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