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 * Copyright (C) 2009 Matt Fleming
6 * Copyright (C) 2002 - 2012 Paul Mundt
7 */
8 #include <linux/kallsyms.h>
9 #include <linux/ftrace.h>
10 #include <linux/debug_locks.h>
11 #include <linux/sched/debug.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/kdebug.h>
14 #include <linux/export.h>
15 #include <linux/uaccess.h>
16 #include <asm/unwinder.h>
17 #include <asm/stacktrace.h>
18
19 void dump_mem(const char *str, const char *loglvl, unsigned long bottom,
20 unsigned long top)
21 {
22 unsigned long p;
23 int i;
24
25 printk("%s%s(0x%08lx to 0x%08lx)\n", loglvl, str, bottom, top);
26
27 for (p = bottom & ~31; p < top; ) {
28 printk("%s%04lx: ", loglvl, p & 0xffff);
29
30 for (i = 0; i < 8; i++, p += 4) {
31 unsigned int val;
32
33 if (p < bottom || p >= top)
34 pr_cont(" ");
35 else {
36 if (__get_user(val, (unsigned int __user *)p)) {
37 pr_cont("\n");
38 return;
39 }
40 pr_cont("%08x ", val);
41 }
42 }
43 pr_cont("\n");
44 }
45 }
46
47 void printk_address(unsigned long address, int reliable)
48 {
49 pr_cont(" [<%px>] %s%pS\n", (void *) address,
50 reliable ? "" : "? ", (void *) address);
51 }
52
53 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
54 static void
55 print_ftrace_graph_addr(unsigned long addr, void *data,
56 const struct stacktrace_ops *ops,
57 struct thread_info *tinfo, int *graph)
58 {
59 struct task_struct *task = tinfo->task;
60 struct ftrace_ret_stack *ret_stack;
61 unsigned long ret_addr;
62
63 if (addr != (unsigned long)return_to_handler)
64 return;
65
66 if (!task->ret_stack)
67 return;
68
69 ret_stack = ftrace_graph_get_ret_stack(task, *graph);
70 if (!ret_stack)
71 return;
72
73 ret_addr = ret_stack->ret;
74
75 ops->address(data, ret_addr, 1);
76
77 (*graph)++;
78 }
79 #else
80 static inline void
81 print_ftrace_graph_addr(unsigned long addr, void *data,
82 const struct stacktrace_ops *ops,
83 struct thread_info *tinfo, int *graph)
84 { }
85 #endif
86
87 void
88 stack_reader_dump(struct task_struct *task, struct pt_regs *regs,
89 unsigned long *sp, const struct stacktrace_ops *ops,
90 void *data)
91 {
92 struct thread_info *context;
93 int graph = 0;
94
95 context = (struct thread_info *)
96 ((unsigned long)sp & (~(THREAD_SIZE - 1)));
97
98 while (!kstack_end(sp)) {
99 unsigned long addr = *sp++;
100
101 if (__kernel_text_address(addr)) {
102 ops->address(data, addr, 1);
103
104 print_ftrace_graph_addr(addr, data, ops,
105 context, &graph);
106 }
107 }
108 }
109
110 /*
111 * Print one address/symbol entries per line.
112 */
113 static void print_trace_address(void *data, unsigned long addr, int reliable)
114 {
115 printk("%s", (char *)data);
116 printk_address(addr, reliable);
117 }
118
119 static const struct stacktrace_ops print_trace_ops = {
120 .address = print_trace_address,
121 };
122
123 void show_trace(struct task_struct *tsk, unsigned long *sp,
124 struct pt_regs *regs, const char *loglvl)
125 {
126 if (regs && user_mode(regs))
127 return;
128
129 printk("%s\nCall trace:\n", loglvl);
130
131 unwind_stack(tsk, regs, sp, &print_trace_ops, (void *)loglvl);
132
133 pr_cont("\n");
134
135 if (!tsk)
136 tsk = current;
137
138 debug_show_held_locks(tsk);
139 }
140
141 void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
142 {
143 unsigned long stack;
144
145 if (!tsk)
146 tsk = current;
147 if (tsk == current)
148 sp = (unsigned long *)current_stack_pointer;
149 else
150 sp = (unsigned long *)tsk->thread.sp;
151
152 stack = (unsigned long)sp;
153 dump_mem("Stack: ", loglvl, stack, THREAD_SIZE +
154 (unsigned long)task_stack_page(tsk));
155 show_trace(tsk, sp, NULL, loglvl);
156 }
157
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