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                 sp = sp & PSW_ADDR_INSN;
  20                 if (sp < low || sp > high - sizeof(*sf))
  21                         return sp;
  22                 sf = (struct stack_frame *) sp;
  23                 (*depth)--;
  24                 oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
  25
  26                 /* Follow the backchain.  */
  27                 while (*depth) {
  28                         low = sp;
  29                         sp = sf->back_chain & PSW_ADDR_INSN;
  30                         if (!sp)
  31                                 break;
  32                         if (sp <= low || sp > high - sizeof(*sf))
  33                                 return sp;
  34                         sf = (struct stack_frame *) sp;
  35                         (*depth)--;
  36                         oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
  37
  38                 }
  39
  40                 if (*depth == 0)
  41                         break;
  42
  43                 /* Zero backchain detected, check for interrupt frame.  */
  44                 sp = (unsigned long) (sf + 1);
  45                 if (sp <= low || sp > high - sizeof(*regs))
  46                         return sp;
  47                 regs = (struct pt_regs *) sp;
  48                 (*depth)--;
  49                 oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
  50                 low = sp;
  51                 sp = regs->gprs[15];
  52         }
  53         return sp;
  54 }
  55
  56 void s390_backtrace(struct pt_regs * const regs, unsigned int depth)
  57 {
  58         unsigned long head;
  59         struct stack_frame* head_sf;
  60
  61         if (user_mode(regs))
  62                 return;
  63
  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, S390_lowcore.async_stack - ASYNC_SIZE,
  73                             S390_lowcore.async_stack);
  74
  75         __show_trace(&depth, head, S390_lowcore.thread_info,
  76                      S390_lowcore.thread_info + THREAD_SIZE);
  77 }