1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/kernel/stacktrace.c
4 *
5 * Stack trace management functions
6 *
7 * Copyright (C) 2006 - 2008 Paul Mundt
8 */
9 #include <linux/sched.h>
10 #include <linux/sched/debug.h>
11 #include <linux/stacktrace.h>
12 #include <linux/thread_info.h>
13 #include <linux/module.h>
14 #include <asm/unwinder.h>
15 #include <asm/ptrace.h>
16 #include <asm/stacktrace.h>
17
18 /*
19 * Save stack-backtrace addresses into a stack_trace buffer.
20 */
save_stack_address(void * data,unsigned long addr,int reliable)21 static void save_stack_address(void *data, unsigned long addr, int reliable)
22 {
23 struct stack_trace *trace = data;
24
25 if (!reliable)
26 return;
27
28 if (trace->skip > 0) {
29 trace->skip--;
30 return;
31 }
32
33 if (trace->nr_entries < trace->max_entries)
34 trace->entries[trace->nr_entries++] = addr;
35 }
36
37 static const struct stacktrace_ops save_stack_ops = {
38 .address = save_stack_address,
39 };
40
save_stack_trace(struct stack_trace * trace)41 void save_stack_trace(struct stack_trace *trace)
42 {
43 unsigned long *sp = (unsigned long *)current_stack_pointer;
44
45 unwind_stack(current, NULL, sp, &save_stack_ops, trace);
46 }
47 EXPORT_SYMBOL_GPL(save_stack_trace);
48
49 static void
save_stack_address_nosched(void * data,unsigned long addr,int reliable)50 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
51 {
52 struct stack_trace *trace = (struct stack_trace *)data;
53
54 if (!reliable)
55 return;
56
57 if (in_sched_functions(addr))
58 return;
59
60 if (trace->skip > 0) {
61 trace->skip--;
62 return;
63 }
64
65 if (trace->nr_entries < trace->max_entries)
66 trace->entries[trace->nr_entries++] = addr;
67 }
68
69 static const struct stacktrace_ops save_stack_ops_nosched = {
70 .address = save_stack_address_nosched,
71 };
72
save_stack_trace_tsk(struct task_struct * tsk,struct stack_trace * trace)73 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
74 {
75 unsigned long *sp = (unsigned long *)tsk->thread.sp;
76
77 unwind_stack(current, NULL, sp, &save_stack_ops_nosched, trace);
78 }
79 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
80
