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lib/list_sort: test: check element addresses

Improve 'lib_sort()' test and check that:
 o 'cmp()' is called only for elements which were present in the original list,
   i.e., the 'a' and 'b' parameters are valid
 o the resulted (sorted) list consists onlly of the original elements
 o intdoruce "poison" fields to make sure data around 'struc list_head' field
   are not corrupted.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Don Mullis <don.mullis@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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1 parent 014afa9 commit 041b78f232bb87b2de8ca3fed50384bc7dc9c2de Artem Bityutskiy committed with torvalds Oct 26, 2010
Showing with 67 additions and 8 deletions.
  1. +67 −8 lib/list_sort.c
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75 lib/list_sort.c
@@ -145,23 +145,65 @@ EXPORT_SYMBOL(list_sort);
#include <linux/random.h>
+/*
+ * The pattern of set bits in the list length determines which cases
+ * are hit in list_sort().
+ */
+#define TEST_LIST_LEN (512+128+2) /* not including head */
+
+#define TEST_POISON1 0xDEADBEEF
+#define TEST_POISON2 0xA324354C
+
struct debug_el {
+ unsigned int poison1;
struct list_head list;
+ unsigned int poison2;
int value;
unsigned serial;
};
-static int cmp(void *priv, struct list_head *a, struct list_head *b)
+/* Array, containing pointers to all elements in the test list */
+static struct debug_el **elts __initdata;
+
+static int __init check(struct debug_el *ela, struct debug_el *elb)
{
- return container_of(a, struct debug_el, list)->value
- - container_of(b, struct debug_el, list)->value;
+ if (ela->serial >= TEST_LIST_LEN) {
+ printk(KERN_ERR "list_sort_test: error: incorrect serial %d\n",
+ ela->serial);
+ return -EINVAL;
+ }
+ if (elb->serial >= TEST_LIST_LEN) {
+ printk(KERN_ERR "list_sort_test: error: incorrect serial %d\n",
+ elb->serial);
+ return -EINVAL;
+ }
+ if (elts[ela->serial] != ela || elts[elb->serial] != elb) {
+ printk(KERN_ERR "list_sort_test: error: phantom element\n");
+ return -EINVAL;
+ }
+ if (ela->poison1 != TEST_POISON1 || ela->poison2 != TEST_POISON2) {
+ printk(KERN_ERR "list_sort_test: error: bad poison: %#x/%#x\n",
+ ela->poison1, ela->poison2);
+ return -EINVAL;
+ }
+ if (elb->poison1 != TEST_POISON1 || elb->poison2 != TEST_POISON2) {
+ printk(KERN_ERR "list_sort_test: error: bad poison: %#x/%#x\n",
+ elb->poison1, elb->poison2);
+ return -EINVAL;
+ }
+ return 0;
}
-/*
- * The pattern of set bits in the list length determines which cases
- * are hit in list_sort().
- */
-#define TEST_LIST_LEN (512+128+2) /* not including head */
+static int __init cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct debug_el *ela, *elb;
+
+ ela = container_of(a, struct debug_el, list);
+ elb = container_of(b, struct debug_el, list);
+
+ check(ela, elb);
+ return ela->value - elb->value;
+}
static int __init list_sort_test(void)
{
@@ -172,6 +214,13 @@ static int __init list_sort_test(void)
printk(KERN_DEBUG "list_sort_test: start testing list_sort()\n");
+ elts = kmalloc(sizeof(void *) * TEST_LIST_LEN, GFP_KERNEL);
+ if (!elts) {
+ printk(KERN_ERR "list_sort_test: error: cannot allocate "
+ "memory\n");
+ goto exit;
+ }
+
for (i = 0; i < TEST_LIST_LEN; i++) {
el = kmalloc(sizeof(*el), GFP_KERNEL);
if (!el) {
@@ -182,6 +231,9 @@ static int __init list_sort_test(void)
/* force some equivalencies */
el->value = random32() % (TEST_LIST_LEN/3);
el->serial = i;
+ el->poison1 = TEST_POISON1;
+ el->poison2 = TEST_POISON2;
+ elts[i] = el;
list_add_tail(&el->list, &head);
}
@@ -211,6 +263,12 @@ static int __init list_sort_test(void)
"equivalent elements not preserved\n");
goto exit;
}
+
+ if (check(el, el1)) {
+ printk(KERN_ERR "list_sort_test: error: element check "
+ "failed\n");
+ goto exit;
+ }
count++;
}
@@ -222,6 +280,7 @@ static int __init list_sort_test(void)
err = 0;
exit:
+ kfree(elts);
list_for_each_safe(cur, tmp, &head) {
list_del(cur);
kfree(container_of(cur, struct debug_el, list));

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