The patch titled
Subject: lib: list_sort_test(): simplify and harden cleanup
has been added to the -mm tree. Its filename is
lib-list_sort_test-simplify-and-harden-cleanup.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-list_sort_test-simplify-and-harden-cleanup.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-list_sort_test-simplify-and-harden-cleanup.patch
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------------------------------------------------------
From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Subject: lib: list_sort_test(): simplify and harden cleanup
There is no reason to maintain the list structure while freeing the debug
elements. Aside from the redundant pointer manipulations, it is also
inefficient from a locality-of-reference viewpoint, since they are visited
in a random order (wrt. the order they were allocated). Furthermore, if
we jumped to exit: after detecting list corruption, it is actually
dangerous.
So just free the elements in the order they were allocated, using the
backing array elts. Allocate that using kcalloc(), so that if allocation
of one of the debug element fails, we just end up calling kfree(NULL) for
the trailing elements.
Minor details: Use sizeof(*elts) instead of sizeof(void *), and return err
immediately when allocation of elts fails, to avoid introducing another
label just before the final return statement.
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Artem Bityutskiy <artem.bityutskiy@xxxxxxxxxxxxxxx>
Cc: Don Mullis <don.mullis@xxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/list_sort.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff -puN lib/list_sort.c~lib-list_sort_test-simplify-and-harden-cleanup lib/list_sort.c
--- a/lib/list_sort.c~lib-list_sort_test-simplify-and-harden-cleanup
+++ a/lib/list_sort.c
@@ -209,16 +209,16 @@ static int __init list_sort_test(void)
{
int i, count = 1, err = -ENOMEM;
struct debug_el *el;
- struct list_head *cur, *tmp;
+ struct list_head *cur;
LIST_HEAD(head);
printk(KERN_DEBUG "list_sort_test: start testing list_sort()\n");
- elts = kmalloc(sizeof(void *) * TEST_LIST_LEN, GFP_KERNEL);
+ elts = kcalloc(TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
if (!elts) {
printk(KERN_ERR "list_sort_test: error: cannot allocate "
"memory\n");
- goto exit;
+ return err;
}
for (i = 0; i < TEST_LIST_LEN; i++) {
@@ -286,11 +286,9 @@ static int __init list_sort_test(void)
err = 0;
exit:
+ for (i = 0; i < TEST_LIST_LEN; i++)
+ kfree(elts[i]);
kfree(elts);
- list_for_each_safe(cur, tmp, &head) {
- list_del(cur);
- kfree(container_of(cur, struct debug_el, list));
- }
return err;
}
module_init(list_sort_test);
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are
origin.patch
lib-list_sort_test-return-enomem-when-allocation-fails.patch
lib-list_sort_test-add-extra-corruption-check.patch
lib-list_sort_test-simplify-and-harden-cleanup.patch
checkpatchpl-also-suggest-else-if-when-if-follows-brace.patch
linux-next.patch
lib-list_sortc-limit-number-of-unused-cmp-callbacks.patch
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