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 <registers.h>
15 #include <asm/ptrace-abi.h>
16
17 /*
18 * determines which flags the user has access to.
19 * 1 = access 0 = no access
20 */
21 #define FLAG_MASK 0x44dd5UL
22
23 static const int reg_offsets[] =
24 {
25 [R8 >> 3] = HOST_R8,
26 [R9 >> 3] = HOST_R9,
27 [R10 >> 3] = HOST_R10,
28 [R11 >> 3] = HOST_R11,
29 [R12 >> 3] = HOST_R12,
30 [R13 >> 3] = HOST_R13,
31 [R14 >> 3] = HOST_R14,
32 [R15 >> 3] = HOST_R15,
33 [RIP >> 3] = HOST_IP,
34 [RSP >> 3] = HOST_SP,
35 [RAX >> 3] = HOST_AX,
36 [RBX >> 3] = HOST_BX,
37 [RCX >> 3] = HOST_CX,
38 [RDX >> 3] = HOST_DX,
39 [RSI >> 3] = HOST_SI,
40 [RDI >> 3] = HOST_DI,
41 [RBP >> 3] = HOST_BP,
42 [CS >> 3] = HOST_CS,
43 [SS >> 3] = HOST_SS,
44 [FS_BASE >> 3] = HOST_FS_BASE,
45 [GS_BASE >> 3] = HOST_GS_BASE,
46 [DS >> 3] = HOST_DS,
47 [ES >> 3] = HOST_ES,
48 [FS >> 3] = HOST_FS,
49 [GS >> 3] = HOST_GS,
50 [EFLAGS >> 3] = HOST_EFLAGS,
51 [ORIG_RAX >> 3] = HOST_ORIG_AX,
52 };
53
putreg(struct task_struct * child,int regno,unsigned long value)54 int putreg(struct task_struct *child, int regno, unsigned long value)
55 {
56 switch (regno) {
57 case R8:
58 case R9:
59 case R10:
60 case R11:
61 case R12:
62 case R13:
63 case R14:
64 case R15:
65 case RIP:
66 case RSP:
67 case RAX:
68 case RBX:
69 case RCX:
70 case RDX:
71 case RSI:
72 case RDI:
73 case RBP:
74 break;
75
76 case ORIG_RAX:
77 /* Update the syscall number. */
78 UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
79 break;
80
81 case FS:
82 case GS:
83 case DS:
84 case ES:
85 case SS:
86 case CS:
87 if (value && (value & 3) != 3)
88 return -EIO;
89 value &= 0xffff;
90 break;
91
92 case FS_BASE:
93 case GS_BASE:
94 if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
95 return -EIO;
96 break;
97
98 case EFLAGS:
99 value &= FLAG_MASK;
100 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
101 return 0;
102
103 default:
104 panic("Bad register in putreg(): %d\n", regno);
105 }
106
107 child->thread.regs.regs.gp[reg_offsets[regno >> 3]] = value;
108 return 0;
109 }
110
poke_user(struct task_struct * child,long addr,long data)111 int poke_user(struct task_struct *child, long addr, long data)
112 {
113 if ((addr & 3) || addr < 0)
114 return -EIO;
115
116 if (addr < MAX_REG_OFFSET)
117 return putreg(child, addr, data);
118 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
119 (addr <= offsetof(struct user, u_debugreg[7]))) {
120 addr -= offsetof(struct user, u_debugreg[0]);
121 addr = addr >> 3;
122 if ((addr == 4) || (addr == 5))
123 return -EIO;
124 child->thread.arch.debugregs[addr] = data;
125 return 0;
126 }
127 return -EIO;
128 }
129
getreg(struct task_struct * child,int regno)130 unsigned long getreg(struct task_struct *child, int regno)
131 {
132 unsigned long mask = ~0UL;
133
134 switch (regno) {
135 case R8:
136 case R9:
137 case R10:
138 case R11:
139 case R12:
140 case R13:
141 case R14:
142 case R15:
143 case RIP:
144 case RSP:
145 case RAX:
146 case RBX:
147 case RCX:
148 case RDX:
149 case RSI:
150 case RDI:
151 case RBP:
152 case ORIG_RAX:
153 case EFLAGS:
154 case FS_BASE:
155 case GS_BASE:
156 break;
157 case FS:
158 case GS:
159 case DS:
160 case ES:
161 case SS:
162 case CS:
163 mask = 0xffff;
164 break;
165 default:
166 panic("Bad register in getreg: %d\n", regno);
167 }
168 return mask & child->thread.regs.regs.gp[reg_offsets[regno >> 3]];
169 }
170
peek_user(struct task_struct * child,long addr,long data)171 int peek_user(struct task_struct *child, long addr, long data)
172 {
173 /* read the word at location addr in the USER area. */
174 unsigned long tmp;
175
176 if ((addr & 3) || addr < 0)
177 return -EIO;
178
179 tmp = 0; /* Default return condition */
180 if (addr < MAX_REG_OFFSET)
181 tmp = getreg(child, addr);
182 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
183 (addr <= offsetof(struct user, u_debugreg[7]))) {
184 addr -= offsetof(struct user, u_debugreg[0]);
185 addr = addr >> 2;
186 tmp = child->thread.arch.debugregs[addr];
187 }
188 return put_user(tmp, (unsigned long *) data);
189 }
190
191 /* XXX Mostly copied from sys-i386 */
is_syscall(unsigned long addr)192 int is_syscall(unsigned long addr)
193 {
194 unsigned short instr;
195 int n;
196
197 n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
198 if (n) {
199 /*
200 * access_process_vm() grants access to vsyscall and stub,
201 * while copy_from_user doesn't. Maybe access_process_vm is
202 * slow, but that doesn't matter, since it will be called only
203 * in case of singlestepping, if copy_from_user failed.
204 */
205 n = access_process_vm(current, addr, &instr, sizeof(instr),
206 FOLL_FORCE);
207 if (n != sizeof(instr)) {
208 printk("is_syscall : failed to read instruction from "
209 "0x%lx\n", addr);
210 return 1;
211 }
212 }
213 /* sysenter */
214 return instr == 0x050f;
215 }
216
get_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)217 static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
218 {
219 int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
220 struct user_i387_struct fpregs;
221
222 err = save_i387_registers(userspace_pid[cpu],
223 (unsigned long *) &fpregs);
224 if (err)
225 return err;
226
227 n = copy_to_user(buf, &fpregs, sizeof(fpregs));
228 if (n > 0)
229 return -EFAULT;
230
231 return n;
232 }
233
set_fpregs(struct user_i387_struct __user * buf,struct task_struct * child)234 static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
235 {
236 int n, cpu = ((struct thread_info *) child->stack)->cpu;
237 struct user_i387_struct fpregs;
238
239 n = copy_from_user(&fpregs, buf, sizeof(fpregs));
240 if (n > 0)
241 return -EFAULT;
242
243 return restore_i387_registers(userspace_pid[cpu],
244 (unsigned long *) &fpregs);
245 }
246
subarch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)247 long subarch_ptrace(struct task_struct *child, long request,
248 unsigned long addr, unsigned long data)
249 {
250 int ret = -EIO;
251 void __user *datap = (void __user *) data;
252
253 switch (request) {
254 case PTRACE_GETFPREGS: /* Get the child FPU state. */
255 ret = get_fpregs(datap, child);
256 break;
257 case PTRACE_SETFPREGS: /* Set the child FPU state. */
258 ret = set_fpregs(datap, child);
259 break;
260 case PTRACE_ARCH_PRCTL:
261 /* XXX Calls ptrace on the host - needs some SMP thinking */
262 ret = arch_prctl(child, data, (void __user *) addr);
263 break;
264 }
265
266 return ret;
267 }
268
