summaryrefslogtreecommitdiffstats
path: root/arch/avr32/kernel/traps.c
blob: adc01a12d15487ff8ae335f8352b9820d00b9395 (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
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
/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/notifier.h>

#include <asm/traps.h>
#include <asm/sysreg.h>
#include <asm/addrspace.h>
#include <asm/ocd.h>
#include <asm/mmu_context.h>
#include <asm/uaccess.h>

static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
{
	unsigned long p;
	int i;

	printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);

	for (p = bottom & ~31; p < top; ) {
		printk("%04lx: ", p & 0xffff);

		for (i = 0; i < 8; i++, p += 4) {
			unsigned int val;

			if (p < bottom || p >= top)
				printk("         ");
			else {
				if (__get_user(val, (unsigned int __user *)p)) {
					printk("\n");
					goto out;
				}
				printk("%08x ", val);
			}
		}
		printk("\n");
	}

out:
	return;
}

static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
{
	return (p > (unsigned long)tinfo)
		&& (p < (unsigned long)tinfo + THREAD_SIZE - 3);
}

#ifdef CONFIG_FRAME_POINTER
static inline void __show_trace(struct task_struct *tsk, unsigned long *sp,
				struct pt_regs *regs)
{
	unsigned long lr, fp;
	struct thread_info *tinfo;

	tinfo = (struct thread_info *)
		((unsigned long)sp & ~(THREAD_SIZE - 1));

	if (regs)
		fp = regs->r7;
	else if (tsk == current)
		asm("mov %0, r7" : "=r"(fp));
	else
		fp = tsk->thread.cpu_context.r7;

	/*
	 * Walk the stack as long as the frame pointer (a) is within
	 * the kernel stack of the task, and (b) it doesn't move
	 * downwards.
	 */
	while (valid_stack_ptr(tinfo, fp)) {
		unsigned long new_fp;

		lr = *(unsigned long *)fp;
		printk(" [<%08lx>] ", lr);
		print_symbol("%s\n", lr);

		new_fp = *(unsigned long *)(fp + 4);
		if (new_fp <= fp)
			break;
		fp = new_fp;
	}
	printk("\n");
}
#else
static inline void __show_trace(struct task_struct *tsk, unsigned long *sp,
				struct pt_regs *regs)
{
	unsigned long addr;

	while (!kstack_end(sp)) {
		addr = *sp++;
		if (kernel_text_address(addr)) {
			printk(" [<%08lx>] ", addr);
			print_symbol("%s\n", addr);
		}
	}
}
#endif

void show_trace(struct task_struct *tsk, unsigned long *sp,
		       struct pt_regs *regs)
{
	if (regs &&
	    (((regs->sr & MODE_MASK) == MODE_EXCEPTION) ||
	     ((regs->sr & MODE_MASK) == MODE_USER)))
		return;

	printk ("Call trace:");
#ifdef CONFIG_KALLSYMS
	printk("\n");
#endif

	__show_trace(tsk, sp, regs);
	printk("\n");
}

void show_stack(struct task_struct *tsk, unsigned long *sp)
{
	unsigned long stack;

	if (!tsk)
		tsk = current;
	if (sp == 0) {
		if (tsk == current) {
			register unsigned long *real_sp __asm__("sp");
			sp = real_sp;
		} else {
			sp = (unsigned long *)tsk->thread.cpu_context.ksp;
		}
	}

	stack = (unsigned long)sp;
	dump_mem("Stack: ", stack,
		 THREAD_SIZE + (unsigned long)tsk->thread_info);
	show_trace(tsk, sp, NULL);
}

void dump_stack(void)
{
	show_stack(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);

ATOMIC_NOTIFIER_HEAD(avr32_die_chain);

int register_die_notifier(struct notifier_block *nb)
{
	pr_debug("register_die_notifier: %p\n", nb);

	return atomic_notifier_chain_register(&avr32_die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);

int unregister_die_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_unregister(&avr32_die_chain, nb);
}
EXPORT_SYMBOL(unregister_die_notifier);

static DEFINE_SPINLOCK(die_lock);

void __die(const char *str, struct pt_regs *regs, unsigned long err,
	   const char *file, const char *func, unsigned long line)
{
	struct task_struct *tsk = current;
	static int die_counter;

	console_verbose();
	spin_lock_irq(&die_lock);
	bust_spinlocks(1);

	printk(KERN_ALERT "%s", str);
	if (file && func)
		printk(" in %s:%s, line %ld", file, func, line);
	printk("[#%d]:\n", ++die_counter);
	print_modules();
	show_regs(regs);
	printk("Process %s (pid: %d, stack limit = 0x%p)\n",
	       tsk->comm, tsk->pid, tsk->thread_info + 1);

	if (!user_mode(regs) || in_interrupt()) {
		dump_mem("Stack: ", regs->sp,
			 THREAD_SIZE + (unsigned long)tsk->thread_info);
	}

	bust_spinlocks(0);
	spin_unlock_irq(&die_lock);
	do_exit(SIGSEGV);
}

void __die_if_kernel(const char *str, struct pt_regs *regs, unsigned long err,
		     const char *file, const char *func, unsigned long line)
{
	if (!user_mode(regs))
		__die(str, regs, err, file, func, line);
}

asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
{
#ifdef CONFIG_SUBARCH_AVR32B
	/*
	 * The exception entry always saves RSR_EX. For NMI, this is
	 * wrong; it should be RSR_NMI
	 */
	regs->sr = sysreg_read(RSR_NMI);
#endif

	printk("NMI taken!!!!\n");
	die("NMI", regs, ecr);
	BUG();
}

asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
{
	printk("Unable to handle critical exception %lu at pc = %08lx!\n",
	       ecr, regs->pc);
	die("Oops", regs, ecr);
	BUG();
}

asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
{
	siginfo_t info;

	die_if_kernel("Oops: Address exception in kernel mode", regs, ecr);

#ifdef DEBUG
	if (ecr == ECR_ADDR_ALIGN_X)
		pr_debug("Instruction Address Exception at pc = %08lx\n",
			 regs->pc);
	else if (ecr == ECR_ADDR_ALIGN_R)
		pr_debug("Data Address Exception (Read) at pc = %08lx\n",
			 regs->pc);
	else if (ecr == ECR_ADDR_ALIGN_W)
		pr_debug("Data Address Exception (Write) at pc = %08lx\n",
			 regs->pc);
	else
		BUG();

	show_regs(regs);
#endif

	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRALN;
	info.si_addr = (void __user *)regs->pc;

	force_sig_info(SIGBUS, &info, current);
}

/* This way of handling undefined instructions is stolen from ARM */
static LIST_HEAD(undef_hook);
static spinlock_t undef_lock = SPIN_LOCK_UNLOCKED;

void register_undef_hook(struct undef_hook *hook)
{
	spin_lock_irq(&undef_lock);
	list_add(&hook->node, &undef_hook);
	spin_unlock_irq(&undef_lock);
}

void unregister_undef_hook(struct undef_hook *hook)
{
	spin_lock_irq(&undef_lock);
	list_del(&hook->node);
	spin_unlock_irq(&undef_lock);
}

static int do_cop_absent(u32 insn)
{
	int cop_nr;
	u32 cpucr;
	if ( (insn & 0xfdf00000) == 0xf1900000 )
		/* LDC0 */
		cop_nr = 0;
	else
		cop_nr = (insn >> 13) & 0x7;

	/* Try enabling the coprocessor */
	cpucr = sysreg_read(CPUCR);
	cpucr |= (1 << (24 + cop_nr));
	sysreg_write(CPUCR, cpucr);

	cpucr = sysreg_read(CPUCR);
	if ( !(cpucr & (1 << (24 + cop_nr))) ){
		printk("Coprocessor #%i not found!\n", cop_nr);
		return -1;
	}

	return 0;
}

#ifdef CONFIG_BUG
#ifdef CONFIG_DEBUG_BUGVERBOSE
static inline void do_bug_verbose(struct pt_regs *regs, u32 insn)
{
	char *file;
	u16 line;
	char c;

	if (__get_user(line, (u16 __user *)(regs->pc + 2)))
		return;
	if (__get_user(file, (char * __user *)(regs->pc + 4))
	    || (unsigned long)file < PAGE_OFFSET
	    || __get_user(c, file))
		file = "<bad filename>";

	printk(KERN_ALERT "kernel BUG at %s:%d!\n", file, line);
}
#else
static inline void do_bug_verbose(struct pt_regs *regs, u32 insn)
{

}
#endif
#endif

asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
{
	u32 insn;
	struct undef_hook *hook;
	siginfo_t info;
	void __user *pc;

	if (!user_mode(regs))
		goto kernel_trap;

	local_irq_enable();

	pc = (void __user *)instruction_pointer(regs);
	if (__get_user(insn, (u32 __user *)pc))
		goto invalid_area;

        if (ecr == ECR_COPROC_ABSENT) {
		if (do_cop_absent(insn) == 0)
			return;
        }

	spin_lock_irq(&undef_lock);
	list_for_each_entry(hook, &undef_hook, node) {
		if ((insn & hook->insn_mask) == hook->insn_val) {
			if (hook->fn(regs, insn) == 0) {
				spin_unlock_irq(&undef_lock);
				return;
			}
		}
	}
	spin_unlock_irq(&undef_lock);

invalid_area:

#ifdef DEBUG
	printk("Illegal instruction at pc = %08lx\n", regs->pc);
	if (regs->pc < TASK_SIZE) {
		unsigned long ptbr, pgd, pte, *p;

		ptbr = sysreg_read(PTBR);
		p = (unsigned long *)ptbr;
		pgd = p[regs->pc >> 22];
		p = (unsigned long *)((pgd & 0x1ffff000) | 0x80000000);
		pte = p[(regs->pc >> 12) & 0x3ff];
		printk("page table: 0x%08lx -> 0x%08lx -> 0x%08lx\n", ptbr, pgd, pte);
	}
#endif

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_addr = (void __user *)regs->pc;
	switch (ecr) {
	case ECR_ILLEGAL_OPCODE:
	case ECR_UNIMPL_INSTRUCTION:
		info.si_code = ILL_ILLOPC;
		break;
	case ECR_PRIVILEGE_VIOLATION:
		info.si_code = ILL_PRVOPC;
		break;
	case ECR_COPROC_ABSENT:
		info.si_code = ILL_COPROC;
		break;
	default:
		BUG();
	}

	force_sig_info(SIGILL, &info, current);
	return;

kernel_trap:
#ifdef CONFIG_BUG
	if (__kernel_text_address(instruction_pointer(regs))) {
		insn = *(u16 *)instruction_pointer(regs);
		if (insn == AVR32_BUG_OPCODE) {
			do_bug_verbose(regs, insn);
			die("Kernel BUG", regs, 0);
			return;
		}
	}
#endif

	die("Oops: Illegal instruction in kernel code", regs, ecr);
}

asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
{
	siginfo_t info;

	printk("Floating-point exception at pc = %08lx\n", regs->pc);

	/* We have no FPU... */
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_addr = (void __user *)regs->pc;
	info.si_code = ILL_COPROC;

	force_sig_info(SIGILL, &info, current);
}


void __init trap_init(void)
{

}