1/*
2 *  linux/arch/cris/traps.c
3 *
4 *  Here we handle the break vectors not used by the system call
5 *  mechanism, as well as some general stack/register dumping
6 *  things.
7 *
8 *  Copyright (C) 2000-2007 Axis Communications AB
9 *
10 *  Authors:   Bjorn Wesen
11 *             Hans-Peter Nilsson
12 *
13 */
14
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/utsname.h>
18#ifdef CONFIG_KALLSYMS
19#include <linux/kallsyms.h>
20#endif
21
22#include <asm/pgtable.h>
23#include <asm/uaccess.h>
24#include <arch/system.h>
25
26extern void arch_enable_nmi(void);
27extern void stop_watchdog(void);
28extern void reset_watchdog(void);
29extern void show_registers(struct pt_regs *regs);
30
31#ifdef CONFIG_DEBUG_BUGVERBOSE
32extern void handle_BUG(struct pt_regs *regs);
33#else
34#define handle_BUG(regs)
35#endif
36
37static int kstack_depth_to_print = 24;
38
39void (*nmi_handler)(struct pt_regs *);
40
41void show_trace(unsigned long *stack)
42{
43	unsigned long addr, module_start, module_end;
44	extern char _stext, _etext;
45	int i;
46
47	pr_err("\nCall Trace: ");
48
49	i = 1;
50	module_start = VMALLOC_START;
51	module_end = VMALLOC_END;
52
53	while (((long)stack & (THREAD_SIZE - 1)) != 0) {
54		if (__get_user(addr, stack)) {
55			/* This message matches "failing address" marked
56			   s390 in ksymoops, so lines containing it will
57			   not be filtered out by ksymoops.  */
58			pr_err("Failing address 0x%lx\n", (unsigned long)stack);
59			break;
60		}
61		stack++;
62
63		/*
64		 * If the address is either in the text segment of the
65		 * kernel, or in the region which contains vmalloc'ed
66		 * memory, it *may* be the address of a calling
67		 * routine; if so, print it so that someone tracing
68		 * down the cause of the crash will be able to figure
69		 * out the call path that was taken.
70		 */
71		if (((addr >= (unsigned long)&_stext) &&
72		     (addr <= (unsigned long)&_etext)) ||
73		    ((addr >= module_start) && (addr <= module_end))) {
74#ifdef CONFIG_KALLSYMS
75			print_ip_sym(addr);
76#else
77			if (i && ((i % 8) == 0))
78				pr_err("\n       ");
79			pr_err("[<%08lx>] ", addr);
80			i++;
81#endif
82		}
83	}
84}
85
86/*
87 * These constants are for searching for possible module text
88 * segments. MODULE_RANGE is a guess of how much space is likely
89 * to be vmalloced.
90 */
91
92#define MODULE_RANGE (8*1024*1024)
93
94/*
95 * The output (format, strings and order) is adjusted to be usable with
96 * ksymoops-2.4.1 with some necessary CRIS-specific patches.  Please don't
97 * change it unless you're serious about adjusting ksymoops and syncing
98 * with the ksymoops maintainer.
99 */
100
101void
102show_stack(struct task_struct *task, unsigned long *sp)
103{
104	unsigned long *stack, addr;
105	int i;
106
107	/*
108	 * debugging aid: "show_stack(NULL);" prints a
109	 * back trace.
110	 */
111
112	if (sp == NULL) {
113		if (task)
114			sp = (unsigned long*)task->thread.ksp;
115		else
116			sp = (unsigned long*)rdsp();
117	}
118
119	stack = sp;
120
121	pr_err("\nStack from %08lx:\n       ", (unsigned long)stack);
122	for (i = 0; i < kstack_depth_to_print; i++) {
123		if (((long)stack & (THREAD_SIZE-1)) == 0)
124			break;
125		if (i && ((i % 8) == 0))
126			pr_err("\n       ");
127		if (__get_user(addr, stack)) {
128			/* This message matches "failing address" marked
129			   s390 in ksymoops, so lines containing it will
130			   not be filtered out by ksymoops.  */
131			pr_err("Failing address 0x%lx\n", (unsigned long)stack);
132			break;
133		}
134		stack++;
135		pr_err("%08lx ", addr);
136	}
137	show_trace(sp);
138}
139
140#if 0
141/* displays a short stack trace */
142
143int
144show_stack(void)
145{
146	unsigned long *sp = (unsigned long *)rdusp();
147	int i;
148
149	pr_err("Stack dump [0x%08lx]:\n", (unsigned long)sp);
150	for (i = 0; i < 16; i++)
151		pr_err("sp + %d: 0x%08lx\n", i*4, sp[i]);
152	return 0;
153}
154#endif
155
156void set_nmi_handler(void (*handler)(struct pt_regs *))
157{
158	nmi_handler = handler;
159	arch_enable_nmi();
160}
161
162#ifdef CONFIG_DEBUG_NMI_OOPS
163void oops_nmi_handler(struct pt_regs *regs)
164{
165	stop_watchdog();
166	oops_in_progress = 1;
167	pr_err("NMI!\n");
168	show_registers(regs);
169	oops_in_progress = 0;
170	oops_exit();
171	pr_err("\n"); /* Flush mtdoops.  */
172}
173
174static int __init oops_nmi_register(void)
175{
176	set_nmi_handler(oops_nmi_handler);
177	return 0;
178}
179
180__initcall(oops_nmi_register);
181
182#endif
183
184/*
185 * This gets called from entry.S when the watchdog has bitten. Show something
186 * similar to an Oops dump, and if the kernel is configured to be a nice
187 * doggy, then halt instead of reboot.
188 */
189void watchdog_bite_hook(struct pt_regs *regs)
190{
191#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
192	local_irq_disable();
193	stop_watchdog();
194	show_registers(regs);
195
196	while (1)
197		; /* Do nothing. */
198#else
199	show_registers(regs);
200#endif
201}
202
203/* This is normally the Oops function. */
204void die_if_kernel(const char *str, struct pt_regs *regs, long err)
205{
206	if (user_mode(regs))
207		return;
208
209#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
210	/*
211	 * This printout might take too long and could trigger
212	 * the watchdog normally. If NICE_DOGGY is set, simply
213	 * stop the watchdog during the printout.
214	 */
215	stop_watchdog();
216#endif
217
218	oops_enter();
219	handle_BUG(regs);
220
221	pr_err("Linux %s %s\n", utsname()->release, utsname()->version);
222	pr_err("%s: %04lx\n", str, err & 0xffff);
223
224	show_registers(regs);
225
226	oops_exit();
227	oops_in_progress = 0;
228	pr_err("\n"); /* Flush mtdoops.  */
229
230#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
231	reset_watchdog();
232#endif
233	do_exit(SIGSEGV);
234}
235
236void __init trap_init(void)
237{
238	/* Nothing needs to be done */
239}
240