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From:   Kassey <kassey1216@gmail.com>
Date:   Tue, 12 Jun 2018 17:53:12 +0800
Message-ID: <CAKwPUoz5uz+nxvjBo9nw2fNYcCJRk2-aCzPNcrCzg9-383D7AA@mail.gmail.com>
Subject: Re: [PATCH] inotify: add error handling for kmem_cache_create
To:     "cgxu519@gmx.com" <cgxu519@gmx.com>
Cc:     Zhouyang Jia <jiazhouyang09@gmail.com>, Jan Kara <jack@suse.cz>,
        Amir Goldstein <amir73il@gmail.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
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in __kmem_cache_create->kmem_cache_open

with SLAB_PANIC, kernel will panic if it fail

On Tue, Jun 12, 2018 at 3:41 PM, cgxu519@gmx.com <cgxu519@gmx.com> wrote:
>
>> =E5=9C=A8 2018=E5=B9=B46=E6=9C=8812=E6=97=A5=EF=BC=8C=E4=B8=8B=E5=8D=881=
2:22=EF=BC=8CZhouyang Jia <jiazhouyang09@gmail.com> =E5=86=99=E9=81=93=EF=
=BC=9A
>>
>> When kmem_cache_create fails, the lack of error-handling code may
>> cause unexpected results.
>>
>> This patch adds error-handling code after calling kmem_cache_create.
>
> I think SLAB_PANIC can handle this case.
>
> Thanks,
> Chengguang.
>
>>
>> Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
>> ---
>> fs/notify/inotify/inotify_user.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotif=
y_user.c
>> index ef32f36..0704bab 100644
>> --- a/fs/notify/inotify/inotify_user.c
>> +++ b/fs/notify/inotify/inotify_user.c
>> @@ -805,6 +805,8 @@ static int __init inotify_user_setup(void)
>>       BUG_ON(hweight32(ALL_INOTIFY_BITS) !=3D 21);
>>
>>       inotify_inode_mark_cachep =3D KMEM_CACHE(inotify_inode_mark, SLAB_=
PANIC);
>> +     if (!inotify_inode_mark_cachep)
>> +             return -ENOMEM;
>>
>>       inotify_max_queued_events =3D 16384;
>>       init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES] =3D 128;
>> --
>> 2.7.4
>>
>


--=20
Best regards
Kassey