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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
19static void *is_irq_stack(void *p, void *irq)
20{
21 if (p < irq || p >= (irq + THREAD_SIZE))
22 return NULL;
23 return irq + THREAD_SIZE;
24}
25
26
27static void *is_hardirq_stack(unsigned long *stack, int cpu)
28{
29 void *irq = per_cpu(hardirq_stack, cpu);
30
31 return is_irq_stack(stack, irq);
32}
33
34static void *is_softirq_stack(unsigned long *stack, int cpu)
35{
36 void *irq = per_cpu(softirq_stack, cpu);
37
38 return is_irq_stack(stack, irq);
39}
40
41void dump_trace(struct task_struct *task, struct pt_regs *regs,
42 unsigned long *stack, unsigned long bp,
43 const struct stacktrace_ops *ops, void *data)
44{
45 const unsigned cpu = get_cpu();
46 int graph = 0;
47 u32 *prev_esp;
48
49 if (!task)
50 task = current;
51
52 if (!stack) {
53 unsigned long dummy;
54
55 stack = &dummy;
56 if (task != current)
57 stack = (unsigned long *)task->thread.sp;
58 }
59
60 if (!bp)
61 bp = stack_frame(task, regs);
62
63 for (;;) {
64 struct thread_info *context;
65 void *end_stack;
66
67 end_stack = is_hardirq_stack(stack, cpu);
68 if (!end_stack)
69 end_stack = is_softirq_stack(stack, cpu);
70
71 context = task_thread_info(task);
72 bp = ops->walk_stack(context, stack, bp, ops, data,
73 end_stack, &graph);
74
75 /* Stop if not on irq stack */
76 if (!end_stack)
77 break;
78
79 /* The previous esp is saved on the bottom of the stack */
80 prev_esp = (u32 *)(end_stack - THREAD_SIZE);
81 stack = (unsigned long *)*prev_esp;
82 if (!stack)
83 break;
84
85 if (ops->stack(data, "IRQ") < 0)
86 break;
87 touch_nmi_watchdog();
88 }
89 put_cpu();
90}
91EXPORT_SYMBOL(dump_trace);
92
93void
94show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
95 unsigned long *sp, unsigned long bp, char *log_lvl)
96{
97 unsigned long *stack;
98 int i;
99
100 if (sp == NULL) {
101 if (task)
102 sp = (unsigned long *)task->thread.sp;
103 else
104 sp = (unsigned long *)&sp;
105 }
106
107 stack = sp;
108 for (i = 0; i < kstack_depth_to_print; i++) {
109 if (kstack_end(stack))
110 break;
111 if ((i % STACKSLOTS_PER_LINE) == 0) {
112 if (i != 0)
113 pr_cont("\n");
114 printk("%s %08lx", log_lvl, *stack++);
115 } else
116 pr_cont(" %08lx", *stack++);
117 touch_nmi_watchdog();
118 }
119 pr_cont("\n");
120 show_trace_log_lvl(task, regs, sp, bp, log_lvl);
121}
122
123
124void show_regs(struct pt_regs *regs)
125{
126 int i;
127
128 show_regs_print_info(KERN_EMERG);
129 __show_regs(regs, !user_mode(regs));
130
131 /*
132 * When in-kernel, we also print out the stack and code at the
133 * time of the fault..
134 */
135 if (!user_mode(regs)) {
136 unsigned int code_prologue = code_bytes * 43 / 64;
137 unsigned int code_len = code_bytes;
138 unsigned char c;
139 u8 *ip;
140
141 pr_emerg("Stack:\n");
142 show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
143
144 pr_emerg("Code:");
145
146 ip = (u8 *)regs->ip - code_prologue;
147 if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
148 /* try starting at IP */
149 ip = (u8 *)regs->ip;
150 code_len = code_len - code_prologue + 1;
151 }
152 for (i = 0; i < code_len; i++, ip++) {
153 if (ip < (u8 *)PAGE_OFFSET ||
154 probe_kernel_address(ip, c)) {
155 pr_cont(" Bad EIP value.");
156 break;
157 }
158 if (ip == (u8 *)regs->ip)
159 pr_cont(" <%02x>", c);
160 else
161 pr_cont(" %02x", c);
162 }
163 }
164 pr_cont("\n");
165}
166
167int is_valid_bugaddr(unsigned long ip)
168{
169 unsigned short ud2;
170
171 if (ip < PAGE_OFFSET)
172 return 0;
173 if (probe_kernel_address((unsigned short *)ip, ud2))
174 return 0;
175
176 return ud2 == 0x0b0f;
177}