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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc/kernel/ptrace.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ppc/kernel/ptrace.c')
-rw-r--r--arch/ppc/kernel/ptrace.c474
1 files changed, 474 insertions, 0 deletions
diff --git a/arch/ppc/kernel/ptrace.c b/arch/ppc/kernel/ptrace.c
new file mode 100644
index 000000000000..426b6f7d9de3
--- /dev/null
+++ b/arch/ppc/kernel/ptrace.c
@@ -0,0 +1,474 @@
1/*
2 * arch/ppc/kernel/ptrace.c
3 *
4 * PowerPC version
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 *
7 * Derived from "arch/m68k/kernel/ptrace.c"
8 * Copyright (C) 1994 by Hamish Macdonald
9 * Taken from linux/kernel/ptrace.c and modified for M680x0.
10 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
11 *
12 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
13 * and Paul Mackerras (paulus@linuxcare.com.au).
14 *
15 * This file is subject to the terms and conditions of the GNU General
16 * Public License. See the file README.legal in the main directory of
17 * this archive for more details.
18 */
19
20#include <linux/kernel.h>
21#include <linux/sched.h>
22#include <linux/mm.h>
23#include <linux/smp.h>
24#include <linux/smp_lock.h>
25#include <linux/errno.h>
26#include <linux/ptrace.h>
27#include <linux/user.h>
28#include <linux/security.h>
29
30#include <asm/uaccess.h>
31#include <asm/page.h>
32#include <asm/pgtable.h>
33#include <asm/system.h>
34
35/*
36 * Set of msr bits that gdb can change on behalf of a process.
37 */
38#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
39#define MSR_DEBUGCHANGE 0
40#else
41#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
42#endif
43
44/*
45 * does not yet catch signals sent when the child dies.
46 * in exit.c or in signal.c.
47 */
48
49/*
50 * Get contents of register REGNO in task TASK.
51 */
52static inline unsigned long get_reg(struct task_struct *task, int regno)
53{
54 if (regno < sizeof(struct pt_regs) / sizeof(unsigned long)
55 && task->thread.regs != NULL)
56 return ((unsigned long *)task->thread.regs)[regno];
57 return (0);
58}
59
60/*
61 * Write contents of register REGNO in task TASK.
62 */
63static inline int put_reg(struct task_struct *task, int regno,
64 unsigned long data)
65{
66 if (regno <= PT_MQ && task->thread.regs != NULL) {
67 if (regno == PT_MSR)
68 data = (data & MSR_DEBUGCHANGE)
69 | (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
70 ((unsigned long *)task->thread.regs)[regno] = data;
71 return 0;
72 }
73 return -EIO;
74}
75
76#ifdef CONFIG_ALTIVEC
77/*
78 * Get contents of AltiVec register state in task TASK
79 */
80static inline int get_vrregs(unsigned long __user *data, struct task_struct *task)
81{
82 int i, j;
83
84 if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long)))
85 return -EFAULT;
86
87 /* copy AltiVec registers VR[0] .. VR[31] */
88 for (i = 0; i < 32; i++)
89 for (j = 0; j < 4; j++, data++)
90 if (__put_user(task->thread.vr[i].u[j], data))
91 return -EFAULT;
92
93 /* copy VSCR */
94 for (i = 0; i < 4; i++, data++)
95 if (__put_user(task->thread.vscr.u[i], data))
96 return -EFAULT;
97
98 /* copy VRSAVE */
99 if (__put_user(task->thread.vrsave, data))
100 return -EFAULT;
101
102 return 0;
103}
104
105/*
106 * Write contents of AltiVec register state into task TASK.
107 */
108static inline int set_vrregs(struct task_struct *task, unsigned long __user *data)
109{
110 int i, j;
111
112 if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long)))
113 return -EFAULT;
114
115 /* copy AltiVec registers VR[0] .. VR[31] */
116 for (i = 0; i < 32; i++)
117 for (j = 0; j < 4; j++, data++)
118 if (__get_user(task->thread.vr[i].u[j], data))
119 return -EFAULT;
120
121 /* copy VSCR */
122 for (i = 0; i < 4; i++, data++)
123 if (__get_user(task->thread.vscr.u[i], data))
124 return -EFAULT;
125
126 /* copy VRSAVE */
127 if (__get_user(task->thread.vrsave, data))
128 return -EFAULT;
129
130 return 0;
131}
132#endif
133
134#ifdef CONFIG_SPE
135
136/*
137 * For get_evrregs/set_evrregs functions 'data' has the following layout:
138 *
139 * struct {
140 * u32 evr[32];
141 * u64 acc;
142 * u32 spefscr;
143 * }
144 */
145
146/*
147 * Get contents of SPE register state in task TASK.
148 */
149static inline int get_evrregs(unsigned long *data, struct task_struct *task)
150{
151 int i;
152
153 if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
154 return -EFAULT;
155
156 /* copy SPEFSCR */
157 if (__put_user(task->thread.spefscr, &data[34]))
158 return -EFAULT;
159
160 /* copy SPE registers EVR[0] .. EVR[31] */
161 for (i = 0; i < 32; i++, data++)
162 if (__put_user(task->thread.evr[i], data))
163 return -EFAULT;
164
165 /* copy ACC */
166 if (__put_user64(task->thread.acc, (unsigned long long *)data))
167 return -EFAULT;
168
169 return 0;
170}
171
172/*
173 * Write contents of SPE register state into task TASK.
174 */
175static inline int set_evrregs(struct task_struct *task, unsigned long *data)
176{
177 int i;
178
179 if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
180 return -EFAULT;
181
182 /* copy SPEFSCR */
183 if (__get_user(task->thread.spefscr, &data[34]))
184 return -EFAULT;
185
186 /* copy SPE registers EVR[0] .. EVR[31] */
187 for (i = 0; i < 32; i++, data++)
188 if (__get_user(task->thread.evr[i], data))
189 return -EFAULT;
190 /* copy ACC */
191 if (__get_user64(task->thread.acc, (unsigned long long*)data))
192 return -EFAULT;
193
194 return 0;
195}
196#endif /* CONFIG_SPE */
197
198static inline void
199set_single_step(struct task_struct *task)
200{
201 struct pt_regs *regs = task->thread.regs;
202
203 if (regs != NULL) {
204#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
205 task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
206 regs->msr |= MSR_DE;
207#else
208 regs->msr |= MSR_SE;
209#endif
210 }
211}
212
213static inline void
214clear_single_step(struct task_struct *task)
215{
216 struct pt_regs *regs = task->thread.regs;
217
218 if (regs != NULL) {
219#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
220 task->thread.dbcr0 = 0;
221 regs->msr &= ~MSR_DE;
222#else
223 regs->msr &= ~MSR_SE;
224#endif
225 }
226}
227
228/*
229 * Called by kernel/ptrace.c when detaching..
230 *
231 * Make sure single step bits etc are not set.
232 */
233void ptrace_disable(struct task_struct *child)
234{
235 /* make sure the single step bit is not set. */
236 clear_single_step(child);
237}
238
239int sys_ptrace(long request, long pid, long addr, long data)
240{
241 struct task_struct *child;
242 int ret = -EPERM;
243
244 lock_kernel();
245 if (request == PTRACE_TRACEME) {
246 /* are we already being traced? */
247 if (current->ptrace & PT_PTRACED)
248 goto out;
249 ret = security_ptrace(current->parent, current);
250 if (ret)
251 goto out;
252 /* set the ptrace bit in the process flags. */
253 current->ptrace |= PT_PTRACED;
254 ret = 0;
255 goto out;
256 }
257 ret = -ESRCH;
258 read_lock(&tasklist_lock);
259 child = find_task_by_pid(pid);
260 if (child)
261 get_task_struct(child);
262 read_unlock(&tasklist_lock);
263 if (!child)
264 goto out;
265
266 ret = -EPERM;
267 if (pid == 1) /* you may not mess with init */
268 goto out_tsk;
269
270 if (request == PTRACE_ATTACH) {
271 ret = ptrace_attach(child);
272 goto out_tsk;
273 }
274
275 ret = ptrace_check_attach(child, request == PTRACE_KILL);
276 if (ret < 0)
277 goto out_tsk;
278
279 switch (request) {
280 /* when I and D space are separate, these will need to be fixed. */
281 case PTRACE_PEEKTEXT: /* read word at location addr. */
282 case PTRACE_PEEKDATA: {
283 unsigned long tmp;
284 int copied;
285
286 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
287 ret = -EIO;
288 if (copied != sizeof(tmp))
289 break;
290 ret = put_user(tmp,(unsigned long __user *) data);
291 break;
292 }
293
294 /* read the word at location addr in the USER area. */
295 /* XXX this will need fixing for 64-bit */
296 case PTRACE_PEEKUSR: {
297 unsigned long index, tmp;
298
299 ret = -EIO;
300 /* convert to index and check */
301 index = (unsigned long) addr >> 2;
302 if ((addr & 3) || index > PT_FPSCR
303 || child->thread.regs == NULL)
304 break;
305
306 CHECK_FULL_REGS(child->thread.regs);
307 if (index < PT_FPR0) {
308 tmp = get_reg(child, (int) index);
309 } else {
310 preempt_disable();
311 if (child->thread.regs->msr & MSR_FP)
312 giveup_fpu(child);
313 preempt_enable();
314 tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
315 }
316 ret = put_user(tmp,(unsigned long __user *) data);
317 break;
318 }
319
320 /* If I and D space are separate, this will have to be fixed. */
321 case PTRACE_POKETEXT: /* write the word at location addr. */
322 case PTRACE_POKEDATA:
323 ret = 0;
324 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
325 break;
326 ret = -EIO;
327 break;
328
329 /* write the word at location addr in the USER area */
330 case PTRACE_POKEUSR: {
331 unsigned long index;
332
333 ret = -EIO;
334 /* convert to index and check */
335 index = (unsigned long) addr >> 2;
336 if ((addr & 3) || index > PT_FPSCR
337 || child->thread.regs == NULL)
338 break;
339
340 CHECK_FULL_REGS(child->thread.regs);
341 if (index == PT_ORIG_R3)
342 break;
343 if (index < PT_FPR0) {
344 ret = put_reg(child, index, data);
345 } else {
346 preempt_disable();
347 if (child->thread.regs->msr & MSR_FP)
348 giveup_fpu(child);
349 preempt_enable();
350 ((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
351 ret = 0;
352 }
353 break;
354 }
355
356 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
357 case PTRACE_CONT: { /* restart after signal. */
358 ret = -EIO;
359 if ((unsigned long) data > _NSIG)
360 break;
361 if (request == PTRACE_SYSCALL) {
362 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
363 } else {
364 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
365 }
366 child->exit_code = data;
367 /* make sure the single step bit is not set. */
368 clear_single_step(child);
369 wake_up_process(child);
370 ret = 0;
371 break;
372 }
373
374/*
375 * make the child exit. Best I can do is send it a sigkill.
376 * perhaps it should be put in the status that it wants to
377 * exit.
378 */
379 case PTRACE_KILL: {
380 ret = 0;
381 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
382 break;
383 child->exit_code = SIGKILL;
384 /* make sure the single step bit is not set. */
385 clear_single_step(child);
386 wake_up_process(child);
387 break;
388 }
389
390 case PTRACE_SINGLESTEP: { /* set the trap flag. */
391 ret = -EIO;
392 if ((unsigned long) data > _NSIG)
393 break;
394 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
395 set_single_step(child);
396 child->exit_code = data;
397 /* give it a chance to run. */
398 wake_up_process(child);
399 ret = 0;
400 break;
401 }
402
403 case PTRACE_DETACH:
404 ret = ptrace_detach(child, data);
405 break;
406
407#ifdef CONFIG_ALTIVEC
408 case PTRACE_GETVRREGS:
409 /* Get the child altivec register state. */
410 preempt_disable();
411 if (child->thread.regs->msr & MSR_VEC)
412 giveup_altivec(child);
413 preempt_enable();
414 ret = get_vrregs((unsigned long __user *)data, child);
415 break;
416
417 case PTRACE_SETVRREGS:
418 /* Set the child altivec register state. */
419 /* this is to clear the MSR_VEC bit to force a reload
420 * of register state from memory */
421 preempt_disable();
422 if (child->thread.regs->msr & MSR_VEC)
423 giveup_altivec(child);
424 preempt_enable();
425 ret = set_vrregs(child, (unsigned long __user *)data);
426 break;
427#endif
428#ifdef CONFIG_SPE
429 case PTRACE_GETEVRREGS:
430 /* Get the child spe register state. */
431 if (child->thread.regs->msr & MSR_SPE)
432 giveup_spe(child);
433 ret = get_evrregs((unsigned long __user *)data, child);
434 break;
435
436 case PTRACE_SETEVRREGS:
437 /* Set the child spe register state. */
438 /* this is to clear the MSR_SPE bit to force a reload
439 * of register state from memory */
440 if (child->thread.regs->msr & MSR_SPE)
441 giveup_spe(child);
442 ret = set_evrregs(child, (unsigned long __user *)data);
443 break;
444#endif
445
446 default:
447 ret = ptrace_request(child, request, addr, data);
448 break;
449 }
450out_tsk:
451 put_task_struct(child);
452out:
453 unlock_kernel();
454 return ret;
455}
456
457void do_syscall_trace(void)
458{
459 if (!test_thread_flag(TIF_SYSCALL_TRACE)
460 || !(current->ptrace & PT_PTRACED))
461 return;
462 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
463 ? 0x80 : 0));
464
465 /*
466 * this isn't the same as continuing with a signal, but it will do
467 * for normal use. strace only continues with a signal if the
468 * stopping signal is not SIGTRAP. -brl
469 */
470 if (current->exit_code) {
471 send_sig(current->exit_code, current, 1);
472 current->exit_code = 0;
473 }
474}