summaryrefslogtreecommitdiffstats
path: root/arch/xtensa/kernel/ptrace.c
blob: 9d4e1ceb3f09db9234919dc3b0279dd5178f71e4 (plain)
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
// TODO some minor issues
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2007  Tensilica Inc.
 *
 * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
 * Chris Zankel <chris@zankel.net>
 * Scott Foehner<sfoehner@yahoo.com>,
 * Kevin Chea
 * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
 */

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

#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/elf.h>
#include <asm/coprocessor.h>


void user_enable_single_step(struct task_struct *child)
{
	child->ptrace |= PT_SINGLESTEP;
}

void user_disable_single_step(struct task_struct *child)
{
	child->ptrace &= ~PT_SINGLESTEP;
}

/*
 * Called by kernel/ptrace.c when detaching to disable single stepping.
 */

void ptrace_disable(struct task_struct *child)
{
	/* Nothing to do.. */
}

int ptrace_getregs(struct task_struct *child, void __user *uregs)
{
	struct pt_regs *regs = task_pt_regs(child);
	xtensa_gregset_t __user *gregset = uregs;
	unsigned long wm = regs->wmask;
	unsigned long wb = regs->windowbase;
	int live, i;

	if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
		return -EIO;

	__put_user(regs->pc, &gregset->pc);
	__put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
	__put_user(regs->lbeg, &gregset->lbeg);
	__put_user(regs->lend, &gregset->lend);
	__put_user(regs->lcount, &gregset->lcount);
	__put_user(regs->windowstart, &gregset->windowstart);
	__put_user(regs->windowbase, &gregset->windowbase);

	live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;

	for (i = 0; i < live; i++)
		__put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
	for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++)
		__put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));

	return 0;
}

int ptrace_setregs(struct task_struct *child, void __user *uregs)
{
	struct pt_regs *regs = task_pt_regs(child);
	xtensa_gregset_t *gregset = uregs;
	const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
	unsigned long ps;
	unsigned long wb;

	if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
		return -EIO;

	__get_user(regs->pc, &gregset->pc);
	__get_user(ps, &gregset->ps);
	__get_user(regs->lbeg, &gregset->lbeg);
	__get_user(regs->lend, &gregset->lend);
	__get_user(regs->lcount, &gregset->lcount);
	__get_user(regs->windowstart, &gregset->windowstart);
	__get_user(wb, &gregset->windowbase);

	regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);

	if (wb >= XCHAL_NUM_AREGS / 4)
		return -EFAULT;

	regs->windowbase = wb;

	if (wb != 0 &&  __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
					 gregset->a, wb * 16))
		return -EFAULT;

	if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16))
		return -EFAULT;

	return 0;
}


int ptrace_getxregs(struct task_struct *child, void __user *uregs)
{
	struct pt_regs *regs = task_pt_regs(child);
	struct thread_info *ti = task_thread_info(child);
	elf_xtregs_t __user *xtregs = uregs;
	int ret = 0;

	if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
		return -EIO;

#if XTENSA_HAVE_COPROCESSORS
	/* Flush all coprocessor registers to memory. */
	coprocessor_flush_all(ti);
	ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
			      sizeof(xtregs_coprocessor_t));
#endif
	ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
			      sizeof(xtregs->opt));
	ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
			      sizeof(xtregs->user));

	return ret ? -EFAULT : 0;
}

int ptrace_setxregs(struct task_struct *child, void __user *uregs)
{
	struct thread_info *ti = task_thread_info(child);
	struct pt_regs *regs = task_pt_regs(child);
	elf_xtregs_t *xtregs = uregs;
	int ret = 0;

#if XTENSA_HAVE_COPROCESSORS
	/* Flush all coprocessors before we overwrite them. */
	coprocessor_flush_all(ti);
	coprocessor_release_all(ti);

	ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0, 
				sizeof(xtregs_coprocessor_t));
#endif
	ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
				sizeof(xtregs->opt));
	ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
				sizeof(xtregs->user));

	return ret ? -EFAULT : 0;
}

int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret)
{
	struct pt_regs *regs;
	unsigned long tmp;

	regs = task_pt_regs(child);
	tmp = 0;  /* Default return value. */

	switch(regno) {

		case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
			tmp = regs->areg[regno - REG_AR_BASE];
			break;

		case REG_A_BASE ... REG_A_BASE + 15:
			tmp = regs->areg[regno - REG_A_BASE];
			break;

		case REG_PC:
			tmp = regs->pc;
			break;

		case REG_PS:
			/* Note:  PS.EXCM is not set while user task is running;
			 * its being set in regs is for exception handling
			 * convenience.  */
			tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
			break;

		case REG_WB:
			break;		/* tmp = 0 */

		case REG_WS:
		{
			unsigned long wb = regs->windowbase;
			unsigned long ws = regs->windowstart;
			tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1);
			break;
		}
		case REG_LBEG:
			tmp = regs->lbeg;
			break;

		case REG_LEND:
			tmp = regs->lend;
			break;

		case REG_LCOUNT:
			tmp = regs->lcount;
			break;

		case REG_SAR:
			tmp = regs->sar;
			break;

		case SYSCALL_NR:
			tmp = regs->syscall;
			break;

		default:
			return -EIO;
	}
	return put_user(tmp, ret);
}

int ptrace_pokeusr(struct task_struct *child, long regno, long val)
{
	struct pt_regs *regs;
	regs = task_pt_regs(child);

	switch (regno) {
		case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
			regs->areg[regno - REG_AR_BASE] = val;
			break;

		case REG_A_BASE ... REG_A_BASE + 15:
			regs->areg[regno - REG_A_BASE] = val;
			break;

		case REG_PC:
			regs->pc = val;
			break;

		case SYSCALL_NR:
			regs->syscall = val;
			break;

		default:
			return -EIO;
	}
	return 0;
}

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

	switch (request) {
	case PTRACE_PEEKTEXT:	/* read word at location addr. */
	case PTRACE_PEEKDATA:
		ret = generic_ptrace_peekdata(child, addr, data);
		break;

	case PTRACE_PEEKUSR:	/* read register specified by addr. */
		ret = ptrace_peekusr(child, addr, (void __user *) data);
		break;

	case PTRACE_POKETEXT:	/* write the word at location addr. */
	case PTRACE_POKEDATA:
		ret = generic_ptrace_pokedata(child, addr, data);
		break;

	case PTRACE_POKEUSR:	/* write register specified by addr. */
		ret = ptrace_pokeusr(child, addr, data);
		break;

	case PTRACE_GETREGS:
		ret = ptrace_getregs(child, (void __user *) data);
		break;

	case PTRACE_SETREGS:
		ret = ptrace_setregs(child, (void __user *) data);
		break;

	case PTRACE_GETXTREGS:
		ret = ptrace_getxregs(child, (void __user *) data);
		break;

	case PTRACE_SETXTREGS:
		ret = ptrace_setxregs(child, (void __user *) data);
		break;

	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

void do_syscall_trace(void)
{
	/*
	 * The 0x80 provides a way for the tracing parent to distinguish
	 * between a syscall stop and SIGTRAP delivery
	 */
	ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));

	/*
	 * this isn't the same as continuing with a signal, but it will do
	 * for normal use.  strace only continues with a signal if the
	 * stopping signal is not SIGTRAP.  -brl
	 */
	if (current->exit_code) {
		send_sig(current->exit_code, current, 1);
		current->exit_code = 0;
	}
}

void do_syscall_trace_enter(struct pt_regs *regs)
{
	if (test_thread_flag(TIF_SYSCALL_TRACE)
			&& (current->ptrace & PT_PTRACED))
		do_syscall_trace();

#if 0
	if (unlikely(current->audit_context))
		audit_syscall_entry(current, AUDIT_ARCH_XTENSA..);
#endif
}

void do_syscall_trace_leave(struct pt_regs *regs)
{
	if ((test_thread_flag(TIF_SYSCALL_TRACE))
			&& (current->ptrace & PT_PTRACED))
		do_syscall_trace();
}

OpenPOWER on IntegriCloud