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
__save_stack_trace(struct thread_info * tp,struct stack_trace * trace,bool skip_sched)13 static 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
save_stack_trace(struct stack_trace * trace)77 void save_stack_trace(struct stack_trace *trace)
78 {
79 __save_stack_trace(current_thread_info(), trace, false);
80 }
81 EXPORT_SYMBOL_GPL(save_stack_trace);
82
save_stack_trace_tsk(struct task_struct * tsk,struct stack_trace * trace)83 void 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 }
89 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
90