summaryrefslogtreecommitdiffstats
path: root/arch/nios2/kernel/traps.c
blob: 8184e7d6b3857d3a9588b556e89f76b5a6d42c6a (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
/*
 * Hardware exception handling
 *
 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
 * Copyright (C) 2004 Microtronix Datacom Ltd.
 * Copyright (C) 2001 Vic Phillips
 *
 * 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.
 */

#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/ptrace.h>

#include <asm/traps.h>
#include <asm/sections.h>
#include <linux/uaccess.h>

static DEFINE_SPINLOCK(die_lock);

static void _send_sig(int signo, int code, unsigned long addr)
{
	siginfo_t info;

	info.si_signo = signo;
	info.si_errno = 0;
	info.si_code = code;
	info.si_addr = (void __user *) addr;
	force_sig_info(signo, &info, current);
}

void die(const char *str, struct pt_regs *regs, long err)
{
	console_verbose();
	spin_lock_irq(&die_lock);
	pr_warn("Oops: %s, sig: %ld\n", str, err);
	show_regs(regs);
	spin_unlock_irq(&die_lock);
	/*
	 * do_exit() should take care of panic'ing from an interrupt
	 * context so we don't handle it here
	 */
	do_exit(err);
}

void _exception(int signo, struct pt_regs *regs, int code, unsigned long addr)
{
	if (!user_mode(regs))
		die("Exception in kernel mode", regs, signo);

	_send_sig(signo, code, addr);
}

/*
 * The show_stack is an external API which we do not use ourselves.
 */

int kstack_depth_to_print = 48;

void show_stack(struct task_struct *task, unsigned long *stack)
{
	unsigned long *endstack, addr;
	int i;

	if (!stack) {
		if (task)
			stack = (unsigned long *)task->thread.ksp;
		else
			stack = (unsigned long *)&stack;
	}

	addr = (unsigned long) stack;
	endstack = (unsigned long *) PAGE_ALIGN(addr);

	pr_emerg("Stack from %08lx:", (unsigned long)stack);
	for (i = 0; i < kstack_depth_to_print; i++) {
		if (stack + 1 > endstack)
			break;
		if (i % 8 == 0)
			pr_emerg("\n       ");
		pr_emerg(" %08lx", *stack++);
	}

	pr_emerg("\nCall Trace:");
	i = 0;
	while (stack + 1 <= endstack) {
		addr = *stack++;
		/*
		 * If the address is either in the text segment of the
		 * kernel, or in the region which contains vmalloc'ed
		 * memory, it *may* be the address of a calling
		 * routine; if so, print it so that someone tracing
		 * down the cause of the crash will be able to figure
		 * out the call path that was taken.
		 */
		if (((addr >= (unsigned long) _stext) &&
		     (addr <= (unsigned long) _etext))) {
			if (i % 4 == 0)
				pr_emerg("\n       ");
			pr_emerg(" [<%08lx>]", addr);
			i++;
		}
	}
	pr_emerg("\n");
}

void __init trap_init(void)
{
	/* Nothing to do here */
}

/* Breakpoint handler */
asmlinkage void breakpoint_c(struct pt_regs *fp)
{
	/*
	 * The breakpoint entry code has moved the PC on by 4 bytes, so we must
	 * move it back. This could be done on the host but we do it here
	 * because monitor.S of JTAG gdbserver does it too.
	 */
	fp->ea -= 4;
	_exception(SIGTRAP, fp, TRAP_BRKPT, fp->ea);
}

#ifndef CONFIG_NIOS2_ALIGNMENT_TRAP
/* Alignment exception handler */
asmlinkage void handle_unaligned_c(struct pt_regs *fp, int cause)
{
	unsigned long addr = RDCTL(CTL_BADADDR);

	cause >>= 2;
	fp->ea -= 4;

	if (fixup_exception(fp))
		return;

	if (!user_mode(fp)) {
		pr_alert("Unaligned access from kernel mode, this might be a hardware\n");
		pr_alert("problem, dump registers and restart the instruction\n");
		pr_alert("  BADADDR 0x%08lx\n", addr);
		pr_alert("  cause   %d\n", cause);
		pr_alert("  op-code 0x%08lx\n", *(unsigned long *)(fp->ea));
		show_regs(fp);
		return;
	}

	_exception(SIGBUS, fp, BUS_ADRALN, addr);
}
#endif /* CONFIG_NIOS2_ALIGNMENT_TRAP */

/* Illegal instruction handler */
asmlinkage void handle_illegal_c(struct pt_regs *fp)
{
	fp->ea -= 4;
	_exception(SIGILL, fp, ILL_ILLOPC, fp->ea);
}

/* Supervisor instruction handler */
asmlinkage void handle_supervisor_instr(struct pt_regs *fp)
{
	fp->ea -= 4;
	_exception(SIGILL, fp, ILL_PRVOPC, fp->ea);
}

/* Division error handler */
asmlinkage void handle_diverror_c(struct pt_regs *fp)
{
	fp->ea -= 4;
	_exception(SIGFPE, fp, FPE_INTDIV, fp->ea);
}

/* Unhandled exception handler */
asmlinkage void unhandled_exception(struct pt_regs *regs, int cause)
{
	unsigned long addr = RDCTL(CTL_BADADDR);

	cause /= 4;

	pr_emerg("Unhandled exception #%d in %s mode (badaddr=0x%08lx)\n",
			cause, user_mode(regs) ? "user" : "kernel", addr);

	regs->ea -= 4;
	show_regs(regs);

	pr_emerg("opcode: 0x%08lx\n", *(unsigned long *)(regs->ea));
}

asmlinkage void handle_trap_1_c(struct pt_regs *fp)
{
	_send_sig(SIGUSR1, 0, fp->ea);
}

asmlinkage void handle_trap_2_c(struct pt_regs *fp)
{
	_send_sig(SIGUSR2, 0, fp->ea);
}

asmlinkage void handle_trap_3_c(struct pt_regs *fp)
{
	_send_sig(SIGILL, ILL_ILLTRP, fp->ea);
}
OpenPOWER on IntegriCloud