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-rw-r--r--arch/sh64/kernel/ptrace.c376
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diff --git a/arch/sh64/kernel/ptrace.c b/arch/sh64/kernel/ptrace.c
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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * arch/sh64/kernel/ptrace.c
7 *
8 * Copyright (C) 2000, 2001 Paolo Alberelli
9 * Copyright (C) 2003 Paul Mundt
10 *
11 * Started from SH3/4 version:
12 * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
13 *
14 * Original x86 implementation:
15 * By Ross Biro 1/23/92
16 * edited by Linus Torvalds
17 *
18 */
19
20#include <linux/config.h>
21#include <linux/kernel.h>
22#include <linux/rwsem.h>
23#include <linux/sched.h>
24#include <linux/mm.h>
25#include <linux/smp.h>
26#include <linux/smp_lock.h>
27#include <linux/errno.h>
28#include <linux/ptrace.h>
29#include <linux/user.h>
30
31#include <asm/io.h>
32#include <asm/uaccess.h>
33#include <asm/pgtable.h>
34#include <asm/system.h>
35#include <asm/processor.h>
36#include <asm/mmu_context.h>
37
38/* This mask defines the bits of the SR which the user is not allowed to
39 change, which are everything except S, Q, M, PR, SZ, FR. */
40#define SR_MASK (0xffff8cfd)
41
42/*
43 * does not yet catch signals sent when the child dies.
44 * in exit.c or in signal.c.
45 */
46
47/*
48 * This routine will get a word from the user area in the process kernel stack.
49 */
50static inline int get_stack_long(struct task_struct *task, int offset)
51{
52 unsigned char *stack;
53
54 stack = (unsigned char *)(task->thread.uregs);
55 stack += offset;
56 return (*((int *)stack));
57}
58
59static inline unsigned long
60get_fpu_long(struct task_struct *task, unsigned long addr)
61{
62 unsigned long tmp;
63 struct pt_regs *regs;
64 regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;
65
66 if (!tsk_used_math(task)) {
67 if (addr == offsetof(struct user_fpu_struct, fpscr)) {
68 tmp = FPSCR_INIT;
69 } else {
70 tmp = 0xffffffffUL; /* matches initial value in fpu.c */
71 }
72 return tmp;
73 }
74
75 if (last_task_used_math == task) {
76 grab_fpu();
77 fpsave(&task->thread.fpu.hard);
78 release_fpu();
79 last_task_used_math = 0;
80 regs->sr |= SR_FD;
81 }
82
83 tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)];
84 return tmp;
85}
86
87/*
88 * This routine will put a word into the user area in the process kernel stack.
89 */
90static inline int put_stack_long(struct task_struct *task, int offset,
91 unsigned long data)
92{
93 unsigned char *stack;
94
95 stack = (unsigned char *)(task->thread.uregs);
96 stack += offset;
97 *(unsigned long *) stack = data;
98 return 0;
99}
100
101static inline int
102put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data)
103{
104 struct pt_regs *regs;
105
106 regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1;
107
108 if (!tsk_used_math(task)) {
109 fpinit(&task->thread.fpu.hard);
110 set_stopped_child_used_math(task);
111 } else if (last_task_used_math == task) {
112 grab_fpu();
113 fpsave(&task->thread.fpu.hard);
114 release_fpu();
115 last_task_used_math = 0;
116 regs->sr |= SR_FD;
117 }
118
119 ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data;
120 return 0;
121}
122
123asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
124{
125 struct task_struct *child;
126 extern void poke_real_address_q(unsigned long long addr, unsigned long long data);
127#define WPC_DBRMODE 0x0d104008
128 static int first_call = 1;
129 int ret;
130
131 lock_kernel();
132
133 if (first_call) {
134 /* Set WPC.DBRMODE to 0. This makes all debug events get
135 * delivered through RESVEC, i.e. into the handlers in entry.S.
136 * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE
137 * would normally be left set to 1, which makes debug events get
138 * delivered through DBRVEC, i.e. into the remote gdb's
139 * handlers. This prevents ptrace getting them, and confuses
140 * the remote gdb.) */
141 printk("DBRMODE set to 0 to permit native debugging\n");
142 poke_real_address_q(WPC_DBRMODE, 0);
143 first_call = 0;
144 }
145
146 ret = -EPERM;
147 if (request == PTRACE_TRACEME) {
148 /* are we already being traced? */
149 if (current->ptrace & PT_PTRACED)
150 goto out;
151 /* set the ptrace bit in the process flags. */
152 current->ptrace |= PT_PTRACED;
153 ret = 0;
154 goto out;
155 }
156 ret = -ESRCH;
157 read_lock(&tasklist_lock);
158 child = find_task_by_pid(pid);
159 if (child)
160 get_task_struct(child);
161 read_unlock(&tasklist_lock);
162 if (!child)
163 goto out;
164
165 ret = -EPERM;
166 if (pid == 1) /* you may not mess with init */
167 goto out_tsk;
168
169 if (request == PTRACE_ATTACH) {
170 ret = ptrace_attach(child);
171 goto out_tsk;
172 }
173
174 ret = ptrace_check_attach(child, request == PTRACE_KILL);
175 if (ret < 0)
176 goto out_tsk;
177
178 switch (request) {
179 /* when I and D space are separate, these will need to be fixed. */
180 case PTRACE_PEEKTEXT: /* read word at location addr. */
181 case PTRACE_PEEKDATA: {
182 unsigned long tmp;
183 int copied;
184
185 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
186 ret = -EIO;
187 if (copied != sizeof(tmp))
188 break;
189 ret = put_user(tmp,(unsigned long *) data);
190 break;
191 }
192
193 /* read the word at location addr in the USER area. */
194 case PTRACE_PEEKUSR: {
195 unsigned long tmp;
196
197 ret = -EIO;
198 if ((addr & 3) || addr < 0)
199 break;
200
201 if (addr < sizeof(struct pt_regs))
202 tmp = get_stack_long(child, addr);
203 else if ((addr >= offsetof(struct user, fpu)) &&
204 (addr < offsetof(struct user, u_fpvalid))) {
205 tmp = get_fpu_long(child, addr - offsetof(struct user, fpu));
206 } else if (addr == offsetof(struct user, u_fpvalid)) {
207 tmp = !!tsk_used_math(child);
208 } else {
209 break;
210 }
211 ret = put_user(tmp, (unsigned long *)data);
212 break;
213 }
214
215 /* when I and D space are separate, this will have to be fixed. */
216 case PTRACE_POKETEXT: /* write the word at location addr. */
217 case PTRACE_POKEDATA:
218 ret = 0;
219 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
220 break;
221 ret = -EIO;
222 break;
223
224 case PTRACE_POKEUSR:
225 /* write the word at location addr in the USER area. We must
226 disallow any changes to certain SR bits or u_fpvalid, since
227 this could crash the kernel or result in a security
228 loophole. */
229 ret = -EIO;
230 if ((addr & 3) || addr < 0)
231 break;
232
233 if (addr < sizeof(struct pt_regs)) {
234 /* Ignore change of top 32 bits of SR */
235 if (addr == offsetof (struct pt_regs, sr)+4)
236 {
237 ret = 0;
238 break;
239 }
240 /* If lower 32 bits of SR, ignore non-user bits */
241 if (addr == offsetof (struct pt_regs, sr))
242 {
243 long cursr = get_stack_long(child, addr);
244 data &= ~(SR_MASK);
245 data |= (cursr & SR_MASK);
246 }
247 ret = put_stack_long(child, addr, data);
248 }
249 else if ((addr >= offsetof(struct user, fpu)) &&
250 (addr < offsetof(struct user, u_fpvalid))) {
251 ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data);
252 }
253 break;
254
255 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
256 case PTRACE_CONT: { /* restart after signal. */
257 ret = -EIO;
258 if ((unsigned long) data > _NSIG)
259 break;
260 if (request == PTRACE_SYSCALL)
261 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
262 else
263 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
264 child->exit_code = data;
265 wake_up_process(child);
266 ret = 0;
267 break;
268 }
269
270/*
271 * make the child exit. Best I can do is send it a sigkill.
272 * perhaps it should be put in the status that it wants to
273 * exit.
274 */
275 case PTRACE_KILL: {
276 ret = 0;
277 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
278 break;
279 child->exit_code = SIGKILL;
280 wake_up_process(child);
281 break;
282 }
283
284 case PTRACE_SINGLESTEP: { /* set the trap flag. */
285 struct pt_regs *regs;
286
287 ret = -EIO;
288 if ((unsigned long) data > _NSIG)
289 break;
290 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
291 if ((child->ptrace & PT_DTRACE) == 0) {
292 /* Spurious delayed TF traps may occur */
293 child->ptrace |= PT_DTRACE;
294 }
295
296 regs = child->thread.uregs;
297
298 regs->sr |= SR_SSTEP; /* auto-resetting upon exception */
299
300 child->exit_code = data;
301 /* give it a chance to run. */
302 wake_up_process(child);
303 ret = 0;
304 break;
305 }
306
307 case PTRACE_DETACH: /* detach a process that was attached. */
308 ret = ptrace_detach(child, data);
309 break;
310
311 default:
312 ret = ptrace_request(child, request, addr, data);
313 break;
314 }
315out_tsk:
316 put_task_struct(child);
317out:
318 unlock_kernel();
319 return ret;
320}
321
322asmlinkage void syscall_trace(void)
323{
324 struct task_struct *tsk = current;
325
326 if (!test_thread_flag(TIF_SYSCALL_TRACE))
327 return;
328 if (!(tsk->ptrace & PT_PTRACED))
329 return;
330
331 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
332 ? 0x80 : 0));
333 /*
334 * this isn't the same as continuing with a signal, but it will do
335 * for normal use. strace only continues with a signal if the
336 * stopping signal is not SIGTRAP. -brl
337 */
338 if (tsk->exit_code) {
339 send_sig(tsk->exit_code, tsk, 1);
340 tsk->exit_code = 0;
341 }
342}
343
344/* Called with interrupts disabled */
345asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs)
346{
347 /* This is called after a single step exception (DEBUGSS).
348 There is no need to change the PC, as it is a post-execution
349 exception, as entry.S does not do anything to the PC for DEBUGSS.
350 We need to clear the Single Step setting in SR to avoid
351 continually stepping. */
352 local_irq_enable();
353 regs->sr &= ~SR_SSTEP;
354 force_sig(SIGTRAP, current);
355}
356
357/* Called with interrupts disabled */
358asmlinkage void do_software_break_point(unsigned long long vec,
359 struct pt_regs *regs)
360{
361 /* We need to forward step the PC, to counteract the backstep done
362 in signal.c. */
363 local_irq_enable();
364 force_sig(SIGTRAP, current);
365 regs->pc += 4;
366}
367
368/*
369 * Called by kernel/ptrace.c when detaching..
370 *
371 * Make sure single step bits etc are not set.
372 */
373void ptrace_disable(struct task_struct *child)
374{
375 /* nothing to do.. */
376}
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