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1/*2 * Copyright 2006, Red Hat, Inc., Dave Jones3 * Released under the General Public License (GPL).4 *5 * This file contains the linked list validation and error reporting for6 * LIST_HARDENED and DEBUG_LIST.7 */8 9#include <linux/export.h>10#include <linux/list.h>11#include <linux/bug.h>12#include <linux/kernel.h>13#include <linux/rculist.h>14 15/*16 * Check that the data structures for the list manipulations are reasonably17 * valid. Failures here indicate memory corruption (and possibly an exploit18 * attempt).19 */20 21__list_valid_slowpath22bool __list_add_valid_or_report(struct list_head *new, struct list_head *prev,23 struct list_head *next)24{25 if (CHECK_DATA_CORRUPTION(prev == NULL,26 "list_add corruption. prev is NULL.\n") ||27 CHECK_DATA_CORRUPTION(next == NULL,28 "list_add corruption. next is NULL.\n") ||29 CHECK_DATA_CORRUPTION(next->prev != prev,30 "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",31 prev, next->prev, next) ||32 CHECK_DATA_CORRUPTION(prev->next != next,33 "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",34 next, prev->next, prev) ||35 CHECK_DATA_CORRUPTION(new == prev || new == next,36 "list_add double add: new=%px, prev=%px, next=%px.\n",37 new, prev, next))38 return false;39 40 return true;41}42EXPORT_SYMBOL(__list_add_valid_or_report);43 44__list_valid_slowpath45bool __list_del_entry_valid_or_report(struct list_head *entry)46{47 struct list_head *prev, *next;48 49 prev = entry->prev;50 next = entry->next;51 52 if (CHECK_DATA_CORRUPTION(next == NULL,53 "list_del corruption, %px->next is NULL\n", entry) ||54 CHECK_DATA_CORRUPTION(prev == NULL,55 "list_del corruption, %px->prev is NULL\n", entry) ||56 CHECK_DATA_CORRUPTION(next == LIST_POISON1,57 "list_del corruption, %px->next is LIST_POISON1 (%px)\n",58 entry, LIST_POISON1) ||59 CHECK_DATA_CORRUPTION(prev == LIST_POISON2,60 "list_del corruption, %px->prev is LIST_POISON2 (%px)\n",61 entry, LIST_POISON2) ||62 CHECK_DATA_CORRUPTION(prev->next != entry,63 "list_del corruption. prev->next should be %px, but was %px. (prev=%px)\n",64 entry, prev->next, prev) ||65 CHECK_DATA_CORRUPTION(next->prev != entry,66 "list_del corruption. next->prev should be %px, but was %px. (next=%px)\n",67 entry, next->prev, next))68 return false;69 70 return true;71}72EXPORT_SYMBOL(__list_del_entry_valid_or_report);73