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 <registers.h>
11 #include <skas.h>
12
13 extern int arch_switch_tls(struct task_struct *to);
14
arch_switch_to(struct task_struct * to)15 void arch_switch_to(struct task_struct *to)
16 {
17 int err = arch_switch_tls(to);
18 if (!err)
19 return;
20
21 if (err != -EINVAL)
22 printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
23 "not EINVAL\n", -err);
24 else
25 printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
26 }
27
is_syscall(unsigned long addr)28 int is_syscall(unsigned long addr)
29 {
30 unsigned short instr;
31 int n;
32
33 n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
34 if (n) {
35 /* access_process_vm() grants access to vsyscall and stub,
36 * while copy_from_user doesn't. Maybe access_process_vm is
37 * slow, but that doesn't matter, since it will be called only
38 * in case of singlestepping, if copy_from_user failed.
39 */
40 n = access_process_vm(current, addr, &instr, sizeof(instr),
41 FOLL_FORCE);
42 if (n != sizeof(instr)) {
43 printk(KERN_ERR "is_syscall : failed to read "
44 "instruction from 0x%lx\n", addr);
45 return 1;
46 }
47 }
48 /* int 0x80 or sysenter */
49 return (instr == 0x80cd) || (instr == 0x340f);
50 }
51
52 /* determines which flags the user has access to. */
53 /* 1 = access 0 = no access */
54 #define FLAG_MASK 0x00044dd5
55
56 static const int reg_offsets[] = {
57 [EBX] = HOST_BX,
58 [ECX] = HOST_CX,
59 [EDX] = HOST_DX,
60 [ESI] = HOST_SI,
61 [EDI] = HOST_DI,
62 [EBP] = HOST_BP,
63 [EAX] = HOST_AX,
64 [DS] = HOST_DS,
65 [ES] = HOST_ES,
66 [FS] = HOST_FS,
67 [GS] = HOST_GS,
68 [EIP] = HOST_IP,
69 [CS] = HOST_CS,
70 [EFL] = HOST_EFLAGS,
71 [UESP] = HOST_SP,
72 [SS] = HOST_SS,
73 [ORIG_EAX] = HOST_ORIG_AX,
74 };
75
putreg(struct task_struct * child,int regno,unsigned long value)76 int putreg(struct task_struct *child, int regno, unsigned long value)
77 {
78 regno >>= 2;
79 switch (regno) {
80 case EBX:
81 case ECX:
82 case EDX:
83 case ESI:
84 case EDI:
85 case EBP:
86 case EAX:
87 case EIP:
88 case UESP:
89 break;
90 case ORIG_EAX:
91 /* Update the syscall number. */
92 UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
93 break;
94 case FS:
95 if (value && (value & 3) != 3)
96 return -EIO;
97 break;
98 case GS:
99 if (value && (value & 3) != 3)
100 return -EIO;
101 break;
102 case DS:
103 case ES:
104 if (value && (value & 3) != 3)
105 return -EIO;
106 value &= 0xffff;
107 break;
108 case SS:
109 case CS:
110 if ((value & 3) != 3)
111 return -EIO;
112 value &= 0xffff;
113 break;
114 case EFL:
115 value &= FLAG_MASK;
116 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
117 return 0;
118 default :
119 panic("Bad register in putreg() : %d\n", regno);
120 }
121 child->thread.regs.regs.gp[reg_offsets[regno]] = value;
122 return 0;
123 }
124
poke_user(struct task_struct * child,long addr,long data)125 int poke_user(struct task_struct *child, long addr, long data)
126 {
127 if ((addr & 3) || addr < 0)
128 return -EIO;
129
130 if (addr < MAX_REG_OFFSET)
131 return putreg(child, addr, data);
132 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
133 (addr <= offsetof(struct user, u_debugreg[7]))) {
134 addr -= offsetof(struct user, u_debugreg[0]);
135 addr = addr >> 2;
136 if ((addr == 4) || (addr == 5))
137 return -EIO;
138 child->thread.arch.debugregs[addr] = data;
139 return 0;
140 }
141 return -EIO;
142 }
143
getreg(struct task_struct * child,int regno)144 unsigned long getreg(struct task_struct *child, int regno)
145 {
146 unsigned long mask = ~0UL;
147
148 regno >>= 2;
149 switch (regno) {
150 case FS:
151 case GS:
152 case DS:
153 case ES:
154 case SS:
155 case CS:
156 mask = 0xffff;
157 break;
158 case EIP:
159 case UESP:
160 case EAX:
161 case EBX:
162 case ECX:
163 case EDX:
164 case ESI:
165 case EDI:
166 case EBP:
167 case EFL:
168 case ORIG_EAX:
169 break;
170 default:
171 panic("Bad register in getreg() : %d\n", regno);
172 }
173 return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
174 }
175
176 /* read the word at location addr in the USER area. */
peek_user(struct task_struct * child,long addr,long data)177 int peek_user(struct task_struct *child, long addr, long data)
178 {
179 unsigned long tmp;
180
181 if ((addr & 3) || addr < 0)
182 return -EIO;
183
184 tmp = 0; /* Default return condition */
185 if (addr < MAX_REG_OFFSET) {
186 tmp = getreg(child, addr);
187 }
188 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
189 (addr <= offsetof(struct user, u_debugreg[7]))) {
190 addr -= offsetof(struct user, u_debugreg[0]);
191 addr = addr >> 2;
192 tmp = child->thread.arch.debugregs[addr];
193 }
194 return put_user(tmp, (unsigned long __user *) data);
195 }
196
get_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)197 static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
198 {
199 int err, n, cpu = task_cpu(child);
200 struct user_i387_struct fpregs;
201
202 err = save_i387_registers(userspace_pid[cpu],
203 (unsigned long *) &fpregs);
204 if (err)
205 return err;
206
207 n = copy_to_user(buf, &fpregs, sizeof(fpregs));
208 if(n > 0)
209 return -EFAULT;
210
211 return n;
212 }
213
set_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)214 static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
215 {
216 int n, cpu = task_cpu(child);
217 struct user_i387_struct fpregs;
218
219 n = copy_from_user(&fpregs, buf, sizeof(fpregs));
220 if (n > 0)
221 return -EFAULT;
222
223 return restore_i387_registers(userspace_pid[cpu],
224 (unsigned long *) &fpregs);
225 }
226
get_fpxregs(struct user_fxsr_struct __user * buf,struct task_struct * child)227 static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
228 {
229 int err, n, cpu = task_cpu(child);
230 struct user_fxsr_struct fpregs;
231
232 err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
233 if (err)
234 return err;
235
236 n = copy_to_user(buf, &fpregs, sizeof(fpregs));
237 if(n > 0)
238 return -EFAULT;
239
240 return n;
241 }
242
set_fpxregs(struct user_fxsr_struct __user * buf,struct task_struct * child)243 static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
244 {
245 int n, cpu = task_cpu(child);
246 struct user_fxsr_struct fpregs;
247
248 n = copy_from_user(&fpregs, buf, sizeof(fpregs));
249 if (n > 0)
250 return -EFAULT;
251
252 return restore_fpx_registers(userspace_pid[cpu],
253 (unsigned long *) &fpregs);
254 }
255
subarch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)256 long subarch_ptrace(struct task_struct *child, long request,
257 unsigned long addr, unsigned long data)
258 {
259 int ret = -EIO;
260 void __user *datap = (void __user *) data;
261 switch (request) {
262 case PTRACE_GETFPREGS: /* Get the child FPU state. */
263 ret = get_fpregs(datap, child);
264 break;
265 case PTRACE_SETFPREGS: /* Set the child FPU state. */
266 ret = set_fpregs(datap, child);
267 break;
268 case PTRACE_GETFPXREGS: /* Get the child FPU state. */
269 ret = get_fpxregs(datap, child);
270 break;
271 case PTRACE_SETFPXREGS: /* Set the child FPU state. */
272 ret = set_fpxregs(datap, child);
273 break;
274 default:
275 ret = -EIO;
276 }
277 return ret;
278 }
279