1 /*
2 * Stack trace utility for OpenRISC
3 *
4 * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
5 *
6 * This file is licensed under the terms of the GNU General Public License
7 * version 2. This program is licensed "as is" without any warranty of any
8 * kind, whether express or implied.
9 *
10 * Losely based on work from sh and powerpc.
11 */
12
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/sched/debug.h>
16 #include <linux/stacktrace.h>
17
18 #include <asm/processor.h>
19 #include <asm/unwinder.h>
20
21 /*
22 * Save stack-backtrace addresses into a stack_trace buffer.
23 */
24 static void
save_stack_address(void * data,unsigned long addr,int reliable)25 save_stack_address(void *data, unsigned long addr, int reliable)
26 {
27 struct stack_trace *trace = data;
28
29 if (!reliable)
30 return;
31
32 if (trace->skip > 0) {
33 trace->skip--;
34 return;
35 }
36
37 if (trace->nr_entries < trace->max_entries)
38 trace->entries[trace->nr_entries++] = addr;
39 }
40
save_stack_trace(struct stack_trace * trace)41 void save_stack_trace(struct stack_trace *trace)
42 {
43 unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
44 }
45 EXPORT_SYMBOL_GPL(save_stack_trace);
46
47 static void
save_stack_address_nosched(void * data,unsigned long addr,int reliable)48 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
49 {
50 struct stack_trace *trace = (struct stack_trace *)data;
51
52 if (!reliable)
53 return;
54
55 if (in_sched_functions(addr))
56 return;
57
58 if (trace->skip > 0) {
59 trace->skip--;
60 return;
61 }
62
63 if (trace->nr_entries < trace->max_entries)
64 trace->entries[trace->nr_entries++] = addr;
65 }
66
save_stack_trace_tsk(struct task_struct * tsk,struct stack_trace * trace)67 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
68 {
69 unsigned long *sp = NULL;
70
71 if (tsk == current)
72 sp = (unsigned long *) &sp;
73 else
74 sp = (unsigned long *) KSTK_ESP(tsk);
75
76 unwind_stack(trace, sp, save_stack_address_nosched);
77 }
78 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
79
80 void
save_stack_trace_regs(struct pt_regs * regs,struct stack_trace * trace)81 save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
82 {
83 unwind_stack(trace, (unsigned long *) regs->sp,
84 save_stack_address_nosched);
85 }
86 EXPORT_SYMBOL_GPL(save_stack_trace_regs);
87
