1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /*---------------------------------------------------------------------------+ |
3 | | fpu_system.h | |
4 | | | |
5 | | Copyright (C) 1992,1994,1997 | |
6 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | |
7 | | Australia. E-mail billm@suburbia.net | |
8 | | | |
9 | +---------------------------------------------------------------------------*/ |
10 | |
11 | #ifndef _FPU_SYSTEM_H |
12 | #define _FPU_SYSTEM_H |
13 | |
14 | /* system dependent definitions */ |
15 | |
16 | #include <linux/sched.h> |
17 | #include <linux/kernel.h> |
18 | #include <linux/mm.h> |
19 | |
20 | #include <asm/desc.h> |
21 | #include <asm/mmu_context.h> |
22 | |
23 | static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg) |
24 | { |
25 | static struct desc_struct zero_desc; |
26 | struct desc_struct ret = zero_desc; |
27 | |
28 | #ifdef CONFIG_MODIFY_LDT_SYSCALL |
29 | seg >>= 3; |
30 | mutex_lock(¤t->mm->context.lock); |
31 | if (current->mm->context.ldt && seg < current->mm->context.ldt->nr_entries) |
32 | ret = current->mm->context.ldt->entries[seg]; |
33 | mutex_unlock(lock: ¤t->mm->context.lock); |
34 | #endif |
35 | return ret; |
36 | } |
37 | |
38 | #define SEG_TYPE_WRITABLE (1U << 1) |
39 | #define SEG_TYPE_EXPANDS_DOWN (1U << 2) |
40 | #define SEG_TYPE_EXECUTE (1U << 3) |
41 | #define SEG_TYPE_EXPAND_MASK (SEG_TYPE_EXPANDS_DOWN | SEG_TYPE_EXECUTE) |
42 | #define SEG_TYPE_EXECUTE_MASK (SEG_TYPE_WRITABLE | SEG_TYPE_EXECUTE) |
43 | |
44 | static inline unsigned long seg_get_base(struct desc_struct *d) |
45 | { |
46 | unsigned long base = (unsigned long)d->base2 << 24; |
47 | |
48 | return base | ((unsigned long)d->base1 << 16) | d->base0; |
49 | } |
50 | |
51 | static inline unsigned long seg_get_limit(struct desc_struct *d) |
52 | { |
53 | return ((unsigned long)d->limit1 << 16) | d->limit0; |
54 | } |
55 | |
56 | static inline unsigned long seg_get_granularity(struct desc_struct *d) |
57 | { |
58 | return d->g ? 4096 : 1; |
59 | } |
60 | |
61 | static inline bool seg_expands_down(struct desc_struct *d) |
62 | { |
63 | return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN; |
64 | } |
65 | |
66 | static inline bool seg_execute_only(struct desc_struct *d) |
67 | { |
68 | return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE; |
69 | } |
70 | |
71 | static inline bool seg_writable(struct desc_struct *d) |
72 | { |
73 | return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_WRITABLE; |
74 | } |
75 | |
76 | #define I387 (¤t->thread.fpu.fpstate->regs) |
77 | #define FPU_info (I387->soft.info) |
78 | |
79 | #define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs)) |
80 | #define FPU_SS (*(unsigned short *) &(FPU_info->regs->ss)) |
81 | #define FPU_DS (*(unsigned short *) &(FPU_info->regs->ds)) |
82 | #define FPU_EAX (FPU_info->regs->ax) |
83 | #define FPU_EFLAGS (FPU_info->regs->flags) |
84 | #define FPU_EIP (FPU_info->regs->ip) |
85 | #define FPU_ORIG_EIP (FPU_info->___orig_eip) |
86 | |
87 | #define FPU_lookahead (I387->soft.lookahead) |
88 | |
89 | /* nz if ip_offset and cs_selector are not to be set for the current |
90 | instruction. */ |
91 | #define no_ip_update (*(u_char *)&(I387->soft.no_update)) |
92 | #define FPU_rm (*(u_char *)&(I387->soft.rm)) |
93 | |
94 | /* Number of bytes of data which can be legally accessed by the current |
95 | instruction. This only needs to hold a number <= 108, so a byte will do. */ |
96 | #define access_limit (*(u_char *)&(I387->soft.alimit)) |
97 | |
98 | #define partial_status (I387->soft.swd) |
99 | #define control_word (I387->soft.cwd) |
100 | #define fpu_tag_word (I387->soft.twd) |
101 | #define registers (I387->soft.st_space) |
102 | #define top (I387->soft.ftop) |
103 | |
104 | #define instruction_address (*(struct address *)&I387->soft.fip) |
105 | #define operand_address (*(struct address *)&I387->soft.foo) |
106 | |
107 | #define FPU_access_ok(y,z) if ( !access_ok(y,z) ) \ |
108 | math_abort(FPU_info,SIGSEGV) |
109 | #define FPU_abort math_abort(FPU_info, SIGSEGV) |
110 | #define FPU_copy_from_user(to, from, n) \ |
111 | do { if (copy_from_user(to, from, n)) FPU_abort; } while (0) |
112 | |
113 | #undef FPU_IGNORE_CODE_SEGV |
114 | #ifdef FPU_IGNORE_CODE_SEGV |
115 | /* access_ok() is very expensive, and causes the emulator to run |
116 | about 20% slower if applied to the code. Anyway, errors due to bad |
117 | code addresses should be much rarer than errors due to bad data |
118 | addresses. */ |
119 | #define FPU_code_access_ok(z) |
120 | #else |
121 | /* A simpler test than access_ok() can probably be done for |
122 | FPU_code_access_ok() because the only possible error is to step |
123 | past the upper boundary of a legal code area. */ |
124 | #define FPU_code_access_ok(z) FPU_access_ok((void __user *)FPU_EIP,z) |
125 | #endif |
126 | |
127 | #define FPU_get_user(x,y) do { if (get_user((x),(y))) FPU_abort; } while (0) |
128 | #define FPU_put_user(x,y) do { if (put_user((x),(y))) FPU_abort; } while (0) |
129 | |
130 | #endif |
131 | |