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Message-ID: <4FE84352.8090303@cn.fujitsu.com>
Date: Mon, 25 Jun 2012 18:54:10 +0800
From: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reply-To: gaowanlong@cn.fujitsu.com
MIME-Version: 1.0
Subject: Re: [PATCH SLUB 1/2] duplicate the cache name in saved_alias list
References: <1340617984.13778.37.camel@ThinkPad-T420>
In-Reply-To: <1340617984.13778.37.camel@ThinkPad-T420>
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To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Christoph Lameter <cl@linux-foundation.org>, Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, linux-mm <linux-mm@kvack.org>, PowerPC email list <linuxppc-dev@lists.ozlabs.org>

On 06/25/2012 05:53 PM, Li Zhong wrote:
> SLUB duplicates the cache name in kmem_cache_create(). However if the
> cache could be merged to others during early booting, the name pointer
> is saved in saved_alias list, and the string needs to be kept valid
> before slab_sysfs_init() is called. 
> 
> This patch tries to duplicate the cache name in saved_alias list, so
> that the cache name could be safely kfreed after calling
> kmem_cache_create(), if that name is kmalloced. 
> 
> Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
> ---
>  mm/slub.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 8c691fa..3dc8ed5 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -5373,6 +5373,11 @@ static int sysfs_slab_alias(struct kmem_cache *s,
> const char *name)
>  
>  	al->s = s;
>  	al->name = name;
> +	al->name = kstrdup(name, GFP_KERNEL);

dup assigned the al->name ?


Thanks,
Wanlong Gao

> +	if (!al->name) {
> +		kfree(al);
> +		return -ENOMEM;
> +	}
>  	al->next = alias_list;
>  	alias_list = al;
>  	return 0;
> @@ -5409,6 +5414,7 @@ static int __init slab_sysfs_init(void)
>  		if (err)
>  			printk(KERN_ERR "SLUB: Unable to add boot slab alias"
>  					" %s to sysfs\n", s->name);
> +		kfree(al->name);
>  		kfree(al);
>  	}
>  
> 


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