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