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author | 2013-07-10 21:06:43 -0700 | |
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committer | 2013-08-14 11:42:06 -0700 | |
commit | 01e2b670aa898a39259bc85c78e3d74820f4d3b6 (patch) | |
tree | cd78cea5f92788c213f2eb8ef287535ac1bb3327 /security/apparmor/include/policy.h | |
parent | apparmor: provide base for multiple profiles to be replaced at once (diff) | |
download | linux-01e2b670aa898a39259bc85c78e3d74820f4d3b6.tar.gz linux-01e2b670aa898a39259bc85c78e3d74820f4d3b6.tar.bz2 linux-01e2b670aa898a39259bc85c78e3d74820f4d3b6.zip |
apparmor: convert profile lists to RCU based locking
Signed-off-by: John Johansen <john.johansen@canonical.com>
Diffstat (limited to 'security/apparmor/include/policy.h')
-rw-r--r-- | security/apparmor/include/policy.h | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index b25491a3046a..82487a853353 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -42,6 +42,8 @@ extern const char *const profile_mode_names[]; #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT) +#define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2) + /* * FIXME: currently need a clean way to replace and remove profiles as a * set. It should be done at the namespace level. @@ -75,6 +77,7 @@ struct aa_profile; * @hname - The hierarchical name * @count: reference count of the obj * @list: list policy object is on + * @rcu: rcu head used when removing from @list * @profiles: head of the profiles list contained in the object */ struct aa_policy { @@ -83,6 +86,7 @@ struct aa_policy { struct kref count; struct list_head list; struct list_head profiles; + struct rcu_head rcu; }; /* struct aa_ns_acct - accounting of profiles in namespace @@ -124,7 +128,7 @@ struct aa_ns_acct { struct aa_namespace { struct aa_policy base; struct aa_namespace *parent; - rwlock_t lock; + struct mutex lock; struct aa_ns_acct acct; struct aa_profile *unconfined; struct list_head sub_ns; @@ -166,7 +170,7 @@ struct aa_policydb { * attachments are determined by profile X transition rules. * * The @replacedby field is write protected by the profile lock. Reads - * are assumed to be atomic, and are done without locking. + * are assumed to be atomic. * * Profiles have a hierarchy where hats and children profiles keep * a reference to their parent. @@ -177,7 +181,7 @@ struct aa_policydb { */ struct aa_profile { struct aa_policy base; - struct aa_profile *parent; + struct aa_profile __rcu *parent; struct aa_namespace *ns; struct aa_profile *replacedby; @@ -296,6 +300,41 @@ static inline struct aa_profile *aa_get_profile(struct aa_profile *p) } /** + * aa_get_profile_not0 - increment refcount on profile @p found via lookup + * @p: profile (MAYBE NULL) + * + * Returns: pointer to @p if @p is NULL will return NULL + * Requires: @p must be held with valid refcount when called + */ +static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p) +{ + if (p && kref_get_not0(&p->base.count)) + return p; + + return NULL; +} + +/** + * aa_get_profile_rcu - increment a refcount profile that can be replaced + * @p: pointer to profile that can be replaced (NOT NULL) + * + * Returns: pointer to a refcounted profile. + * else NULL if no profile + */ +static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p) +{ + struct aa_profile *c; + + rcu_read_lock(); + do { + c = rcu_dereference(*p); + } while (c && !kref_get_not0(&c->base.count)); + rcu_read_unlock(); + + return c; +} + +/** * aa_put_profile - decrement refcount on profile @p * @p: profile (MAYBE NULL) */ |