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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 */
6#include <linux/sched/debug.h>
7#include <linux/kallsyms.h>
8#include <linux/kprobes.h>
9#include <linux/uaccess.h>
10#include <linux/hardirq.h>
11#include <linux/kdebug.h>
12#include <linux/export.h>
13#include <linux/ptrace.h>
14#include <linux/kexec.h>
15#include <linux/sysfs.h>
16#include <linux/bug.h>
17#include <linux/nmi.h>
18
19#include <asm/stacktrace.h>
20
21const char *stack_type_name(enum stack_type type)
22{
23 if (type == STACK_TYPE_IRQ)
24 return "IRQ";
25
26 if (type == STACK_TYPE_SOFTIRQ)
27 return "SOFTIRQ";
28
29 if (type == STACK_TYPE_ENTRY)
30 return "ENTRY_TRAMPOLINE";
31
32 return NULL;
33}
34
35static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
36{
37 unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
38 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
39
40 /*
41 * This is a software stack, so 'end' can be a valid stack pointer.
42 * It just means the stack is empty.
43 */
44 if (stack < begin || stack > end)
45 return false;
46
47 info->type = STACK_TYPE_IRQ;
48 info->begin = begin;
49 info->end = end;
50
51 /*
52 * See irq_32.c -- the next stack pointer is stored at the beginning of
53 * the stack.
54 */
55 info->next_sp = (unsigned long *)*begin;
56
57 return true;
58}
59
60static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
61{
62 unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack_ptr);
63 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
64
65 /*
66 * This is a software stack, so 'end' can be a valid stack pointer.
67 * It just means the stack is empty.
68 */
69 if (stack < begin || stack > end)
70 return false;
71
72 info->type = STACK_TYPE_SOFTIRQ;
73 info->begin = begin;
74 info->end = end;
75
76 /*
77 * The next stack pointer is stored at the beginning of the stack.
78 * See irq_32.c.
79 */
80 info->next_sp = (unsigned long *)*begin;
81
82 return true;
83}
84
85int get_stack_info(unsigned long *stack, struct task_struct *task,
86 struct stack_info *info, unsigned long *visit_mask)
87{
88 if (!stack)
89 goto unknown;
90
91 task = task ? : current;
92
93 if (in_task_stack(stack, task, info))
94 goto recursion_check;
95
96 if (task != current)
97 goto unknown;
98
99 if (in_entry_stack(stack, info))
100 goto recursion_check;
101
102 if (in_hardirq_stack(stack, info))
103 goto recursion_check;
104
105 if (in_softirq_stack(stack, info))
106 goto recursion_check;
107
108 goto unknown;
109
110recursion_check:
111 /*
112 * Make sure we don't iterate through any given stack more than once.
113 * If it comes up a second time then there's something wrong going on:
114 * just break out and report an unknown stack type.
115 */
116 if (visit_mask) {
117 if (*visit_mask & (1UL << info->type)) {
118 printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
119 goto unknown;
120 }
121 *visit_mask |= 1UL << info->type;
122 }
123
124 return 0;
125
126unknown:
127 info->type = STACK_TYPE_UNKNOWN;
128 return -EINVAL;
129}
1/*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
4 */
5#include <linux/kallsyms.h>
6#include <linux/kprobes.h>
7#include <linux/uaccess.h>
8#include <linux/hardirq.h>
9#include <linux/kdebug.h>
10#include <linux/module.h>
11#include <linux/ptrace.h>
12#include <linux/kexec.h>
13#include <linux/sysfs.h>
14#include <linux/bug.h>
15#include <linux/nmi.h>
16
17#include <asm/stacktrace.h>
18
19
20void dump_trace(struct task_struct *task, struct pt_regs *regs,
21 unsigned long *stack, unsigned long bp,
22 const struct stacktrace_ops *ops, void *data)
23{
24 int graph = 0;
25
26 if (!task)
27 task = current;
28
29 if (!stack) {
30 unsigned long dummy;
31
32 stack = &dummy;
33 if (task && task != current)
34 stack = (unsigned long *)task->thread.sp;
35 }
36
37 if (!bp)
38 bp = stack_frame(task, regs);
39
40 for (;;) {
41 struct thread_info *context;
42
43 context = (struct thread_info *)
44 ((unsigned long)stack & (~(THREAD_SIZE - 1)));
45 bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
46
47 stack = (unsigned long *)context->previous_esp;
48 if (!stack)
49 break;
50 if (ops->stack(data, "IRQ") < 0)
51 break;
52 touch_nmi_watchdog();
53 }
54}
55EXPORT_SYMBOL(dump_trace);
56
57void
58show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
59 unsigned long *sp, unsigned long bp, char *log_lvl)
60{
61 unsigned long *stack;
62 int i;
63
64 if (sp == NULL) {
65 if (task)
66 sp = (unsigned long *)task->thread.sp;
67 else
68 sp = (unsigned long *)&sp;
69 }
70
71 stack = sp;
72 for (i = 0; i < kstack_depth_to_print; i++) {
73 if (kstack_end(stack))
74 break;
75 if (i && ((i % STACKSLOTS_PER_LINE) == 0))
76 printk(KERN_CONT "\n");
77 printk(KERN_CONT " %08lx", *stack++);
78 touch_nmi_watchdog();
79 }
80 printk(KERN_CONT "\n");
81 show_trace_log_lvl(task, regs, sp, bp, log_lvl);
82}
83
84
85void show_registers(struct pt_regs *regs)
86{
87 int i;
88
89 print_modules();
90 __show_regs(regs, 0);
91
92 printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
93 TASK_COMM_LEN, current->comm, task_pid_nr(current),
94 current_thread_info(), current, task_thread_info(current));
95 /*
96 * When in-kernel, we also print out the stack and code at the
97 * time of the fault..
98 */
99 if (!user_mode_vm(regs)) {
100 unsigned int code_prologue = code_bytes * 43 / 64;
101 unsigned int code_len = code_bytes;
102 unsigned char c;
103 u8 *ip;
104
105 printk(KERN_EMERG "Stack:\n");
106 show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
107
108 printk(KERN_EMERG "Code: ");
109
110 ip = (u8 *)regs->ip - code_prologue;
111 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
112 /* try starting at IP */
113 ip = (u8 *)regs->ip;
114 code_len = code_len - code_prologue + 1;
115 }
116 for (i = 0; i < code_len; i++, ip++) {
117 if (ip < (u8 *)PAGE_OFFSET ||
118 probe_kernel_address(ip, c)) {
119 printk(" Bad EIP value.");
120 break;
121 }
122 if (ip == (u8 *)regs->ip)
123 printk("<%02x> ", c);
124 else
125 printk("%02x ", c);
126 }
127 }
128 printk("\n");
129}
130
131int is_valid_bugaddr(unsigned long ip)
132{
133 unsigned short ud2;
134
135 if (ip < PAGE_OFFSET)
136 return 0;
137 if (probe_kernel_address((unsigned short *)ip, ud2))
138 return 0;
139
140 return ud2 == 0x0b0f;
141}