1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include "linux/mm.h"
#include "linux/sched.h"
#include "asm/uaccess.h"
#include "skas.h"
extern int arch_switch_tls(struct task_struct *to);
void arch_switch_to(struct task_struct *to)
{
int err = arch_switch_tls(to);
if (!err)
return;
if (err != -EINVAL)
printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
"not EINVAL\n", -err);
else
printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
}
int is_syscall(unsigned long addr)
{
unsigned short instr;
int n;
n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
if (n) {
/* access_process_vm() grants access to vsyscall and stub,
* while copy_from_user doesn't. Maybe access_process_vm is
* slow, but that doesn't matter, since it will be called only
* in case of singlestepping, if copy_from_user failed.
*/
n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
if (n != sizeof(instr)) {
printk(KERN_ERR "is_syscall : failed to read "
"instruction from 0x%lx\n", addr);
return 1;
}
}
/* int 0x80 or sysenter */
return (instr == 0x80cd) || (instr == 0x340f);
}
/* determines which flags the user has access to. */
/* 1 = access 0 = no access */
#define FLAG_MASK 0x00044dd5
int putreg(struct task_struct *child, int regno, unsigned long value)
{
regno >>= 2;
switch (regno) {
case FS:
if (value && (value & 3) != 3)
return -EIO;
PT_REGS_FS(&child->thread.regs) = value;
return 0;
case GS:
if (value && (value & 3) != 3)
return -EIO;
PT_REGS_GS(&child->thread.regs) = value;
return 0;
case DS:
case ES:
if (value && (value & 3) != 3)
return -EIO;
value &= 0xffff;
break;
case SS:
case CS:
if ((value & 3) != 3)
return -EIO;
value &= 0xffff;
break;
case EFL:
value &= FLAG_MASK;
value |= PT_REGS_EFLAGS(&child->thread.regs);
break;
}
PT_REGS_SET(&child->thread.regs, regno, value);
return 0;
}
int poke_user(struct task_struct *child, long addr, long data)
{
if ((addr & 3) || addr < 0)
return -EIO;
if (addr < MAX_REG_OFFSET)
return putreg(child, addr, data);
else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
(addr <= offsetof(struct user, u_debugreg[7]))) {
addr -= offsetof(struct user, u_debugreg[0]);
addr = addr >> 2;
if ((addr == 4) || (addr == 5))
return -EIO;
child->thread.arch.debugregs[addr] = data;
return 0;
}
return -EIO;
}
unsigned long getreg(struct task_struct *child, int regno)
{
unsigned long retval = ~0UL;
regno >>= 2;
switch (regno) {
case FS:
case GS:
case DS:
case ES:
case SS:
case CS:
retval = 0xffff;
/* fall through */
default:
retval &= PT_REG(&child->thread.regs, regno);
}
return retval;
}
/* read the word at location addr in the USER area. */
int peek_user(struct task_struct *child, long addr, long data)
{
unsigned long tmp;
if ((addr & 3) || addr < 0)
return -EIO;
tmp = 0; /* Default return condition */
if (addr < MAX_REG_OFFSET) {
tmp = getreg(child, addr);
}
else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
(addr <= offsetof(struct user, u_debugreg[7]))) {
addr -= offsetof(struct user, u_debugreg[0]);
addr = addr >> 2;
tmp = child->thread.arch.debugregs[addr];
}
return put_user(tmp, (unsigned long __user *) data);
}
static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_i387_struct fpregs;
err = save_fp_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
if (err)
return err;
n = copy_to_user(buf, &fpregs, sizeof(fpregs));
if(n > 0)
return -EFAULT;
return n;
}
static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
int n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_i387_struct fpregs;
n = copy_from_user(&fpregs, buf, sizeof(fpregs));
if (n > 0)
return -EFAULT;
return restore_fp_registers(userspace_pid[cpu],
(unsigned long *) &fpregs);
}
static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
{
int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_fxsr_struct fpregs;
err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
if (err)
return err;
n = copy_to_user(buf, &fpregs, sizeof(fpregs));
if(n > 0)
return -EFAULT;
return n;
}
static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
{
int n, cpu = ((struct thread_info *) child->stack)->cpu;
struct user_fxsr_struct fpregs;
n = copy_from_user(&fpregs, buf, sizeof(fpregs));
if (n > 0)
return -EFAULT;
return restore_fpx_registers(userspace_pid[cpu],
(unsigned long *) &fpregs);
}
long subarch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret = -EIO;
void __user *datap = (void __user *) data;
switch (request) {
case PTRACE_GETFPREGS: /* Get the child FPU state. */
ret = get_fpregs(datap, child);
break;
case PTRACE_SETFPREGS: /* Set the child FPU state. */
ret = set_fpregs(datap, child);
break;
case PTRACE_GETFPXREGS: /* Get the child FPU state. */
ret = get_fpxregs(datap, child);
break;
case PTRACE_SETFPXREGS: /* Set the child FPU state. */
ret = set_fpxregs(datap, child);
break;
default:
ret = -EIO;
}
return ret;
}
|
