1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_MPX_H
3#define _ASM_X86_MPX_H
4
5#include <linux/types.h>
6#include <linux/mm_types.h>
7
8#include <asm/ptrace.h>
9#include <asm/insn.h>
10
11/*
12 * NULL is theoretically a valid place to put the bounds
13 * directory, so point this at an invalid address.
14 */
15#define MPX_INVALID_BOUNDS_DIR ((void __user *)-1)
16#define MPX_BNDCFG_ENABLE_FLAG 0x1
17#define MPX_BD_ENTRY_VALID_FLAG 0x1
18
19/*
20 * The upper 28 bits [47:20] of the virtual address in 64-bit
21 * are used to index into bounds directory (BD).
22 *
23 * The directory is 2G (2^31) in size, and with 8-byte entries
24 * it has 2^28 entries.
25 */
26#define MPX_BD_SIZE_BYTES_64 (1UL<<31)
27#define MPX_BD_ENTRY_BYTES_64 8
28#define MPX_BD_NR_ENTRIES_64 (MPX_BD_SIZE_BYTES_64/MPX_BD_ENTRY_BYTES_64)
29
30/*
31 * The 32-bit directory is 4MB (2^22) in size, and with 4-byte
32 * entries it has 2^20 entries.
33 */
34#define MPX_BD_SIZE_BYTES_32 (1UL<<22)
35#define MPX_BD_ENTRY_BYTES_32 4
36#define MPX_BD_NR_ENTRIES_32 (MPX_BD_SIZE_BYTES_32/MPX_BD_ENTRY_BYTES_32)
37
38/*
39 * A 64-bit table is 4MB total in size, and an entry is
40 * 4 64-bit pointers in size.
41 */
42#define MPX_BT_SIZE_BYTES_64 (1UL<<22)
43#define MPX_BT_ENTRY_BYTES_64 32
44#define MPX_BT_NR_ENTRIES_64 (MPX_BT_SIZE_BYTES_64/MPX_BT_ENTRY_BYTES_64)
45
46/*
47 * A 32-bit table is 16kB total in size, and an entry is
48 * 4 32-bit pointers in size.
49 */
50#define MPX_BT_SIZE_BYTES_32 (1UL<<14)
51#define MPX_BT_ENTRY_BYTES_32 16
52#define MPX_BT_NR_ENTRIES_32 (MPX_BT_SIZE_BYTES_32/MPX_BT_ENTRY_BYTES_32)
53
54#define MPX_BNDSTA_TAIL 2
55#define MPX_BNDCFG_TAIL 12
56#define MPX_BNDSTA_ADDR_MASK (~((1UL<<MPX_BNDSTA_TAIL)-1))
57#define MPX_BNDCFG_ADDR_MASK (~((1UL<<MPX_BNDCFG_TAIL)-1))
58#define MPX_BNDSTA_ERROR_CODE 0x3
59
60struct mpx_fault_info {
61 void __user *addr;
62 void __user *lower;
63 void __user *upper;
64};
65
66#ifdef CONFIG_X86_INTEL_MPX
67int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs);
68int mpx_handle_bd_fault(void);
69static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
70{
71 return (mm->context.bd_addr != MPX_INVALID_BOUNDS_DIR);
72}
73static inline void mpx_mm_init(struct mm_struct *mm)
74{
75 /*
76 * NULL is theoretically a valid place to put the bounds
77 * directory, so point this at an invalid address.
78 */
79 mm->context.bd_addr = MPX_INVALID_BOUNDS_DIR;
80}
81void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
82 unsigned long start, unsigned long end);
83
84unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len,
85 unsigned long flags);
86#else
87static inline int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs)
88{
89 return -EINVAL;
90}
91static inline int mpx_handle_bd_fault(void)
92{
93 return -EINVAL;
94}
95static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
96{
97 return 0;
98}
99static inline void mpx_mm_init(struct mm_struct *mm)
100{
101}
102static inline void mpx_notify_unmap(struct mm_struct *mm,
103 struct vm_area_struct *vma,
104 unsigned long start, unsigned long end)
105{
106}
107
108static inline unsigned long mpx_unmapped_area_check(unsigned long addr,
109 unsigned long len, unsigned long flags)
110{
111 return addr;
112}
113#endif /* CONFIG_X86_INTEL_MPX */
114
115#endif /* _ASM_X86_MPX_H */
116