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 <linux/uaccess.h>
9 #include <asm/ptrace-abi.h>
10 #include <skas.h>
11
12 extern int arch_switch_tls(struct task_struct *to);
13
arch_switch_to(struct task_struct * to)14 void arch_switch_to(struct task_struct *to)
15 {
16 int err = arch_switch_tls(to);
17 if (!err)
18 return;
19
20 if (err != -EINVAL)
21 printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
22 "not EINVAL\n", -err);
23 else
24 printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
25 }
26
is_syscall(unsigned long addr)27 int is_syscall(unsigned long addr)
28 {
29 unsigned short instr;
30 int n;
31
32 n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
33 if (n) {
34 /* access_process_vm() grants access to vsyscall and stub,
35 * while copy_from_user doesn't. Maybe access_process_vm is
36 * slow, but that doesn't matter, since it will be called only
37 * in case of singlestepping, if copy_from_user failed.
38 */
39 n = access_process_vm(current, addr, &instr, sizeof(instr),
40 FOLL_FORCE);
41 if (n != sizeof(instr)) {
42 printk(KERN_ERR "is_syscall : failed to read "
43 "instruction from 0x%lx\n", addr);
44 return 1;
45 }
46 }
47 /* int 0x80 or sysenter */
48 return (instr == 0x80cd) || (instr == 0x340f);
49 }
50
51 /* determines which flags the user has access to. */
52 /* 1 = access 0 = no access */
53 #define FLAG_MASK 0x00044dd5
54
55 static const int reg_offsets[] = {
56 [EBX] = HOST_BX,
57 [ECX] = HOST_CX,
58 [EDX] = HOST_DX,
59 [ESI] = HOST_SI,
60 [EDI] = HOST_DI,
61 [EBP] = HOST_BP,
62 [EAX] = HOST_AX,
63 [DS] = HOST_DS,
64 [ES] = HOST_ES,
65 [FS] = HOST_FS,
66 [GS] = HOST_GS,
67 [EIP] = HOST_IP,
68 [CS] = HOST_CS,
69 [EFL] = HOST_EFLAGS,
70 [UESP] = HOST_SP,
71 [SS] = HOST_SS,
72 [ORIG_EAX] = HOST_ORIG_AX,
73 };
74
putreg(struct task_struct * child,int regno,unsigned long value)75 int putreg(struct task_struct *child, int regno, unsigned long value)
76 {
77 regno >>= 2;
78 switch (regno) {
79 case EBX:
80 case ECX:
81 case EDX:
82 case ESI:
83 case EDI:
84 case EBP:
85 case EAX:
86 case EIP:
87 case UESP:
88 break;
89 case ORIG_EAX:
90 /* Update the syscall number. */
91 UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
92 break;
93 case FS:
94 if (value && (value & 3) != 3)
95 return -EIO;
96 break;
97 case GS:
98 if (value && (value & 3) != 3)
99 return -EIO;
100 break;
101 case DS:
102 case ES:
103 if (value && (value & 3) != 3)
104 return -EIO;
105 value &= 0xffff;
106 break;
107 case SS:
108 case CS:
109 if ((value & 3) != 3)
110 return -EIO;
111 value &= 0xffff;
112 break;
113 case EFL:
114 value &= FLAG_MASK;
115 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
116 return 0;
117 default :
118 panic("Bad register in putreg() : %d\n", regno);
119 }
120 child->thread.regs.regs.gp[reg_offsets[regno]] = value;
121 return 0;
122 }
123
poke_user(struct task_struct * child,long addr,long data)124 int poke_user(struct task_struct *child, long addr, long data)
125 {
126 if ((addr & 3) || addr < 0)
127 return -EIO;
128
129 if (addr < MAX_REG_OFFSET)
130 return putreg(child, addr, data);
131 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
132 (addr <= offsetof(struct user, u_debugreg[7]))) {
133 addr -= offsetof(struct user, u_debugreg[0]);
134 addr = addr >> 2;
135 if ((addr == 4) || (addr == 5))
136 return -EIO;
137 child->thread.arch.debugregs[addr] = data;
138 return 0;
139 }
140 return -EIO;
141 }
142
getreg(struct task_struct * child,int regno)143 unsigned long getreg(struct task_struct *child, int regno)
144 {
145 unsigned long mask = ~0UL;
146
147 regno >>= 2;
148 switch (regno) {
149 case FS:
150 case GS:
151 case DS:
152 case ES:
153 case SS:
154 case CS:
155 mask = 0xffff;
156 break;
157 case EIP:
158 case UESP:
159 case EAX:
160 case EBX:
161 case ECX:
162 case EDX:
163 case ESI:
164 case EDI:
165 case EBP:
166 case EFL:
167 case ORIG_EAX:
168 break;
169 default:
170 panic("Bad register in getreg() : %d\n", regno);
171 }
172 return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
173 }
174
175 /* read the word at location addr in the USER area. */
peek_user(struct task_struct * child,long addr,long data)176 int peek_user(struct task_struct *child, long addr, long data)
177 {
178 unsigned long tmp;
179
180 if ((addr & 3) || addr < 0)
181 return -EIO;
182
183 tmp = 0; /* Default return condition */
184 if (addr < MAX_REG_OFFSET) {
185 tmp = getreg(child, addr);
186 }
187 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
188 (addr <= offsetof(struct user, u_debugreg[7]))) {
189 addr -= offsetof(struct user, u_debugreg[0]);
190 addr = addr >> 2;
191 tmp = child->thread.arch.debugregs[addr];
192 }
193 return put_user(tmp, (unsigned long __user *) data);
194 }
195
get_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)196 static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
197 {
198 int err, n, cpu = task_cpu(child);
199 struct user_i387_struct fpregs;
200
201 err = save_i387_registers(userspace_pid[cpu],
202 (unsigned long *) &fpregs);
203 if (err)
204 return err;
205
206 n = copy_to_user(buf, &fpregs, sizeof(fpregs));
207 if(n > 0)
208 return -EFAULT;
209
210 return n;
211 }
212
set_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)213 static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
214 {
215 int n, cpu = task_cpu(child);
216 struct user_i387_struct fpregs;
217
218 n = copy_from_user(&fpregs, buf, sizeof(fpregs));
219 if (n > 0)
220 return -EFAULT;
221
222 return restore_i387_registers(userspace_pid[cpu],
223 (unsigned long *) &fpregs);
224 }
225
get_fpxregs(struct user_fxsr_struct __user * buf,struct task_struct * child)226 static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
227 {
228 int err, n, cpu = task_cpu(child);
229 struct user_fxsr_struct fpregs;
230
231 err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
232 if (err)
233 return err;
234
235 n = copy_to_user(buf, &fpregs, sizeof(fpregs));
236 if(n > 0)
237 return -EFAULT;
238
239 return n;
240 }
241
set_fpxregs(struct user_fxsr_struct __user * buf,struct task_struct * child)242 static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
243 {
244 int n, cpu = task_cpu(child);
245 struct user_fxsr_struct fpregs;
246
247 n = copy_from_user(&fpregs, buf, sizeof(fpregs));
248 if (n > 0)
249 return -EFAULT;
250
251 return restore_fpx_registers(userspace_pid[cpu],
252 (unsigned long *) &fpregs);
253 }
254
subarch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)255 long subarch_ptrace(struct task_struct *child, long request,
256 unsigned long addr, unsigned long data)
257 {
258 int ret = -EIO;
259 void __user *datap = (void __user *) data;
260 switch (request) {
261 case PTRACE_GETFPREGS: /* Get the child FPU state. */
262 ret = get_fpregs(datap, child);
263 break;
264 case PTRACE_SETFPREGS: /* Set the child FPU state. */
265 ret = set_fpregs(datap, child);
266 break;
267 case PTRACE_GETFPXREGS: /* Get the child FPU state. */
268 ret = get_fpxregs(datap, child);
269 break;
270 case PTRACE_SETFPXREGS: /* Set the child FPU state. */
271 ret = set_fpxregs(datap, child);
272 break;
273 default:
274 ret = -EIO;
275 }
276 return ret;
277 }
278