Commit 929126ef authored by Hongru Zhang's avatar Hongru Zhang Committed by Paul Moore
Browse files

selinux: Move avtab_hash() to a shared location for future reuse 



This is a preparation patch, no functional change.

Signed-off-by: default avatarHongru Zhang <zhanghongru@xiaomi.com>
Signed-off-by: default avatarPaul Moore <paul@paul-moore.com>
parent 641e0217

security/selinux/include/hash.h

0 → 100644
+46 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */



#ifndef _SELINUX_HASH_H_

#define _SELINUX_HASH_H_



/* Based on MurmurHash3, written by Austin Appleby and placed in the

 * public domain.

 */

static inline u32 avtab_hash(const struct avtab_key *keyp, u32 mask)

{

	static const u32 c1 = 0xcc9e2d51;

	static const u32 c2 = 0x1b873593;

	static const u32 r1 = 15;

	static const u32 r2 = 13;

	static const u32 m = 5;

	static const u32 n = 0xe6546b64;



	u32 hash = 0;



#define mix(input)                                         \

	do {                                               \

		u32 v = input;                             \

		v *= c1;                                   \

		v = (v << r1) | (v >> (32 - r1));          \

		v *= c2;                                   \

		hash ^= v;                                 \

		hash = (hash << r2) | (hash >> (32 - r2)); \

		hash = hash * m + n;                       \

	} while (0)



	mix(keyp->target_class);

	mix(keyp->target_type);

	mix(keyp->source_type);



#undef mix



	hash ^= hash >> 16;

	hash *= 0x85ebca6b;

	hash ^= hash >> 13;

	hash *= 0xc2b2ae35;

	hash ^= hash >> 16;



	return hash & mask;

}



#endif /* _SELINUX_HASH_H_ */

security/selinux/ss/avtab.c

+1 −40
Original line number Diff line number Diff line
@@ -20,50 +20,11 @@ 
#include <linux/errno.h>

#include "avtab.h"

#include "policydb.h"

#include "hash.h"



static struct kmem_cache *avtab_node_cachep __ro_after_init;

static struct kmem_cache *avtab_xperms_cachep __ro_after_init;



/* Based on MurmurHash3, written by Austin Appleby and placed in the

 * public domain.

 */

static inline u32 avtab_hash(const struct avtab_key *keyp, u32 mask)

{

	static const u32 c1 = 0xcc9e2d51;

	static const u32 c2 = 0x1b873593;

	static const u32 r1 = 15;

	static const u32 r2 = 13;

	static const u32 m = 5;

	static const u32 n = 0xe6546b64;



	u32 hash = 0;



#define mix(input)                                         \

	do {                                               \

		u32 v = input;                             \

		v *= c1;                                   \

		v = (v << r1) | (v >> (32 - r1));          \

		v *= c2;                                   \

		hash ^= v;                                 \

		hash = (hash << r2) | (hash >> (32 - r2)); \

		hash = hash * m + n;                       \

	} while (0)



	mix(keyp->target_class);

	mix(keyp->target_type);

	mix(keyp->source_type);



#undef mix



	hash ^= hash >> 16;

	hash *= 0x85ebca6b;

	hash ^= hash >> 13;

	hash *= 0xc2b2ae35;

	hash ^= hash >> 16;



	return hash & mask;

}



static struct avtab_node *avtab_insert_node(struct avtab *h,

					    struct avtab_node **dst,

					    const struct avtab_key *key,