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141c943f G |
1 | /* |
2 | * linux/arch/unicore32/kernel/traps.c | |
3 | * | |
4 | * Code specific to PKUnity SoC and UniCore ISA | |
5 | * | |
6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | * 'traps.c' handles hardware exceptions after we have saved some state. | |
13 | * Mostly a debugging aid, but will probably kill the offending process. | |
14 | */ | |
15 | #include <linux/module.h> | |
16 | #include <linux/signal.h> | |
3f07c014 | 17 | #include <linux/sched/signal.h> |
b17b0153 | 18 | #include <linux/sched/debug.h> |
68db0cf1 | 19 | #include <linux/sched/task_stack.h> |
141c943f G |
20 | #include <linux/spinlock.h> |
21 | #include <linux/personality.h> | |
22 | #include <linux/kallsyms.h> | |
23 | #include <linux/kdebug.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/hardirq.h> | |
27 | #include <linux/init.h> | |
141c943f G |
28 | #include <linux/atomic.h> |
29 | #include <linux/unistd.h> | |
30 | ||
31 | #include <asm/cacheflush.h> | |
141c943f G |
32 | #include <asm/traps.h> |
33 | ||
34 | #include "setup.h" | |
35 | ||
36 | static void dump_mem(const char *, const char *, unsigned long, unsigned long); | |
37 | ||
38 | void dump_backtrace_entry(unsigned long where, | |
39 | unsigned long from, unsigned long frame) | |
40 | { | |
41 | #ifdef CONFIG_KALLSYMS | |
42 | printk(KERN_DEFAULT "[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", | |
43 | where, (void *)where, from, (void *)from); | |
44 | #else | |
45 | printk(KERN_DEFAULT "Function entered at [<%08lx>] from [<%08lx>]\n", | |
46 | where, from); | |
47 | #endif | |
48 | } | |
49 | ||
50 | /* | |
51 | * Stack pointers should always be within the kernels view of | |
52 | * physical memory. If it is not there, then we can't dump | |
53 | * out any information relating to the stack. | |
54 | */ | |
55 | static int verify_stack(unsigned long sp) | |
56 | { | |
57 | if (sp < PAGE_OFFSET || | |
58 | (sp > (unsigned long)high_memory && high_memory != NULL)) | |
59 | return -EFAULT; | |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
64 | /* | |
65 | * Dump out the contents of some memory nicely... | |
66 | */ | |
67 | static void dump_mem(const char *lvl, const char *str, unsigned long bottom, | |
68 | unsigned long top) | |
69 | { | |
70 | unsigned long first; | |
71 | mm_segment_t fs; | |
72 | int i; | |
73 | ||
74 | /* | |
75 | * We need to switch to kernel mode so that we can use __get_user | |
76 | * to safely read from kernel space. Note that we now dump the | |
77 | * code first, just in case the backtrace kills us. | |
78 | */ | |
79 | fs = get_fs(); | |
80 | set_fs(KERNEL_DS); | |
81 | ||
82 | printk(KERN_DEFAULT "%s%s(0x%08lx to 0x%08lx)\n", | |
83 | lvl, str, bottom, top); | |
84 | ||
85 | for (first = bottom & ~31; first < top; first += 32) { | |
86 | unsigned long p; | |
87 | char str[sizeof(" 12345678") * 8 + 1]; | |
88 | ||
89 | memset(str, ' ', sizeof(str)); | |
90 | str[sizeof(str) - 1] = '\0'; | |
91 | ||
92 | for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { | |
93 | if (p >= bottom && p < top) { | |
94 | unsigned long val; | |
95 | if (__get_user(val, (unsigned long *)p) == 0) | |
96 | sprintf(str + i * 9, " %08lx", val); | |
97 | else | |
98 | sprintf(str + i * 9, " ????????"); | |
99 | } | |
100 | } | |
101 | printk(KERN_DEFAULT "%s%04lx:%s\n", lvl, first & 0xffff, str); | |
102 | } | |
103 | ||
104 | set_fs(fs); | |
105 | } | |
106 | ||
107 | static void dump_instr(const char *lvl, struct pt_regs *regs) | |
108 | { | |
109 | unsigned long addr = instruction_pointer(regs); | |
110 | const int width = 8; | |
111 | mm_segment_t fs; | |
112 | char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; | |
113 | int i; | |
114 | ||
115 | /* | |
116 | * We need to switch to kernel mode so that we can use __get_user | |
117 | * to safely read from kernel space. Note that we now dump the | |
118 | * code first, just in case the backtrace kills us. | |
119 | */ | |
120 | fs = get_fs(); | |
121 | set_fs(KERNEL_DS); | |
122 | ||
123 | for (i = -4; i < 1; i++) { | |
124 | unsigned int val, bad; | |
125 | ||
126 | bad = __get_user(val, &((u32 *)addr)[i]); | |
127 | ||
128 | if (!bad) | |
129 | p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", | |
130 | width, val); | |
131 | else { | |
132 | p += sprintf(p, "bad PC value"); | |
133 | break; | |
134 | } | |
135 | } | |
136 | printk(KERN_DEFAULT "%sCode: %s\n", lvl, str); | |
137 | ||
138 | set_fs(fs); | |
139 | } | |
140 | ||
141 | static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) | |
142 | { | |
143 | unsigned int fp, mode; | |
144 | int ok = 1; | |
145 | ||
146 | printk(KERN_DEFAULT "Backtrace: "); | |
147 | ||
148 | if (!tsk) | |
149 | tsk = current; | |
150 | ||
151 | if (regs) { | |
152 | fp = regs->UCreg_fp; | |
153 | mode = processor_mode(regs); | |
154 | } else if (tsk != current) { | |
155 | fp = thread_saved_fp(tsk); | |
156 | mode = 0x10; | |
157 | } else { | |
158 | asm("mov %0, fp" : "=r" (fp) : : "cc"); | |
159 | mode = 0x10; | |
160 | } | |
161 | ||
162 | if (!fp) { | |
163 | printk("no frame pointer"); | |
164 | ok = 0; | |
165 | } else if (verify_stack(fp)) { | |
166 | printk("invalid frame pointer 0x%08x", fp); | |
167 | ok = 0; | |
168 | } else if (fp < (unsigned long)end_of_stack(tsk)) | |
169 | printk("frame pointer underflow"); | |
170 | printk("\n"); | |
171 | ||
172 | if (ok) | |
173 | c_backtrace(fp, mode); | |
174 | } | |
175 | ||
141c943f G |
176 | void show_stack(struct task_struct *tsk, unsigned long *sp) |
177 | { | |
178 | dump_backtrace(NULL, tsk); | |
179 | barrier(); | |
180 | } | |
181 | ||
182 | static int __die(const char *str, int err, struct thread_info *thread, | |
183 | struct pt_regs *regs) | |
184 | { | |
185 | struct task_struct *tsk = thread->task; | |
186 | static int die_counter; | |
187 | int ret; | |
188 | ||
189 | printk(KERN_EMERG "Internal error: %s: %x [#%d]\n", | |
190 | str, err, ++die_counter); | |
141c943f G |
191 | |
192 | /* trap and error numbers are mostly meaningless on UniCore */ | |
193 | ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, \ | |
194 | SIGSEGV); | |
195 | if (ret == NOTIFY_STOP) | |
196 | return ret; | |
197 | ||
198 | print_modules(); | |
199 | __show_regs(regs); | |
200 | printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", | |
201 | TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); | |
202 | ||
203 | if (!user_mode(regs) || in_interrupt()) { | |
204 | dump_mem(KERN_EMERG, "Stack: ", regs->UCreg_sp, | |
205 | THREAD_SIZE + (unsigned long)task_stack_page(tsk)); | |
206 | dump_backtrace(regs, tsk); | |
207 | dump_instr(KERN_EMERG, regs); | |
208 | } | |
209 | ||
210 | return ret; | |
211 | } | |
212 | ||
213 | DEFINE_SPINLOCK(die_lock); | |
214 | ||
215 | /* | |
216 | * This function is protected against re-entrancy. | |
217 | */ | |
218 | void die(const char *str, struct pt_regs *regs, int err) | |
219 | { | |
220 | struct thread_info *thread = current_thread_info(); | |
221 | int ret; | |
222 | ||
223 | oops_enter(); | |
224 | ||
225 | spin_lock_irq(&die_lock); | |
226 | console_verbose(); | |
227 | bust_spinlocks(1); | |
228 | ret = __die(str, err, thread, regs); | |
229 | ||
230 | bust_spinlocks(0); | |
373d4d09 | 231 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
141c943f G |
232 | spin_unlock_irq(&die_lock); |
233 | oops_exit(); | |
234 | ||
235 | if (in_interrupt()) | |
236 | panic("Fatal exception in interrupt"); | |
237 | if (panic_on_oops) | |
238 | panic("Fatal exception"); | |
239 | if (ret != NOTIFY_STOP) | |
240 | do_exit(SIGSEGV); | |
241 | } | |
242 | ||
243 | void uc32_notify_die(const char *str, struct pt_regs *regs, | |
ccebcb1f EB |
244 | int sig, int code, void __user *addr, |
245 | unsigned long err, unsigned long trap) | |
141c943f G |
246 | { |
247 | if (user_mode(regs)) { | |
248 | current->thread.error_code = err; | |
249 | current->thread.trap_no = trap; | |
250 | ||
2e1661d2 | 251 | force_sig_fault(sig, code, addr); |
141c943f G |
252 | } else |
253 | die(str, regs, err); | |
254 | } | |
255 | ||
256 | /* | |
257 | * bad_mode handles the impossible case in the vectors. If you see one of | |
258 | * these, then it's extremely serious, and could mean you have buggy hardware. | |
259 | * It never returns, and never tries to sync. We hope that we can at least | |
260 | * dump out some state information... | |
261 | */ | |
262 | asmlinkage void bad_mode(struct pt_regs *regs, unsigned int reason) | |
263 | { | |
264 | console_verbose(); | |
265 | ||
266 | printk(KERN_CRIT "Bad mode detected with reason 0x%x\n", reason); | |
267 | ||
268 | die("Oops - bad mode", regs, 0); | |
269 | local_irq_disable(); | |
270 | panic("bad mode"); | |
271 | } | |
272 | ||
273 | void __pte_error(const char *file, int line, unsigned long val) | |
274 | { | |
275 | printk(KERN_DEFAULT "%s:%d: bad pte %08lx.\n", file, line, val); | |
276 | } | |
277 | ||
278 | void __pmd_error(const char *file, int line, unsigned long val) | |
279 | { | |
280 | printk(KERN_DEFAULT "%s:%d: bad pmd %08lx.\n", file, line, val); | |
281 | } | |
282 | ||
283 | void __pgd_error(const char *file, int line, unsigned long val) | |
284 | { | |
285 | printk(KERN_DEFAULT "%s:%d: bad pgd %08lx.\n", file, line, val); | |
286 | } | |
287 | ||
288 | asmlinkage void __div0(void) | |
289 | { | |
290 | printk(KERN_DEFAULT "Division by zero in kernel.\n"); | |
291 | dump_stack(); | |
292 | } | |
293 | EXPORT_SYMBOL(__div0); | |
294 | ||
295 | void abort(void) | |
296 | { | |
297 | BUG(); | |
298 | ||
299 | /* if that doesn't kill us, halt */ | |
300 | panic("Oops failed to kill thread"); | |
301 | } | |
141c943f G |
302 | |
303 | void __init trap_init(void) | |
304 | { | |
305 | return; | |
306 | } | |
307 | ||
308 | void __init early_trap_init(void) | |
309 | { | |
310 | unsigned long vectors = VECTORS_BASE; | |
311 | ||
312 | /* | |
313 | * Copy the vectors, stubs (in entry-unicore.S) | |
314 | * into the vector page, mapped at 0xffff0000, and ensure these | |
315 | * are visible to the instruction stream. | |
316 | */ | |
317 | memcpy((void *)vectors, | |
318 | __vectors_start, | |
319 | __vectors_end - __vectors_start); | |
320 | memcpy((void *)vectors + 0x200, | |
321 | __stubs_start, | |
322 | __stubs_end - __stubs_start); | |
323 | ||
324 | early_signal_init(); | |
325 | ||
326 | flush_icache_range(vectors, vectors + PAGE_SIZE); | |
327 | } |