tracing: extend sched_pi_setprio

[deliverable/linux.git] / lib / list_debug.c

diff --git a/lib/list_debug.c b/lib/list_debug.c
index 3859bf63561c63936947b007fe3ee20e822509a1..7f7bfa55eb6df3e9c9c3c2a244ff02d475197e9d 100644 (file)
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -2,8 +2,7 @@
  * Copyright 2006, Red Hat, Inc., Dave Jones
  * Released under the General Public License (GPL).
  *
- * This file contains the linked list implementations for
- * DEBUG_LIST.
+ * This file contains the linked list validation for DEBUG_LIST.
  */
 
 #include <linux/export.h>
@@ -13,88 +12,48 @@
 #include <linux/rculist.h>
 
 /*
- * Insert a new entry between two known consecutive entries.
- *
- * This is only for internal list manipulation where we know
- * the prev/next entries already!
+ * Check that the data structures for the list manipulations are reasonably
+ * valid. Failures here indicate memory corruption (and possibly an exploit
+ * attempt).
  */
 
-void __list_add(struct list_head *new,
-                             struct list_head *prev,
-                             struct list_head *next)
+bool __list_add_valid(struct list_head *new, struct list_head *prev,
+                     struct list_head *next)
 {
-       WARN(next->prev != prev,
-               "list_add corruption. next->prev should be "
-               "prev (%p), but was %p. (next=%p).\n",
+       CHECK_DATA_CORRUPTION(next->prev != prev,
+               "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
                prev, next->prev, next);
-       WARN(prev->next != next,
-               "list_add corruption. prev->next should be "
-               "next (%p), but was %p. (prev=%p).\n",
+       CHECK_DATA_CORRUPTION(prev->next != next,
+               "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
                next, prev->next, prev);
-       WARN(new == prev || new == next,
-            "list_add double add: new=%p, prev=%p, next=%p.\n",
-            new, prev, next);
-       next->prev = new;
-       new->next = next;
-       new->prev = prev;
-       WRITE_ONCE(prev->next, new);
+       CHECK_DATA_CORRUPTION(new == prev || new == next,
+               "list_add double add: new=%p, prev=%p, next=%p.\n",
+               new, prev, next);
+
+       return true;
 }
-EXPORT_SYMBOL(__list_add);
+EXPORT_SYMBOL(__list_add_valid);
 
-void __list_del_entry(struct list_head *entry)
+bool __list_del_entry_valid(struct list_head *entry)
 {
        struct list_head *prev, *next;
 
        prev = entry->prev;
        next = entry->next;
 
-       if (WARN(next == LIST_POISON1,
+       CHECK_DATA_CORRUPTION(next == LIST_POISON1,
                "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
-               entry, LIST_POISON1) ||
-           WARN(prev == LIST_POISON2,
+               entry, LIST_POISON1);
+       CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
                "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
-               entry, LIST_POISON2) ||
-           WARN(prev->next != entry,
-               "list_del corruption. prev->next should be %p, "
-               "but was %p\n", entry, prev->next) ||
-           WARN(next->prev != entry,
-               "list_del corruption. next->prev should be %p, "
-               "but was %p\n", entry, next->prev))
-               return;
-
-       __list_del(prev, next);
-}
-EXPORT_SYMBOL(__list_del_entry);
+               entry, LIST_POISON2);
+       CHECK_DATA_CORRUPTION(prev->next != entry,
+               "list_del corruption. prev->next should be %p, but was %p\n",
+               entry, prev->next);
+       CHECK_DATA_CORRUPTION(next->prev != entry,
+               "list_del corruption. next->prev should be %p, but was %p\n",
+               entry, next->prev);
+       return true;
 
-/**
- * list_del - deletes entry from list.
- * @entry: the element to delete from the list.
- * Note: list_empty on entry does not return true after this, the entry is
- * in an undefined state.
- */
-void list_del(struct list_head *entry)
-{
-       __list_del_entry(entry);
-       entry->next = LIST_POISON1;
-       entry->prev = LIST_POISON2;
-}
-EXPORT_SYMBOL(list_del);
-
-/*
- * RCU variants.
- */
-void __list_add_rcu(struct list_head *new,
-                   struct list_head *prev, struct list_head *next)
-{
-       WARN(next->prev != prev,
-               "list_add_rcu corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
-               prev, next->prev, next);
-       WARN(prev->next != next,
-               "list_add_rcu corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
-               next, prev->next, prev);
-       new->next = next;
-       new->prev = prev;
-       rcu_assign_pointer(list_next_rcu(prev), new);
-       next->prev = new;
 }
-EXPORT_SYMBOL(__list_add_rcu);
+EXPORT_SYMBOL(__list_del_entry_valid);