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
 6extern 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#define PKEY_DEDICATED_EXECUTE_ONLY 15
14extern int __execute_only_pkey(struct mm_struct *mm);
15static inline int execute_only_pkey(struct mm_struct *mm)
16{
17	if (!boot_cpu_has(X86_FEATURE_OSPKE))
18		return 0;
19
20	return __execute_only_pkey(mm);
21}
22
23extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
24		int prot, int pkey);
25static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
26		int prot, int pkey)
27{
28	if (!boot_cpu_has(X86_FEATURE_OSPKE))
29		return 0;
30
31	return __arch_override_mprotect_pkey(vma, prot, pkey);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
32}
33
34#endif /*_ASM_X86_PKEYS_H */

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_X86_PKEYS_H
  3#define _ASM_X86_PKEYS_H
  4
  5/*
  6 * If more than 16 keys are ever supported, a thorough audit
  7 * will be necessary to ensure that the types that store key
  8 * numbers and masks have sufficient capacity.
  9 */
 10#define arch_max_pkey() (cpu_feature_enabled(X86_FEATURE_OSPKE) ? 16 : 1)
 11
 12extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 13		unsigned long init_val);
 14
 15static inline bool arch_pkeys_enabled(void)
 16{
 17	return cpu_feature_enabled(X86_FEATURE_OSPKE);
 18}
 19
 20/*
 21 * Try to dedicate one of the protection keys to be used as an
 22 * execute-only protection key.
 23 */
 
 24extern int __execute_only_pkey(struct mm_struct *mm);
 25static inline int execute_only_pkey(struct mm_struct *mm)
 26{
 27	if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
 28		return ARCH_DEFAULT_PKEY;
 29
 30	return __execute_only_pkey(mm);
 31}
 32
 33extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
 34		int prot, int pkey);
 35static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
 36		int prot, int pkey)
 37{
 38	if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
 39		return 0;
 40
 41	return __arch_override_mprotect_pkey(vma, prot, pkey);
 42}
 43
 44#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | VM_PKEY_BIT3)
 45
 46#define mm_pkey_allocation_map(mm)	(mm->context.pkey_allocation_map)
 47#define mm_set_pkey_allocated(mm, pkey) do {		\
 48	mm_pkey_allocation_map(mm) |= (1U << pkey);	\
 49} while (0)
 50#define mm_set_pkey_free(mm, pkey) do {			\
 51	mm_pkey_allocation_map(mm) &= ~(1U << pkey);	\
 52} while (0)
 53
 54static inline
 55bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
 56{
 57	/*
 58	 * "Allocated" pkeys are those that have been returned
 59	 * from pkey_alloc() or pkey 0 which is allocated
 60	 * implicitly when the mm is created.
 61	 */
 62	if (pkey < 0)
 63		return false;
 64	if (pkey >= arch_max_pkey())
 65		return false;
 66	/*
 67	 * The exec-only pkey is set in the allocation map, but
 68	 * is not available to any of the user interfaces like
 69	 * mprotect_pkey().
 70	 */
 71	if (pkey == mm->context.execute_only_pkey)
 72		return false;
 73
 74	return mm_pkey_allocation_map(mm) & (1U << pkey);
 75}
 76
 77/*
 78 * Returns a positive, 4-bit key on success, or -1 on failure.
 79 */
 80static inline
 81int mm_pkey_alloc(struct mm_struct *mm)
 82{
 83	/*
 84	 * Note: this is the one and only place we make sure
 85	 * that the pkey is valid as far as the hardware is
 86	 * concerned.  The rest of the kernel trusts that
 87	 * only good, valid pkeys come out of here.
 88	 */
 89	u16 all_pkeys_mask = ((1U << arch_max_pkey()) - 1);
 90	int ret;
 91
 92	/*
 93	 * Are we out of pkeys?  We must handle this specially
 94	 * because ffz() behavior is undefined if there are no
 95	 * zeros.
 96	 */
 97	if (mm_pkey_allocation_map(mm) == all_pkeys_mask)
 98		return -1;
 99
100	ret = ffz(mm_pkey_allocation_map(mm));
101
102	mm_set_pkey_allocated(mm, ret);
103
104	return ret;
105}
106
107static inline
108int mm_pkey_free(struct mm_struct *mm, int pkey)
109{
110	if (!mm_pkey_is_allocated(mm, pkey))
111		return -EINVAL;
112
113	mm_set_pkey_free(mm, pkey);
114
115	return 0;
116}
117
118static inline int vma_pkey(struct vm_area_struct *vma)
119{
120	unsigned long vma_pkey_mask = VM_PKEY_BIT0 | VM_PKEY_BIT1 |
121				      VM_PKEY_BIT2 | VM_PKEY_BIT3;
122
123	return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT;
124}
125
126#endif /*_ASM_X86_PKEYS_H */