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1da177e4 LT |
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> | |
7ed20e1a | 30 | #include <linux/signal.h> |
1da177e4 LT |
31 | |
32 | #include <asm/io.h> | |
33 | #include <asm/uaccess.h> | |
34 | #include <asm/pgtable.h> | |
35 | #include <asm/system.h> | |
36 | #include <asm/processor.h> | |
37 | #include <asm/mmu_context.h> | |
38 | ||
39 | /* This mask defines the bits of the SR which the user is not allowed to | |
40 | change, which are everything except S, Q, M, PR, SZ, FR. */ | |
41 | #define SR_MASK (0xffff8cfd) | |
42 | ||
43 | /* | |
44 | * does not yet catch signals sent when the child dies. | |
45 | * in exit.c or in signal.c. | |
46 | */ | |
47 | ||
48 | /* | |
49 | * This routine will get a word from the user area in the process kernel stack. | |
50 | */ | |
51 | static inline int get_stack_long(struct task_struct *task, int offset) | |
52 | { | |
53 | unsigned char *stack; | |
54 | ||
55 | stack = (unsigned char *)(task->thread.uregs); | |
56 | stack += offset; | |
57 | return (*((int *)stack)); | |
58 | } | |
59 | ||
60 | static inline unsigned long | |
61 | get_fpu_long(struct task_struct *task, unsigned long addr) | |
62 | { | |
63 | unsigned long tmp; | |
64 | struct pt_regs *regs; | |
65 | regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; | |
66 | ||
67 | if (!tsk_used_math(task)) { | |
68 | if (addr == offsetof(struct user_fpu_struct, fpscr)) { | |
69 | tmp = FPSCR_INIT; | |
70 | } else { | |
71 | tmp = 0xffffffffUL; /* matches initial value in fpu.c */ | |
72 | } | |
73 | return tmp; | |
74 | } | |
75 | ||
76 | if (last_task_used_math == task) { | |
77 | grab_fpu(); | |
78 | fpsave(&task->thread.fpu.hard); | |
79 | release_fpu(); | |
80 | last_task_used_math = 0; | |
81 | regs->sr |= SR_FD; | |
82 | } | |
83 | ||
84 | tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)]; | |
85 | return tmp; | |
86 | } | |
87 | ||
88 | /* | |
89 | * This routine will put a word into the user area in the process kernel stack. | |
90 | */ | |
91 | static inline int put_stack_long(struct task_struct *task, int offset, | |
92 | unsigned long data) | |
93 | { | |
94 | unsigned char *stack; | |
95 | ||
96 | stack = (unsigned char *)(task->thread.uregs); | |
97 | stack += offset; | |
98 | *(unsigned long *) stack = data; | |
99 | return 0; | |
100 | } | |
101 | ||
102 | static inline int | |
103 | put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data) | |
104 | { | |
105 | struct pt_regs *regs; | |
106 | ||
107 | regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; | |
108 | ||
109 | if (!tsk_used_math(task)) { | |
110 | fpinit(&task->thread.fpu.hard); | |
111 | set_stopped_child_used_math(task); | |
112 | } else if (last_task_used_math == task) { | |
113 | grab_fpu(); | |
114 | fpsave(&task->thread.fpu.hard); | |
115 | release_fpu(); | |
116 | last_task_used_math = 0; | |
117 | regs->sr |= SR_FD; | |
118 | } | |
119 | ||
120 | ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data; | |
121 | return 0; | |
122 | } | |
123 | ||
dfb7dac3 | 124 | asmlinkage long sys_ptrace(long request, long pid, long addr, long data) |
1da177e4 LT |
125 | { |
126 | struct task_struct *child; | |
127 | extern void poke_real_address_q(unsigned long long addr, unsigned long long data); | |
128 | #define WPC_DBRMODE 0x0d104008 | |
129 | static int first_call = 1; | |
130 | int ret; | |
131 | ||
132 | lock_kernel(); | |
133 | ||
134 | if (first_call) { | |
135 | /* Set WPC.DBRMODE to 0. This makes all debug events get | |
136 | * delivered through RESVEC, i.e. into the handlers in entry.S. | |
137 | * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE | |
138 | * would normally be left set to 1, which makes debug events get | |
139 | * delivered through DBRVEC, i.e. into the remote gdb's | |
140 | * handlers. This prevents ptrace getting them, and confuses | |
141 | * the remote gdb.) */ | |
142 | printk("DBRMODE set to 0 to permit native debugging\n"); | |
143 | poke_real_address_q(WPC_DBRMODE, 0); | |
144 | first_call = 0; | |
145 | } | |
146 | ||
147 | ret = -EPERM; | |
148 | if (request == PTRACE_TRACEME) { | |
149 | /* are we already being traced? */ | |
150 | if (current->ptrace & PT_PTRACED) | |
151 | goto out; | |
152 | /* set the ptrace bit in the process flags. */ | |
153 | current->ptrace |= PT_PTRACED; | |
154 | ret = 0; | |
155 | goto out; | |
156 | } | |
157 | ret = -ESRCH; | |
158 | read_lock(&tasklist_lock); | |
159 | child = find_task_by_pid(pid); | |
160 | if (child) | |
161 | get_task_struct(child); | |
162 | read_unlock(&tasklist_lock); | |
163 | if (!child) | |
164 | goto out; | |
165 | ||
166 | ret = -EPERM; | |
167 | if (pid == 1) /* you may not mess with init */ | |
168 | goto out_tsk; | |
169 | ||
170 | if (request == PTRACE_ATTACH) { | |
171 | ret = ptrace_attach(child); | |
172 | goto out_tsk; | |
173 | } | |
174 | ||
175 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
176 | if (ret < 0) | |
177 | goto out_tsk; | |
178 | ||
179 | switch (request) { | |
180 | /* when I and D space are separate, these will need to be fixed. */ | |
181 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
182 | case PTRACE_PEEKDATA: { | |
183 | unsigned long tmp; | |
184 | int copied; | |
185 | ||
186 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
187 | ret = -EIO; | |
188 | if (copied != sizeof(tmp)) | |
189 | break; | |
190 | ret = put_user(tmp,(unsigned long *) data); | |
191 | break; | |
192 | } | |
193 | ||
194 | /* read the word at location addr in the USER area. */ | |
195 | case PTRACE_PEEKUSR: { | |
196 | unsigned long tmp; | |
197 | ||
198 | ret = -EIO; | |
199 | if ((addr & 3) || addr < 0) | |
200 | break; | |
201 | ||
202 | if (addr < sizeof(struct pt_regs)) | |
203 | tmp = get_stack_long(child, addr); | |
204 | else if ((addr >= offsetof(struct user, fpu)) && | |
205 | (addr < offsetof(struct user, u_fpvalid))) { | |
206 | tmp = get_fpu_long(child, addr - offsetof(struct user, fpu)); | |
207 | } else if (addr == offsetof(struct user, u_fpvalid)) { | |
208 | tmp = !!tsk_used_math(child); | |
209 | } else { | |
210 | break; | |
211 | } | |
212 | ret = put_user(tmp, (unsigned long *)data); | |
213 | break; | |
214 | } | |
215 | ||
216 | /* when I and D space are separate, this will have to be fixed. */ | |
217 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
218 | case PTRACE_POKEDATA: | |
219 | ret = 0; | |
220 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
221 | break; | |
222 | ret = -EIO; | |
223 | break; | |
224 | ||
225 | case PTRACE_POKEUSR: | |
226 | /* write the word at location addr in the USER area. We must | |
227 | disallow any changes to certain SR bits or u_fpvalid, since | |
228 | this could crash the kernel or result in a security | |
229 | loophole. */ | |
230 | ret = -EIO; | |
231 | if ((addr & 3) || addr < 0) | |
232 | break; | |
233 | ||
234 | if (addr < sizeof(struct pt_regs)) { | |
235 | /* Ignore change of top 32 bits of SR */ | |
236 | if (addr == offsetof (struct pt_regs, sr)+4) | |
237 | { | |
238 | ret = 0; | |
239 | break; | |
240 | } | |
241 | /* If lower 32 bits of SR, ignore non-user bits */ | |
242 | if (addr == offsetof (struct pt_regs, sr)) | |
243 | { | |
244 | long cursr = get_stack_long(child, addr); | |
245 | data &= ~(SR_MASK); | |
246 | data |= (cursr & SR_MASK); | |
247 | } | |
248 | ret = put_stack_long(child, addr, data); | |
249 | } | |
250 | else if ((addr >= offsetof(struct user, fpu)) && | |
251 | (addr < offsetof(struct user, u_fpvalid))) { | |
252 | ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data); | |
253 | } | |
254 | break; | |
255 | ||
256 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
257 | case PTRACE_CONT: { /* restart after signal. */ | |
258 | ret = -EIO; | |
7ed20e1a | 259 | if (!valid_signal(data)) |
1da177e4 LT |
260 | break; |
261 | if (request == PTRACE_SYSCALL) | |
262 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
263 | else | |
264 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
265 | child->exit_code = data; | |
266 | wake_up_process(child); | |
267 | ret = 0; | |
268 | break; | |
269 | } | |
270 | ||
271 | /* | |
272 | * make the child exit. Best I can do is send it a sigkill. | |
273 | * perhaps it should be put in the status that it wants to | |
274 | * exit. | |
275 | */ | |
276 | case PTRACE_KILL: { | |
277 | ret = 0; | |
278 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
279 | break; | |
280 | child->exit_code = SIGKILL; | |
281 | wake_up_process(child); | |
282 | break; | |
283 | } | |
284 | ||
285 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
286 | struct pt_regs *regs; | |
287 | ||
288 | ret = -EIO; | |
7ed20e1a | 289 | if (!valid_signal(data)) |
1da177e4 LT |
290 | break; |
291 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
292 | if ((child->ptrace & PT_DTRACE) == 0) { | |
293 | /* Spurious delayed TF traps may occur */ | |
294 | child->ptrace |= PT_DTRACE; | |
295 | } | |
296 | ||
297 | regs = child->thread.uregs; | |
298 | ||
299 | regs->sr |= SR_SSTEP; /* auto-resetting upon exception */ | |
300 | ||
301 | child->exit_code = data; | |
302 | /* give it a chance to run. */ | |
303 | wake_up_process(child); | |
304 | ret = 0; | |
305 | break; | |
306 | } | |
307 | ||
308 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
309 | ret = ptrace_detach(child, data); | |
310 | break; | |
311 | ||
312 | default: | |
313 | ret = ptrace_request(child, request, addr, data); | |
314 | break; | |
315 | } | |
316 | out_tsk: | |
317 | put_task_struct(child); | |
318 | out: | |
319 | unlock_kernel(); | |
320 | return ret; | |
321 | } | |
322 | ||
323 | asmlinkage void syscall_trace(void) | |
324 | { | |
325 | struct task_struct *tsk = current; | |
326 | ||
327 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
328 | return; | |
329 | if (!(tsk->ptrace & PT_PTRACED)) | |
330 | return; | |
331 | ||
332 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
333 | ? 0x80 : 0)); | |
334 | /* | |
335 | * this isn't the same as continuing with a signal, but it will do | |
336 | * for normal use. strace only continues with a signal if the | |
337 | * stopping signal is not SIGTRAP. -brl | |
338 | */ | |
339 | if (tsk->exit_code) { | |
340 | send_sig(tsk->exit_code, tsk, 1); | |
341 | tsk->exit_code = 0; | |
342 | } | |
343 | } | |
344 | ||
345 | /* Called with interrupts disabled */ | |
346 | asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs) | |
347 | { | |
348 | /* This is called after a single step exception (DEBUGSS). | |
349 | There is no need to change the PC, as it is a post-execution | |
350 | exception, as entry.S does not do anything to the PC for DEBUGSS. | |
351 | We need to clear the Single Step setting in SR to avoid | |
352 | continually stepping. */ | |
353 | local_irq_enable(); | |
354 | regs->sr &= ~SR_SSTEP; | |
355 | force_sig(SIGTRAP, current); | |
356 | } | |
357 | ||
358 | /* Called with interrupts disabled */ | |
359 | asmlinkage void do_software_break_point(unsigned long long vec, | |
360 | struct pt_regs *regs) | |
361 | { | |
362 | /* We need to forward step the PC, to counteract the backstep done | |
363 | in signal.c. */ | |
364 | local_irq_enable(); | |
365 | force_sig(SIGTRAP, current); | |
366 | regs->pc += 4; | |
367 | } | |
368 | ||
369 | /* | |
370 | * Called by kernel/ptrace.c when detaching.. | |
371 | * | |
372 | * Make sure single step bits etc are not set. | |
373 | */ | |
374 | void ptrace_disable(struct task_struct *child) | |
375 | { | |
376 | /* nothing to do.. */ | |
377 | } |