From: Vitaly Wool <vitalywool@gmail.com>
To: Linux-MM <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Cc: Dan Streetman <ddstreet@ieee.org>,
Vlastimil Babka <vbabka@suse.cz>,
markus.linnala@gmail.com
Subject: [PATCH] z3fold: fix memory leak in kmem cache
Date: Tue, 17 Sep 2019 18:53:52 +0300 [thread overview]
Message-ID: <20190917185352.44cf285d3ebd9e64548de5de@gmail.com> (raw)
Currently there is a leak in init_z3fold_page() -- it allocates
handles from kmem cache even for headless pages, but then they are
never used and never freed, so eventually kmem cache may get
exhausted. This patch provides a fix for that.
Reported-by: Markus Linnala <markus.linnala@gmail.com>
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
---
mm/z3fold.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 6397725b5ec6..7dffef2599c3 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -301,14 +301,11 @@ static void z3fold_unregister_migration(struct z3fold_pool *pool)
}
/* Initializes the z3fold header of a newly allocated z3fold page */
-static struct z3fold_header *init_z3fold_page(struct page *page,
+static struct z3fold_header *init_z3fold_page(struct page *page, bool headless,
struct z3fold_pool *pool, gfp_t gfp)
{
struct z3fold_header *zhdr = page_address(page);
- struct z3fold_buddy_slots *slots = alloc_slots(pool, gfp);
-
- if (!slots)
- return NULL;
+ struct z3fold_buddy_slots *slots;
INIT_LIST_HEAD(&page->lru);
clear_bit(PAGE_HEADLESS, &page->private);
@@ -316,6 +313,12 @@ static struct z3fold_header *init_z3fold_page(struct page *page,
clear_bit(NEEDS_COMPACTING, &page->private);
clear_bit(PAGE_STALE, &page->private);
clear_bit(PAGE_CLAIMED, &page->private);
+ if (headless)
+ return zhdr;
+
+ slots = alloc_slots(pool, gfp);
+ if (!slots)
+ return NULL;
spin_lock_init(&zhdr->page_lock);
kref_init(&zhdr->refcount);
@@ -962,7 +965,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
if (!page)
return -ENOMEM;
- zhdr = init_z3fold_page(page, pool, gfp);
+ zhdr = init_z3fold_page(page, bud == HEADLESS, pool, gfp);
if (!zhdr) {
__free_page(page);
return -ENOMEM;
--
2.17.1
next reply other threads:[~2019-09-17 15:53 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-17 15:53 Vitaly Wool [this message]
2019-09-18 7:31 ` [PATCH] z3fold: fix memory leak in kmem cache Vlastimil Babka
2019-09-19 7:59 ` Vitaly Wool
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190917185352.44cf285d3ebd9e64548de5de@gmail.com \
--to=vitalywool@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=ddstreet@ieee.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=markus.linnala@gmail.com \
--cc=vbabka@suse.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).