arch/sparc/kernel/stacktrace.c

   1 #include <linux/sched.h>
   2 #include <linux/stacktrace.h>
   3 #include <linux/thread_info.h>
   4 #include <linux/ftrace.h>
   5 #include <linux/module.h>
   6 #include <asm/ptrace.h>
   7 #include <asm/stacktrace.h>
   8
   9 #include "kstack.h"
  10
  11 static 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
  73 void save_stack_trace(struct stack_trace *trace)
  74 {
  75         __save_stack_trace(current_thread_info(), trace, false);
  76 }
  77 EXPORT_SYMBOL_GPL(save_stack_trace);
  78
  79 void 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 }
  85 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);