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