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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/*---------------------------------------------------------------------------+
2 | fpu_system.h |
3 | |
4 | Copyright (C) 1992,1994,1997 |
5 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
6 | Australia. E-mail billm@suburbia.net |
7 | |
8 +---------------------------------------------------------------------------*/
9
10#ifndef _FPU_SYSTEM_H
11#define _FPU_SYSTEM_H
12
13/* system dependent definitions */
14
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
18
19/* s is always from a cpu register, and the cpu does bounds checking
20 * during register load --> no further bounds checks needed */
21#define LDT_DESCRIPTOR(s) (((struct desc_struct *)current->mm->context.ldt)[(s) >> 3])
22#define SEG_D_SIZE(x) ((x).b & (3 << 21))
23#define SEG_G_BIT(x) ((x).b & (1 << 23))
24#define SEG_GRANULARITY(x) (((x).b & (1 << 23)) ? 4096 : 1)
25#define SEG_286_MODE(x) ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
26#define SEG_BASE_ADDR(s) (((s).b & 0xff000000) \
27 | (((s).b & 0xff) << 16) | ((s).a >> 16))
28#define SEG_LIMIT(s) (((s).b & 0xff0000) | ((s).a & 0xffff))
29#define SEG_EXECUTE_ONLY(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
30#define SEG_WRITE_PERM(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
31#define SEG_EXPAND_DOWN(s) (((s).b & ((1 << 11) | (1 << 10))) \
32 == (1 << 10))
33
34#define I387 (current->thread.fpu.state)
35#define FPU_info (I387->soft.info)
36
37#define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs))
38#define FPU_SS (*(unsigned short *) &(FPU_info->regs->ss))
39#define FPU_DS (*(unsigned short *) &(FPU_info->regs->ds))
40#define FPU_EAX (FPU_info->regs->ax)
41#define FPU_EFLAGS (FPU_info->regs->flags)
42#define FPU_EIP (FPU_info->regs->ip)
43#define FPU_ORIG_EIP (FPU_info->___orig_eip)
44
45#define FPU_lookahead (I387->soft.lookahead)
46
47/* nz if ip_offset and cs_selector are not to be set for the current
48 instruction. */
49#define no_ip_update (*(u_char *)&(I387->soft.no_update))
50#define FPU_rm (*(u_char *)&(I387->soft.rm))
51
52/* Number of bytes of data which can be legally accessed by the current
53 instruction. This only needs to hold a number <= 108, so a byte will do. */
54#define access_limit (*(u_char *)&(I387->soft.alimit))
55
56#define partial_status (I387->soft.swd)
57#define control_word (I387->soft.cwd)
58#define fpu_tag_word (I387->soft.twd)
59#define registers (I387->soft.st_space)
60#define top (I387->soft.ftop)
61
62#define instruction_address (*(struct address *)&I387->soft.fip)
63#define operand_address (*(struct address *)&I387->soft.foo)
64
65#define FPU_access_ok(x,y,z) if ( !access_ok(x,y,z) ) \
66 math_abort(FPU_info,SIGSEGV)
67#define FPU_abort math_abort(FPU_info, SIGSEGV)
68
69#undef FPU_IGNORE_CODE_SEGV
70#ifdef FPU_IGNORE_CODE_SEGV
71/* access_ok() is very expensive, and causes the emulator to run
72 about 20% slower if applied to the code. Anyway, errors due to bad
73 code addresses should be much rarer than errors due to bad data
74 addresses. */
75#define FPU_code_access_ok(z)
76#else
77/* A simpler test than access_ok() can probably be done for
78 FPU_code_access_ok() because the only possible error is to step
79 past the upper boundary of a legal code area. */
80#define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z)
81#endif
82
83#define FPU_get_user(x,y) get_user((x),(y))
84#define FPU_put_user(x,y) put_user((x),(y))
85
86#endif