lkml.org 
[lkml]   [2007]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [-mm3 patch]Warning fix: check the return value of kobject_add etc.
On Sat, 31 Mar 2007 10:30:31 +0800 "Cong WANG" <xiyou.wangcong@gmail.com> wrote:

> Since kobject_add, sysfs_create_link and sysfs_create_file are marked
> as '__must_check', so we must always check their return values, or gcc
> will give us warnings.
>
> Signed-off-by: Cong WANG <xiyou.wangcong@gmail.com>
>
> ---
> --- fs/partitions/check.c.orig 2007-03-30 21:35:45.000000000 +0800
> +++ fs/partitions/check.c 2007-03-30 21:49:53.000000000 +0800
> @@ -385,10 +385,16 @@ void add_partition(struct gendisk *disk,
> p->kobj.parent = &disk->kobj;
> p->kobj.ktype = &ktype_part;
> kobject_init(&p->kobj);
> - kobject_add(&p->kobj);
> + if (kobject_add(&p->kobj)) {
> + kfree(p);
> + return;
> + }
> if (!disk->part_uevent_suppress)
> kobject_uevent(&p->kobj, KOBJ_ADD);
> - sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem");
> + if (sysfs_create_link(&p->kobj, &block_subsys.kset.kobj, "subsystem")) {
> + kfree(p);
> + return;
> + }
> if (flags & ADDPART_FLAG_WHOLEDISK) {
> static struct attribute addpartattr = {
> .name = "whole_disk",
> @@ -396,7 +402,10 @@ void add_partition(struct gendisk *disk,
> .owner = THIS_MODULE,
> };
>
> - sysfs_create_file(&p->kobj, &addpartattr);
> + if (sysfs_create_file(&p->kobj, &addpartattr)) {
> + kfree(p);
> + return;
> + }
> }
> partition_sysfs_add_subdir(p);
> disk->part[part-1] = p;

Well yes, but the point here it to fix kernel bugs, not to just make the
warnings go away.

The bugs here are that the effects of the kobject_add() and the
sysfs_create_link() are not undone on the error path.

Also, please always prepare patches in `patch -p1' form, as per
http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt, thanks.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-01 07:35    [W:0.534 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site