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-rw-r--r--arch/avr32/kernel/ptrace.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/arch/avr32/kernel/ptrace.c b/arch/avr32/kernel/ptrace.c
new file mode 100644
index 000000000000..3c89e59029ab
--- /dev/null
+++ b/arch/avr32/kernel/ptrace.c
@@ -0,0 +1,371 @@
1/*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8#undef DEBUG
9#include <linux/kernel.h>
10#include <linux/sched.h>
11#include <linux/mm.h>
12#include <linux/smp_lock.h>
13#include <linux/ptrace.h>
14#include <linux/errno.h>
15#include <linux/user.h>
16#include <linux/security.h>
17#include <linux/unistd.h>
18#include <linux/notifier.h>
19
20#include <asm/traps.h>
21#include <asm/uaccess.h>
22#include <asm/ocd.h>
23#include <asm/mmu_context.h>
24#include <asm/kdebug.h>
25
26static struct pt_regs *get_user_regs(struct task_struct *tsk)
27{
28 return (struct pt_regs *)((unsigned long) tsk->thread_info +
29 THREAD_SIZE - sizeof(struct pt_regs));
30}
31
32static void ptrace_single_step(struct task_struct *tsk)
33{
34 pr_debug("ptrace_single_step: pid=%u, SR=0x%08lx\n",
35 tsk->pid, tsk->thread.cpu_context.sr);
36 if (!(tsk->thread.cpu_context.sr & SR_D)) {
37 /*
38 * Set a breakpoint at the current pc to force the
39 * process into debug mode. The syscall/exception
40 * exit code will set a breakpoint at the return
41 * address when this flag is set.
42 */
43 pr_debug("ptrace_single_step: Setting TIF_BREAKPOINT\n");
44 set_tsk_thread_flag(tsk, TIF_BREAKPOINT);
45 }
46
47 /* The monitor code will do the actual step for us */
48 set_tsk_thread_flag(tsk, TIF_SINGLE_STEP);
49}
50
51/*
52 * Called by kernel/ptrace.c when detaching
53 *
54 * Make sure any single step bits, etc. are not set
55 */
56void ptrace_disable(struct task_struct *child)
57{
58 clear_tsk_thread_flag(child, TIF_SINGLE_STEP);
59}
60
61/*
62 * Handle hitting a breakpoint
63 */
64static void ptrace_break(struct task_struct *tsk, struct pt_regs *regs)
65{
66 siginfo_t info;
67
68 info.si_signo = SIGTRAP;
69 info.si_errno = 0;
70 info.si_code = TRAP_BRKPT;
71 info.si_addr = (void __user *)instruction_pointer(regs);
72
73 pr_debug("ptrace_break: Sending SIGTRAP to PID %u (pc = 0x%p)\n",
74 tsk->pid, info.si_addr);
75 force_sig_info(SIGTRAP, &info, tsk);
76}
77
78/*
79 * Read the word at offset "offset" into the task's "struct user". We
80 * actually access the pt_regs struct stored on the kernel stack.
81 */
82static int ptrace_read_user(struct task_struct *tsk, unsigned long offset,
83 unsigned long __user *data)
84{
85 unsigned long *regs;
86 unsigned long value;
87
88 pr_debug("ptrace_read_user(%p, %#lx, %p)\n",
89 tsk, offset, data);
90
91 if (offset & 3 || offset >= sizeof(struct user)) {
92 printk("ptrace_read_user: invalid offset 0x%08lx\n", offset);
93 return -EIO;
94 }
95
96 regs = (unsigned long *)get_user_regs(tsk);
97
98 value = 0;
99 if (offset < sizeof(struct pt_regs))
100 value = regs[offset / sizeof(regs[0])];
101
102 return put_user(value, data);
103}
104
105/*
106 * Write the word "value" to offset "offset" into the task's "struct
107 * user". We actually access the pt_regs struct stored on the kernel
108 * stack.
109 */
110static int ptrace_write_user(struct task_struct *tsk, unsigned long offset,
111 unsigned long value)
112{
113 unsigned long *regs;
114
115 if (offset & 3 || offset >= sizeof(struct user)) {
116 printk("ptrace_write_user: invalid offset 0x%08lx\n", offset);
117 return -EIO;
118 }
119
120 if (offset >= sizeof(struct pt_regs))
121 return 0;
122
123 regs = (unsigned long *)get_user_regs(tsk);
124 regs[offset / sizeof(regs[0])] = value;
125
126 return 0;
127}
128
129static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
130{
131 struct pt_regs *regs = get_user_regs(tsk);
132
133 return copy_to_user(uregs, regs, sizeof(*regs)) ? -EFAULT : 0;
134}
135
136static int ptrace_setregs(struct task_struct *tsk, const void __user *uregs)
137{
138 struct pt_regs newregs;
139 int ret;
140
141 ret = -EFAULT;
142 if (copy_from_user(&newregs, uregs, sizeof(newregs)) == 0) {
143 struct pt_regs *regs = get_user_regs(tsk);
144
145 ret = -EINVAL;
146 if (valid_user_regs(&newregs)) {
147 *regs = newregs;
148 ret = 0;
149 }
150 }
151
152 return ret;
153}
154
155long arch_ptrace(struct task_struct *child, long request, long addr, long data)
156{
157 unsigned long tmp;
158 int ret;
159
160 pr_debug("arch_ptrace(%ld, %ld, %#lx, %#lx)\n",
161 request, child->pid, addr, data);
162
163 pr_debug("ptrace: Enabling monitor mode...\n");
164 __mtdr(DBGREG_DC, __mfdr(DBGREG_DC) | DC_MM | DC_DBE);
165
166 switch (request) {
167 /* Read the word at location addr in the child process */
168 case PTRACE_PEEKTEXT:
169 case PTRACE_PEEKDATA:
170 ret = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
171 if (ret == sizeof(tmp))
172 ret = put_user(tmp, (unsigned long __user *)data);
173 else
174 ret = -EIO;
175 break;
176
177 case PTRACE_PEEKUSR:
178 ret = ptrace_read_user(child, addr,
179 (unsigned long __user *)data);
180 break;
181
182 /* Write the word in data at location addr */
183 case PTRACE_POKETEXT:
184 case PTRACE_POKEDATA:
185 ret = access_process_vm(child, addr, &data, sizeof(data), 1);
186 if (ret == sizeof(data))
187 ret = 0;
188 else
189 ret = -EIO;
190 break;
191
192 case PTRACE_POKEUSR:
193 ret = ptrace_write_user(child, addr, data);
194 break;
195
196 /* continue and stop at next (return from) syscall */
197 case PTRACE_SYSCALL:
198 /* restart after signal */
199 case PTRACE_CONT:
200 ret = -EIO;
201 if (!valid_signal(data))
202 break;
203 if (request == PTRACE_SYSCALL)
204 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
205 else
206 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
207 child->exit_code = data;
208 /* XXX: Are we sure no breakpoints are active here? */
209 wake_up_process(child);
210 ret = 0;
211 break;
212
213 /*
214 * Make the child exit. Best I can do is send it a
215 * SIGKILL. Perhaps it should be put in the status that it
216 * wants to exit.
217 */
218 case PTRACE_KILL:
219 ret = 0;
220 if (child->exit_state == EXIT_ZOMBIE)
221 break;
222 child->exit_code = SIGKILL;
223 wake_up_process(child);
224 break;
225
226 /*
227 * execute single instruction.
228 */
229 case PTRACE_SINGLESTEP:
230 ret = -EIO;
231 if (!valid_signal(data))
232 break;
233 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
234 ptrace_single_step(child);
235 child->exit_code = data;
236 wake_up_process(child);
237 ret = 0;
238 break;
239
240 /* Detach a process that was attached */
241 case PTRACE_DETACH:
242 ret = ptrace_detach(child, data);
243 break;
244
245 case PTRACE_GETREGS:
246 ret = ptrace_getregs(child, (void __user *)data);
247 break;
248
249 case PTRACE_SETREGS:
250 ret = ptrace_setregs(child, (const void __user *)data);
251 break;
252
253 default:
254 ret = ptrace_request(child, request, addr, data);
255 break;
256 }
257
258 pr_debug("sys_ptrace returning %d (DC = 0x%08lx)\n", ret, __mfdr(DBGREG_DC));
259 return ret;
260}
261
262asmlinkage void syscall_trace(void)
263{
264 pr_debug("syscall_trace called\n");
265 if (!test_thread_flag(TIF_SYSCALL_TRACE))
266 return;
267 if (!(current->ptrace & PT_PTRACED))
268 return;
269
270 pr_debug("syscall_trace: notifying parent\n");
271 /* The 0x80 provides a way for the tracing parent to
272 * distinguish between a syscall stop and SIGTRAP delivery */
273 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
274 ? 0x80 : 0));
275
276 /*
277 * this isn't the same as continuing with a signal, but it
278 * will do for normal use. strace only continues with a
279 * signal if the stopping signal is not SIGTRAP. -brl
280 */
281 if (current->exit_code) {
282 pr_debug("syscall_trace: sending signal %d to PID %u\n",
283 current->exit_code, current->pid);
284 send_sig(current->exit_code, current, 1);
285 current->exit_code = 0;
286 }
287}
288
289asmlinkage void do_debug_priv(struct pt_regs *regs)
290{
291 unsigned long dc, ds;
292 unsigned long die_val;
293
294 ds = __mfdr(DBGREG_DS);
295
296 pr_debug("do_debug_priv: pc = %08lx, ds = %08lx\n", regs->pc, ds);
297
298 if (ds & DS_SSS)
299 die_val = DIE_SSTEP;
300 else
301 die_val = DIE_BREAKPOINT;
302
303 if (notify_die(die_val, regs, 0, SIGTRAP) == NOTIFY_STOP)
304 return;
305
306 if (likely(ds & DS_SSS)) {
307 extern void itlb_miss(void);
308 extern void tlb_miss_common(void);
309 struct thread_info *ti;
310
311 dc = __mfdr(DBGREG_DC);
312 dc &= ~DC_SS;
313 __mtdr(DBGREG_DC, dc);
314
315 ti = current_thread_info();
316 ti->flags |= _TIF_BREAKPOINT;
317
318 /* The TLB miss handlers don't check thread flags */
319 if ((regs->pc >= (unsigned long)&itlb_miss)
320 && (regs->pc <= (unsigned long)&tlb_miss_common)) {
321 __mtdr(DBGREG_BWA2A, sysreg_read(RAR_EX));
322 __mtdr(DBGREG_BWC2A, 0x40000001 | (get_asid() << 1));
323 }
324
325 /*
326 * If we're running in supervisor mode, the breakpoint
327 * will take us where we want directly, no need to
328 * single step.
329 */
330 if ((regs->sr & MODE_MASK) != MODE_SUPERVISOR)
331 ti->flags |= TIF_SINGLE_STEP;
332 } else {
333 panic("Unable to handle debug trap at pc = %08lx\n",
334 regs->pc);
335 }
336}
337
338/*
339 * Handle breakpoints, single steps and other debuggy things. To keep
340 * things simple initially, we run with interrupts and exceptions
341 * disabled all the time.
342 */
343asmlinkage void do_debug(struct pt_regs *regs)
344{
345 unsigned long dc, ds;
346
347 ds = __mfdr(DBGREG_DS);
348 pr_debug("do_debug: pc = %08lx, ds = %08lx\n", regs->pc, ds);
349
350 if (test_thread_flag(TIF_BREAKPOINT)) {
351 pr_debug("TIF_BREAKPOINT set\n");
352 /* We're taking care of it */
353 clear_thread_flag(TIF_BREAKPOINT);
354 __mtdr(DBGREG_BWC2A, 0);
355 }
356
357 if (test_thread_flag(TIF_SINGLE_STEP)) {
358 pr_debug("TIF_SINGLE_STEP set, ds = 0x%08lx\n", ds);
359 if (ds & DS_SSS) {
360 dc = __mfdr(DBGREG_DC);
361 dc &= ~DC_SS;
362 __mtdr(DBGREG_DC, dc);
363
364 clear_thread_flag(TIF_SINGLE_STEP);
365 ptrace_break(current, regs);
366 }
367 } else {
368 /* regular breakpoint */
369 ptrace_break(current, regs);
370 }
371}