arch/x86/kernel/unwind_guess.c

   1 #include <linux/sched.h>
   2 #include <linux/ftrace.h>
   3 #include <asm/ptrace.h>
   4 #include <asm/bitops.h>
   5 #include <asm/stacktrace.h>
   6 #include <asm/unwind.h>
   7
   8 bool unwind_next_frame(struct unwind_state *state)
   9 {
  10         struct stack_info *info = &state->stack_info;
  11
  12         if (unwind_done(state))
  13                 return false;
  14
  15         do {
  16                 for (state->sp++; state->sp < info->end; state->sp++)
  17                         if (__kernel_text_address(*state->sp))
  18                                 return true;
  19
  20                 state->sp = info->next_sp;
  21
  22         } while (!get_stack_info(state->sp, state->task, info,
  23                                  &state->stack_mask));
  24
  25         return false;
  26 }
  27 EXPORT_SYMBOL_GPL(unwind_next_frame);
  28
  29 void __unwind_start(struct unwind_state *state, struct task_struct *task,
  30                     struct pt_regs *regs, unsigned long *first_frame)
  31 {
  32         memset(state, 0, sizeof(*state));
  33
  34         state->task = task;
  35         state->sp   = first_frame;
  36
  37         get_stack_info(first_frame, state->task, &state->stack_info,
  38                        &state->stack_mask);
  39
  40         if (!__kernel_text_address(*first_frame))
  41                 unwind_next_frame(state);
  42 }
  43 EXPORT_SYMBOL_GPL(__unwind_start);