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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293/* SPDX-License-Identifier: GPL-2.0 *//* * linux/ipc/util.h * Copyright (C) 1999 Christoph Rohland * * ipc helper functions (c) 1999 Manfred Spraul <manfred@colorfullife.com> * namespaces support. 2006 OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> */
#ifndef _IPC_UTIL_H#define _IPC_UTIL_H
#include <linux/unistd.h>#include <linux/err.h>#include <linux/ipc_namespace.h>#include <linux/pid.h>
/* * The IPC ID contains 2 separate numbers - index and sequence number. * By default, * bits 0-14: index (32k, 15 bits) * bits 15-30: sequence number (64k, 16 bits) * * When IPCMNI extension mode is turned on, the composition changes: * bits 0-23: index (16M, 24 bits) * bits 24-30: sequence number (128, 7 bits) */#define IPCMNI_SHIFT 15#define IPCMNI_EXTEND_SHIFT 24#define IPCMNI_EXTEND_MIN_CYCLE (RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE)#define IPCMNI (1 << IPCMNI_SHIFT)#define IPCMNI_EXTEND (1 << IPCMNI_EXTEND_SHIFT)
#ifdef CONFIG_SYSVIPC_SYSCTLextern int ipc_mni;extern int ipc_mni_shift;extern int ipc_min_cycle;
#define ipcmni_seq_shift() ipc_mni_shift#define IPCMNI_IDX_MASK ((1 << ipc_mni_shift) - 1)
#else /* CONFIG_SYSVIPC_SYSCTL */
#define ipc_mni IPCMNI#define ipc_min_cycle ((int)RADIX_TREE_MAP_SIZE)#define ipcmni_seq_shift() IPCMNI_SHIFT#define IPCMNI_IDX_MASK ((1 << IPCMNI_SHIFT) - 1)#endif /* CONFIG_SYSVIPC_SYSCTL */
void sem_init(void);void msg_init(void);void shm_init(void);
struct ipc_namespace;struct pid_namespace;
#ifdef CONFIG_POSIX_MQUEUEextern void mq_clear_sbinfo(struct ipc_namespace *ns);#elsestatic inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }#endif
#ifdef CONFIG_SYSVIPCvoid sem_init_ns(struct ipc_namespace *ns);int msg_init_ns(struct ipc_namespace *ns);void shm_init_ns(struct ipc_namespace *ns);
void sem_exit_ns(struct ipc_namespace *ns);void msg_exit_ns(struct ipc_namespace *ns);void shm_exit_ns(struct ipc_namespace *ns);#elsestatic inline void sem_init_ns(struct ipc_namespace *ns) { }static inline int msg_init_ns(struct ipc_namespace *ns) { return 0; }static inline void shm_init_ns(struct ipc_namespace *ns) { }
static inline void sem_exit_ns(struct ipc_namespace *ns) { }static inline void msg_exit_ns(struct ipc_namespace *ns) { }static inline void shm_exit_ns(struct ipc_namespace *ns) { }#endif
/* * Structure that holds the parameters needed by the ipc operations * (see after) */struct ipc_params { key_t key; int flg; union { size_t size; /* for shared memories */ int nsems; /* for semaphores */ } u; /* holds the getnew() specific param */};
/* * Structure that holds some ipc operations. This structure is used to unify * the calls to sys_msgget(), sys_semget(), sys_shmget() * . routine to call to create a new ipc object. Can be one of newque, * newary, newseg * . routine to call to check permissions for a new ipc object. * Can be one of security_msg_associate, security_sem_associate, * security_shm_associate * . routine to call for an extra check if needed */struct ipc_ops { int (*getnew)(struct ipc_namespace *, struct ipc_params *); int (*associate)(struct kern_ipc_perm *, int); int (*more_checks)(struct kern_ipc_perm *, struct ipc_params *);};
struct seq_file;struct ipc_ids;
void ipc_init_ids(struct ipc_ids *ids);#ifdef CONFIG_PROC_FSvoid __init ipc_init_proc_interface(const char *path, const char *header, int ids, int (*show)(struct seq_file *, void *));struct pid_namespace *ipc_seq_pid_ns(struct seq_file *);#else#define ipc_init_proc_interface(path, header, ids, show) do {} while (0)#endif
#define IPC_SEM_IDS 0#define IPC_MSG_IDS 1#define IPC_SHM_IDS 2
#define ipcid_to_idx(id) ((id) & IPCMNI_IDX_MASK)#define ipcid_to_seqx(id) ((id) >> ipcmni_seq_shift())#define ipcid_seq_max() (INT_MAX >> ipcmni_seq_shift())
/* must be called with ids->rwsem acquired for writing */int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
/* must be called with both locks acquired. */void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
/* must be called with both locks acquired. */void ipc_set_key_private(struct ipc_ids *, struct kern_ipc_perm *);
/* must be called with ipcp locked */int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
/** * ipc_get_maxidx - get the highest assigned index * @ids: ipc identifier set * * The function returns the highest assigned index for @ids. The function * doesn't scan the idr tree, it uses a cached value. * * Called with ipc_ids.rwsem held for reading. */static inline int ipc_get_maxidx(struct ipc_ids *ids){ if (ids->in_use == 0) return -1;
if (ids->in_use == ipc_mni) return ipc_mni - 1;
return ids->max_idx;}
/* * For allocation that need to be freed by RCU. * Objects are reference counted, they start with reference count 1. * getref increases the refcount, the putref call that reduces the recount * to 0 schedules the rcu destruction. Caller must guarantee locking. * * refcount is initialized by ipc_addid(), before that point call_rcu() * must be used. */bool ipc_rcu_getref(struct kern_ipc_perm *ptr);void ipc_rcu_putref(struct kern_ipc_perm *ptr, void (*func)(struct rcu_head *head));
struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns, struct ipc_ids *ids, int id, int cmd, struct ipc64_perm *perm, int extra_perm);
static inline void ipc_update_pid(struct pid **pos, struct pid *pid){ struct pid *old = *pos; if (old != pid) { *pos = get_pid(pid); put_pid(old); }}
#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSIONint ipc_parse_version(int *cmd);#endif
extern void free_msg(struct msg_msg *msg);extern struct msg_msg *load_msg(const void __user *src, size_t len);extern struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst);extern int store_msg(void __user *dest, struct msg_msg *msg, size_t len);
static inline int ipc_checkid(struct kern_ipc_perm *ipcp, int id){ return ipcid_to_seqx(id) != ipcp->seq;}
static inline void ipc_lock_object(struct kern_ipc_perm *perm){ spin_lock(&perm->lock);}
static inline void ipc_unlock_object(struct kern_ipc_perm *perm){ spin_unlock(&perm->lock);}
static inline void ipc_assert_locked_object(struct kern_ipc_perm *perm){ assert_spin_locked(&perm->lock);}
static inline void ipc_unlock(struct kern_ipc_perm *perm){ ipc_unlock_object(perm); rcu_read_unlock();}
/* * ipc_valid_object() - helper to sort out IPC_RMID races for codepaths * where the respective ipc_ids.rwsem is not being held down. * Checks whether the ipc object is still around or if it's gone already, as * ipc_rmid() may have already freed the ID while the ipc lock was spinning. * Needs to be called with kern_ipc_perm.lock held -- exception made for one * checkpoint case at sys_semtimedop() as noted in code commentary. */static inline bool ipc_valid_object(struct kern_ipc_perm *perm){ return !perm->deleted;}
struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id);int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids, const struct ipc_ops *ops, struct ipc_params *params);void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
static inline int sem_check_semmni(struct ipc_namespace *ns) { /* * Check semmni range [0, ipc_mni] * semmni is the last element of sem_ctls[4] array */ return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > ipc_mni)) ? -ERANGE : 0;}
#ifdef CONFIG_COMPAT#include <linux/compat.h>struct compat_ipc_perm { key_t key; __compat_uid_t uid; __compat_gid_t gid; __compat_uid_t cuid; __compat_gid_t cgid; compat_mode_t mode; unsigned short seq;};
void to_compat_ipc_perm(struct compat_ipc_perm *, struct ipc64_perm *);void to_compat_ipc64_perm(struct compat_ipc64_perm *, struct ipc64_perm *);int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *);int get_compat_ipc64_perm(struct ipc64_perm *, struct compat_ipc64_perm __user *);
static inline int compat_ipc_parse_version(int *cmd){ int version = *cmd & IPC_64; *cmd &= ~IPC_64; return version;}
long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg);long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr);long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, compat_long_t msgtyp, int msgflg);long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, int msgflg);long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr);
#endif
#endif