1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 * Copyright (C) 2013 Richard Weinberger <richard@nod.at>
5 * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com>
6 */
7
8 #include <linux/kallsyms.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/stacktrace.h>
12 #include <linux/module.h>
13 #include <linux/uaccess.h>
14 #include <asm/stacktrace.h>
15
dump_trace(struct task_struct * tsk,const struct stacktrace_ops * ops,void * data)16 void dump_trace(struct task_struct *tsk,
17 const struct stacktrace_ops *ops,
18 void *data)
19 {
20 int reliable = 0;
21 unsigned long *sp, bp, addr;
22 struct pt_regs *segv_regs = tsk->thread.segv_regs;
23 struct stack_frame *frame;
24
25 bp = get_frame_pointer(tsk, segv_regs);
26 sp = get_stack_pointer(tsk, segv_regs);
27
28 frame = (struct stack_frame *)bp;
29 while (((long) sp & (THREAD_SIZE-1)) != 0) {
30 addr = READ_ONCE_NOCHECK(*sp);
31 if (__kernel_text_address(addr)) {
32 reliable = 0;
33 if ((unsigned long) sp == bp + sizeof(long)) {
34 frame = frame ? frame->next_frame : NULL;
35 bp = (unsigned long)frame;
36 reliable = 1;
37 }
38 ops->address(data, addr, reliable);
39 }
40 sp++;
41 }
42 }
43
save_addr(void * data,unsigned long address,int reliable)44 static void save_addr(void *data, unsigned long address, int reliable)
45 {
46 struct stack_trace *trace = data;
47
48 if (!reliable)
49 return;
50 if (trace->nr_entries >= trace->max_entries)
51 return;
52
53 trace->entries[trace->nr_entries++] = address;
54 }
55
56 static const struct stacktrace_ops dump_ops = {
57 .address = save_addr
58 };
59
__save_stack_trace(struct task_struct * tsk,struct stack_trace * trace)60 static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace)
61 {
62 dump_trace(tsk, &dump_ops, trace);
63 }
64
save_stack_trace(struct stack_trace * trace)65 void save_stack_trace(struct stack_trace *trace)
66 {
67 __save_stack_trace(current, trace);
68 }
69 EXPORT_SYMBOL_GPL(save_stack_trace);
70
save_stack_trace_tsk(struct task_struct * tsk,struct stack_trace * trace)71 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
72 {
73 __save_stack_trace(tsk, trace);
74 }
75 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
76
