Subject: [PATCH SLUB 1/2] duplicate the cache name in saved_alias list

From: Li Zhong <[email-masked]>
Date: Mon, 25 Jun 2012 17:53:04 +0800

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 <[email-masked]>
---
 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);
+	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);
 	}
 
-- 
1.7.1