stacktrace.c 2.2 KB

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  1. /*
  2. * arch/s390/kernel/stacktrace.c
  3. *
  4. * Stack trace management functions
  5. *
  6. * Copyright (C) IBM Corp. 2006
  7. * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
  8. */
  9. #include <linux/sched.h>
  10. #include <linux/stacktrace.h>
  11. #include <linux/kallsyms.h>
  12. static unsigned long save_context_stack(struct stack_trace *trace,
  13. unsigned int *skip,
  14. unsigned long sp,
  15. unsigned long low,
  16. unsigned long high)
  17. {
  18. struct stack_frame *sf;
  19. struct pt_regs *regs;
  20. unsigned long addr;
  21. while(1) {
  22. sp &= PSW_ADDR_INSN;
  23. if (sp < low || sp > high)
  24. return sp;
  25. sf = (struct stack_frame *)sp;
  26. while(1) {
  27. addr = sf->gprs[8] & PSW_ADDR_INSN;
  28. if (!(*skip))
  29. trace->entries[trace->nr_entries++] = addr;
  30. else
  31. (*skip)--;
  32. if (trace->nr_entries >= trace->max_entries)
  33. return sp;
  34. low = sp;
  35. sp = sf->back_chain & PSW_ADDR_INSN;
  36. if (!sp)
  37. break;
  38. if (sp <= low || sp > high - sizeof(*sf))
  39. return sp;
  40. sf = (struct stack_frame *)sp;
  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. addr = regs->psw.addr & PSW_ADDR_INSN;
  48. if (!(*skip))
  49. trace->entries[trace->nr_entries++] = addr;
  50. else
  51. (*skip)--;
  52. if (trace->nr_entries >= trace->max_entries)
  53. return sp;
  54. low = sp;
  55. sp = regs->gprs[15];
  56. }
  57. }
  58. void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
  59. {
  60. register unsigned long sp asm ("15");
  61. unsigned long orig_sp, new_sp;
  62. orig_sp = sp & PSW_ADDR_INSN;
  63. new_sp = save_context_stack(trace, &trace->skip, orig_sp,
  64. S390_lowcore.panic_stack - PAGE_SIZE,
  65. S390_lowcore.panic_stack);
  66. if ((new_sp != orig_sp) && !trace->all_contexts)
  67. return;
  68. new_sp = save_context_stack(trace, &trace->skip, new_sp,
  69. S390_lowcore.async_stack - ASYNC_SIZE,
  70. S390_lowcore.async_stack);
  71. if ((new_sp != orig_sp) && !trace->all_contexts)
  72. return;
  73. if (task)
  74. save_context_stack(trace, &trace->skip, new_sp,
  75. (unsigned long) task_stack_page(task),
  76. (unsigned long) task_stack_page(task) + THREAD_SIZE);
  77. else
  78. save_context_stack(trace, &trace->skip, new_sp,
  79. S390_lowcore.thread_info,
  80. S390_lowcore.thread_info + THREAD_SIZE);
  81. return;
  82. }