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Catalin Marinas60ffc302012-03-05 11:49:27 +00001/*
2 * Based on arch/arm/kernel/traps.c
3 *
4 * Copyright (C) 1995-2009 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/signal.h>
21#include <linux/personality.h>
22#include <linux/kallsyms.h>
23#include <linux/spinlock.h>
24#include <linux/uaccess.h>
25#include <linux/hardirq.h>
26#include <linux/kdebug.h>
27#include <linux/module.h>
28#include <linux/kexec.h>
29#include <linux/delay.h>
30#include <linux/init.h>
31#include <linux/sched.h>
32#include <linux/syscalls.h>
33
34#include <asm/atomic.h>
35#include <asm/traps.h>
36#include <asm/stacktrace.h>
37#include <asm/exception.h>
38#include <asm/system_misc.h>
39
40static const char *handler[]= {
41 "Synchronous Abort",
42 "IRQ",
43 "FIQ",
44 "Error"
45};
46
47int show_unhandled_signals = 1;
48
49/*
50 * Dump out the contents of some memory nicely...
51 */
52static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
53 unsigned long top)
54{
55 unsigned long first;
56 mm_segment_t fs;
57 int i;
58
59 /*
60 * We need to switch to kernel mode so that we can use __get_user
61 * to safely read from kernel space. Note that we now dump the
62 * code first, just in case the backtrace kills us.
63 */
64 fs = get_fs();
65 set_fs(KERNEL_DS);
66
67 printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);
68
69 for (first = bottom & ~31; first < top; first += 32) {
70 unsigned long p;
71 char str[sizeof(" 12345678") * 8 + 1];
72
73 memset(str, ' ', sizeof(str));
74 str[sizeof(str) - 1] = '\0';
75
76 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
77 if (p >= bottom && p < top) {
78 unsigned int val;
79 if (__get_user(val, (unsigned int *)p) == 0)
80 sprintf(str + i * 9, " %08x", val);
81 else
82 sprintf(str + i * 9, " ????????");
83 }
84 }
85 printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
86 }
87
88 set_fs(fs);
89}
90
91static void dump_backtrace_entry(unsigned long where, unsigned long stack)
92{
93 print_ip_sym(where);
94 if (in_exception_text(where))
95 dump_mem("", "Exception stack", stack,
96 stack + sizeof(struct pt_regs));
97}
98
99static void dump_instr(const char *lvl, struct pt_regs *regs)
100{
101 unsigned long addr = instruction_pointer(regs);
102 mm_segment_t fs;
103 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
104 int i;
105
106 /*
107 * We need to switch to kernel mode so that we can use __get_user
108 * to safely read from kernel space. Note that we now dump the
109 * code first, just in case the backtrace kills us.
110 */
111 fs = get_fs();
112 set_fs(KERNEL_DS);
113
114 for (i = -4; i < 1; i++) {
115 unsigned int val, bad;
116
117 bad = __get_user(val, &((u32 *)addr)[i]);
118
119 if (!bad)
120 p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
121 else {
122 p += sprintf(p, "bad PC value");
123 break;
124 }
125 }
126 printk("%sCode: %s\n", lvl, str);
127
128 set_fs(fs);
129}
130
131static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
132{
133 struct stackframe frame;
134 const register unsigned long current_sp asm ("sp");
135
136 pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
137
138 if (!tsk)
139 tsk = current;
140
141 if (regs) {
142 frame.fp = regs->regs[29];
143 frame.sp = regs->sp;
144 frame.pc = regs->pc;
145 } else if (tsk == current) {
146 frame.fp = (unsigned long)__builtin_frame_address(0);
147 frame.sp = current_sp;
148 frame.pc = (unsigned long)dump_backtrace;
149 } else {
150 /*
151 * task blocked in __switch_to
152 */
153 frame.fp = thread_saved_fp(tsk);
154 frame.sp = thread_saved_sp(tsk);
155 frame.pc = thread_saved_pc(tsk);
156 }
157
158 printk("Call trace:\n");
159 while (1) {
160 unsigned long where = frame.pc;
161 int ret;
162
163 ret = unwind_frame(&frame);
164 if (ret < 0)
165 break;
166 dump_backtrace_entry(where, frame.sp);
167 }
168}
169
Catalin Marinas60ffc302012-03-05 11:49:27 +0000170void show_stack(struct task_struct *tsk, unsigned long *sp)
171{
172 dump_backtrace(NULL, tsk);
173 barrier();
174}
175
176#ifdef CONFIG_PREEMPT
177#define S_PREEMPT " PREEMPT"
178#else
179#define S_PREEMPT ""
180#endif
181#ifdef CONFIG_SMP
182#define S_SMP " SMP"
183#else
184#define S_SMP ""
185#endif
186
187static int __die(const char *str, int err, struct thread_info *thread,
188 struct pt_regs *regs)
189{
190 struct task_struct *tsk = thread->task;
191 static int die_counter;
192 int ret;
193
194 pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
195 str, err, ++die_counter);
196
197 /* trap and error numbers are mostly meaningless on ARM */
198 ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
199 if (ret == NOTIFY_STOP)
200 return ret;
201
202 print_modules();
203 __show_regs(regs);
204 pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
205 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
206
207 if (!user_mode(regs) || in_interrupt()) {
208 dump_mem(KERN_EMERG, "Stack: ", regs->sp,
209 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
210 dump_backtrace(regs, tsk);
211 dump_instr(KERN_EMERG, regs);
212 }
213
214 return ret;
215}
216
217static DEFINE_RAW_SPINLOCK(die_lock);
218
219/*
220 * This function is protected against re-entrancy.
221 */
222void die(const char *str, struct pt_regs *regs, int err)
223{
224 struct thread_info *thread = current_thread_info();
225 int ret;
226
227 oops_enter();
228
229 raw_spin_lock_irq(&die_lock);
230 console_verbose();
231 bust_spinlocks(1);
232 ret = __die(str, err, thread, regs);
233
234 if (regs && kexec_should_crash(thread->task))
235 crash_kexec(regs);
236
237 bust_spinlocks(0);
Rusty Russell373d4d02013-01-21 17:17:39 +1030238 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
Catalin Marinas60ffc302012-03-05 11:49:27 +0000239 raw_spin_unlock_irq(&die_lock);
240 oops_exit();
241
242 if (in_interrupt())
243 panic("Fatal exception in interrupt");
244 if (panic_on_oops)
245 panic("Fatal exception");
246 if (ret != NOTIFY_STOP)
247 do_exit(SIGSEGV);
248}
249
250void arm64_notify_die(const char *str, struct pt_regs *regs,
251 struct siginfo *info, int err)
252{
253 if (user_mode(regs))
254 force_sig_info(info->si_signo, info, current);
255 else
256 die(str, regs, err);
257}
258
259asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
260{
261 siginfo_t info;
262 void __user *pc = (void __user *)instruction_pointer(regs);
263
264#ifdef CONFIG_COMPAT
265 /* check for AArch32 breakpoint instructions */
266 if (compat_user_mode(regs) && aarch32_break_trap(regs) == 0)
267 return;
268#endif
269
270 if (show_unhandled_signals) {
271 pr_info("%s[%d]: undefined instruction: pc=%p\n",
272 current->comm, task_pid_nr(current), pc);
273 dump_instr(KERN_INFO, regs);
274 }
275
276 info.si_signo = SIGILL;
277 info.si_errno = 0;
278 info.si_code = ILL_ILLOPC;
279 info.si_addr = pc;
280
281 arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
282}
283
284long compat_arm_syscall(struct pt_regs *regs);
285
286asmlinkage long do_ni_syscall(struct pt_regs *regs)
287{
288#ifdef CONFIG_COMPAT
289 long ret;
290 if (is_compat_task()) {
291 ret = compat_arm_syscall(regs);
292 if (ret != -ENOSYS)
293 return ret;
294 }
295#endif
296
297 if (show_unhandled_signals) {
298 pr_info("%s[%d]: syscall %d\n", current->comm,
299 task_pid_nr(current), (int)regs->syscallno);
300 dump_instr("", regs);
301 if (user_mode(regs))
302 __show_regs(regs);
303 }
304
305 return sys_ni_syscall();
306}
307
308/*
309 * bad_mode handles the impossible case in the exception vector.
310 */
311asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
312{
313 console_verbose();
314
315 pr_crit("Bad mode in %s handler detected, code 0x%08x\n",
316 handler[reason], esr);
317
318 die("Oops - bad mode", regs, 0);
319 local_irq_disable();
320 panic("bad mode");
321}
322
323void __pte_error(const char *file, int line, unsigned long val)
324{
325 printk("%s:%d: bad pte %016lx.\n", file, line, val);
326}
327
328void __pmd_error(const char *file, int line, unsigned long val)
329{
330 printk("%s:%d: bad pmd %016lx.\n", file, line, val);
331}
332
333void __pgd_error(const char *file, int line, unsigned long val)
334{
335 printk("%s:%d: bad pgd %016lx.\n", file, line, val);
336}
337
338void __init trap_init(void)
339{
340 return;
341}