2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 #include <linux/kallsyms.h>
6 #include <linux/kprobes.h>
7 #include <linux/uaccess.h>
8 #include <linux/utsname.h>
9 #include <linux/hardirq.h>
10 #include <linux/kdebug.h>
11 #include <linux/module.h>
12 #include <linux/ptrace.h>
13 #include <linux/ftrace.h>
14 #include <linux/kexec.h>
15 #include <linux/bug.h>
16 #include <linux/nmi.h>
17 #include <linux/sysfs.h>
19 #include <asm/stacktrace.h>
22 int panic_on_unrecovered_nmi;
24 unsigned int code_bytes = 64;
25 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
26 static int die_counter;
28 static void printk_stack_address(unsigned long address, int reliable,
31 printk("%s [<%p>] %s%pB\n",
32 (char *)data, (void *)address, reliable ? "" : "? ",
36 void printk_address(unsigned long address)
38 pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
41 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
43 print_ftrace_graph_addr(unsigned long addr, void *data,
44 const struct stacktrace_ops *ops,
45 struct task_struct *task, int *graph)
47 unsigned long ret_addr;
50 if (addr != (unsigned long)return_to_handler)
53 index = task->curr_ret_stack;
55 if (!task->ret_stack || index < *graph)
59 ret_addr = task->ret_stack[index].ret;
61 ops->address(data, ret_addr, 1);
67 print_ftrace_graph_addr(unsigned long addr, void *data,
68 const struct stacktrace_ops *ops,
69 struct task_struct *task, int *graph)
74 * x86-64 can have up to three kernel stacks:
77 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
80 static inline int valid_stack_ptr(struct task_struct *task,
81 void *p, unsigned int size, void *end)
83 void *t = task_stack_page(task);
85 if (p < end && p >= (end-THREAD_SIZE))
90 return p >= t && p < t + THREAD_SIZE - size;
94 print_context_stack(struct task_struct *task,
95 unsigned long *stack, unsigned long bp,
96 const struct stacktrace_ops *ops, void *data,
97 unsigned long *end, int *graph)
99 struct stack_frame *frame = (struct stack_frame *)bp;
102 * If we overflowed the stack into a guard page, jump back to the
103 * bottom of the usable stack.
105 if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
107 stack = (unsigned long *)task_stack_page(task);
109 while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
113 if (__kernel_text_address(addr)) {
114 if ((unsigned long) stack == bp + sizeof(long)) {
115 ops->address(data, addr, 1);
116 frame = frame->next_frame;
117 bp = (unsigned long) frame;
119 ops->address(data, addr, 0);
121 print_ftrace_graph_addr(addr, data, ops, task, graph);
127 EXPORT_SYMBOL_GPL(print_context_stack);
130 print_context_stack_bp(struct task_struct *task,
131 unsigned long *stack, unsigned long bp,
132 const struct stacktrace_ops *ops, void *data,
133 unsigned long *end, int *graph)
135 struct stack_frame *frame = (struct stack_frame *)bp;
136 unsigned long *ret_addr = &frame->return_address;
138 while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) {
139 unsigned long addr = *ret_addr;
141 if (!__kernel_text_address(addr))
144 if (ops->address(data, addr, 1))
146 frame = frame->next_frame;
147 ret_addr = &frame->return_address;
148 print_ftrace_graph_addr(addr, data, ops, task, graph);
151 return (unsigned long)frame;
153 EXPORT_SYMBOL_GPL(print_context_stack_bp);
155 static int print_trace_stack(void *data, char *name)
157 printk("%s <%s> ", (char *)data, name);
162 * Print one address/symbol entries per line.
164 static int print_trace_address(void *data, unsigned long addr, int reliable)
166 touch_nmi_watchdog();
167 printk_stack_address(addr, reliable, data);
171 static const struct stacktrace_ops print_trace_ops = {
172 .stack = print_trace_stack,
173 .address = print_trace_address,
174 .walk_stack = print_context_stack,
178 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
179 unsigned long *stack, unsigned long bp, char *log_lvl)
181 printk("%sCall Trace:\n", log_lvl);
182 dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
185 void show_trace(struct task_struct *task, struct pt_regs *regs,
186 unsigned long *stack, unsigned long bp)
188 show_trace_log_lvl(task, regs, stack, bp, "");
191 void show_stack(struct task_struct *task, unsigned long *sp)
193 unsigned long bp = 0;
197 * Stack frames below this one aren't interesting. Don't show them
198 * if we're printing for %current.
200 if (!sp && (!task || task == current)) {
202 bp = stack_frame(current, NULL);
205 show_stack_log_lvl(task, NULL, sp, bp, "");
208 void show_stack_regs(struct pt_regs *regs)
210 show_stack_log_lvl(current, regs, (unsigned long *)regs->sp, regs->bp, "");
213 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
214 static int die_owner = -1;
215 static unsigned int die_nest_count;
217 unsigned long oops_begin(void)
224 /* racy, but better than risking deadlock. */
225 raw_local_irq_save(flags);
226 cpu = smp_processor_id();
227 if (!arch_spin_trylock(&die_lock)) {
228 if (cpu == die_owner)
229 /* nested oops. should stop eventually */;
231 arch_spin_lock(&die_lock);
239 EXPORT_SYMBOL_GPL(oops_begin);
240 NOKPROBE_SYMBOL(oops_begin);
242 void __noreturn rewind_stack_do_exit(int signr);
244 void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
246 if (regs && kexec_should_crash(current))
251 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
254 /* Nest count reaches zero, release the lock. */
255 arch_spin_unlock(&die_lock);
256 raw_local_irq_restore(flags);
262 panic("Fatal exception in interrupt");
264 panic("Fatal exception");
267 * We're not going to return, but we might be on an IST stack or
268 * have very little stack space left. Rewind the stack and kill
271 rewind_stack_do_exit(signr);
273 NOKPROBE_SYMBOL(oops_end);
275 int __die(const char *str, struct pt_regs *regs, long err)
282 "%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter,
283 IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
284 IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
285 debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
286 IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "");
288 if (notify_die(DIE_OOPS, str, regs, err,
289 current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
295 if (user_mode(regs)) {
297 ss = regs->ss & 0xffff;
299 sp = kernel_stack_pointer(regs);
302 printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
303 print_symbol("%s", regs->ip);
304 printk(" SS:ESP %04x:%08lx\n", ss, sp);
306 /* Executive summary in case the oops scrolled away */
307 printk(KERN_ALERT "RIP ");
308 printk_address(regs->ip);
309 printk(" RSP <%016lx>\n", regs->sp);
313 NOKPROBE_SYMBOL(__die);
316 * This is gone through when something in the kernel has done something bad
317 * and is about to be terminated:
319 void die(const char *str, struct pt_regs *regs, long err)
321 unsigned long flags = oops_begin();
324 if (!user_mode(regs))
325 report_bug(regs->ip, regs);
327 if (__die(str, regs, err))
329 oops_end(flags, regs, sig);
332 static int __init kstack_setup(char *s)
340 ret = kstrtoul(s, 0, &val);
343 kstack_depth_to_print = val;
346 early_param("kstack", kstack_setup);
348 static int __init code_bytes_setup(char *s)
356 ret = kstrtoul(s, 0, &val);
361 if (code_bytes > 8192)
366 __setup("code_bytes=", code_bytes_setup);