1#include <linux/sched.h>
2#include <linux/stacktrace.h>
3#include <linux/thread_info.h>
4#include <linux/ftrace.h>
5#include <linux/export.h>
6#include <asm/ptrace.h>
7#include <asm/stacktrace.h>
8
9#include "kstack.h"
10
11static void __save_stack_trace(struct thread_info *tp,
12			       struct stack_trace *trace,
13			       bool skip_sched)
14{
15	unsigned long ksp, fp;
16#ifdef CONFIG_FUNCTION_GRAPH_TRACER
17	struct task_struct *t;
18	int graph = 0;
19#endif
20
21	if (tp == current_thread_info()) {
22		stack_trace_flush();
23		__asm__ __volatile__("mov %%fp, %0" : "=r" (ksp));
24	} else {
25		ksp = tp->ksp;
26	}
27
28	fp = ksp + STACK_BIAS;
29#ifdef CONFIG_FUNCTION_GRAPH_TRACER
30	t = tp->task;
31#endif
32	do {
33		struct sparc_stackf *sf;
34		struct pt_regs *regs;
35		unsigned long pc;
36
37		if (!kstack_valid(tp, fp))
38			break;
39
40		sf = (struct sparc_stackf *) fp;
41		regs = (struct pt_regs *) (sf + 1);
42
43		if (kstack_is_trap_frame(tp, regs)) {
44			if (!(regs->tstate & TSTATE_PRIV))
45				break;
46			pc = regs->tpc;
47			fp = regs->u_regs[UREG_I6] + STACK_BIAS;
48		} else {
49			pc = sf->callers_pc;
50			fp = (unsigned long)sf->fp + STACK_BIAS;
51		}
52
53		if (trace->skip > 0)
54			trace->skip--;
55		else if (!skip_sched || !in_sched_functions(pc)) {
56			trace->entries[trace->nr_entries++] = pc;
57#ifdef CONFIG_FUNCTION_GRAPH_TRACER
58			if ((pc + 8UL) == (unsigned long) &return_to_handler) {
59				int index = t->curr_ret_stack;
60				if (t->ret_stack && index >= graph) {
61					pc = t->ret_stack[index - graph].ret;
62					if (trace->nr_entries <
63					    trace->max_entries)
64						trace->entries[trace->nr_entries++] = pc;
65					graph++;
66				}
67			}
68#endif
69		}
70	} while (trace->nr_entries < trace->max_entries);
71}
72
73void save_stack_trace(struct stack_trace *trace)
74{
75	__save_stack_trace(current_thread_info(), trace, false);
76}
77EXPORT_SYMBOL_GPL(save_stack_trace);
78
79void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
80{
81	struct thread_info *tp = task_thread_info(tsk);
82
83	__save_stack_trace(tp, trace, true);
84}
85EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
86