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NetLabel: Remove unneeded RCU read locks

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This patch removes some unneeded RCU read locks as we can treat the reads as
"safe" even without RCU.  It also converts the NetLabel configuration refcount
from a spinlock protected u32 into atomic_t to be more consistent with the rest
of the kernel.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
Paul Moore 2008-01-29 08:37:52 -05:00 committed by James Morris
parent 0ba6c33bcd
commit c783f1ce57
5 changed files with 15 additions and 85 deletions
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5
net/netlabel/netlabel_cipso_v4.c
View file

@ -38,6 +38,7 @@
#include <net/genetlink.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/atomic.h>
#include "netlabel_user.h"
#include "netlabel_cipso_v4.h"
@ -421,7 +422,7 @@ static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)
break;
}
if (ret_val == 0)
netlbl_mgmt_protocount_inc();
atomic_inc(&netlabel_mgmt_protocount);
audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD,
&audit_info);
@ -698,7 +699,7 @@ static int netlbl_cipsov4_remove(struct sk_buff *skb, struct genl_info *info)
&audit_info,
netlbl_cipsov4_doi_free);
if (ret_val == 0)
netlbl_mgmt_protocount_dec();
atomic_dec(&netlabel_mgmt_protocount);
audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_DEL,
&audit_info);

3
net/netlabel/netlabel_kapi.c
View file

@ -34,6 +34,7 @@
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/bug.h>
#include <asm/atomic.h>
#include "netlabel_domainhash.h"
#include "netlabel_unlabeled.h"
@ -262,7 +263,7 @@ int netlbl_enabled(void)
/* At some point we probably want to expose this mechanism to the user
* as well so that admins can toggle NetLabel regardless of the
* configuration */
return (netlbl_mgmt_protocount_value() > 0 ? 1 : 0);
return (atomic_read(&netlabel_mgmt_protocount) > 0);
}
/**

63
net/netlabel/netlabel_mgmt.c
View file

@ -37,14 +37,14 @@
#include <net/genetlink.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <asm/atomic.h>
#include "netlabel_domainhash.h"
#include "netlabel_user.h"
#include "netlabel_mgmt.h"
/* NetLabel configured protocol count */
static DEFINE_SPINLOCK(netlabel_mgmt_protocount_lock);
static u32 netlabel_mgmt_protocount = 0;
/* NetLabel configured protocol counter */
atomic_t netlabel_mgmt_protocount = ATOMIC_INIT(0);
/* Argument struct for netlbl_domhsh_walk() */
struct netlbl_domhsh_walk_arg {
@ -70,63 +70,6 @@ static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
};
/*
* NetLabel Misc Management Functions
*/
/**
* netlbl_mgmt_protocount_inc - Increment the configured labeled protocol count
*
* Description:
* Increment the number of labeled protocol configurations in the current
* NetLabel configuration. Keep track of this for use in determining if
* NetLabel label enforcement should be active/enabled or not in the LSM.
*
*/
void netlbl_mgmt_protocount_inc(void)
{
spin_lock(&netlabel_mgmt_protocount_lock);
netlabel_mgmt_protocount++;
spin_unlock(&netlabel_mgmt_protocount_lock);
}
/**
* netlbl_mgmt_protocount_dec - Decrement the configured labeled protocol count
*
* Description:
* Decrement the number of labeled protocol configurations in the current
* NetLabel configuration. Keep track of this for use in determining if
* NetLabel label enforcement should be active/enabled or not in the LSM.
*
*/
void netlbl_mgmt_protocount_dec(void)
{
spin_lock(&netlabel_mgmt_protocount_lock);
if (netlabel_mgmt_protocount > 0)
netlabel_mgmt_protocount--;
spin_unlock(&netlabel_mgmt_protocount_lock);
}
/**
* netlbl_mgmt_protocount_value - Return the number of configured protocols
*
* Description:
* Return the number of labeled protocols in the current NetLabel
* configuration. This value is useful in determining if NetLabel label
* enforcement should be active/enabled or not in the LSM.
*
*/
u32 netlbl_mgmt_protocount_value(void)
{
u32 val;
rcu_read_lock();
val = netlabel_mgmt_protocount;
rcu_read_unlock();
return val;
}
/*
* NetLabel Command Handlers
*/

7
net/netlabel/netlabel_mgmt.h
View file

@ -32,6 +32,7 @@
#define _NETLABEL_MGMT_H
#include <net/netlabel.h>
#include <asm/atomic.h>
/*
* The following NetLabel payloads are supported by the management interface.
@ -168,9 +169,7 @@ enum {
/* NetLabel protocol functions */
int netlbl_mgmt_genl_init(void);
/* NetLabel misc management functions */
void netlbl_mgmt_protocount_inc(void);
void netlbl_mgmt_protocount_dec(void);
u32 netlbl_mgmt_protocount_value(void);
/* NetLabel configured protocol reference counter */
extern atomic_t netlabel_mgmt_protocount;
#endif

22
net/netlabel/netlabel_unlabeled.c
View file

@ -29,7 +29,6 @@
*/
#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/socket.h>
@ -48,7 +47,6 @@
#include "netlabel_unlabeled.h"
/* Accept unlabeled packets flag */
static DEFINE_SPINLOCK(netlabel_unlabel_acceptflg_lock);
static u8 netlabel_unlabel_acceptflg = 0;
/* NetLabel Generic NETLINK CIPSOv4 family */
@ -84,11 +82,8 @@ static void netlbl_unlabel_acceptflg_set(u8 value,
struct audit_buffer *audit_buf;
u8 old_val;
spin_lock(&netlabel_unlabel_acceptflg_lock);
old_val = netlabel_unlabel_acceptflg;
netlabel_unlabel_acceptflg = value;
spin_unlock(&netlabel_unlabel_acceptflg_lock);
audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
audit_info);
if (audit_buf != NULL) {
@ -155,11 +150,9 @@ static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
goto list_failure;
}
rcu_read_lock();
ret_val = nla_put_u8(ans_skb,
NLBL_UNLABEL_A_ACPTFLG,
netlabel_unlabel_acceptflg);
rcu_read_unlock();
if (ret_val != 0)
goto list_failure;
@ -245,17 +238,10 @@ int netlbl_unlabel_genl_init(void)
*/
int netlbl_unlabel_getattr(struct netlbl_lsm_secattr *secattr)
{
int ret_val;
rcu_read_lock();
if (netlabel_unlabel_acceptflg == 1) {
netlbl_secattr_init(secattr);
ret_val = 0;
} else
ret_val = -ENOMSG;
rcu_read_unlock();
return ret_val;
if (netlabel_unlabel_acceptflg == 0)
return -ENOMSG;
netlbl_secattr_init(secattr);
return 0;
}
/**