diff options
Diffstat (limited to 'include')
39 files changed, 1231 insertions, 628 deletions
diff --git a/include/crypto/aes.h b/include/crypto/aes.h index 40008d67ee3..656a4c66a56 100644 --- a/include/crypto/aes.h +++ b/include/crypto/aes.h @@ -23,10 +23,10 @@ struct crypto_aes_ctx { u32 key_dec[AES_MAX_KEYLENGTH_U32]; }; -extern u32 crypto_ft_tab[4][256]; -extern u32 crypto_fl_tab[4][256]; -extern u32 crypto_it_tab[4][256]; -extern u32 crypto_il_tab[4][256]; +extern const u32 crypto_ft_tab[4][256]; +extern const u32 crypto_fl_tab[4][256]; +extern const u32 crypto_it_tab[4][256]; +extern const u32 crypto_il_tab[4][256]; int crypto_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, unsigned int key_len); diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h index 60d06e784be..010545436ef 100644 --- a/include/crypto/algapi.h +++ b/include/crypto/algapi.h @@ -22,9 +22,18 @@ struct seq_file; struct crypto_type { unsigned int (*ctxsize)(struct crypto_alg *alg, u32 type, u32 mask); + unsigned int (*extsize)(struct crypto_alg *alg, + const struct crypto_type *frontend); int (*init)(struct crypto_tfm *tfm, u32 type, u32 mask); - void (*exit)(struct crypto_tfm *tfm); + int (*init_tfm)(struct crypto_tfm *tfm, + const struct crypto_type *frontend); void (*show)(struct seq_file *m, struct crypto_alg *alg); + struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask); + + unsigned int type; + unsigned int maskclear; + unsigned int maskset; + unsigned int tfmsize; }; struct crypto_instance { @@ -239,6 +248,11 @@ static inline struct crypto_hash *crypto_spawn_hash(struct crypto_spawn *spawn) return __crypto_hash_cast(crypto_spawn_tfm(spawn, type, mask)); } +static inline void *crypto_hash_ctx(struct crypto_hash *tfm) +{ + return crypto_tfm_ctx(&tfm->base); +} + static inline void *crypto_hash_ctx_aligned(struct crypto_hash *tfm) { return crypto_tfm_ctx_aligned(&tfm->base); diff --git a/include/crypto/hash.h b/include/crypto/hash.h index ee48ef8fb2e..cd16d6e668c 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -15,10 +15,40 @@ #include <linux/crypto.h> +struct shash_desc { + struct crypto_shash *tfm; + u32 flags; + + void *__ctx[] CRYPTO_MINALIGN_ATTR; +}; + +struct shash_alg { + int (*init)(struct shash_desc *desc); + int (*reinit)(struct shash_desc *desc); + int (*update)(struct shash_desc *desc, const u8 *data, + unsigned int len); + int (*final)(struct shash_desc *desc, u8 *out); + int (*finup)(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out); + int (*digest)(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out); + int (*setkey)(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen); + + unsigned int descsize; + unsigned int digestsize; + + struct crypto_alg base; +}; + struct crypto_ahash { struct crypto_tfm base; }; +struct crypto_shash { + struct crypto_tfm base; +}; + static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm) { return (struct crypto_ahash *)tfm; @@ -87,6 +117,11 @@ static inline unsigned int crypto_ahash_reqsize(struct crypto_ahash *tfm) return crypto_ahash_crt(tfm)->reqsize; } +static inline void *ahash_request_ctx(struct ahash_request *req) +{ + return req->__ctx; +} + static inline int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key, unsigned int keylen) { @@ -101,6 +136,14 @@ static inline int crypto_ahash_digest(struct ahash_request *req) return crt->digest(req); } +static inline void crypto_ahash_export(struct ahash_request *req, u8 *out) +{ + memcpy(out, ahash_request_ctx(req), + crypto_ahash_reqsize(crypto_ahash_reqtfm(req))); +} + +int crypto_ahash_import(struct ahash_request *req, const u8 *in); + static inline int crypto_ahash_init(struct ahash_request *req) { struct ahash_tfm *crt = crypto_ahash_crt(crypto_ahash_reqtfm(req)); @@ -169,4 +212,86 @@ static inline void ahash_request_set_crypt(struct ahash_request *req, req->result = result; } +struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type, + u32 mask); + +static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm) +{ + return &tfm->base; +} + +static inline void crypto_free_shash(struct crypto_shash *tfm) +{ + crypto_free_tfm(crypto_shash_tfm(tfm)); +} + +static inline unsigned int crypto_shash_alignmask( + struct crypto_shash *tfm) +{ + return crypto_tfm_alg_alignmask(crypto_shash_tfm(tfm)); +} + +static inline struct shash_alg *__crypto_shash_alg(struct crypto_alg *alg) +{ + return container_of(alg, struct shash_alg, base); +} + +static inline struct shash_alg *crypto_shash_alg(struct crypto_shash *tfm) +{ + return __crypto_shash_alg(crypto_shash_tfm(tfm)->__crt_alg); +} + +static inline unsigned int crypto_shash_digestsize(struct crypto_shash *tfm) +{ + return crypto_shash_alg(tfm)->digestsize; +} + +static inline u32 crypto_shash_get_flags(struct crypto_shash *tfm) +{ + return crypto_tfm_get_flags(crypto_shash_tfm(tfm)); +} + +static inline void crypto_shash_set_flags(struct crypto_shash *tfm, u32 flags) +{ + crypto_tfm_set_flags(crypto_shash_tfm(tfm), flags); +} + +static inline void crypto_shash_clear_flags(struct crypto_shash *tfm, u32 flags) +{ + crypto_tfm_clear_flags(crypto_shash_tfm(tfm), flags); +} + +static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm) +{ + return crypto_shash_alg(tfm)->descsize; +} + +static inline void *shash_desc_ctx(struct shash_desc *desc) +{ + return desc->__ctx; +} + +int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key, + unsigned int keylen); +int crypto_shash_digest(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out); + +static inline void crypto_shash_export(struct shash_desc *desc, u8 *out) +{ + memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm)); +} + +int crypto_shash_import(struct shash_desc *desc, const u8 *in); + +static inline int crypto_shash_init(struct shash_desc *desc) +{ + return crypto_shash_alg(desc->tfm)->init(desc); +} + +int crypto_shash_update(struct shash_desc *desc, const u8 *data, + unsigned int len); +int crypto_shash_final(struct shash_desc *desc, u8 *out); +int crypto_shash_finup(struct shash_desc *desc, const u8 *data, + unsigned int len, u8 *out); + #endif /* _CRYPTO_HASH_H */ diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h index 917ae57bad4..82b70564bca 100644 --- a/include/crypto/internal/hash.h +++ b/include/crypto/internal/hash.h @@ -39,6 +39,12 @@ extern const struct crypto_type crypto_ahash_type; int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err); int crypto_hash_walk_first(struct ahash_request *req, struct crypto_hash_walk *walk); +int crypto_hash_walk_first_compat(struct hash_desc *hdesc, + struct crypto_hash_walk *walk, + struct scatterlist *sg, unsigned int len); + +int crypto_register_shash(struct shash_alg *alg); +int crypto_unregister_shash(struct shash_alg *alg); static inline void *crypto_ahash_ctx(struct crypto_ahash *tfm) { @@ -63,16 +69,16 @@ static inline struct ahash_request *ahash_dequeue_request( return ahash_request_cast(crypto_dequeue_request(queue)); } -static inline void *ahash_request_ctx(struct ahash_request *req) -{ - return req->__ctx; -} - static inline int ahash_tfm_in_queue(struct crypto_queue *queue, struct crypto_ahash *tfm) { return crypto_tfm_in_queue(queue, crypto_ahash_tfm(tfm)); } +static inline void *crypto_shash_ctx(struct crypto_shash *tfm) +{ + return crypto_tfm_ctx(&tfm->base); +} + #endif /* _CRYPTO_INTERNAL_HASH_H */ diff --git a/include/keys/keyring-type.h b/include/keys/keyring-type.h new file mode 100644 index 00000000000..843f872a4b6 --- /dev/null +++ b/include/keys/keyring-type.h @@ -0,0 +1,31 @@ +/* Keyring key type + * + * 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 License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _KEYS_KEYRING_TYPE_H +#define _KEYS_KEYRING_TYPE_H + +#include <linux/key.h> +#include <linux/rcupdate.h> + +/* + * the keyring payload contains a list of the keys to which the keyring is + * subscribed + */ +struct keyring_list { + struct rcu_head rcu; /* RCU deletion hook */ + unsigned short maxkeys; /* max keys this list can hold */ + unsigned short nkeys; /* number of keys currently held */ + unsigned short delkey; /* key to be unlinked by RCU */ + struct key *keys[0]; +}; + + +#endif /* _KEYS_KEYRING_TYPE_H */ diff --git a/include/linux/audit.h b/include/linux/audit.h index 8f0672d13eb..26c4f6f65a4 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -99,6 +99,8 @@ #define AUDIT_OBJ_PID 1318 /* ptrace target */ #define AUDIT_TTY 1319 /* Input on an administrative TTY */ #define AUDIT_EOE 1320 /* End of multi-record event */ +#define AUDIT_BPRM_FCAPS 1321 /* Information about fcaps increasing perms */ +#define AUDIT_CAPSET 1322 /* Record showing argument to sys_capset */ #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */ #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */ @@ -453,6 +455,10 @@ extern int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_pr extern int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __user *u_msg_prio, const struct timespec __user *u_abs_timeout); extern int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification); extern int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat); +extern int __audit_log_bprm_fcaps(struct linux_binprm *bprm, + const struct cred *new, + const struct cred *old); +extern int __audit_log_capset(pid_t pid, const struct cred *new, const struct cred *old); static inline int audit_ipc_obj(struct kern_ipc_perm *ipcp) { @@ -502,6 +508,24 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) return __audit_mq_getsetattr(mqdes, mqstat); return 0; } + +static inline int audit_log_bprm_fcaps(struct linux_binprm *bprm, + const struct cred *new, + const struct cred *old) +{ + if (unlikely(!audit_dummy_context())) + return __audit_log_bprm_fcaps(bprm, new, old); + return 0; +} + +static inline int audit_log_capset(pid_t pid, const struct cred *new, + const struct cred *old) +{ + if (unlikely(!audit_dummy_context())) + return __audit_log_capset(pid, new, old); + return 0; +} + extern int audit_n_rules; extern int audit_signals; #else @@ -534,6 +558,8 @@ extern int audit_signals; #define audit_mq_timedreceive(d,l,p,t) ({ 0; }) #define audit_mq_notify(d,n) ({ 0; }) #define audit_mq_getsetattr(d,s) ({ 0; }) +#define audit_log_bprm_fcaps(b, ncr, ocr) ({ 0; }) +#define audit_log_capset(pid, ncr, ocr) ({ 0; }) #define audit_ptrace(t) ((void)0) #define audit_n_rules 0 #define audit_signals 0 diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 7394b5b349f..6cbfbe29718 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -35,16 +35,20 @@ struct linux_binprm{ struct mm_struct *mm; unsigned long p; /* current top of mem */ unsigned int sh_bang:1, - misc_bang:1; + misc_bang:1, + cred_prepared:1,/* true if creds already prepared (multiple + * preps happen for interpreters) */ + cap_effective:1;/* true if has elevated effective capabilities, + * false if not; except for init which inherits + * its parent's caps anyway */ #ifdef __alpha__ unsigned int taso:1; #endif unsigned int recursion_depth; struct file * file; - int e_uid, e_gid; - kernel_cap_t cap_post_exec_permitted; - bool cap_effective; - void *security; + struct cred *cred; /* new credentials */ + int unsafe; /* how unsafe this exec is (mask of LSM_UNSAFE_*) */ + unsigned int per_clear; /* bits to clear in current->personality */ int argc, envc; char * filename; /* Name of binary as seen by procps */ char * interp; /* Name of the binary really executed. Most @@ -101,7 +105,7 @@ extern int setup_arg_pages(struct linux_binprm * bprm, int executable_stack); extern int bprm_mm_init(struct linux_binprm *bprm); extern int copy_strings_kernel(int argc,char ** argv,struct linux_binprm *bprm); -extern void compute_creds(struct linux_binprm *binprm); +extern void install_exec_creds(struct linux_binprm *bprm); extern int do_coredump(long signr, int exit_code, struct pt_regs * regs); extern int set_binfmt(struct linux_binfmt *new); extern void free_bprm(struct linux_binprm *); diff --git a/include/linux/capability.h b/include/linux/capability.h index 9d1fe30b6f6..e22f48c2a46 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -53,6 +53,7 @@ typedef struct __user_cap_data_struct { #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX #define VFS_CAP_REVISION_MASK 0xFF000000 +#define VFS_CAP_REVISION_SHIFT 24 #define VFS_CAP_FLAGS_MASK ~VFS_CAP_REVISION_MASK #define VFS_CAP_FLAGS_EFFECTIVE 0x000001 @@ -68,6 +69,9 @@ typedef struct __user_cap_data_struct { #define VFS_CAP_U32 VFS_CAP_U32_2 #define VFS_CAP_REVISION VFS_CAP_REVISION_2 +#ifdef CONFIG_SECURITY_FILE_CAPABILITIES +extern int file_caps_enabled; +#endif struct vfs_cap_data { __le32 magic_etc; /* Little endian */ @@ -96,6 +100,13 @@ typedef struct kernel_cap_struct { __u32 cap[_KERNEL_CAPABILITY_U32S]; } kernel_cap_t; +/* exact same as vfs_cap_data but in cpu endian and always filled completely */ +struct cpu_vfs_cap_data { + __u32 magic_etc; + kernel_cap_t permitted; + kernel_cap_t inheritable; +}; + #define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct)) #define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t)) @@ -454,6 +465,13 @@ static inline int cap_isclear(const kernel_cap_t a) return 1; } +/* + * Check if "a" is a subset of "set". + * return 1 if ALL of the capabilities in "a" are also in "set" + * cap_issubset(0101, 1111) will return 1 + * return 0 if ANY of the capabilities in "a" are not in "set" + * cap_issubset(1111, 0101) will return 0 + */ static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set) { kernel_cap_t dest; @@ -501,8 +519,6 @@ extern const kernel_cap_t __cap_empty_set; extern const kernel_cap_t __cap_full_set; extern const kernel_cap_t __cap_init_eff_set; -kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); - /** * has_capability - Determine if a task has a superior capability available * @t: The task in question @@ -514,9 +530,14 @@ kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); * Note that this does not set PF_SUPERPRIV on the task. */ #define has_capability(t, cap) (security_capable((t), (cap)) == 0) +#define has_capability_noaudit(t, cap) (security_capable_noaudit((t), (cap)) == 0) extern int capable(int cap); +/* audit system wants to get cap info from files as well */ +struct dentry; +extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); + #endif /* __KERNEL__ */ #endif /* !_LINUX_CAPABILITY_H */ diff --git a/include/linux/crc32c.h b/include/linux/crc32c.h index 508f512e5a2..bd8b44d96bd 100644 --- a/include/linux/crc32c.h +++ b/include/linux/crc32c.h @@ -3,9 +3,9 @@ #include <linux/types.h> -extern u32 crc32c_le(u32 crc, unsigned char const *address, size_t length); -extern u32 crc32c_be(u32 crc, unsigned char const *address, size_t length); +extern u32 crc32c(u32 crc, const void *address, unsigned int length); -#define crc32c(seed, data, length) crc32c_le(seed, (unsigned char const *)data, length) +/* This macro exists for backwards-compatibility. */ +#define crc32c_le crc32c #endif /* _LINUX_CRC32C_H */ diff --git a/include/linux/cred.h b/include/linux/cred.h index b69222cc1fd..3282ee4318e 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -1,4 +1,4 @@ -/* Credentials management +/* Credentials management - see Documentation/credentials.txt * * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -12,39 +12,335 @@ #ifndef _LINUX_CRED_H #define _LINUX_CRED_H -#define get_current_user() (get_uid(current->user)) +#include <linux/capability.h> +#include <linux/key.h> +#include <asm/atomic.h> -#define task_uid(task) ((task)->uid) -#define task_gid(task) ((task)->gid) -#define task_euid(task) ((task)->euid) -#define task_egid(task) ((task)->egid) +struct user_struct; +struct cred; +struct inode; -#define current_uid() (current->uid) -#define current_gid() (current->gid) -#define current_euid() (current->euid) -#define current_egid() (current->egid) -#define current_suid() (current->suid) -#define current_sgid() (current->sgid) -#define current_fsuid() (current->fsuid) -#define current_fsgid() (current->fsgid) -#define current_cap() (current->cap_effective) +/* + * 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; + 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 int copy_creds(struct task_struct *, unsigned long); +extern struct cred *prepare_creds(void); +extern struct cred *prepare_exec_creds(void); +extern struct cred *prepare_usermodehelper_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); + +/** + * 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) +{ + return get_new_cred((struct cred *) 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; + + BUG_ON(atomic_read(&(cred)->usage) <= 0); + 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((task)->real_cred))) + +/** + * 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. |