1 /* MN10300 Process tracing
2 *
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Modified by David Howells (dhowells@redhat.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/smp_lock.h>
17 #include <linux/errno.h>
18 #include <linux/ptrace.h>
19 #include <linux/user.h>
20 #include <asm/uaccess.h>
21 #include <asm/pgtable.h>
22 #include <asm/system.h>
23 #include <asm/processor.h>
24 #include <asm/cacheflush.h>
25 #include <asm/fpu.h>
26 #include <asm/asm-offsets.h>
27
28 /*
29 * translate ptrace register IDs into struct pt_regs offsets
30 */
31 static const u8 ptrace_regid_to_frame[] = {
32 [PT_A3 << 2] = REG_A3,
33 [PT_A2 << 2] = REG_A2,
34 [PT_D3 << 2] = REG_D3,
35 [PT_D2 << 2] = REG_D2,
36 [PT_MCVF << 2] = REG_MCVF,
37 [PT_MCRL << 2] = REG_MCRL,
38 [PT_MCRH << 2] = REG_MCRH,
39 [PT_MDRQ << 2] = REG_MDRQ,
40 [PT_E1 << 2] = REG_E1,
41 [PT_E0 << 2] = REG_E0,
42 [PT_E7 << 2] = REG_E7,
43 [PT_E6 << 2] = REG_E6,
44 [PT_E5 << 2] = REG_E5,
45 [PT_E4 << 2] = REG_E4,
46 [PT_E3 << 2] = REG_E3,
47 [PT_E2 << 2] = REG_E2,
48 [PT_SP << 2] = REG_SP,
49 [PT_LAR << 2] = REG_LAR,
50 [PT_LIR << 2] = REG_LIR,
51 [PT_MDR << 2] = REG_MDR,
52 [PT_A1 << 2] = REG_A1,
53 [PT_A0 << 2] = REG_A0,
54 [PT_D1 << 2] = REG_D1,
55 [PT_D0 << 2] = REG_D0,
56 [PT_ORIG_D0 << 2] = REG_ORIG_D0,
57 [PT_EPSW << 2] = REG_EPSW,
58 [PT_PC << 2] = REG_PC,
59 };
60
get_stack_long(struct task_struct * task,int offset)61 static inline int get_stack_long(struct task_struct *task, int offset)
62 {
63 return *(unsigned long *)
64 ((unsigned long) task->thread.uregs + offset);
65 }
66
67 /*
68 * this routine will put a word on the processes privileged stack.
69 * the offset is how far from the base addr as stored in the TSS.
70 * this routine assumes that all the privileged stacks are in our
71 * data space.
72 */
73 static inline
put_stack_long(struct task_struct * task,int offset,unsigned long data)74 int put_stack_long(struct task_struct *task, int offset, unsigned long data)
75 {
76 unsigned long stack;
77
78 stack = (unsigned long) task->thread.uregs + offset;
79 *(unsigned long *) stack = data;
80 return 0;
81 }
82
get_fpregs(struct fpu_state_struct * buf,struct task_struct * tsk)83 static inline unsigned long get_fpregs(struct fpu_state_struct *buf,
84 struct task_struct *tsk)
85 {
86 return __copy_to_user(buf, &tsk->thread.fpu_state,
87 sizeof(struct fpu_state_struct));
88 }
89
set_fpregs(struct task_struct * tsk,struct fpu_state_struct * buf)90 static inline unsigned long set_fpregs(struct task_struct *tsk,
91 struct fpu_state_struct *buf)
92 {
93 return __copy_from_user(&tsk->thread.fpu_state, buf,
94 sizeof(struct fpu_state_struct));
95 }
96
fpsave_init(struct task_struct * task)97 static inline void fpsave_init(struct task_struct *task)
98 {
99 memset(&task->thread.fpu_state, 0, sizeof(struct fpu_state_struct));
100 }
101
102 /*
103 * make sure the single step bit is not set
104 */
ptrace_disable(struct task_struct * child)105 void ptrace_disable(struct task_struct *child)
106 {
107 #ifndef CONFIG_MN10300_USING_JTAG
108 struct user *dummy = NULL;
109 long tmp;
110
111 tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
112 tmp &= ~EPSW_T;
113 put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
114 #endif
115 }
116
117 /*
118 * set the single step bit
119 */
ptrace_enable(struct task_struct * child)120 void ptrace_enable(struct task_struct *child)
121 {
122 #ifndef CONFIG_MN10300_USING_JTAG
123 struct user *dummy = NULL;
124 long tmp;
125
126 tmp = get_stack_long(child, (unsigned long) &dummy->regs.epsw);
127 tmp |= EPSW_T;
128 put_stack_long(child, (unsigned long) &dummy->regs.epsw, tmp);
129 #endif
130 }
131
132 /*
133 * handle the arch-specific side of process tracing
134 */
arch_ptrace(struct task_struct * child,long request,long addr,long data)135 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
136 {
137 struct fpu_state_struct fpu_state;
138 int i, ret;
139
140 switch (request) {
141 /* read the word at location addr. */
142 case PTRACE_PEEKTEXT: {
143 unsigned long tmp;
144 int copied;
145
146 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
147 ret = -EIO;
148 if (copied != sizeof(tmp))
149 break;
150 ret = put_user(tmp, (unsigned long *) data);
151 break;
152 }
153
154 /* read the word at location addr. */
155 case PTRACE_PEEKDATA: {
156 unsigned long tmp;
157 int copied;
158
159 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
160 ret = -EIO;
161 if (copied != sizeof(tmp))
162 break;
163 ret = put_user(tmp, (unsigned long *) data);
164 break;
165 }
166
167 /* read the word at location addr in the USER area. */
168 case PTRACE_PEEKUSR: {
169 unsigned long tmp;
170
171 ret = -EIO;
172 if ((addr & 3) || addr < 0 ||
173 addr > sizeof(struct user) - 3)
174 break;
175
176 tmp = 0; /* Default return condition */
177 if (addr < NR_PTREGS << 2)
178 tmp = get_stack_long(child,
179 ptrace_regid_to_frame[addr]);
180 ret = put_user(tmp, (unsigned long *) data);
181 break;
182 }
183
184 /* write the word at location addr. */
185 case PTRACE_POKETEXT:
186 case PTRACE_POKEDATA:
187 if (access_process_vm(child, addr, &data, sizeof(data), 1) ==
188 sizeof(data))
189 ret = 0;
190 else
191 ret = -EIO;
192 break;
193
194 /* write the word at location addr in the USER area */
195 case PTRACE_POKEUSR:
196 ret = -EIO;
197 if ((addr & 3) || addr < 0 ||
198 addr > sizeof(struct user) - 3)
199 break;
200
201 ret = 0;
202 if (addr < NR_PTREGS << 2)
203 ret = put_stack_long(child, ptrace_regid_to_frame[addr],
204 data);
205 break;
206
207 /* continue and stop at next (return from) syscall */
208 case PTRACE_SYSCALL:
209 /* restart after signal. */
210 case PTRACE_CONT:
211 ret = -EIO;
212 if ((unsigned long) data > _NSIG)
213 break;
214 if (request == PTRACE_SYSCALL)
215 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
216 else
217 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
218 child->exit_code = data;
219 ptrace_disable(child);
220 wake_up_process(child);
221 ret = 0;
222 break;
223
224 /*
225 * make the child exit
226 * - the 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 ret = 0;
232 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
233 break;
234 child->exit_code = SIGKILL;
235 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
236 ptrace_disable(child);
237 wake_up_process(child);
238 break;
239
240 case PTRACE_SINGLESTEP: /* set the trap flag. */
241 #ifndef CONFIG_MN10300_USING_JTAG
242 ret = -EIO;
243 if ((unsigned long) data > _NSIG)
244 break;
245 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
246 ptrace_enable(child);
247 child->exit_code = data;
248 wake_up_process(child);
249 ret = 0;
250 #else
251 ret = -EINVAL;
252 #endif
253 break;
254
255 case PTRACE_DETACH: /* detach a process that was attached. */
256 ret = ptrace_detach(child, data);
257 break;
258
259 /* Get all gp regs from the child. */
260 case PTRACE_GETREGS: {
261 unsigned long tmp;
262
263 if (!access_ok(VERIFY_WRITE, (unsigned *) data, NR_PTREGS << 2)) {
264 ret = -EIO;
265 break;
266 }
267
268 for (i = 0; i < NR_PTREGS << 2; i += 4) {
269 tmp = get_stack_long(child, ptrace_regid_to_frame[i]);
270 __put_user(tmp, (unsigned long *) data);
271 data += sizeof(tmp);
272 }
273 ret = 0;
274 break;
275 }
276
277 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
278 unsigned long tmp;
279
280 if (!access_ok(VERIFY_READ, (unsigned long *)data,
281 sizeof(struct pt_regs))) {
282 ret = -EIO;
283 break;
284 }
285
286 for (i = 0; i < NR_PTREGS << 2; i += 4) {
287 __get_user(tmp, (unsigned long *) data);
288 put_stack_long(child, ptrace_regid_to_frame[i], tmp);
289 data += sizeof(tmp);
290 }
291 ret = 0;
292 break;
293 }
294
295 case PTRACE_GETFPREGS: { /* Get the child FPU state. */
296 if (is_using_fpu(child)) {
297 unlazy_fpu(child);
298 fpu_state = child->thread.fpu_state;
299 } else {
300 memset(&fpu_state, 0, sizeof(fpu_state));
301 }
302
303 ret = -EIO;
304 if (copy_to_user((void *) data, &fpu_state,
305 sizeof(fpu_state)) == 0)
306 ret = 0;
307 break;
308 }
309
310 case PTRACE_SETFPREGS: { /* Set the child FPU state. */
311 ret = -EFAULT;
312 if (copy_from_user(&fpu_state, (const void *) data,
313 sizeof(fpu_state)) == 0) {
314 fpu_kill_state(child);
315 child->thread.fpu_state = fpu_state;
316 set_using_fpu(child);
317 ret = 0;
318 }
319 break;
320 }
321
322 case PTRACE_SETOPTIONS: {
323 if (data & PTRACE_O_TRACESYSGOOD)
324 child->ptrace |= PT_TRACESYSGOOD;
325 else
326 child->ptrace &= ~PT_TRACESYSGOOD;
327 ret = 0;
328 break;
329 }
330
331 default:
332 ret = -EIO;
333 break;
334 }
335
336 return ret;
337 }
338
339 /*
340 * notification of system call entry/exit
341 * - triggered by current->work.syscall_trace
342 */
do_syscall_trace(struct pt_regs * regs,int entryexit)343 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
344 {
345 #if 0
346 /* just in case... */
347 printk(KERN_DEBUG "[%d] syscall_%lu(%lx,%lx,%lx,%lx) = %lx\n",
348 current->pid,
349 regs->orig_d0,
350 regs->a0,
351 regs->d1,
352 regs->a3,
353 regs->a2,
354 regs->d0);
355 return;
356 #endif
357
358 if (!test_thread_flag(TIF_SYSCALL_TRACE) &&
359 !test_thread_flag(TIF_SINGLESTEP))
360 return;
361 if (!(current->ptrace & PT_PTRACED))
362 return;
363
364 /* the 0x80 provides a way for the tracing parent to distinguish
365 between a syscall stop and SIGTRAP delivery */
366 ptrace_notify(SIGTRAP |
367 ((current->ptrace & PT_TRACESYSGOOD) &&
368 !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0));
369
370 /*
371 * this isn't the same as continuing with a signal, but it will do
372 * for normal use. strace only continues with a signal if the
373 * stopping signal is not SIGTRAP. -brl
374 */
375 if (current->exit_code) {
376 send_sig(current->exit_code, current, 1);
377 current->exit_code = 0;
378 }
379 }
380