Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
/*
 *  linux/arch/ppc64/kernel/ptrace32.c
 *
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "arch/m68k/kernel/ptrace.c"
 *  Copyright (C) 1994 by Hamish Macdonald
 *  Taken from linux/kernel/ptrace.c and modified for M680x0.
 *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
 *
 * Modified by Cort Dougan (cort@hq.fsmlabs.com)
 * and Paul Mackerras (paulus@linuxcare.com.au).
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file README.legal in the main directory of
 * this archive for more details.
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/ptrace-common.h>

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

int sys32_ptrace(long request, long pid, unsigned long addr, unsigned long data)
{
	struct task_struct *child;
	int ret = -EPERM;

	lock_kernel();
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		ret = security_ptrace(current->parent, current);
		if (ret)
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}
	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;

	ret = -EPERM;
	if (pid == 1)		/* you may not mess with init */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		ret = ptrace_attach(child);
		goto out_tsk;
	}

	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	if (ret < 0)
		goto out_tsk;

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKTEXT: /* read word at location addr. */ 
	case PTRACE_PEEKDATA: {
		unsigned int tmp;
		int copied;

		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
		ret = -EIO;
		if (copied != sizeof(tmp))
			break;
		ret = put_user(tmp, (u32 __user *)data);
		break;
	}

	/*
	 * Read 4 bytes of the other process' storage
	 *  data is a pointer specifying where the user wants the
	 *	4 bytes copied into
	 *  addr is a pointer in the user's storage that contains an 8 byte
	 *	address in the other process of the 4 bytes that is to be read
	 * (this is run in a 32-bit process looking at a 64-bit process)
	 * when I and D space are separate, these will need to be fixed.
	 */
	case PPC_PTRACE_PEEKTEXT_3264:
	case PPC_PTRACE_PEEKDATA_3264: {
		u32 tmp;
		int copied;
		u32 __user * addrOthers;

		ret = -EIO;

		/* Get the addr in the other process that we want to read */
		if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
			break;

		copied = access_process_vm(child, (u64)addrOthers, &tmp,
				sizeof(tmp), 0);
		if (copied != sizeof(tmp))
			break;
		ret = put_user(tmp, (u32 __user *)data);
		break;
	}

	/* Read a register (specified by ADDR) out of the "user area" */
	case PTRACE_PEEKUSR: {
		int index;
		unsigned long tmp;

		ret = -EIO;
		/* convert to index and check */
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || (index > PT_FPSCR32))
			break;

		if (index < PT_FPR0) {
			tmp = get_reg(child, index);
		} else {
			flush_fp_to_thread(child);
			/*
			 * the user space code considers the floating point
			 * to be an array of unsigned int (32 bits) - the
			 * index passed in is based on this assumption.
			 */
			tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
		}
		ret = put_user((unsigned int)tmp, (u32 __user *)data);
		break;
	}
  
	/*
	 * Read 4 bytes out of the other process' pt_regs area
	 *  data is a pointer specifying where the user wants the
	 *	4 bytes copied into
	 *  addr is the offset into the other process' pt_regs structure
	 *	that is to be read
	 * (this is run in a 32-bit process looking at a 64-bit process)
	 */
	case PPC_PTRACE_PEEKUSR_3264: {
		u32 index;
		u32 reg32bits;
		u64 tmp;
		u32 numReg;
		u32 part;

		ret = -EIO;
		/* Determine which register the user wants */
		index = (u64)addr >> 2;
		numReg = index / 2;
		/* Determine which part of the register the user wants */
		if (index % 2)
			part = 1;  /* want the 2nd half of the register (right-most). */
		else
			part = 0;  /* want the 1st half of the register (left-most). */

		/* Validate the input - check to see if address is on the wrong boundary or beyond the end of the user area */
		if ((addr & 3) || numReg > PT_FPSCR)
			break;

		if (numReg >= PT_FPR0) {
			flush_fp_to_thread(child);
			tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
		} else { /* register within PT_REGS struct */
			tmp = get_reg(child, numReg);
		} 
		reg32bits = ((u32*)&tmp)[part];
		ret = put_user(reg32bits, (u32 __user *)data);
		break;
	}

	/* If I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA: {
		unsigned int tmp;
		tmp = data;
		ret = 0;
		if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1)
				== sizeof(tmp))
			break;
		ret = -EIO;
		break;
	}

	/*
	 * Write 4 bytes into the other process' storage
	 *  data is the 4 bytes that the user wants written
	 *  addr is a pointer in the user's storage that contains an
	 *	8 byte address in the other process where the 4 bytes
	 *	that is to be written
	 * (this is run in a 32-bit process looking at a 64-bit process)
	 * when I and D space are separate, these will need to be fixed.
	 */
	case PPC_PTRACE_POKETEXT_3264:
	case PPC_PTRACE_POKEDATA_3264: {
		u32 tmp = data;
		u32 __user * addrOthers;

		/* Get the addr in the other process that we want to write into */
		ret = -EIO;
		if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
			break;
		ret = 0;
		if (access_process_vm(child, (u64)addrOthers, &tmp,
					sizeof(tmp), 1) == sizeof(tmp))
			break;
		ret = -EIO;
		break;
	}

	/* write the word at location addr in the USER area */
	case PTRACE_POKEUSR: {
		unsigned long index;

		ret = -EIO;
		/* convert to index and check */
		index = (unsigned long) addr >> 2;
		if ((addr & 3) || (index > PT_FPSCR32))
			break;

		if (index == PT_ORIG_R3)
			break;
		if (index < PT_FPR0) {
			ret = put_reg(child, index, data);
		} else {
			flush_fp_to_thread(child);
			/*
			 * the user space code considers the floating point
			 * to be an array of unsigned int (32 bits) - the
			 * index passed in is based on this assumption.
			 */
			((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
			ret = 0;
		}
		break;
	}

	/*
	 * Write 4 bytes into the other process' pt_regs area
	 *  data is the 4 bytes that the user wants written
	 *  addr is the offset into the other process' pt_regs structure
	 *	that is to be written into
	 * (this is run in a 32-bit process looking at a 64-bit process)
	 */
	case PPC_PTRACE_POKEUSR_3264: {
		u32 index;
		u32 numReg;

		ret = -EIO;
		/* Determine which register the user wants */
		index = (u64)addr >> 2;
		numReg = index / 2;
		/*
		 * Validate the input - check to see if address is on the
		 * wrong boundary or beyond the end of the user area
		 */
		if ((addr & 3) || (numReg > PT_FPSCR))
			break;
		/* Insure it is a register we let them change */
		if ((numReg == PT_ORIG_R3)
				|| ((numReg > PT_CCR) && (numReg < PT_FPR0)))
			break;
		if (numReg >= PT_FPR0) {
			flush_fp_to_thread(child);
		}
		if (numReg == PT_MSR)
			data = (data & MSR_DEBUGCHANGE)
				| (child->thread.regs->msr & ~MSR_DEBUGCHANGE);
		((u32*)child->thread.regs)[index] = data;
		ret = 0;
		break;
	}

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT: { /* restart after signal. */
		ret = -EIO;
		if (!valid_signal(data))
			break;
		if (request == PTRACE_SYSCALL)
			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		else
			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		child->exit_code = data;
		/* make sure the single step bit is not set. */
		clear_single_step(child);
		wake_up_process(child);
		ret = 0;
		break;
	}

	/*
	 * make the child exit.  Best I can do is send it a sigkill.
	 * perhaps it should be put in the status that it wants to
	 * exit.
	 */
	case PTRACE_KILL: {
		ret = 0;
		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
			break;
		child->exit_code = SIGKILL;
		/* make sure the single step bit is not set. */
		clear_single_step(child);
		wake_up_process(child);
		break;
	}

	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
		ret = -EIO;
		if (!valid_signal(data))
			break;
		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		set_single_step(child);
		child->exit_code = data;
		/* give it a chance to run. */
		wake_up_process(child);
		ret = 0;
		break;
	}

	case PTRACE_GET_DEBUGREG: {
		ret = -EINVAL;
		/* We only support one DABR and no IABRS at the moment */
		if (addr > 0)
			break;
		ret = put_user(child->thread.dabr, (u32 __user *)data);
		break;
	}

	case PTRACE_SET_DEBUGREG:
		ret = ptrace_set_debugreg(child, addr, data);
		break;

	case PTRACE_DETACH:
		ret = ptrace_detach(child, data);
		break;

	case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
		int i;
		unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
		unsigned int __user *tmp = (unsigned int __user *)addr;

		for (i = 0; i < 32; i++) {
			ret = put_user(*reg, tmp);
			if (ret)
				break;
			reg++;
			tmp++;
		}
		break;
	}

	case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
		int i;
		unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
		unsigned int __user *tmp = (unsigned int __user *)addr;

		for (i = 0; i < 32; i++) {
			ret = get_user(*reg, tmp);
			if (ret)
				break;
			reg++;
			tmp++;
		}
		break;
	}

	case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
		int i;
		unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
		unsigned int __user *tmp = (unsigned int __user *)addr;

		flush_fp_to_thread(child);

		for (i = 0; i < 32; i++) {
			ret = put_user(*reg, tmp);
			if (ret)
				break;
			reg++;
			tmp++;
		}
		break;
	}

	case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
		int i;
		unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
		unsigned int __user *tmp = (unsigned int __user *)addr;

		flush_fp_to_thread(child);

		for (i = 0; i < 32; i++) {
			ret = get_user(*reg, tmp);
			if (ret)
				break;
			reg++;
			tmp++;
		}
		break;
	}

	case PTRACE_GETEVENTMSG:
		ret = put_user(child->ptrace_message, (unsigned int __user *) data);
		break;

#ifdef CONFIG_ALTIVEC
	case PTRACE_GETVRREGS:
		/* Get the child altivec register state. */
		flush_altivec_to_thread(child);
		ret = get_vrregs((unsigned long __user *)data, child);
		break;

	case PTRACE_SETVRREGS:
		/* Set the child altivec register state. */
		flush_altivec_to_thread(child);
		ret = set_vrregs(child, (unsigned long __user *)data);
		break;
#endif

	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}
out_tsk:
	put_task_struct(child);
out:
	unlock_kernel();
	return ret;
}