LXR linux/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
  11static 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
  56void 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}
  78