arch/s390/oprofile/backtrace.c

   1 /*
   2  * S390 Version
   3  *   Copyright IBM Corp. 2005
   4  *   Author(s): Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
   5  */
   6
   7 #include <linux/oprofile.h>
   8
   9 #include <asm/processor.h> /* for struct stack_frame */
  10
  11 static unsigned long
  12 __show_trace(unsigned int *depth, unsigned long sp,
  13              unsigned long low, unsigned long high)
  14 {
  15         struct stack_frame *sf;
  16         struct pt_regs *regs;
  17
  18         while (*depth) {
  19                 if (sp < low || sp > high - sizeof(*sf))
  20                         return sp;
  21                 sf = (struct stack_frame *) sp;
  22                 (*depth)--;
  23                 oprofile_add_trace(sf->gprs[8]);
  24
  25                 /* Follow the backchain.  */
  26                 while (*depth) {
  27                         low = sp;
  28                         sp = sf->back_chain;
  29                         if (!sp)
  30                                 break;
  31                         if (sp <= low || sp > high - sizeof(*sf))
  32                                 return sp;
  33                         sf = (struct stack_frame *) sp;
  34                         (*depth)--;
  35                         oprofile_add_trace(sf->gprs[8]);
  36
  37                 }
  38
  39                 if (*depth == 0)
  40                         break;
  41
  42                 /* Zero backchain detected, check for interrupt frame.  */
  43                 sp = (unsigned long) (sf + 1);
  44                 if (sp <= low || sp > high - sizeof(*regs))
  45                         return sp;
  46                 regs = (struct pt_regs *) sp;
  47                 (*depth)--;
  48                 oprofile_add_trace(sf->gprs[8]);
  49                 low = sp;
  50                 sp = regs->gprs[15];
  51         }
  52         return sp;
  53 }
  54
  55 void s390_backtrace(struct pt_regs * const regs, unsigned int depth)
  56 {
  57         unsigned long head, frame_size;
  58         struct stack_frame* head_sf;
  59
  60         if (user_mode(regs))
  61                 return;
  62
  63         frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
  64         head = regs->gprs[15];
  65         head_sf = (struct stack_frame*)head;
  66
  67         if (!head_sf->back_chain)
  68                 return;
  69
  70         head = head_sf->back_chain;
  71
  72         head = __show_trace(&depth, head,
  73                             S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
  74                             S390_lowcore.async_stack + frame_size);
  75
  76         __show_trace(&depth, head, S390_lowcore.thread_info,
  77                      S390_lowcore.thread_info + THREAD_SIZE);
  78 }