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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
23static 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(¤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
44static 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
51static inline unsigned long seg_get_limit(struct desc_struct *d)
52{
53 return ((unsigned long)d->limit1 << 16) | d->limit0;
54}
55
56static inline unsigned long seg_get_granularity(struct desc_struct *d)
57{
58 return d->g ? 4096 : 1;
59}
60
61static inline bool seg_expands_down(struct desc_struct *d)
62{
63 return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN;
64}
65
66static inline bool seg_execute_only(struct desc_struct *d)
67{
68 return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE;
69}
70
71static 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
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
23static 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(¤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
44static 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
51static inline unsigned long seg_get_limit(struct desc_struct *d)
52{
53 return ((unsigned long)d->limit1 << 16) | d->limit0;
54}
55
56static inline unsigned long seg_get_granularity(struct desc_struct *d)
57{
58 return d->g ? 4096 : 1;
59}
60
61static inline bool seg_expands_down(struct desc_struct *d)
62{
63 return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN;
64}
65
66static inline bool seg_execute_only(struct desc_struct *d)
67{
68 return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE;
69}
70
71static 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