1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Stack trace management functions
4 *
5 * Copyright IBM Corp. 2006
6 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
7 */
8
9 #include <linux/sched.h>
10 #include <linux/sched/debug.h>
11 #include <linux/stacktrace.h>
12 #include <linux/kallsyms.h>
13 #include <linux/export.h>
14
__save_address(void * data,unsigned long address,int nosched)15 static int __save_address(void *data, unsigned long address, int nosched)
16 {
17 struct stack_trace *trace = data;
18
19 if (nosched && in_sched_functions(address))
20 return 0;
21 if (trace->skip > 0) {
22 trace->skip--;
23 return 0;
24 }
25 if (trace->nr_entries < trace->max_entries) {
26 trace->entries[trace->nr_entries++] = address;
27 return 0;
28 }
29 return 1;
30 }
31
save_address(void * data,unsigned long address,int reliable)32 static int save_address(void *data, unsigned long address, int reliable)
33 {
34 return __save_address(data, address, 0);
35 }
36
save_address_nosched(void * data,unsigned long address,int reliable)37 static int save_address_nosched(void *data, unsigned long address, int reliable)
38 {
39 return __save_address(data, address, 1);
40 }
41
save_stack_trace(struct stack_trace * trace)42 void save_stack_trace(struct stack_trace *trace)
43 {
44 unsigned long sp;
45
46 sp = current_stack_pointer();
47 dump_trace(save_address, trace, NULL, sp);
48 if (trace->nr_entries < trace->max_entries)
49 trace->entries[trace->nr_entries++] = ULONG_MAX;
50 }
51 EXPORT_SYMBOL_GPL(save_stack_trace);
52
save_stack_trace_tsk(struct task_struct * tsk,struct stack_trace * trace)53 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
54 {
55 unsigned long sp;
56
57 sp = tsk->thread.ksp;
58 if (tsk == current)
59 sp = current_stack_pointer();
60 dump_trace(save_address_nosched, trace, tsk, sp);
61 if (trace->nr_entries < trace->max_entries)
62 trace->entries[trace->nr_entries++] = ULONG_MAX;
63 }
64 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
65
save_stack_trace_regs(struct pt_regs * regs,struct stack_trace * trace)66 void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
67 {
68 unsigned long sp;
69
70 sp = kernel_stack_pointer(regs);
71 dump_trace(save_address, trace, NULL, sp);
72 if (trace->nr_entries < trace->max_entries)
73 trace->entries[trace->nr_entries++] = ULONG_MAX;
74 }
75 EXPORT_SYMBOL_GPL(save_stack_trace_regs);
76
