CRED: Detach the credentials from task_struct
Detach the credentials from task_struct, duplicating them in copy_process()
and releasing them in __put_task_struct().
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 3e65587..a7a6860 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -158,4 +158,33 @@
*(_gid) = current->cred->fsgid; \
} while(0)
+extern void __put_cred(struct cred *);
+extern int copy_creds(struct task_struct *, unsigned long);
+
+/**
+ * get_cred - Get a reference on a set of credentials
+ * @cred: The credentials to reference
+ *
+ * Get a reference on the specified set of credentials. The caller must
+ * release the reference.
+ */
+static inline struct cred *get_cred(struct cred *cred)
+{
+ atomic_inc(&cred->usage);
+ return cred;
+}
+
+/**
+ * put_cred - Release a reference to a set of credentials
+ * @cred: The credentials to release
+ *
+ * Release a reference to a set of credentials, deleting them when the last ref
+ * is released.
+ */
+static inline void put_cred(struct cred *cred)
+{
+ if (atomic_dec_and_test(&(cred)->usage))
+ __put_cred(cred);
+}
+
#endif /* _LINUX_CRED_H */
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 9de41cc..5e24c54 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -115,19 +115,6 @@
extern struct cred init_cred;
-#define INIT_CRED(p) \
-{ \
- .usage = ATOMIC_INIT(3), \
- .securebits = SECUREBITS_DEFAULT, \
- .cap_inheritable = CAP_INIT_INH_SET, \
- .cap_permitted = CAP_FULL_SET, \
- .cap_effective = CAP_INIT_EFF_SET, \
- .cap_bset = CAP_INIT_BSET, \
- .user = INIT_USER, \
- .group_info = &init_groups, \
- .lock = __SPIN_LOCK_UNLOCKED(p.lock), \
-}
-
/*
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
@@ -162,8 +149,7 @@
.children = LIST_HEAD_INIT(tsk.children), \
.sibling = LIST_HEAD_INIT(tsk.sibling), \
.group_leader = &tsk, \
- .__temp_cred = INIT_CRED(tsk.__temp_cred), \
- .cred = &tsk.__temp_cred, \
+ .cred = &init_cred, \
.comm = "swapper", \
.thread = INIT_THREAD, \
.fs = &init_fs, \
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c8b9250..740cf94 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1151,7 +1151,6 @@
struct list_head cpu_timers[3];
/* process credentials */
- struct cred __temp_cred __deprecated; /* temporary credentials to be removed */
struct cred *cred; /* actual/objective task credentials */
char comm[TASK_COMM_LEN]; /* executable name excluding path
diff --git a/include/linux/security.h b/include/linux/security.h
index 9f305d4..9239cc1 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -593,15 +593,15 @@
* manual page for definitions of the @clone_flags.
* @clone_flags contains the flags indicating what should be shared.
* Return 0 if permission is granted.
- * @task_alloc_security:
- * @p contains the task_struct for child process.
- * Allocate and attach a security structure to the p->security field. The
- * security field is initialized to NULL when the task structure is
+ * @cred_alloc_security:
+ * @cred contains the cred struct for child process.
+ * Allocate and attach a security structure to the cred->security field.
+ * The security field is initialized to NULL when the task structure is
* allocated.
* Return 0 if operation was successful.
- * @task_free_security:
- * @p contains the task_struct for process.
- * Deallocate and clear the p->security field.
+ * @cred_free:
+ * @cred points to the credentials.
+ * Deallocate and clear the cred->security field in a set of credentials.
* @task_setuid:
* Check permission before setting one or more of the user identity
* attributes of the current process. The @flags parameter indicates
@@ -1405,8 +1405,8 @@
int (*dentry_open) (struct file *file);
int (*task_create) (unsigned long clone_flags);
- int (*task_alloc_security) (struct task_struct *p);
- void (*task_free_security) (struct task_struct *p);
+ int (*cred_alloc_security) (struct cred *cred);
+ void (*cred_free) (struct cred *cred);
int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags);
int (*task_post_setuid) (uid_t old_ruid /* or fsuid */ ,
uid_t old_euid, uid_t old_suid, int flags);
@@ -1660,8 +1660,8 @@
int security_file_receive(struct file *file);
int security_dentry_open(struct file *file);
int security_task_create(unsigned long clone_flags);
-int security_task_alloc(struct task_struct *p);
-void security_task_free(struct task_struct *p);
+int security_cred_alloc(struct cred *cred);
+void security_cred_free(struct cred *cred);
int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags);
int security_task_post_setuid(uid_t old_ruid, uid_t old_euid,
uid_t old_suid, int flags);
@@ -2181,12 +2181,12 @@
return 0;
}
-static inline int security_task_alloc(struct task_struct *p)
+static inline int security_cred_alloc(struct cred *cred)
{
return 0;
}
-static inline void security_task_free(struct task_struct *p)
+static inline void security_cred_free(struct cred *cred)
{ }
static inline int security_task_setuid(uid_t id0, uid_t id1, uid_t id2,