1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/sched.h>
3#include <linux/sched/debug.h>
4#include <linux/stacktrace.h>
5#include <linux/thread_info.h>
6#include <linux/ftrace.h>
7#include <linux/export.h>
8#include <asm/ptrace.h>
9#include <asm/stacktrace.h>
10
11#include "kstack.h"
12
13static void __save_stack_trace(struct thread_info *tp,
14			       struct stack_trace *trace,
15			       bool skip_sched)
16{
17	unsigned long ksp, fp;
18#ifdef CONFIG_FUNCTION_GRAPH_TRACER
19	struct task_struct *t;
20	int graph = 0;
21#endif
22
23	if (tp == current_thread_info()) {
24		stack_trace_flush();
25		__asm__ __volatile__("mov %%fp, %0" : "=r" (ksp));
26	} else {
27		ksp = tp->ksp;
28	}
29
30	fp = ksp + STACK_BIAS;
31#ifdef CONFIG_FUNCTION_GRAPH_TRACER
32	t = tp->task;
33#endif
34	do {
35		struct sparc_stackf *sf;
36		struct pt_regs *regs;
37		unsigned long pc;
38
39		if (!kstack_valid(tp, fp))
40			break;
41
42		sf = (struct sparc_stackf *) fp;
43		regs = (struct pt_regs *) (sf + 1);
44
45		if (kstack_is_trap_frame(tp, regs)) {
46			if (!(regs->tstate & TSTATE_PRIV))
47				break;
48			pc = regs->tpc;
49			fp = regs->u_regs[UREG_I6] + STACK_BIAS;
50		} else {
51			pc = sf->callers_pc;
52			fp = (unsigned long)sf->fp + STACK_BIAS;
53		}
54
55		if (trace->skip > 0)
56			trace->skip--;
57		else if (!skip_sched || !in_sched_functions(pc)) {
58			trace->entries[trace->nr_entries++] = pc;
59#ifdef CONFIG_FUNCTION_GRAPH_TRACER
60			if ((pc + 8UL) == (unsigned long) &return_to_handler) {
61				struct ftrace_ret_stack *ret_stack;
62				ret_stack = ftrace_graph_get_ret_stack(t,
63								       graph);
64				if (ret_stack) {
65					pc = ret_stack->ret;
66					if (trace->nr_entries <
67					    trace->max_entries)
68						trace->entries[trace->nr_entries++] = pc;
69					graph++;
70				}
71			}
72#endif
73		}
74	} while (trace->nr_entries < trace->max_entries);
75}
76
77void save_stack_trace(struct stack_trace *trace)
78{
79	__save_stack_trace(current_thread_info(), trace, false);
80}
81EXPORT_SYMBOL_GPL(save_stack_trace);
82
83void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
84{
85	struct thread_info *tp = task_thread_info(tsk);
86
87	__save_stack_trace(tp, trace, true);
88}
89EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
90