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 | |
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(task: tsk, regs: segv_regs); |
26 | sp = get_stack_pointer(task: tsk, regs: 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 | |
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 | |
60 | static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace) |
61 | { |
62 | dump_trace(tsk, ops: &dump_ops, data: trace); |
63 | } |
64 | |
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 | |
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 | |