list_debug.c 1.8 KB

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  1. /*
  2. * Copyright 2006, Red Hat, Inc., Dave Jones
  3. * Released under the General Public License (GPL).
  4. *
  5. * This file contains the linked list validation for DEBUG_LIST.
  6. */
  7. #include <linux/export.h>
  8. #include <linux/list.h>
  9. #include <linux/bug.h>
  10. #include <linux/kernel.h>
  11. #include <linux/rculist.h>
  12. /*
  13. * Check that the data structures for the list manipulations are reasonably
  14. * valid. Failures here indicate memory corruption (and possibly an exploit
  15. * attempt).
  16. */
  17. bool __list_add_valid(struct list_head *new, struct list_head *prev,
  18. struct list_head *next)
  19. {
  20. if (CHECK_DATA_CORRUPTION(next->prev != prev,
  21. "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
  22. prev, next->prev, next) ||
  23. CHECK_DATA_CORRUPTION(prev->next != next,
  24. "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
  25. next, prev->next, prev) ||
  26. CHECK_DATA_CORRUPTION(new == prev || new == next,
  27. "list_add double add: new=%px, prev=%px, next=%px.\n",
  28. new, prev, next))
  29. return false;
  30. return true;
  31. }
  32. EXPORT_SYMBOL(__list_add_valid);
  33. bool __list_del_entry_valid(struct list_head *entry)
  34. {
  35. struct list_head *prev, *next;
  36. prev = entry->prev;
  37. next = entry->next;
  38. if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
  39. "list_del corruption, %px->next is LIST_POISON1 (%px)\n",
  40. entry, LIST_POISON1) ||
  41. CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
  42. "list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
  43. entry, LIST_POISON2) ||
  44. CHECK_DATA_CORRUPTION(prev->next != entry,
  45. "list_del corruption. prev->next should be %px, but was %px\n",
  46. entry, prev->next) ||
  47. CHECK_DATA_CORRUPTION(next->prev != entry,
  48. "list_del corruption. next->prev should be %px, but was %px\n",
  49. entry, next->prev))
  50. return false;
  51. return true;
  52. }
  53. EXPORT_SYMBOL(__list_del_entry_valid);