1 /*
2 * Copyright 2003 PathScale, Inc.
3 * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 *
5 * Licensed under the GPL
6 */
7
8 #include <linux/mm.h>
9 #include <linux/sched.h>
10 #include <linux/errno.h>
11 #define __FRAME_OFFSETS
12 #include <asm/ptrace.h>
13 #include <linux/uaccess.h>
14 #include <asm/ptrace-abi.h>
15
16 /*
17 * determines which flags the user has access to.
18 * 1 = access 0 = no access
19 */
20 #define FLAG_MASK 0x44dd5UL
21
22 static const int reg_offsets[] =
23 {
24 [R8 >> 3] = HOST_R8,
25 [R9 >> 3] = HOST_R9,
26 [R10 >> 3] = HOST_R10,
27 [R11 >> 3] = HOST_R11,
28 [R12 >> 3] = HOST_R12,
29 [R13 >> 3] = HOST_R13,
30 [R14 >> 3] = HOST_R14,
31 [R15 >> 3] = HOST_R15,
32 [RIP >> 3] = HOST_IP,
33 [RSP >> 3] = HOST_SP,
34 [RAX >> 3] = HOST_AX,
35 [RBX >> 3] = HOST_BX,
36 [RCX >> 3] = HOST_CX,
37 [RDX >> 3] = HOST_DX,
38 [RSI >> 3] = HOST_SI,
39 [RDI >> 3] = HOST_DI,
40 [RBP >> 3] = HOST_BP,
41 [CS >> 3] = HOST_CS,
42 [SS >> 3] = HOST_SS,
43 [FS_BASE >> 3] = HOST_FS_BASE,
44 [GS_BASE >> 3] = HOST_GS_BASE,
45 [DS >> 3] = HOST_DS,
46 [ES >> 3] = HOST_ES,
47 [FS >> 3] = HOST_FS,
48 [GS >> 3] = HOST_GS,
49 [EFLAGS >> 3] = HOST_EFLAGS,
50 [ORIG_RAX >> 3] = HOST_ORIG_AX,
51 };
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 switch (regno) {
56 case R8:
57 case R9:
58 case R10:
59 case R11:
60 case R12:
61 case R13:
62 case R14:
63 case R15:
64 case RIP:
65 case RSP:
66 case RAX:
67 case RBX:
68 case RCX:
69 case RDX:
70 case RSI:
71 case RDI:
72 case RBP:
73 break;
74
75 case ORIG_RAX:
76 /* Update the syscall number. */
77 UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
78 break;
79
80 case FS:
81 case GS:
82 case DS:
83 case ES:
84 case SS:
85 case CS:
86 if (value && (value & 3) != 3)
87 return -EIO;
88 value &= 0xffff;
89 break;
90
91 case FS_BASE:
92 case GS_BASE:
93 if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
94 return -EIO;
95 break;
96
97 case EFLAGS:
98 value &= FLAG_MASK;
99 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
100 return 0;
101
102 default:
103 panic("Bad register in putreg(): %d\n", regno);
104 }
105
106 child->thread.regs.regs.gp[reg_offsets[regno >> 3]] = value;
107 return 0;
108 }
109
poke_user(struct task_struct * child,long addr,long data)110 int poke_user(struct task_struct *child, long addr, long data)
111 {
112 if ((addr & 3) || addr < 0)
113 return -EIO;
114
115 if (addr < MAX_REG_OFFSET)
116 return putreg(child, addr, data);
117 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
118 (addr <= offsetof(struct user, u_debugreg[7]))) {
119 addr -= offsetof(struct user, u_debugreg[0]);
120 addr = addr >> 3;
121 if ((addr == 4) || (addr == 5))
122 return -EIO;
123 child->thread.arch.debugregs[addr] = data;
124 return 0;
125 }
126 return -EIO;
127 }
128
getreg(struct task_struct * child,int regno)129 unsigned long getreg(struct task_struct *child, int regno)
130 {
131 unsigned long mask = ~0UL;
132
133 switch (regno) {
134 case R8:
135 case R9:
136 case R10:
137 case R11:
138 case R12:
139 case R13:
140 case R14:
141 case R15:
142 case RIP:
143 case RSP:
144 case RAX:
145 case RBX:
146 case RCX:
147 case RDX:
148 case RSI:
149 case RDI:
150 case RBP:
151 case ORIG_RAX:
152 case EFLAGS:
153 case FS_BASE:
154 case GS_BASE:
155 break;
156 case FS:
157 case GS:
158 case DS:
159 case ES:
160 case SS:
161 case CS:
162 mask = 0xffff;
163 break;
164 default:
165 panic("Bad register in getreg: %d\n", regno);
166 }
167 return mask & child->thread.regs.regs.gp[reg_offsets[regno >> 3]];
168 }
169
peek_user(struct task_struct * child,long addr,long data)170 int peek_user(struct task_struct *child, long addr, long data)
171 {
172 /* read the word at location addr in the USER area. */
173 unsigned long tmp;
174
175 if ((addr & 3) || addr < 0)
176 return -EIO;
177
178 tmp = 0; /* Default return condition */
179 if (addr < MAX_REG_OFFSET)
180 tmp = getreg(child, addr);
181 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
182 (addr <= offsetof(struct user, u_debugreg[7]))) {
183 addr -= offsetof(struct user, u_debugreg[0]);
184 addr = addr >> 2;
185 tmp = child->thread.arch.debugregs[addr];
186 }
187 return put_user(tmp, (unsigned long *) data);
188 }
189
190 /* XXX Mostly copied from sys-i386 */
is_syscall(unsigned long addr)191 int is_syscall(unsigned long addr)
192 {
193 unsigned short instr;
194 int n;
195
196 n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
197 if (n) {
198 /*
199 * access_process_vm() grants access to vsyscall and stub,
200 * while copy_from_user doesn't. Maybe access_process_vm is
201 * slow, but that doesn't matter, since it will be called only
202 * in case of singlestepping, if copy_from_user failed.
203 */
204 n = access_process_vm(current, addr, &instr, sizeof(instr),
205 FOLL_FORCE);
206 if (n != sizeof(instr)) {
207 printk("is_syscall : failed to read instruction from "
208 "0x%lx\n", addr);
209 return 1;
210 }
211 }
212 /* sysenter */
213 return instr == 0x050f;
214 }
215
get_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)216 static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
217 {
218 int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
219 struct user_i387_struct fpregs;
220
221 err = save_i387_registers(userspace_pid[cpu],
222 (unsigned long *) &fpregs);
223 if (err)
224 return err;
225
226 n = copy_to_user(buf, &fpregs, sizeof(fpregs));
227 if (n > 0)
228 return -EFAULT;
229
230 return n;
231 }
232
set_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)233 static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
234 {
235 int n, cpu = ((struct thread_info *) child->stack)->cpu;
236 struct user_i387_struct fpregs;
237
238 n = copy_from_user(&fpregs, buf, sizeof(fpregs));
239 if (n > 0)
240 return -EFAULT;
241
242 return restore_i387_registers(userspace_pid[cpu],
243 (unsigned long *) &fpregs);
244 }
245
subarch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)246 long subarch_ptrace(struct task_struct *child, long request,
247 unsigned long addr, unsigned long data)
248 {
249 int ret = -EIO;
250 void __user *datap = (void __user *) data;
251
252 switch (request) {
253 case PTRACE_GETFPREGS: /* Get the child FPU state. */
254 ret = get_fpregs(datap, child);
255 break;
256 case PTRACE_SETFPREGS: /* Set the child FPU state. */
257 ret = set_fpregs(datap, child);
258 break;
259 case PTRACE_ARCH_PRCTL:
260 /* XXX Calls ptrace on the host - needs some SMP thinking */
261 ret = arch_prctl(child, data, (void __user *) addr);
262 break;
263 }
264
265 return ret;
266 }
267