runtime/stack-x86_64.c

   1 /* -*- linux-c -*-
   2  * x86_64 stack tracing functions
   3  * Copyright (C) 2005, 2006, 2007 Red Hat Inc.
   4  *
   5  * This file is part of systemtap, and is free software.  You can
   6  * redistribute it and/or modify it under the terms of the GNU General
   7  * Public License (GPL); either version 2, or (at your option) any
   8  * later version.
   9  */
  10 #ifdef CONFIG_STACK_UNWIND
  11 #include <linux/unwind.h>
  12
  13 static inline int _stp_valid_stack_ptr(struct unwind_frame_info *info)
  14 {
  15         unsigned long context = (unsigned long)UNW_SP(info) & ~(THREAD_SIZE - 1);
  16         unsigned long p = UNW_PC(info);
  17         return  p > context && p < context + THREAD_SIZE - 3;
  18 }
  19
  20 static int _stp_show_trace_unwind(struct unwind_frame_info *info, int verbose)
  21 {
  22         int n = 0;
  23
  24         while (unwind(info) == 0 && UNW_PC(info)) {
  25                 if (_stp_valid_stack_ptr(info))
  26                         break;
  27                 n++;
  28                 if (verbose) {
  29                         _stp_print_char(' ');
  30                         _stp_symbol_print (UNW_PC(info));
  31                         _stp_print_char('\n');
  32                 } else
  33                         _stp_printf ("%p ", UNW_PC(info));
  34                 if (arch_unw_user_mode(info))
  35                         break;
  36         }
  37         return n;
  38 }
  39 #endif /* CONFIG_STACK_UNWIND */
  40
  41 static void __stp_stack_print (struct pt_regs *regs, int verbose, int levels)
  42 {
  43         unsigned long *stack = (unsigned long *)&REG_SP(regs);
  44         unsigned long addr;
  45         int uw_ret = 0;
  46
  47 #ifdef CONFIG_STACK_UNWIND
  48         struct unwind_frame_info info;
  49         if (unwind_init_frame_info(&info, current, regs) == 0)
  50                 uw_ret = _stp_show_trace_unwind(&info, verbose);
  51         stack = (void *)UNW_SP(&info);
  52 #endif
  53
  54         if (uw_ret == 0)
  55                 _stp_print("Inexact backtrace:\n");
  56
  57         while ((long)stack & (THREAD_SIZE-1)) {
  58                 addr = *stack++;
  59                 if (_stp_kta(addr)) {
  60                         if (verbose) {
  61                                 if (uw_ret) {
  62                                         uw_ret = 0;
  63                                         _stp_print("Leftover inexact backtrace:\n");
  64                                 }
  65                                 _stp_print_char(' ');
  66                                 _stp_symbol_print(addr);
  67                                 _stp_print_char('\n');
  68                         } else
  69                                 _stp_printf("%p ", (void *)addr);
  70                 }
  71         }
  72 }