openrisc: support framepointers and STACKTRACE_SUPPORT
[sfrench/cifs-2.6.git] / arch / openrisc / kernel / stacktrace.c
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
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
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
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
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
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);