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
60 struct mpx_fault_info {
61 void __user *addr;
62 void __user *lower;
63 void __user *upper;
64 };
65
66 #ifdef CONFIG_X86_INTEL_MPX
67
68 extern int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs);
69 extern int mpx_handle_bd_fault(void);
70
kernel_managing_mpx_tables(struct mm_struct * mm)71 static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
72 {
73 return (mm->context.bd_addr != MPX_INVALID_BOUNDS_DIR);
74 }
75
mpx_mm_init(struct mm_struct * mm)76 static inline void mpx_mm_init(struct mm_struct *mm)
77 {
78 /*
79 * NULL is theoretically a valid place to put the bounds
80 * directory, so point this at an invalid address.
81 */
82 mm->context.bd_addr = MPX_INVALID_BOUNDS_DIR;
83 }
84
85 extern void mpx_notify_unmap(struct mm_struct *mm, unsigned long start, unsigned long end);
86 extern unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len, unsigned long flags);
87
88 #else
mpx_fault_info(struct mpx_fault_info * info,struct pt_regs * regs)89 static inline int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs)
90 {
91 return -EINVAL;
92 }
mpx_handle_bd_fault(void)93 static inline int mpx_handle_bd_fault(void)
94 {
95 return -EINVAL;
96 }
kernel_managing_mpx_tables(struct mm_struct * mm)97 static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
98 {
99 return 0;
100 }
mpx_mm_init(struct mm_struct * mm)101 static inline void mpx_mm_init(struct mm_struct *mm)
102 {
103 }
mpx_notify_unmap(struct mm_struct * mm,unsigned long start,unsigned long end)104 static inline void mpx_notify_unmap(struct mm_struct *mm,
105 unsigned long start, unsigned long end)
106 {
107 }
108
mpx_unmapped_area_check(unsigned long addr,unsigned long len,unsigned long flags)109 static inline unsigned long mpx_unmapped_area_check(unsigned long addr,
110 unsigned long len, unsigned long flags)
111 {
112 return addr;
113 }
114 #endif /* CONFIG_X86_INTEL_MPX */
115
116 #endif /* _ASM_X86_MPX_H */
117
