[deliverable/linux.git] / include / linux / cred.h

/* Credentials management - see Documentation/credentials.txt
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#ifndef _LINUX_CRED_H
#define _LINUX_CRED_H

#include <linux/capability.h>
#include <linux/init.h>
#include <linux/key.h>
#include <linux/selinux.h>
#include <asm/atomic.h>

struct user_struct;
struct cred;
struct inode;

/*
 * COW Supplementary groups list
 */
#define NGROUPS_SMALL		32
#define NGROUPS_PER_BLOCK	((unsigned int)(PAGE_SIZE / sizeof(gid_t)))

struct group_info {
	atomic_t	usage;
	int		ngroups;
	int		nblocks;
	gid_t		small_block[NGROUPS_SMALL];
	gid_t		*blocks[0];
};

/**
 * get_group_info - Get a reference to a group info structure
 * @group_info: The group info to reference
 *
 * This gets a reference to a set of supplementary groups.
 *
 * If the caller is accessing a task's credentials, they must hold the RCU read
 * lock when reading.
 */
static inline struct group_info *get_group_info(struct group_info *gi)
{
	atomic_inc(&gi->usage);
	return gi;
}

/**
 * put_group_info - Release a reference to a group info structure
 * @group_info: The group info to release
 */
#define put_group_info(group_info)			\
do {							\
	if (atomic_dec_and_test(&(group_info)->usage))	\
		groups_free(group_info);		\
} while (0)

extern struct group_info *groups_alloc(int);
extern struct group_info init_groups;
extern void groups_free(struct group_info *);
extern int set_current_groups(struct group_info *);
extern int set_groups(struct cred *, struct group_info *);
extern int groups_search(const struct group_info *, gid_t);

/* access the groups "array" with this macro */
#define GROUP_AT(gi, i) \
	((gi)->blocks[(i) / NGROUPS_PER_BLOCK][(i) % NGROUPS_PER_BLOCK])

extern int in_group_p(gid_t);
extern int in_egroup_p(gid_t);

/*
 * The common credentials for a thread group
 * - shared by CLONE_THREAD
 */
#ifdef CONFIG_KEYS
struct thread_group_cred {
	atomic_t	usage;
	pid_t		tgid;			/* thread group process ID */
	spinlock_t	lock;
	struct key	*session_keyring;	/* keyring inherited over fork */
	struct key	*process_keyring;	/* keyring private to this process */
	struct rcu_head	rcu;			/* RCU deletion hook */
};
#endif

/*
 * The security context of a task
 *
 * The parts of the context break down into two categories:
 *
 *  (1) The objective context of a task.  These parts are used when some other
 *	task is attempting to affect this one.
 *
 *  (2) The subjective context.  These details are used when the task is acting
 *	upon another object, be that a file, a task, a key or whatever.
 *
 * Note that some members of this structure belong to both categories - the
 * LSM security pointer for instance.
 *
 * A task has two security pointers.  task->real_cred points to the objective
 * context that defines that task's actual details.  The objective part of this
 * context is used whenever that task is acted upon.
 *
 * task->cred points to the subjective context that defines the details of how
 * that task is going to act upon another object.  This may be overridden
 * temporarily to point to another security context, but normally points to the
 * same context as task->real_cred.
 */
struct cred {
	atomic_t	usage;
#ifdef CONFIG_DEBUG_CREDENTIALS
	atomic_t	subscribers;	/* number of processes subscribed */
	void		*put_addr;
	unsigned	magic;
#define CRED_MAGIC	0x43736564
#define CRED_MAGIC_DEAD	0x44656144
#endif
	uid_t		uid;		/* real UID of the task */
	gid_t		gid;		/* real GID of the task */
	uid_t		suid;		/* saved UID of the task */
	gid_t		sgid;		/* saved GID of the task */
	uid_t		euid;		/* effective UID of the task */
	gid_t		egid;		/* effective GID of the task */
	uid_t		fsuid;		/* UID for VFS ops */
	gid_t		fsgid;		/* GID for VFS ops */
	unsigned	securebits;	/* SUID-less security management */
	kernel_cap_t	cap_inheritable; /* caps our children can inherit */
	kernel_cap_t	cap_permitted;	/* caps we're permitted */
	kernel_cap_t	cap_effective;	/* caps we can actually use */
	kernel_cap_t	cap_bset;	/* capability bounding set */
#ifdef CONFIG_KEYS
	unsigned char	jit_keyring;	/* default keyring to attach requested
					 * keys to */
	struct key	*thread_keyring; /* keyring private to this thread */
	struct key	*request_key_auth; /* assumed request_key authority */
	struct thread_group_cred *tgcred; /* thread-group shared credentials */
#endif
#ifdef CONFIG_SECURITY
	void		*security;	/* subjective LSM security */
#endif
	struct user_struct *user;	/* real user ID subscription */
	struct group_info *group_info;	/* supplementary groups for euid/fsgid */
	struct rcu_head	rcu;		/* RCU deletion hook */
};

extern void __put_cred(struct cred *);
extern void exit_creds(struct task_struct *);
extern int copy_creds(struct task_struct *, unsigned long);
extern struct cred *cred_alloc_blank(void);
extern struct cred *prepare_creds(void);
extern struct cred *prepare_exec_creds(void);
extern int commit_creds(struct cred *);
extern void abort_creds(struct cred *);
extern const struct cred *override_creds(const struct cred *);
extern void revert_creds(const struct cred *);
extern struct cred *prepare_kernel_cred(struct task_struct *);
extern int change_create_files_as(struct cred *, struct inode *);
extern int set_security_override(struct cred *, u32);
extern int set_security_override_from_ctx(struct cred *, const char *);
extern int set_create_files_as(struct cred *, struct inode *);
extern void __init cred_init(void);

/*
 * check for validity of credentials
 */
#ifdef CONFIG_DEBUG_CREDENTIALS
extern void __invalid_creds(const struct cred *, const char *, unsigned);
extern void __validate_process_creds(struct task_struct *,
				     const char *, unsigned);

extern bool creds_are_invalid(const struct cred *cred);

static inline void __validate_creds(const struct cred *cred,
				    const char *file, unsigned line)
{
	if (unlikely(creds_are_invalid(cred)))
		__invalid_creds(cred, file, line);
}

#define validate_creds(cred)				\
do {							\
	__validate_creds((cred), __FILE__, __LINE__);	\
} while(0)

#define validate_process_creds()				\
do {								\
	__validate_process_creds(current, __FILE__, __LINE__);	\
} while(0)

extern void validate_creds_for_do_exit(struct task_struct *);
#else
static inline void validate_creds(const struct cred *cred)
{
}
static inline void validate_creds_for_do_exit(struct task_struct *tsk)
{
}
static inline void validate_process_creds(void)
{
}
#endif

/**
 * get_new_cred - Get a reference on a new set of credentials
 * @cred: The new credentials to reference
 *
 * Get a reference on the specified set of new credentials.  The caller must
 * release the reference.
 */
static inline struct cred *get_new_cred(struct cred *cred)
{
	atomic_inc(&cred->usage);
	return cred;
}

/**
 * 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.
 *
 * This is used to deal with a committed set of credentials.  Although the
 * pointer is const, this will temporarily discard the const and increment the
 * usage count.  The purpose of this is to attempt to catch at compile time the
 * accidental alteration of a set of credentials that should be considered
 * immutable.
 */
static inline const struct cred *get_cred(const struct cred *cred)
{
	struct cred *nonconst_cred = (struct cred *) cred;
	validate_creds(cred);
	return get_new_cred(nonconst_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.
 *
 * This takes a const pointer to a set of credentials because the credentials
 * on task_struct are attached by const pointers to prevent accidental
 * alteration of otherwise immutable credential sets.
 */
static inline void put_cred(const struct cred *_cred)
{
	struct cred *cred = (struct cred *) _cred;

	validate_creds(cred);
	if (atomic_dec_and_test(&(cred)->usage))
		__put_cred(cred);
}

/**
 * current_cred - Access the current task's subjective credentials
 *
 * Access the subjective credentials of the current task.
 */
#define current_cred() \
	(current->cred)

/**
 * __task_cred - Access a task's objective credentials
 * @task: The task to query
 *
 * Access the objective credentials of a task.  The caller must hold the RCU
 * readlock.
 *
 * The caller must make sure task doesn't go away, either by holding a ref on
 * task or by holding tasklist_lock to prevent it from being unlinked.
 */
#define __task_cred(task) \
	((const struct cred *)(rcu_dereference_check((task)->real_cred, rcu_read_lock_held() || lockdep_tasklist_lock_is_held())))

/**
 * get_task_cred - Get another task's objective credentials
 * @task: The task to query
 *
 * Get the objective credentials of a task, pinning them so that they can't go
 * away.  Accessing a task's credentials directly is not permitted.
 *
 * The caller must make sure task doesn't go away, either by holding a ref on
 * task or by holding tasklist_lock to prevent it from being unlinked.
 */
#define get_task_cred(task)				\
({							\
	struct cred *__cred;				\
	rcu_read_lock();				\
	__cred = (struct cred *) __task_cred((task));	\
	get_cred(__cred);				\
	rcu_read_unlock();				\
	__cred;						\
})

/**
 * get_current_cred - Get the current task's subjective credentials
 *
 * Get the subjective credentials of the current task, pinning them so that
 * they can't go away.  Accessing the current task's credentials directly is
 * not permitted.
 */
#define get_current_cred()				\
	(get_cred(current_cred()))

/**
 * get_current_user - Get the current task's user_struct
 *
 * Get the user record of the current task, pinning it so that it can't go
 * away.
 */
#define get_current_user()				\
({							\
	struct user_struct *__u;			\
	struct cred *__cred;				\
	__cred = (struct cred *) current_cred();	\
	__u = get_uid(__cred->user);			\
	__u;						\
})

/**
 * get_current_groups - Get the current task's supplementary group list
 *
 * Get the supplementary group list of the current task, pinning it so that it
 * can't go away.
 */
#define get_current_groups()				\
({							\
	struct group_info *__groups;			\
	struct cred *__cred;				\
	__cred = (struct cred *) current_cred();	\
	__groups = get_group_info(__cred->group_info);	\
	__groups;					\
})

#define task_cred_xxx(task, xxx)			\
({							\
	__typeof__(((struct cred *)NULL)->xxx) ___val;	\
	rcu_read_lock();				\
	___val = __task_cred((task))->xxx;		\
	rcu_read_unlock();				\
	___val;						\
})

#define task_uid(task)		(task_cred_xxx((task), uid))
#define task_euid(task)		(task_cred_xxx((task), euid))

#define current_cred_xxx(xxx)			\
({						\
	current->cred->xxx;			\
})

#define current_uid()		(current_cred_xxx(uid))
#define current_gid()		(current_cred_xxx(gid))
#define current_euid()		(current_cred_xxx(euid))
#define current_egid()		(current_cred_xxx(egid))
#define current_suid()		(current_cred_xxx(suid))
#define current_sgid()		(current_cred_xxx(sgid))
#define current_fsuid() 	(current_cred_xxx(fsuid))
#define current_fsgid() 	(current_cred_xxx(fsgid))
#define current_cap()		(current_cred_xxx(cap_effective))
#define current_user()		(current_cred_xxx(user))
#define current_user_ns()	(current_cred_xxx(user)->user_ns)
#define current_security()	(current_cred_xxx(security))

#define current_uid_gid(_uid, _gid)		\
do {						\
	const struct cred *__cred;		\
	__cred = current_cred();		\
	*(_uid) = __cred->uid;			\
	*(_gid) = __cred->gid;			\
} while(0)

#define current_euid_egid(_euid, _egid)		\
do {						\
	const struct cred *__cred;		\
	__cred = current_cred();		\
	*(_euid) = __cred->euid;		\
	*(_egid) = __cred->egid;		\
} while(0)

#define current_fsuid_fsgid(_fsuid, _fsgid)	\
do {						\
	const struct cred *__cred;		\
	__cred = current_cred();		\
	*(_fsuid) = __cred->fsuid;		\
	*(_fsgid) = __cred->fsgid;		\
} while(0)

#endif /* _LINUX_CRED_H */
Commit	Line	Data
98870ab0	1	/* Credentials management - see Documentation/credentials.txt
9e2b2dc4 DH	2	*
	3	* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#ifndef _LINUX_CRED_H
	13	#define _LINUX_CRED_H
	14
b6dff3ec	15	#include <linux/capability.h>
b2e1feaf	16	#include <linux/init.h>
b6dff3ec	17	#include <linux/key.h>
ed868a56	18	#include <linux/selinux.h>
b6dff3ec DH	19	#include <asm/atomic.h>
	20
	21	struct user_struct;
	22	struct cred;
3a3b7ce9	23	struct inode;
b6dff3ec DH	24
	25	/*
	26	* COW Supplementary groups list
	27	*/
	28	#define NGROUPS_SMALL 32
	29	#define NGROUPS_PER_BLOCK ((unsigned int)(PAGE_SIZE / sizeof(gid_t)))
	30
	31	struct group_info {
	32	atomic_t usage;
	33	int ngroups;
	34	int nblocks;
	35	gid_t small_block[NGROUPS_SMALL];
	36	gid_t *blocks[0];
	37	};
	38
	39	/**
	40	* get_group_info - Get a reference to a group info structure
	41	* @group_info: The group info to reference
	42	*
86a264ab DH	43	* This gets a reference to a set of supplementary groups.
	44	*
	45	* If the caller is accessing a task's credentials, they must hold the RCU read
	46	* lock when reading.
b6dff3ec	47	*/
86a264ab DH	48	static inline struct group_info get_group_info(struct group_info gi)
	49	{
	50	atomic_inc(&gi->usage);
	51	return gi;
	52	}
b6dff3ec DH	53
	54	/**
	55	* put_group_info - Release a reference to a group info structure
	56	* @group_info: The group info to release
	57	*/
	58	#define put_group_info(group_info) \
	59	do { \
	60	if (atomic_dec_and_test(&(group_info)->usage)) \
	61	groups_free(group_info); \
	62	} while (0)
	63
	64	extern struct group_info *groups_alloc(int);
18b6e041	65	extern struct group_info init_groups;
b6dff3ec DH	66	extern void groups_free(struct group_info *);
	67	extern int set_current_groups(struct group_info *);
	68	extern int set_groups(struct cred , struct group_info );
86a264ab	69	extern int groups_search(const struct group_info *, gid_t);
b6dff3ec DH	70
	71	/* access the groups "array" with this macro */
	72	#define GROUP_AT(gi, i) \
	73	((gi)->blocks[(i) / NGROUPS_PER_BLOCK][(i) % NGROUPS_PER_BLOCK])
	74
	75	extern int in_group_p(gid_t);
	76	extern int in_egroup_p(gid_t);
	77
bb952bb9 DH	78	/*
	79	* The common credentials for a thread group
	80	* - shared by CLONE_THREAD
	81	*/
	82	#ifdef CONFIG_KEYS
	83	struct thread_group_cred {
	84	atomic_t usage;
	85	pid_t tgid; /* thread group process ID */
	86	spinlock_t lock;
	87	struct key session_keyring; / keyring inherited over fork */
	88	struct key process_keyring; / keyring private to this process */
	89	struct rcu_head rcu; /* RCU deletion hook */
	90	};
	91	#endif
	92
b6dff3ec DH	93	/*
	94	* The security context of a task
	95	*
	96	* The parts of the context break down into two categories:
	97	*
	98	* (1) The objective context of a task. These parts are used when some other
	99	* task is attempting to affect this one.
	100	*
	101	* (2) The subjective context. These details are used when the task is acting
	102	* upon another object, be that a file, a task, a key or whatever.
	103	*
	104	* Note that some members of this structure belong to both categories - the
	105	* LSM security pointer for instance.
	106	*
	107	* A task has two security pointers. task->real_cred points to the objective
	108	* context that defines that task's actual details. The objective part of this
	109	* context is used whenever that task is acted upon.
	110	*
	111	* task->cred points to the subjective context that defines the details of how
	112	* that task is going to act upon another object. This may be overridden
	113	* temporarily to point to another security context, but normally points to the
	114	* same context as task->real_cred.
	115	*/
	116	struct cred {
	117	atomic_t usage;
e0e81739 DH	118	#ifdef CONFIG_DEBUG_CREDENTIALS
	119	atomic_t subscribers; /* number of processes subscribed */
	120	void *put_addr;
	121	unsigned magic;
	122	#define CRED_MAGIC 0x43736564
	123	#define CRED_MAGIC_DEAD 0x44656144
	124	#endif
b6dff3ec DH	125	uid_t uid; /* real UID of the task */
	126	gid_t gid; /* real GID of the task */
	127	uid_t suid; /* saved UID of the task */
	128	gid_t sgid; /* saved GID of the task */
	129	uid_t euid; /* effective UID of the task */
	130	gid_t egid; /* effective GID of the task */
	131	uid_t fsuid; /* UID for VFS ops */
	132	gid_t fsgid; /* GID for VFS ops */
	133	unsigned securebits; /* SUID-less security management */
	134	kernel_cap_t cap_inheritable; /* caps our children can inherit */
	135	kernel_cap_t cap_permitted; /* caps we're permitted */
	136	kernel_cap_t cap_effective; /* caps we can actually use */
	137	kernel_cap_t cap_bset; /* capability bounding set */
	138	#ifdef CONFIG_KEYS
	139	unsigned char jit_keyring; /* default keyring to attach requested
	140	* keys to */
	141	struct key thread_keyring; / keyring private to this thread */
	142	struct key request_key_auth; / assumed request_key authority */
bb952bb9	143	struct thread_group_cred tgcred; / thread-group shared credentials */
b6dff3ec DH	144	#endif
	145	#ifdef CONFIG_SECURITY
	146	void security; / subjective LSM security */
	147	#endif
	148	struct user_struct user; / real user ID subscription */
	149	struct group_info group_info; / supplementary groups for euid/fsgid */
	150	struct rcu_head rcu; /* RCU deletion hook */
b6dff3ec DH	151	};
b6dff3ec DH	152
f1752eec	153	extern void __put_cred(struct cred *);
e0e81739	154	extern void exit_creds(struct task_struct *);
f1752eec	155	extern int copy_creds(struct task_struct *, unsigned long);
ee18d64c	156	extern struct cred *cred_alloc_blank(void);
d84f4f99	157	extern struct cred *prepare_creds(void);
a6f76f23	158	extern struct cred *prepare_exec_creds(void);
d84f4f99 DH	159	extern int commit_creds(struct cred *);
d84f4f99 DH	160	extern void abort_creds(struct cred *);
3b11a1de DH	161	extern const struct cred override_creds(const struct cred );
3b11a1de DH	162	extern void revert_creds(const struct cred *);
3a3b7ce9 DH	163	extern struct cred prepare_kernel_cred(struct task_struct );
	164	extern int change_create_files_as(struct cred , struct inode );
	165	extern int set_security_override(struct cred *, u32);
	166	extern int set_security_override_from_ctx(struct cred , const char );
	167	extern int set_create_files_as(struct cred , struct inode );
d84f4f99 DH	168	extern void __init cred_init(void);
d84f4f99 DH	169
e0e81739 DH	170	/*
	171	* check for validity of credentials
	172	*/
	173	#ifdef CONFIG_DEBUG_CREDENTIALS
	174	extern void __invalid_creds(const struct cred , const char , unsigned);
	175	extern void __validate_process_creds(struct task_struct *,
	176	const char *, unsigned);
	177
74908a00	178	extern bool creds_are_invalid(const struct cred *cred);
e0e81739 DH	179
	180	static inline void __validate_creds(const struct cred *cred,
	181	const char *file, unsigned line)
	182	{
	183	if (unlikely(creds_are_invalid(cred)))
	184	__invalid_creds(cred, file, line);
	185	}
	186
	187	#define validate_creds(cred) \
	188	do { \
	189	__validate_creds((cred), __FILE__, __LINE__); \
	190	} while(0)
	191
	192	#define validate_process_creds() \
	193	do { \
	194	__validate_process_creds(current, __FILE__, __LINE__); \
	195	} while(0)
	196
	197	extern void validate_creds_for_do_exit(struct task_struct *);
	198	#else
	199	static inline void validate_creds(const struct cred *cred)
	200	{
	201	}
	202	static inline void validate_creds_for_do_exit(struct task_struct *tsk)
	203	{
	204	}
	205	static inline void validate_process_creds(void)
	206	{
	207	}
	208	#endif
	209
d84f4f99 DH	210	/**
	211	* get_new_cred - Get a reference on a new set of credentials
	212	* @cred: The new credentials to reference
	213	*
	214	* Get a reference on the specified set of new credentials. The caller must
	215	* release the reference.
	216	*/
	217	static inline struct cred get_new_cred(struct cred cred)
	218	{
	219	atomic_inc(&cred->usage);
	220	return cred;
	221	}
f1752eec DH	222
	223	/**
	224	* get_cred - Get a reference on a set of credentials
	225	* @cred: The credentials to reference
	226	*
	227	* Get a reference on the specified set of credentials. The caller must
	228	* release the reference.
98870ab0 DH	229	*
	230	* This is used to deal with a committed set of credentials. Although the
	231	* pointer is const, this will temporarily discard the const and increment the
	232	* usage count. The purpose of this is to attempt to catch at compile time the
	233	* accidental alteration of a set of credentials that should be considered
	234	* immutable.
f1752eec	235	*/
d84f4f99	236	static inline const struct cred get_cred(const struct cred cred)
f1752eec	237	{
1c388ad0	238	struct cred nonconst_cred = (struct cred ) cred;
e0e81739	239	validate_creds(cred);
1c388ad0	240	return get_new_cred(nonconst_cred);
f1752eec DH	241	}
	242
	243	/**
	244	* put_cred - Release a reference to a set of credentials
	245	* @cred: The credentials to release
	246	*
	247	* Release a reference to a set of credentials, deleting them when the last ref
	248	* is released.
98870ab0 DH	249	*
	250	* This takes a const pointer to a set of credentials because the credentials
	251	* on task_struct are attached by const pointers to prevent accidental
	252	* alteration of otherwise immutable credential sets.
f1752eec	253	*/
c69e8d9c	254	static inline void put_cred(const struct cred *_cred)
f1752eec	255	{
c69e8d9c	256	struct cred cred = (struct cred ) _cred;
d84f4f99	257
e0e81739	258	validate_creds(cred);
f1752eec DH	259	if (atomic_dec_and_test(&(cred)->usage))
	260	__put_cred(cred);
	261	}
	262
86a264ab	263	/**
3b11a1de	264	* current_cred - Access the current task's subjective credentials
86a264ab	265	*
3b11a1de	266	* Access the subjective credentials of the current task.
86a264ab DH	267	*/
	268	#define current_cred() \
	269	(current->cred)
	270
	271	/**
3b11a1de	272	* __task_cred - Access a task's objective credentials
86a264ab DH	273	* @task: The task to query
86a264ab DH	274	*
3b11a1de DH	275	* Access the objective credentials of a task. The caller must hold the RCU
3b11a1de DH	276	* readlock.
86a264ab DH	277	*
	278	* The caller must make sure task doesn't go away, either by holding a ref on
	279	* task or by holding tasklist_lock to prevent it from being unlinked.
	280	*/
	281	#define __task_cred(task) \
db1466b3	282	((const struct cred *)(rcu_dereference_check((task)->real_cred, rcu_read_lock_held() \|\| lockdep_tasklist_lock_is_held())))
86a264ab DH	283
86a264ab DH	284	/**
3b11a1de	285	* get_task_cred - Get another task's objective credentials
86a264ab DH	286	* @task: The task to query
86a264ab DH	287	*
3b11a1de DH	288	* Get the objective credentials of a task, pinning them so that they can't go
3b11a1de DH	289	* away. Accessing a task's credentials directly is not permitted.
86a264ab DH	290	*
	291	* The caller must make sure task doesn't go away, either by holding a ref on
	292	* task or by holding tasklist_lock to prevent it from being unlinked.
	293	*/
	294	#define get_task_cred(task) \
	295	({ \
	296	struct cred *__cred; \
	297	rcu_read_lock(); \
	298	__cred = (struct cred *) __task_cred((task)); \
	299	get_cred(__cred); \
	300	rcu_read_unlock(); \
	301	__cred; \
	302	})
	303
	304	/**
3b11a1de	305	* get_current_cred - Get the current task's subjective credentials
86a264ab	306	*
3b11a1de DH	307	* Get the subjective credentials of the current task, pinning them so that
	308	* they can't go away. Accessing the current task's credentials directly is
	309	* not permitted.
86a264ab DH	310	*/
	311	#define get_current_cred() \
	312	(get_cred(current_cred()))
	313
	314	/**
	315	* get_current_user - Get the current task's user_struct
	316	*
	317	* Get the user record of the current task, pinning it so that it can't go
	318	* away.
	319	*/
	320	#define get_current_user() \
	321	({ \
	322	struct user_struct *__u; \
	323	struct cred *__cred; \
	324	__cred = (struct cred *) current_cred(); \
	325	__u = get_uid(__cred->user); \
	326	__u; \
	327	})
	328
	329	/**
	330	* get_current_groups - Get the current task's supplementary group list
	331	*
	332	* Get the supplementary group list of the current task, pinning it so that it
	333	* can't go away.
	334	*/
	335	#define get_current_groups() \
	336	({ \
	337	struct group_info *__groups; \
	338	struct cred *__cred; \
	339	__cred = (struct cred *) current_cred(); \
	340	__groups = get_group_info(__cred->group_info); \
	341	__groups; \
	342	})
	343
d84f4f99 DH	344	#define task_cred_xxx(task, xxx) \
	345	({ \
	346	__typeof__(((struct cred *)NULL)->xxx) ___val; \
	347	rcu_read_lock(); \
	348	___val = __task_cred((task))->xxx; \
	349	rcu_read_unlock(); \
	350	___val; \
86a264ab DH	351	})
	352
	353	#define task_uid(task) (task_cred_xxx((task), uid))
	354	#define task_euid(task) (task_cred_xxx((task), euid))
	355
	356	#define current_cred_xxx(xxx) \
	357	({ \
	358	current->cred->xxx; \
	359	})
	360
	361	#define current_uid() (current_cred_xxx(uid))
	362	#define current_gid() (current_cred_xxx(gid))
	363	#define current_euid() (current_cred_xxx(euid))
	364	#define current_egid() (current_cred_xxx(egid))
	365	#define current_suid() (current_cred_xxx(suid))
	366	#define current_sgid() (current_cred_xxx(sgid))
	367	#define current_fsuid() (current_cred_xxx(fsuid))
	368	#define current_fsgid() (current_cred_xxx(fsgid))
	369	#define current_cap() (current_cred_xxx(cap_effective))
	370	#define current_user() (current_cred_xxx(user))
18b6e041	371	#define current_user_ns() (current_cred_xxx(user)->user_ns)
86a264ab DH	372	#define current_security() (current_cred_xxx(security))
	373
	374	#define current_uid_gid(_uid, _gid) \
	375	do { \
	376	const struct cred *__cred; \
	377	__cred = current_cred(); \
	378	*(_uid) = __cred->uid; \
	379	*(_gid) = __cred->gid; \
	380	} while(0)
	381
	382	#define current_euid_egid(_euid, _egid) \
	383	do { \
	384	const struct cred *__cred; \
	385	__cred = current_cred(); \
	386	*(_euid) = __cred->euid; \
	387	*(_egid) = __cred->egid; \
	388	} while(0)
	389
	390	#define current_fsuid_fsgid(_fsuid, _fsgid) \
	391	do { \
	392	const struct cred *__cred; \
	393	__cred = current_cred(); \
	394	*(_fsuid) = __cred->fsuid; \
	395	*(_fsgid) = __cred->fsgid; \
	396	} while(0)
	397
9e2b2dc4	398	#endif /* _LINUX_CRED_H */