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#include <linux/regset.h>
 12#define __FRAME_OFFSETS
 13#include <asm/ptrace.h>
 14#include <linux/uaccess.h>
 15#include <registers.h>
 16#include <asm/ptrace-abi.h>
 17
 18/*
 19 * determines which flags the user has access to.
 20 * 1 = access 0 = no access
 21 */
 22#define FLAG_MASK 0x44dd5UL
 23
 24static const int reg_offsets[] =
 25{
 26	[R8 >> 3] = HOST_R8,
 27	[R9 >> 3] = HOST_R9,
 28	[R10 >> 3] = HOST_R10,
 29	[R11 >> 3] = HOST_R11,
 30	[R12 >> 3] = HOST_R12,
 31	[R13 >> 3] = HOST_R13,
 32	[R14 >> 3] = HOST_R14,
 33	[R15 >> 3] = HOST_R15,
 34	[RIP >> 3] = HOST_IP,
 35	[RSP >> 3] = HOST_SP,
 36	[RAX >> 3] = HOST_AX,
 37	[RBX >> 3] = HOST_BX,
 38	[RCX >> 3] = HOST_CX,
 39	[RDX >> 3] = HOST_DX,
 40	[RSI >> 3] = HOST_SI,
 41	[RDI >> 3] = HOST_DI,
 42	[RBP >> 3] = HOST_BP,
 43	[CS >> 3] = HOST_CS,
 44	[SS >> 3] = HOST_SS,
 45	[FS_BASE >> 3] = HOST_FS_BASE,
 46	[GS_BASE >> 3] = HOST_GS_BASE,
 47	[DS >> 3] = HOST_DS,
 48	[ES >> 3] = HOST_ES,
 49	[FS >> 3] = HOST_FS,
 50	[GS >> 3] = HOST_GS,
 51	[EFLAGS >> 3] = HOST_EFLAGS,
 52	[ORIG_RAX >> 3] = HOST_ORIG_AX,
 53};
 54
 55int putreg(struct task_struct *child, int regno, unsigned long value)
 56{
 57	switch (regno) {
 58	case R8:
 59	case R9:
 60	case R10:
 61	case R11:
 62	case R12:
 63	case R13:
 64	case R14:
 65	case R15:
 66	case RIP:
 67	case RSP:
 68	case RAX:
 69	case RBX:
 70	case RCX:
 71	case RDX:
 72	case RSI:
 73	case RDI:
 74	case RBP:
 75		break;
 76
 77	case ORIG_RAX:
 78		/* Update the syscall number. */
 79		UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
 80		break;
 81
 82	case FS:
 83	case GS:
 84	case DS:
 85	case ES:
 86	case SS:
 87	case CS:
 88		if (value && (value & 3) != 3)
 89			return -EIO;
 90		value &= 0xffff;
 91		break;
 92
 93	case FS_BASE:
 94	case GS_BASE:
 95		if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
 96			return -EIO;
 97		break;
 98
 99	case EFLAGS:
100		value &= FLAG_MASK;
101		child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
102		return 0;
103
104	default:
105		panic("Bad register in putreg(): %d\n", regno);
106	}
107
108	child->thread.regs.regs.gp[reg_offsets[regno >> 3]] = value;
109	return 0;
110}
111
112int poke_user(struct task_struct *child, long addr, long data)
113{
114	if ((addr & 3) || addr < 0)
115		return -EIO;
116
117	if (addr < MAX_REG_OFFSET)
118		return putreg(child, addr, data);
119	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
120		(addr <= offsetof(struct user, u_debugreg[7]))) {
121		addr -= offsetof(struct user, u_debugreg[0]);
122		addr = addr >> 3;
123		if ((addr == 4) || (addr == 5))
124			return -EIO;
125		child->thread.arch.debugregs[addr] = data;
126		return 0;
127	}
128	return -EIO;
129}
130
131unsigned long getreg(struct task_struct *child, int regno)
132{
133	unsigned long mask = ~0UL;
134
135	switch (regno) {
136	case R8:
137	case R9:
138	case R10:
139	case R11:
140	case R12:
141	case R13:
142	case R14:
143	case R15:
144	case RIP:
145	case RSP:
146	case RAX:
147	case RBX:
148	case RCX:
149	case RDX:
150	case RSI:
151	case RDI:
152	case RBP:
153	case ORIG_RAX:
154	case EFLAGS:
155	case FS_BASE:
156	case GS_BASE:
157		break;
158	case FS:
159	case GS:
160	case DS:
161	case ES:
162	case SS:
163	case CS:
164		mask = 0xffff;
165		break;
166	default:
167		panic("Bad register in getreg: %d\n", regno);
168	}
169	return mask & child->thread.regs.regs.gp[reg_offsets[regno >> 3]];
170}
171
172int peek_user(struct task_struct *child, long addr, long data)
173{
174	/* read the word at location addr in the USER area. */
175	unsigned long tmp;
176
177	if ((addr & 3) || addr < 0)
178		return -EIO;
179
180	tmp = 0;  /* Default return condition */
181	if (addr < MAX_REG_OFFSET)
182		tmp = getreg(child, addr);
183	else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
184		(addr <= offsetof(struct user, u_debugreg[7]))) {
185		addr -= offsetof(struct user, u_debugreg[0]);
186		addr = addr >> 2;
187		tmp = child->thread.arch.debugregs[addr];
188	}
189	return put_user(tmp, (unsigned long *) data);
190}
191
192long subarch_ptrace(struct task_struct *child, long request,
193		    unsigned long addr, unsigned long data)
194{
195	int ret = -EIO;
196	void __user *datap = (void __user *) data;
197
198	switch (request) {
199	case PTRACE_GETFPREGS: /* Get the child FPU state. */
200		return copy_regset_to_user(child, task_user_regset_view(child),
201					   REGSET_FP,
202					   0, sizeof(struct user_i387_struct),
203					   datap);
204	case PTRACE_SETFPREGS: /* Set the child FPU state. */
205		return copy_regset_from_user(child, task_user_regset_view(child),
206					     REGSET_FP,
207					     0, sizeof(struct user_i387_struct),
208					     datap);
209	case PTRACE_ARCH_PRCTL:
210		/* XXX Calls ptrace on the host - needs some SMP thinking */
211		ret = arch_prctl(child, data, (void __user *) addr);
212		break;
213	}
214
215	return ret;
216}