ia64/linux-2.6.18-xen.hg

view arch/m68knommu/kernel/ptrace.c @ 0:831230e53067

Import 2.6.18 from kernel.org tarball.
author Ian Campbell <ian.campbell@xensource.com>
date Wed Apr 11 14:15:44 2007 +0100 (2007-04-11)
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1 /*
2 * linux/arch/m68knommu/kernel/ptrace.c
3 *
4 * Copyright (C) 1994 by Hamish Macdonald
5 * Taken from linux/kernel/ptrace.c and modified for M680x0.
6 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
7 *
8 * This file is subject to the terms and conditions of the GNU General
9 * Public License. See the file COPYING in the main directory of
10 * this archive for more details.
11 */
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/mm.h>
16 #include <linux/smp.h>
17 #include <linux/smp_lock.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/user.h>
21 #include <linux/signal.h>
23 #include <asm/uaccess.h>
24 #include <asm/page.h>
25 #include <asm/pgtable.h>
26 #include <asm/system.h>
27 #include <asm/processor.h>
29 /*
30 * does not yet catch signals sent when the child dies.
31 * in exit.c or in signal.c.
32 */
34 /* determines which bits in the SR the user has access to. */
35 /* 1 = access 0 = no access */
36 #define SR_MASK 0x001f
38 /* sets the trace bits. */
39 #define TRACE_BITS 0x8000
41 /* Find the stack offset for a register, relative to thread.esp0. */
42 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
43 #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
44 - sizeof(struct switch_stack))
45 /* Mapping from PT_xxx to the stack offset at which the register is
46 saved. Notice that usp has no stack-slot and needs to be treated
47 specially (see get_reg/put_reg below). */
48 static int regoff[] = {
49 PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4),
50 PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0),
51 PT_REG(a1), PT_REG(a2), SW_REG(a3), SW_REG(a4),
52 SW_REG(a5), SW_REG(a6), PT_REG(d0), -1,
53 PT_REG(orig_d0), PT_REG(sr), PT_REG(pc),
54 };
56 /*
57 * Get contents of register REGNO in task TASK.
58 */
59 static inline long get_reg(struct task_struct *task, int regno)
60 {
61 unsigned long *addr;
63 if (regno == PT_USP)
64 addr = &task->thread.usp;
65 else if (regno < sizeof(regoff)/sizeof(regoff[0]))
66 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
67 else
68 return 0;
69 return *addr;
70 }
72 /*
73 * Write contents of register REGNO in task TASK.
74 */
75 static inline int put_reg(struct task_struct *task, int regno,
76 unsigned long data)
77 {
78 unsigned long *addr;
80 if (regno == PT_USP)
81 addr = &task->thread.usp;
82 else if (regno < sizeof(regoff)/sizeof(regoff[0]))
83 addr = (unsigned long *) (task->thread.esp0 + regoff[regno]);
84 else
85 return -1;
86 *addr = data;
87 return 0;
88 }
90 /*
91 * Called by kernel/ptrace.c when detaching..
92 *
93 * Make sure the single step bit is not set.
94 */
95 void ptrace_disable(struct task_struct *child)
96 {
97 unsigned long tmp;
98 /* make sure the single step bit is not set. */
99 tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
100 put_reg(child, PT_SR, tmp);
101 }
103 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
104 {
105 int ret;
107 switch (request) {
108 /* when I and D space are separate, these will need to be fixed. */
109 case PTRACE_PEEKTEXT: /* read word at location addr. */
110 case PTRACE_PEEKDATA: {
111 unsigned long tmp;
112 int copied;
114 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
115 ret = -EIO;
116 if (copied != sizeof(tmp))
117 break;
118 ret = put_user(tmp,(unsigned long *) data);
119 break;
120 }
122 /* read the word at location addr in the USER area. */
123 case PTRACE_PEEKUSR: {
124 unsigned long tmp;
126 ret = -EIO;
127 if ((addr & 3) || addr < 0 ||
128 addr > sizeof(struct user) - 3)
129 break;
131 tmp = 0; /* Default return condition */
132 addr = addr >> 2; /* temporary hack. */
133 ret = -EIO;
134 if (addr < 19) {
135 tmp = get_reg(child, addr);
136 if (addr == PT_SR)
137 tmp >>= 16;
138 } else if (addr >= 21 && addr < 49) {
139 tmp = child->thread.fp[addr - 21];
140 #ifdef CONFIG_M68KFPU_EMU
141 /* Convert internal fpu reg representation
142 * into long double format
143 */
144 if (FPU_IS_EMU && (addr < 45) && !(addr % 3))
145 tmp = ((tmp & 0xffff0000) << 15) |
146 ((tmp & 0x0000ffff) << 16);
147 #endif
148 } else if (addr == 49) {
149 tmp = child->mm->start_code;
150 } else if (addr == 50) {
151 tmp = child->mm->start_data;
152 } else if (addr == 51) {
153 tmp = child->mm->end_code;
154 } else
155 break;
156 ret = put_user(tmp,(unsigned long *) data);
157 break;
158 }
160 /* when I and D space are separate, this will have to be fixed. */
161 case PTRACE_POKETEXT: /* write the word at location addr. */
162 case PTRACE_POKEDATA:
163 ret = 0;
164 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
165 break;
166 ret = -EIO;
167 break;
169 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
170 ret = -EIO;
171 if ((addr & 3) || addr < 0 ||
172 addr > sizeof(struct user) - 3)
173 break;
175 addr = addr >> 2; /* temporary hack. */
177 if (addr == PT_SR) {
178 data &= SR_MASK;
179 data <<= 16;
180 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
181 }
182 if (addr < 19) {
183 if (put_reg(child, addr, data))
184 break;
185 ret = 0;
186 break;
187 }
188 if (addr >= 21 && addr < 48)
189 {
190 #ifdef CONFIG_M68KFPU_EMU
191 /* Convert long double format
192 * into internal fpu reg representation
193 */
194 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) {
195 data = (unsigned long)data << 15;
196 data = (data & 0xffff0000) |
197 ((data & 0x0000ffff) >> 1);
198 }
199 #endif
200 child->thread.fp[addr - 21] = data;
201 ret = 0;
202 }
203 break;
205 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
206 case PTRACE_CONT: { /* restart after signal. */
207 long tmp;
209 ret = -EIO;
210 if (!valid_signal(data))
211 break;
212 if (request == PTRACE_SYSCALL)
213 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
214 else
215 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
216 child->exit_code = data;
217 /* make sure the single step bit is not set. */
218 tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
219 put_reg(child, PT_SR, tmp);
220 wake_up_process(child);
221 ret = 0;
222 break;
223 }
225 /*
226 * make the child exit. Best I can do is send it a sigkill.
227 * perhaps it should be put in the status that it wants to
228 * exit.
229 */
230 case PTRACE_KILL: {
231 long tmp;
233 ret = 0;
234 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
235 break;
236 child->exit_code = SIGKILL;
237 /* make sure the single step bit is not set. */
238 tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
239 put_reg(child, PT_SR, tmp);
240 wake_up_process(child);
241 break;
242 }
244 case PTRACE_SINGLESTEP: { /* set the trap flag. */
245 long tmp;
247 ret = -EIO;
248 if (!valid_signal(data))
249 break;
250 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
251 tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16);
252 put_reg(child, PT_SR, tmp);
254 child->exit_code = data;
255 /* give it a chance to run. */
256 wake_up_process(child);
257 ret = 0;
258 break;
259 }
261 case PTRACE_DETACH: /* detach a process that was attached. */
262 ret = ptrace_detach(child, data);
263 break;
265 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
266 int i;
267 unsigned long tmp;
268 for (i = 0; i < 19; i++) {
269 tmp = get_reg(child, i);
270 if (i == PT_SR)
271 tmp >>= 16;
272 if (put_user(tmp, (unsigned long *) data)) {
273 ret = -EFAULT;
274 break;
275 }
276 data += sizeof(long);
277 }
278 ret = 0;
279 break;
280 }
282 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
283 int i;
284 unsigned long tmp;
285 for (i = 0; i < 19; i++) {
286 if (get_user(tmp, (unsigned long *) data)) {
287 ret = -EFAULT;
288 break;
289 }
290 if (i == PT_SR) {
291 tmp &= SR_MASK;
292 tmp <<= 16;
293 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16);
294 }
295 put_reg(child, i, tmp);
296 data += sizeof(long);
297 }
298 ret = 0;
299 break;
300 }
302 #ifdef PTRACE_GETFPREGS
303 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
304 ret = 0;
305 if (copy_to_user((void *)data, &child->thread.fp,
306 sizeof(struct user_m68kfp_struct)))
307 ret = -EFAULT;
308 break;
309 }
310 #endif
312 #ifdef PTRACE_SETFPREGS
313 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
314 ret = 0;
315 if (copy_from_user(&child->thread.fp, (void *)data,
316 sizeof(struct user_m68kfp_struct)))
317 ret = -EFAULT;
318 break;
319 }
320 #endif
322 default:
323 ret = -EIO;
324 break;
325 }
326 return ret;
327 }
329 asmlinkage void syscall_trace(void)
330 {
331 if (!test_thread_flag(TIF_SYSCALL_TRACE))
332 return;
333 if (!(current->ptrace & PT_PTRACED))
334 return;
335 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
336 ? 0x80 : 0));
337 /*
338 * this isn't the same as continuing with a signal, but it will do
339 * for normal use. strace only continues with a signal if the
340 * stopping signal is not SIGTRAP. -brl
341 */
342 if (current->exit_code) {
343 send_sig(current->exit_code, current, 1);
344 current->exit_code = 0;
345 }
346 }