1 /*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9 #include <linux/bug.h>
10 #include <linux/hardirq.h>
11 #include <linux/init.h>
12 #include <linux/kallsyms.h>
13 #include <linux/kdebug.h>
14 #include <linux/extable.h>
15 #include <linux/module.h> /* print_modules */
16 #include <linux/notifier.h>
17 #include <linux/sched.h>
18 #include <linux/uaccess.h>
19
20 #include <asm/addrspace.h>
21 #include <asm/mmu_context.h>
22 #include <asm/ocd.h>
23 #include <asm/sysreg.h>
24 #include <asm/traps.h>
25
26 static DEFINE_SPINLOCK(die_lock);
27
die(const char * str,struct pt_regs * regs,long err)28 void die(const char *str, struct pt_regs *regs, long err)
29 {
30 static int die_counter;
31
32 console_verbose();
33 spin_lock_irq(&die_lock);
34 bust_spinlocks(1);
35
36 printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n",
37 str, err, ++die_counter);
38
39 printk(KERN_EMERG);
40
41 #ifdef CONFIG_PREEMPT
42 printk(KERN_CONT "PREEMPT ");
43 #endif
44 #ifdef CONFIG_FRAME_POINTER
45 printk(KERN_CONT "FRAME_POINTER ");
46 #endif
47 if (current_cpu_data.features & AVR32_FEATURE_OCD) {
48 unsigned long did = ocd_read(DID);
49 printk(KERN_CONT "chip: 0x%03lx:0x%04lx rev %lu\n",
50 (did >> 1) & 0x7ff,
51 (did >> 12) & 0x7fff,
52 (did >> 28) & 0xf);
53 } else {
54 printk(KERN_CONT "cpu: arch %u r%u / core %u r%u\n",
55 current_cpu_data.arch_type,
56 current_cpu_data.arch_revision,
57 current_cpu_data.cpu_type,
58 current_cpu_data.cpu_revision);
59 }
60
61 print_modules();
62 show_regs_log_lvl(regs, KERN_EMERG);
63 show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
64 bust_spinlocks(0);
65 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
66 spin_unlock_irq(&die_lock);
67
68 if (in_interrupt())
69 panic("Fatal exception in interrupt");
70
71 if (panic_on_oops)
72 panic("Fatal exception");
73
74 do_exit(err);
75 }
76
_exception(long signr,struct pt_regs * regs,int code,unsigned long addr)77 void _exception(long signr, struct pt_regs *regs, int code,
78 unsigned long addr)
79 {
80 siginfo_t info;
81
82 if (!user_mode(regs)) {
83 const struct exception_table_entry *fixup;
84
85 /* Are we prepared to handle this kernel fault? */
86 fixup = search_exception_tables(regs->pc);
87 if (fixup) {
88 regs->pc = fixup->fixup;
89 return;
90 }
91 die("Unhandled exception in kernel mode", regs, signr);
92 }
93
94 memset(&info, 0, sizeof(info));
95 info.si_signo = signr;
96 info.si_code = code;
97 info.si_addr = (void __user *)addr;
98 force_sig_info(signr, &info, current);
99 }
100
do_nmi(unsigned long ecr,struct pt_regs * regs)101 asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
102 {
103 int ret;
104
105 nmi_enter();
106
107 ret = notify_die(DIE_NMI, "NMI", regs, 0, ecr, SIGINT);
108 switch (ret) {
109 case NOTIFY_OK:
110 case NOTIFY_STOP:
111 break;
112 case NOTIFY_BAD:
113 die("Fatal Non-Maskable Interrupt", regs, SIGINT);
114 default:
115 printk(KERN_ALERT "Got NMI, but nobody cared. Disabling...\n");
116 nmi_disable();
117 break;
118 }
119 nmi_exit();
120 }
121
do_critical_exception(unsigned long ecr,struct pt_regs * regs)122 asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
123 {
124 die("Critical exception", regs, SIGKILL);
125 }
126
do_address_exception(unsigned long ecr,struct pt_regs * regs)127 asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
128 {
129 _exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
130 }
131
132 /* This way of handling undefined instructions is stolen from ARM */
133 static LIST_HEAD(undef_hook);
134 static DEFINE_SPINLOCK(undef_lock);
135
register_undef_hook(struct undef_hook * hook)136 void register_undef_hook(struct undef_hook *hook)
137 {
138 spin_lock_irq(&undef_lock);
139 list_add(&hook->node, &undef_hook);
140 spin_unlock_irq(&undef_lock);
141 }
142
unregister_undef_hook(struct undef_hook * hook)143 void unregister_undef_hook(struct undef_hook *hook)
144 {
145 spin_lock_irq(&undef_lock);
146 list_del(&hook->node);
147 spin_unlock_irq(&undef_lock);
148 }
149
do_cop_absent(u32 insn)150 static int do_cop_absent(u32 insn)
151 {
152 int cop_nr;
153 u32 cpucr;
154
155 if ((insn & 0xfdf00000) == 0xf1900000)
156 /* LDC0 */
157 cop_nr = 0;
158 else
159 cop_nr = (insn >> 13) & 0x7;
160
161 /* Try enabling the coprocessor */
162 cpucr = sysreg_read(CPUCR);
163 cpucr |= (1 << (24 + cop_nr));
164 sysreg_write(CPUCR, cpucr);
165
166 cpucr = sysreg_read(CPUCR);
167 if (!(cpucr & (1 << (24 + cop_nr))))
168 return -ENODEV;
169
170 return 0;
171 }
172
173 #ifdef CONFIG_BUG
is_valid_bugaddr(unsigned long pc)174 int is_valid_bugaddr(unsigned long pc)
175 {
176 unsigned short opcode;
177
178 if (pc < PAGE_OFFSET)
179 return 0;
180 if (probe_kernel_address((u16 *)pc, opcode))
181 return 0;
182
183 return opcode == AVR32_BUG_OPCODE;
184 }
185 #endif
186
do_illegal_opcode(unsigned long ecr,struct pt_regs * regs)187 asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
188 {
189 u32 insn;
190 struct undef_hook *hook;
191 void __user *pc;
192 long code;
193
194 #ifdef CONFIG_BUG
195 if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
196 enum bug_trap_type type;
197
198 type = report_bug(regs->pc, regs);
199 switch (type) {
200 case BUG_TRAP_TYPE_NONE:
201 break;
202 case BUG_TRAP_TYPE_WARN:
203 regs->pc += 2;
204 return;
205 case BUG_TRAP_TYPE_BUG:
206 die("Kernel BUG", regs, SIGKILL);
207 }
208 }
209 #endif
210
211 local_irq_enable();
212
213 if (user_mode(regs)) {
214 pc = (void __user *)instruction_pointer(regs);
215 if (get_user(insn, (u32 __user *)pc))
216 goto invalid_area;
217
218 if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
219 return;
220
221 spin_lock_irq(&undef_lock);
222 list_for_each_entry(hook, &undef_hook, node) {
223 if ((insn & hook->insn_mask) == hook->insn_val) {
224 if (hook->fn(regs, insn) == 0) {
225 spin_unlock_irq(&undef_lock);
226 return;
227 }
228 }
229 }
230 spin_unlock_irq(&undef_lock);
231 }
232
233 switch (ecr) {
234 case ECR_PRIVILEGE_VIOLATION:
235 code = ILL_PRVOPC;
236 break;
237 case ECR_COPROC_ABSENT:
238 code = ILL_COPROC;
239 break;
240 default:
241 code = ILL_ILLOPC;
242 break;
243 }
244
245 _exception(SIGILL, regs, code, regs->pc);
246 return;
247
248 invalid_area:
249 _exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
250 }
251
do_fpe(unsigned long ecr,struct pt_regs * regs)252 asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
253 {
254 /* We have no FPU yet */
255 _exception(SIGILL, regs, ILL_COPROC, regs->pc);
256 }
257
258
trap_init(void)259 void __init trap_init(void)
260 {
261
262 }
263