From ed92616a1a851db5ee2728420bbe1e2da92a2e6f Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Date: Tue, 26 Oct 2010 14:23:07 -0700
Subject: [PATCH] lib/list_sort: test: improve errors handling
The 'lib_sort()' test does not free memory if it fails, and it makes the
kernel panic if it cannot allocate memory. This patch fixes the problem.
This patch also changes several small things:
o use 'list_add()' helper instead of adding manually
o introduce temporary 'el1' variable to avoid ugly and unreadalbe
"if" statement
o make 'head' to be stack variable instead of 'kmalloc()'ed, which
simplifies code a bit
Overall, this patch is of clean-up type.
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>
---
lib/list_sort.c | 65 +++++++++++++++++++++++++++++--------------------
1 file changed, 38 insertions(+), 27 deletions(-)
diff --git a/lib/list_sort.c b/lib/list_sort.c
index 8f3c24415ae51..2b99ff80f4be9 100644
--- a/lib/list_sort.c
+++ b/lib/list_sort.c
@@ -165,56 +165,67 @@ static int cmp(void *priv, struct list_head *a, struct list_head *b)
static int __init list_sort_test(void)
{
- int i, count;
- struct list_head *head = kmalloc(sizeof(*head), GFP_KERNEL);
- struct list_head *cur;
+ int i, count = 1, err = -EINVAL;
+ struct debug_el *el;
+ struct list_head *cur, *tmp;
+ LIST_HEAD(head);
printk(KERN_DEBUG "testing list_sort()\n");
- cur = head;
for (i = 0; i < TEST_LIST_LEN; i++) {
- struct debug_el *el = kmalloc(sizeof(*el), GFP_KERNEL);
- BUG_ON(!el);
+ el = kmalloc(sizeof(*el), GFP_KERNEL);
+ if (!el) {
+ printk(KERN_ERR "cancel list_sort() testing - cannot "
+ "allocate memory\n");
+ goto exit;
+ }
/* force some equivalencies */
el->value = random32() % (TEST_LIST_LEN/3);
el->serial = i;
-
- el->list.prev = cur;
- cur->next = &el->list;
- cur = cur->next;
+ list_add_tail(&el->list, &head);
}
- head->prev = cur;
- list_sort(NULL, head, cmp);
+ list_sort(NULL, &head, cmp);
+
+ for (cur = head.next; cur->next != &head; cur = cur->next) {
+ struct debug_el *el1;
+ int cmp_result;
- count = 1;
- for (cur = head->next; cur->next != head; cur = cur->next) {
- struct debug_el *el = container_of(cur, struct debug_el, list);
- int cmp_result = cmp(NULL, cur, cur->next);
if (cur->next->prev != cur) {
printk(KERN_ERR "list_sort() returned "
"a corrupted list!\n");
- return 1;
- } else if (cmp_result > 0) {
+ goto exit;
+ }
+
+ cmp_result = cmp(NULL, cur, cur->next);
+ if (cmp_result > 0) {
printk(KERN_ERR "list_sort() failed to sort!\n");
- return 1;
- } else if (cmp_result == 0 &&
- el->serial >= container_of(cur->next,
- struct debug_el, list)->serial) {
+ goto exit;
+ }
+
+ el = container_of(cur, struct debug_el, list);
+ el1 = container_of(cur->next, struct debug_el, list);
+ if (cmp_result == 0 && el->serial >= el1->serial) {
printk(KERN_ERR "list_sort() failed to preserve order "
"of equivalent elements!\n");
- return 1;
+ goto exit;
}
- kfree(cur->prev);
count++;
}
- kfree(cur);
+
if (count != TEST_LIST_LEN) {
printk(KERN_ERR "list_sort() returned list of "
"different length!\n");
- return 1;
+ goto exit;
+ }
+
+ err = 0;
+exit:
+ list_for_each_safe(cur, tmp, &head) {
+ list_del(cur);
+ kfree(container_of(cur, struct debug_el, list));
}
- return 0;
+ return err;
}
module_init(list_sort_test);
#endif /* CONFIG_TEST_LIST_SORT */
--
2.39.5