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