arch/sparc/kernel/stacktrace.c

   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
  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
  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
  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);