Re: [PATCH 4/4] integrity: IMA radix tree

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 12 Nov 2008 22:47:14 -0500
Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:

> This version stores integrity information associated with an inode
> in a radix tree in order to avoid bloating the in memory inode.
> As entries can not be added to the radix tree at security_initcall,
> this version removes the dual stage initialization.  Allocating and
> freeing the memory continues to be done at inode_alloc and file_free,
> respectively, except for inodes created before late_initcall.
> 
> Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
> ---
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index bc6460c..0dcdd94 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -683,9 +683,6 @@ struct inode {
>  #ifdef CONFIG_SECURITY
>  	void			*i_security;
>  #endif
> -#ifdef CONFIG_INTEGRITY
> -	void			*i_integrity;
> -#endif

ah, I was going to ask about that..

>  	void			*i_private; /* fs or device private pointer */
>  };
>  
> diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
> index f3aced4..959ae66 100644
> --- a/security/integrity/ima/Makefile
> +++ b/security/integrity/ima/Makefile
> @@ -6,4 +6,4 @@
>  obj-$(CONFIG_IMA) += ima.o
>  
>  ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
> -	 ima_policy.o
> +	 ima_policy.o ima_iint.o
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 9a24305..09a5e1a 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -92,7 +92,6 @@ void ima_store_measurement(void *d);
>  void ima_template_show(struct seq_file *m, void *e,
>  		       enum integrity_show_type show);
>  
> -
>  /*
>   * used to protect h_table and sha_table
>   */
> @@ -109,7 +108,7 @@ extern struct ima_h_table ima_htable;
>  
>  static inline unsigned long IMA_HASH_KEY(u8 *digest)
>  {
> -	 return(hash_long(*digest, IMA_HASH_BITS));
> +	return (hash_long(*digest, IMA_HASH_BITS));

And I _did_ ask about that ;)

>  }
>  
>  /* TPM "Glue" definitions */
> @@ -145,11 +144,36 @@ struct ima_iint_cache {
>  	u8 hmac[IMA_DIGEST_SIZE];
>  	u8 digest[IMA_DIGEST_SIZE];
>  	struct mutex mutex;
> +	atomic_t refcount;
>  };
>  #define IMA_IINT_INIT		1
>  #define IMA_MUST_MEASURE	2
>  #define IMA_MEASURED		4
>  
> +void ima_iint_init(void);
> +struct ima_iint_cache * ima_iint_lookup(struct inode *inode);

checkpatch...

>
> ...
>
> --- /dev/null
> +++ b/security/integrity/ima/ima_iint.c
> @@ -0,0 +1,68 @@
> +/*
> + * Copyright (C) 2008 IBM Corporation
> + *
> + * Authors:
> + * Mimi Zohar <zohar@us.ibm.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation, version 2 of the
> + * License.
> + *
> + * File: ima_iint.c
> + *             cache integrity information associated with an inode
> + *             using a radix tree.
> + */
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/radix-tree.h>
> +#include "ima.h"
> +
> +static struct radix_tree_root ima_iint_store;
> +DEFINE_SPINLOCK(ima_iint_lock);
> +
> +void ima_iint_init(void)
> +{
> +	INIT_RADIX_TREE(&ima_iint_store, GFP_ATOMIC);
> +}

Use the RADIX_TREE() macro, then remove this function.