Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/ipc/util.h |
| 3 | * Copyright (C) 1999 Christoph Rohland |
| 4 | * |
Christian Kujau | 624dffc | 2006-01-15 02:43:54 +0100 | [diff] [blame] | 5 | * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
Kirill Korotaev | 73ea413 | 2006-10-02 02:18:20 -0700 | [diff] [blame] | 6 | * namespaces support. 2006 OpenVZ, SWsoft Inc. |
| 7 | * Pavel Emelianov <xemul@openvz.org> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #ifndef _IPC_UTIL_H |
| 11 | #define _IPC_UTIL_H |
| 12 | |
Johannes Weiner | 232086b | 2009-06-20 02:23:29 +0200 | [diff] [blame] | 13 | #include <linux/unistd.h> |
Nadia Derbey | 023a535 | 2007-10-18 23:40:51 -0700 | [diff] [blame] | 14 | #include <linux/err.h> |
Nadia Derbey | 7ca7e56 | 2007-10-18 23:40:48 -0700 | [diff] [blame] | 15 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #define SEQ_MULTIPLIER (IPCMNI) |
| 17 | |
Manfred Spraul | 239521f | 2014-01-27 17:07:04 -0800 | [diff] [blame] | 18 | void sem_init(void); |
| 19 | void msg_init(void); |
| 20 | void shm_init(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Pavel Emelyanov | ae5e1b2 | 2008-02-08 04:18:22 -0800 | [diff] [blame] | 22 | struct ipc_namespace; |
| 23 | |
Serge E. Hallyn | 614b84c | 2009-04-06 19:01:08 -0700 | [diff] [blame] | 24 | #ifdef CONFIG_POSIX_MQUEUE |
Serge E. Hallyn | 7eafd7c | 2009-04-06 19:01:10 -0700 | [diff] [blame] | 25 | extern void mq_clear_sbinfo(struct ipc_namespace *ns); |
| 26 | extern void mq_put_mnt(struct ipc_namespace *ns); |
Serge E. Hallyn | 614b84c | 2009-04-06 19:01:08 -0700 | [diff] [blame] | 27 | #else |
Serge E. Hallyn | 7eafd7c | 2009-04-06 19:01:10 -0700 | [diff] [blame] | 28 | static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { } |
| 29 | static inline void mq_put_mnt(struct ipc_namespace *ns) { } |
Serge E. Hallyn | 614b84c | 2009-04-06 19:01:08 -0700 | [diff] [blame] | 30 | #endif |
| 31 | |
| 32 | #ifdef CONFIG_SYSVIPC |
Pierre Peiffer | ed2ddbf | 2008-02-08 04:18:57 -0800 | [diff] [blame] | 33 | void sem_init_ns(struct ipc_namespace *ns); |
| 34 | void msg_init_ns(struct ipc_namespace *ns); |
| 35 | void shm_init_ns(struct ipc_namespace *ns); |
Kirill Korotaev | 73ea413 | 2006-10-02 02:18:20 -0700 | [diff] [blame] | 36 | |
| 37 | void sem_exit_ns(struct ipc_namespace *ns); |
| 38 | void msg_exit_ns(struct ipc_namespace *ns); |
| 39 | void shm_exit_ns(struct ipc_namespace *ns); |
Serge E. Hallyn | 614b84c | 2009-04-06 19:01:08 -0700 | [diff] [blame] | 40 | #else |
| 41 | static inline void sem_init_ns(struct ipc_namespace *ns) { } |
| 42 | static inline void msg_init_ns(struct ipc_namespace *ns) { } |
| 43 | static inline void shm_init_ns(struct ipc_namespace *ns) { } |
| 44 | |
| 45 | static inline void sem_exit_ns(struct ipc_namespace *ns) { } |
| 46 | static inline void msg_exit_ns(struct ipc_namespace *ns) { } |
| 47 | static inline void shm_exit_ns(struct ipc_namespace *ns) { } |
| 48 | #endif |
Kirill Korotaev | 73ea413 | 2006-10-02 02:18:20 -0700 | [diff] [blame] | 49 | |
Davidlohr Bueso | 53dad6d | 2013-09-23 17:04:45 -0700 | [diff] [blame] | 50 | struct ipc_rcu { |
| 51 | struct rcu_head rcu; |
| 52 | atomic_t refcount; |
| 53 | } ____cacheline_aligned_in_smp; |
| 54 | |
| 55 | #define ipc_rcu_to_struct(p) ((void *)(p+1)) |
| 56 | |
Nadia Derbey | 7748dbf | 2007-10-18 23:40:49 -0700 | [diff] [blame] | 57 | /* |
| 58 | * Structure that holds the parameters needed by the ipc operations |
| 59 | * (see after) |
| 60 | */ |
| 61 | struct ipc_params { |
| 62 | key_t key; |
| 63 | int flg; |
| 64 | union { |
| 65 | size_t size; /* for shared memories */ |
| 66 | int nsems; /* for semaphores */ |
| 67 | } u; /* holds the getnew() specific param */ |
| 68 | }; |
| 69 | |
| 70 | /* |
| 71 | * Structure that holds some ipc operations. This structure is used to unify |
| 72 | * the calls to sys_msgget(), sys_semget(), sys_shmget() |
| 73 | * . routine to call to create a new ipc object. Can be one of newque, |
| 74 | * newary, newseg |
Nadia Derbey | f4566f0 | 2007-10-18 23:40:53 -0700 | [diff] [blame] | 75 | * . routine to call to check permissions for a new ipc object. |
Nadia Derbey | 7748dbf | 2007-10-18 23:40:49 -0700 | [diff] [blame] | 76 | * Can be one of security_msg_associate, security_sem_associate, |
| 77 | * security_shm_associate |
| 78 | * . routine to call for an extra check if needed |
| 79 | */ |
| 80 | struct ipc_ops { |
Paul McQuade | 46c0a8c | 2014-06-06 14:37:37 -0700 | [diff] [blame] | 81 | int (*getnew)(struct ipc_namespace *, struct ipc_params *); |
| 82 | int (*associate)(struct kern_ipc_perm *, int); |
| 83 | int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *); |
Nadia Derbey | 7748dbf | 2007-10-18 23:40:49 -0700 | [diff] [blame] | 84 | }; |
| 85 | |
Mike Waychison | ae78177 | 2005-09-06 15:17:09 -0700 | [diff] [blame] | 86 | struct seq_file; |
Pierre Peiffer | ed2ddbf | 2008-02-08 04:18:57 -0800 | [diff] [blame] | 87 | struct ipc_ids; |
Cedric Le Goater | 7d69a1f | 2007-07-15 23:40:58 -0700 | [diff] [blame] | 88 | |
Nadia Derbey | 7ca7e56 | 2007-10-18 23:40:48 -0700 | [diff] [blame] | 89 | void ipc_init_ids(struct ipc_ids *); |
Mike Waychison | ae78177 | 2005-09-06 15:17:09 -0700 | [diff] [blame] | 90 | #ifdef CONFIG_PROC_FS |
| 91 | void __init ipc_init_proc_interface(const char *path, const char *header, |
Kirill Korotaev | 73ea413 | 2006-10-02 02:18:20 -0700 | [diff] [blame] | 92 | int ids, int (*show)(struct seq_file *, void *)); |
Mike Waychison | ae78177 | 2005-09-06 15:17:09 -0700 | [diff] [blame] | 93 | #else |
| 94 | #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) |
| 95 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | |
Kirill Korotaev | 73ea413 | 2006-10-02 02:18:20 -0700 | [diff] [blame] | 97 | #define IPC_SEM_IDS 0 |
| 98 | #define IPC_MSG_IDS 1 |
| 99 | #define IPC_SHM_IDS 2 |
| 100 | |
Nadia Derbey | ce621f5 | 2007-10-18 23:40:52 -0700 | [diff] [blame] | 101 | #define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER) |
Stanislav Kinsbursky | 03f5956 | 2013-01-04 15:34:50 -0800 | [diff] [blame] | 102 | #define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER) |
Davidlohr Bueso | daf948c | 2014-01-27 17:07:09 -0800 | [diff] [blame] | 103 | #define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX) |
Nadia Derbey | ce621f5 | 2007-10-18 23:40:52 -0700 | [diff] [blame] | 104 | |
Davidlohr Bueso | d9a605e | 2013-09-11 14:26:24 -0700 | [diff] [blame] | 105 | /* must be called with ids->rwsem acquired for writing */ |
Nadia Derbey | 7ca7e56 | 2007-10-18 23:40:48 -0700 | [diff] [blame] | 106 | int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int); |
Nadia Derbey | 3e148c7 | 2007-10-18 23:40:54 -0700 | [diff] [blame] | 107 | |
Davidlohr Bueso | d9a605e | 2013-09-11 14:26:24 -0700 | [diff] [blame] | 108 | /* must be called with ids->rwsem acquired for reading */ |
Nadia Derbey | 7ca7e56 | 2007-10-18 23:40:48 -0700 | [diff] [blame] | 109 | int ipc_get_maxid(struct ipc_ids *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | |
| 111 | /* must be called with both locks acquired. */ |
Nadia Derbey | 7ca7e56 | 2007-10-18 23:40:48 -0700 | [diff] [blame] | 112 | void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | |
Nadia Derbey | f4566f0 | 2007-10-18 23:40:53 -0700 | [diff] [blame] | 114 | /* must be called with ipcp locked */ |
Serge E. Hallyn | b0e7759 | 2011-03-23 16:43:24 -0700 | [diff] [blame] | 115 | int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
| 117 | /* for rare, potentially huge allocations. |
| 118 | * both function can sleep |
| 119 | */ |
Manfred Spraul | 239521f | 2014-01-27 17:07:04 -0800 | [diff] [blame] | 120 | void *ipc_alloc(int size); |
Tetsuo Handa | 1d5cfdb | 2016-01-22 15:11:02 -0800 | [diff] [blame] | 121 | void ipc_free(void *ptr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
| 123 | /* |
| 124 | * For allocation that need to be freed by RCU. |
| 125 | * Objects are reference counted, they start with reference count 1. |
| 126 | * getref increases the refcount, the putref call that reduces the recount |
| 127 | * to 0 schedules the rcu destruction. Caller must guarantee locking. |
| 128 | */ |
Manfred Spraul | 239521f | 2014-01-27 17:07:04 -0800 | [diff] [blame] | 129 | void *ipc_rcu_alloc(int size); |
Rik van Riel | 6062a8d | 2013-04-30 19:15:44 -0700 | [diff] [blame] | 130 | int ipc_rcu_getref(void *ptr); |
Davidlohr Bueso | 53dad6d | 2013-09-23 17:04:45 -0700 | [diff] [blame] | 131 | void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head)); |
| 132 | void ipc_rcu_free(struct rcu_head *head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Nadia Derbey | 023a535 | 2007-10-18 23:40:51 -0700 | [diff] [blame] | 134 | struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int); |
Davidlohr Bueso | 55b7ae5 | 2015-06-30 14:58:42 -0700 | [diff] [blame] | 135 | struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | |
| 137 | void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); |
| 138 | void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); |
Eric W. Biederman | 1efdb69 | 2012-02-07 16:54:11 -0800 | [diff] [blame] | 139 | int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); |
Davidlohr Bueso | 444d0f6 | 2013-04-30 19:15:24 -0700 | [diff] [blame] | 140 | struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, |
| 141 | struct ipc_ids *ids, int id, int cmd, |
| 142 | struct ipc64_perm *perm, int extra_perm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
Will Deacon | c1d7e01 | 2012-07-30 14:42:46 -0700 | [diff] [blame] | 144 | #ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
Paul McQuade | 46c0a8c | 2014-06-06 14:37:37 -0700 | [diff] [blame] | 145 | /* On IA-64, we always use the "64-bit version" of the IPC structures. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | # define ipc_parse_version(cmd) IPC_64 |
| 147 | #else |
Manfred Spraul | 239521f | 2014-01-27 17:07:04 -0800 | [diff] [blame] | 148 | int ipc_parse_version(int *cmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | #endif |
| 150 | |
| 151 | extern void free_msg(struct msg_msg *msg); |
Mathias Krause | 4e9b45a | 2013-11-12 15:11:47 -0800 | [diff] [blame] | 152 | extern struct msg_msg *load_msg(const void __user *src, size_t len); |
Stanislav Kinsbursky | 4a674f3 | 2013-01-04 15:34:55 -0800 | [diff] [blame] | 153 | extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst); |
Mathias Krause | 4e9b45a | 2013-11-12 15:11:47 -0800 | [diff] [blame] | 154 | extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len); |
Nadia Derbey | 7748dbf | 2007-10-18 23:40:49 -0700 | [diff] [blame] | 155 | |
Nadia Derbey | b6b337a | 2008-04-29 01:00:42 -0700 | [diff] [blame] | 156 | extern void recompute_msgmni(struct ipc_namespace *); |
| 157 | |
Nadia Derbey | 1b531f2 | 2007-10-18 23:40:55 -0700 | [diff] [blame] | 158 | static inline int ipc_buildid(int id, int seq) |
Nadia Derbey | 2802831 | 2007-10-18 23:40:52 -0700 | [diff] [blame] | 159 | { |
| 160 | return SEQ_MULTIPLIER * seq + id; |
| 161 | } |
| 162 | |
Nadia Derbey | 1b531f2 | 2007-10-18 23:40:55 -0700 | [diff] [blame] | 163 | static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int uid) |
Nadia Derbey | 023a535 | 2007-10-18 23:40:51 -0700 | [diff] [blame] | 164 | { |
Davidlohr Bueso | 7bb4def | 2013-04-30 19:15:14 -0700 | [diff] [blame] | 165 | return uid / SEQ_MULTIPLIER != ipcp->seq; |
Nadia Derbey | 023a535 | 2007-10-18 23:40:51 -0700 | [diff] [blame] | 166 | } |
| 167 | |
Davidlohr Bueso | 1ca7003 | 2013-07-08 16:01:10 -0700 | [diff] [blame] | 168 | static inline void ipc_lock_object(struct kern_ipc_perm *perm) |
| 169 | { |
| 170 | spin_lock(&perm->lock); |
| 171 | } |
| 172 | |
| 173 | static inline void ipc_unlock_object(struct kern_ipc_perm *perm) |
| 174 | { |
| 175 | spin_unlock(&perm->lock); |
| 176 | } |
| 177 | |
| 178 | static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm) |
| 179 | { |
| 180 | assert_spin_locked(&perm->lock); |
| 181 | } |
| 182 | |
Nadia Derbey | 023a535 | 2007-10-18 23:40:51 -0700 | [diff] [blame] | 183 | static inline void ipc_unlock(struct kern_ipc_perm *perm) |
| 184 | { |
Davidlohr Bueso | cf9d5d7 | 2013-07-08 16:01:11 -0700 | [diff] [blame] | 185 | ipc_unlock_object(perm); |
Nadia Derbey | 023a535 | 2007-10-18 23:40:51 -0700 | [diff] [blame] | 186 | rcu_read_unlock(); |
| 187 | } |
| 188 | |
Rafael Aquini | 0f3d2b0 | 2014-01-27 17:07:01 -0800 | [diff] [blame] | 189 | /* |
| 190 | * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths |
| 191 | * where the respective ipc_ids.rwsem is not being held down. |
| 192 | * Checks whether the ipc object is still around or if it's gone already, as |
| 193 | * ipc_rmid() may have already freed the ID while the ipc lock was spinning. |
| 194 | * Needs to be called with kern_ipc_perm.lock held -- exception made for one |
| 195 | * checkpoint case at sys_semtimedop() as noted in code commentary. |
| 196 | */ |
| 197 | static inline bool ipc_valid_object(struct kern_ipc_perm *perm) |
| 198 | { |
Rafael Aquini | 72a8ff2 | 2014-01-27 17:07:02 -0800 | [diff] [blame] | 199 | return !perm->deleted; |
Rafael Aquini | 0f3d2b0 | 2014-01-27 17:07:01 -0800 | [diff] [blame] | 200 | } |
| 201 | |
Davidlohr Bueso | 4d2bff5 | 2013-04-30 19:15:19 -0700 | [diff] [blame] | 202 | struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id); |
Pavel Emelyanov | b2d75cd | 2008-02-08 04:18:54 -0800 | [diff] [blame] | 203 | int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, |
Mathias Krause | eb66ec4 | 2014-06-06 14:37:36 -0700 | [diff] [blame] | 204 | const struct ipc_ops *ops, struct ipc_params *params); |
Alexey Dobriyan | 665c774 | 2009-06-17 16:27:57 -0700 | [diff] [blame] | 205 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, |
| 206 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | #endif |