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 5e8c24d3aSDave Hansen #define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1) 666d37570SDave Hansen 784594296SDave Hansen extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 884594296SDave Hansen unsigned long init_val); 984594296SDave Hansen 1062b5f7d0SDave Hansen /* 1162b5f7d0SDave Hansen * Try to dedicate one of the protection keys to be used as an 1262b5f7d0SDave Hansen * execute-only protection key. 1362b5f7d0SDave Hansen */ 1462b5f7d0SDave Hansen extern int __execute_only_pkey(struct mm_struct *mm); 1562b5f7d0SDave Hansen static inline int execute_only_pkey(struct mm_struct *mm) 1662b5f7d0SDave Hansen { 1762b5f7d0SDave Hansen if (!boot_cpu_has(X86_FEATURE_OSPKE)) 1862b5f7d0SDave Hansen return 0; 1962b5f7d0SDave Hansen 2062b5f7d0SDave Hansen return __execute_only_pkey(mm); 2162b5f7d0SDave Hansen } 2262b5f7d0SDave Hansen 2362b5f7d0SDave Hansen extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma, 2462b5f7d0SDave Hansen int prot, int pkey); 2562b5f7d0SDave Hansen static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, 2662b5f7d0SDave Hansen int prot, int pkey) 2762b5f7d0SDave Hansen { 2862b5f7d0SDave Hansen if (!boot_cpu_has(X86_FEATURE_OSPKE)) 2962b5f7d0SDave Hansen return 0; 3062b5f7d0SDave Hansen 3162b5f7d0SDave Hansen return __arch_override_mprotect_pkey(vma, prot, pkey); 3262b5f7d0SDave Hansen } 3362b5f7d0SDave Hansen 347d06d9c9SDave Hansen extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 357d06d9c9SDave Hansen unsigned long init_val); 367d06d9c9SDave Hansen 37a8502b67SDave Hansen #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3) 38a8502b67SDave Hansen 39e8c24d3aSDave Hansen #define mm_pkey_allocation_map(mm) (mm->context.pkey_allocation_map) 40e8c24d3aSDave Hansen #define mm_set_pkey_allocated(mm, pkey) do { \ 41e8c24d3aSDave Hansen mm_pkey_allocation_map(mm) |= (1U << pkey); \ 42e8c24d3aSDave Hansen } while (0) 43e8c24d3aSDave Hansen #define mm_set_pkey_free(mm, pkey) do { \ 44e8c24d3aSDave Hansen mm_pkey_allocation_map(mm) &= ~(1U << pkey); \ 45e8c24d3aSDave Hansen } while (0) 46e8c24d3aSDave Hansen 47e8c24d3aSDave Hansen static inline 48e8c24d3aSDave Hansen bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey) 49e8c24d3aSDave Hansen { 5058ab9a08SDave Hansen /* 5158ab9a08SDave Hansen * "Allocated" pkeys are those that have been returned 5258ab9a08SDave Hansen * from pkey_alloc(). pkey 0 is special, and never 5358ab9a08SDave Hansen * returned from pkey_alloc(). 5458ab9a08SDave Hansen */ 5558ab9a08SDave Hansen if (pkey <= 0) 5658ab9a08SDave Hansen return false; 5758ab9a08SDave Hansen if (pkey >= arch_max_pkey()) 5858ab9a08SDave Hansen return false; 59e8c24d3aSDave Hansen return mm_pkey_allocation_map(mm) & (1U << pkey); 60e8c24d3aSDave Hansen } 61e8c24d3aSDave Hansen 62e8c24d3aSDave Hansen /* 63e8c24d3aSDave Hansen * Returns a positive, 4-bit key on success, or -1 on failure. 64e8c24d3aSDave Hansen */ 65e8c24d3aSDave Hansen static inline 66e8c24d3aSDave Hansen int mm_pkey_alloc(struct mm_struct *mm) 67e8c24d3aSDave Hansen { 68e8c24d3aSDave Hansen /* 69e8c24d3aSDave Hansen * Note: this is the one and only place we make sure 70e8c24d3aSDave Hansen * that the pkey is valid as far as the hardware is 71e8c24d3aSDave Hansen * concerned. The rest of the kernel trusts that 72e8c24d3aSDave Hansen * only good, valid pkeys come out of here. 73e8c24d3aSDave Hansen */ 74e8c24d3aSDave Hansen u16 all_pkeys_mask = ((1U << arch_max_pkey()) - 1); 75e8c24d3aSDave Hansen int ret; 76e8c24d3aSDave Hansen 77e8c24d3aSDave Hansen /* 78e8c24d3aSDave Hansen * Are we out of pkeys? We must handle this specially 79e8c24d3aSDave Hansen * because ffz() behavior is undefined if there are no 80e8c24d3aSDave Hansen * zeros. 81e8c24d3aSDave Hansen */ 82e8c24d3aSDave Hansen if (mm_pkey_allocation_map(mm) == all_pkeys_mask) 83e8c24d3aSDave Hansen return -1; 84e8c24d3aSDave Hansen 85e8c24d3aSDave Hansen ret = ffz(mm_pkey_allocation_map(mm)); 86e8c24d3aSDave Hansen 87e8c24d3aSDave Hansen mm_set_pkey_allocated(mm, ret); 88e8c24d3aSDave Hansen 89e8c24d3aSDave Hansen return ret; 90e8c24d3aSDave Hansen } 91e8c24d3aSDave Hansen 92e8c24d3aSDave Hansen static inline 93e8c24d3aSDave Hansen int mm_pkey_free(struct mm_struct *mm, int pkey) 94e8c24d3aSDave Hansen { 95e8c24d3aSDave Hansen if (!mm_pkey_is_allocated(mm, pkey)) 96e8c24d3aSDave Hansen return -EINVAL; 97e8c24d3aSDave Hansen 98e8c24d3aSDave Hansen mm_set_pkey_free(mm, pkey); 99e8c24d3aSDave Hansen 100e8c24d3aSDave Hansen return 0; 101e8c24d3aSDave Hansen } 102e8c24d3aSDave Hansen 103e8c24d3aSDave Hansen extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 104e8c24d3aSDave Hansen unsigned long init_val); 105e8c24d3aSDave Hansen extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, 106e8c24d3aSDave Hansen unsigned long init_val); 107acd547b2SDave Hansen extern void copy_init_pkru_to_fpregs(void); 108e8c24d3aSDave Hansen 109555934a7SMichael Ellerman static inline int vma_pkey(struct vm_area_struct *vma) 110555934a7SMichael Ellerman { 111555934a7SMichael Ellerman unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 | 112555934a7SMichael Ellerman VM_PKEY_BIT2 | VM_PKEY_BIT3; 113555934a7SMichael Ellerman 114555934a7SMichael Ellerman return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; 115555934a7SMichael Ellerman } 116555934a7SMichael Ellerman 11766d37570SDave Hansen #endif /*_ASM_X86_PKEYS_H */ 118