From: Minchan Kim <minchan@kernel.org>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
gregkh@linuxfoundation.org, surenb@google.com,
joaodias@google.com, willy@infradead.org, digetx@gmail.com
Subject: Re: [PATCH v6] mm: cma: support sysfs
Date: Tue, 23 Mar 2021 22:44:26 -0700 [thread overview]
Message-ID: <YFrRugjVLlazTNPy@google.com> (raw)
In-Reply-To: <d224c6bd-f5b1-74f6-2afc-c3d5b0519ba4@nvidia.com>
On Tue, Mar 23, 2021 at 09:47:27PM -0700, John Hubbard wrote:
> On 3/23/21 8:27 PM, Minchan Kim wrote:
> ...
> > > > +static int __init cma_sysfs_init(void)
> > > > +{
> > > > + unsigned int i;
> > > > +
> > > > + cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
> > > > + if (!cma_kobj_root)
> > > > + return -ENOMEM;
> > > > +
> > > > + for (i = 0; i < cma_area_count; i++) {
> > > > + int err;
> > > > + struct cma *cma;
> > > > + struct cma_kobject *cma_kobj;
> > > > +
> > > > + cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
> > > > + if (!cma_kobj) {
> > > > + kobject_put(cma_kobj_root);
> > > > + return -ENOMEM;
> > >
> > > This leaks little cma_kobj's all over the floor. :)
> >
> > I thought kobject_put(cma_kobj_root) should deal with it. No?
> >
> If this fails when i > 0, there will be cma_kobj instances that
> were stashed in the cma_areas[] array. But this code only deletes
> the most recently allocated cma_kobj, not anything allocated on
> previous iterations of the loop.
Oh, I misunderstood that destroying of root kobject will release
children recursively. Seems not true. Go back to old version.
index 16c81c9cb9b7..418951a3f138 100644
--- a/mm/cma_sysfs.c
+++ b/mm/cma_sysfs.c
@@ -80,20 +80,19 @@ static struct kobj_type cma_ktype = {
static int __init cma_sysfs_init(void)
{
unsigned int i;
+ int err;
+ struct cma *cma;
+ struct cma_kobject *cma_kobj;
cma_kobj_root = kobject_create_and_add("cma", mm_kobj);
if (!cma_kobj_root)
return -ENOMEM;
for (i = 0; i < cma_area_count; i++) {
- int err;
- struct cma *cma;
- struct cma_kobject *cma_kobj;
-
cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL);
if (!cma_kobj) {
- kobject_put(cma_kobj_root);
- return -ENOMEM;
+ err = -ENOMEM;
+ goto out;
}
cma = &cma_areas[i];
@@ -103,11 +102,21 @@ static int __init cma_sysfs_init(void)
cma_kobj_root, "%s", cma->name);
if (err) {
kobject_put(&cma_kobj->kobj);
- kobject_put(cma_kobj_root);
- return err;
+ goto out;
}
}
return 0;
+out:
+ while (--i >= 0) {
+ cma = &cma_areas[i];
+
+ kobject_put(&cma->kobj->kobj);
+ kfree(cma->kobj);
+ cma->kobj = NULL;
+ }
+ kobject_put(cma_kobj_root);
+
+ return err;
}
subsys_initcall(cma_sysfs_init);
next prev parent reply other threads:[~2021-03-24 5:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 1:05 [PATCH v6] mm: cma: support sysfs Minchan Kim
2021-03-24 2:34 ` John Hubbard
2021-03-24 3:27 ` Minchan Kim
2021-03-24 4:47 ` John Hubbard
2021-03-24 5:44 ` Minchan Kim [this message]
2021-03-24 6:26 ` John Hubbard
2021-03-24 6:57 ` Minchan Kim
2021-03-24 7:10 ` John Hubbard
2021-03-24 12:37 ` Dmitry Osipenko
2021-03-24 15:18 ` Minchan Kim
2021-03-24 12:33 ` Dmitry Osipenko
2021-03-24 15:12 ` Minchan Kim
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