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
 23static 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
 54int 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
111int 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
130unsigned 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
171int 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
191static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
192{
193	int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
194	struct user_i387_struct fpregs;
195
196	err = save_i387_registers(userspace_pid[cpu],
197				  (unsigned long *) &fpregs);
198	if (err)
199		return err;
200
201	n = copy_to_user(buf, &fpregs, sizeof(fpregs));
202	if (n > 0)
203		return -EFAULT;
204
205	return n;
206}
207
208static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
209{
210	int n, cpu = ((struct thread_info *) child->stack)->cpu;
211	struct user_i387_struct fpregs;
212
213	n = copy_from_user(&fpregs, buf, sizeof(fpregs));
214	if (n > 0)
215		return -EFAULT;
216
217	return restore_i387_registers(userspace_pid[cpu],
218				      (unsigned long *) &fpregs);
219}
220
221long subarch_ptrace(struct task_struct *child, long request,
222		    unsigned long addr, unsigned long data)
223{
224	int ret = -EIO;
225	void __user *datap = (void __user *) data;
226
227	switch (request) {
228	case PTRACE_GETFPREGS: /* Get the child FPU state. */
229		ret = get_fpregs(datap, child);
230		break;
231	case PTRACE_SETFPREGS: /* Set the child FPU state. */
232		ret = set_fpregs(datap, child);
233		break;
234	case PTRACE_ARCH_PRCTL:
235		/* XXX Calls ptrace on the host - needs some SMP thinking */
236		ret = arch_prctl(child, data, (void __user *) addr);
237		break;
238	}
239
240	return ret;
241}