey(struct vm_area_struct *vma) 130555934a7SMichael Ellerman { 131555934a7SMichael Ellerman unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 | 132555934a7SMichael Ellerman VM_PKEY_BIT2 | VM_PKEY_BIT3; 133555934a7SMichael Ellerman 134555934a7SMichael Ellerman return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; 135555934a7SMichael Ellerman } 136555934a7SMichael Ellerman 13766d37570SDave Hansen #endif /*_ASM_X86_PKEYS_H */ 138