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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 if (type == STACK_TYPE_EXCEPTION)
33 return "#DF";
34
35 return NULL;
36}
37
38static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
39{
40 unsigned long *begin = (unsigned long *)this_cpu_read(pcpu_hot.hardirq_stack_ptr);
41 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
42
43 /*
44 * This is a software stack, so 'end' can be a valid stack pointer.
45 * It just means the stack is empty.
46 */
47 if (stack < begin || stack > end)
48 return false;
49
50 info->type = STACK_TYPE_IRQ;
51 info->begin = begin;
52 info->end = end;
53
54 /*
55 * See irq_32.c -- the next stack pointer is stored at the beginning of
56 * the stack.
57 */
58 info->next_sp = (unsigned long *)*begin;
59
60 return true;
61}
62
63static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
64{
65 unsigned long *begin = (unsigned long *)this_cpu_read(pcpu_hot.softirq_stack_ptr);
66 unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
67
68 /*
69 * This is a software stack, so 'end' can be a valid stack pointer.
70 * It just means the stack is empty.
71 */
72 if (stack < begin || stack > end)
73 return false;
74
75 info->type = STACK_TYPE_SOFTIRQ;
76 info->begin = begin;
77 info->end = end;
78
79 /*
80 * The next stack pointer is stored at the beginning of the stack.
81 * See irq_32.c.
82 */
83 info->next_sp = (unsigned long *)*begin;
84
85 return true;
86}
87
88static bool in_doublefault_stack(unsigned long *stack, struct stack_info *info)
89{
90 struct cpu_entry_area *cea = get_cpu_entry_area(raw_smp_processor_id());
91 struct doublefault_stack *ss = &cea->doublefault_stack;
92
93 void *begin = ss->stack;
94 void *end = begin + sizeof(ss->stack);
95
96 if ((void *)stack < begin || (void *)stack >= end)
97 return false;
98
99 info->type = STACK_TYPE_EXCEPTION;
100 info->begin = begin;
101 info->end = end;
102 info->next_sp = (unsigned long *)this_cpu_read(cpu_tss_rw.x86_tss.sp);
103
104 return true;
105}
106
107
108int get_stack_info(unsigned long *stack, struct task_struct *task,
109 struct stack_info *info, unsigned long *visit_mask)
110{
111 if (!stack)
112 goto unknown;
113
114 task = task ? : current;
115
116 if (in_task_stack(stack, task, info))
117 goto recursion_check;
118
119 if (task != current)
120 goto unknown;
121
122 if (in_entry_stack(stack, info))
123 goto recursion_check;
124
125 if (in_hardirq_stack(stack, info))
126 goto recursion_check;
127
128 if (in_softirq_stack(stack, info))
129 goto recursion_check;
130
131 if (in_doublefault_stack(stack, info))
132 goto recursion_check;
133
134 goto unknown;
135
136recursion_check:
137 /*
138 * Make sure we don't iterate through any given stack more than once.
139 * If it comes up a second time then there's something wrong going on:
140 * just break out and report an unknown stack type.
141 */
142 if (visit_mask) {
143 if (*visit_mask & (1UL << info->type)) {
144 printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
145 goto unknown;
146 }
147 *visit_mask |= 1UL << info->type;
148 }
149
150 return 0;
151
152unknown:
153 info->type = STACK_TYPE_UNKNOWN;
154 return -EINVAL;
155}
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}