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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /ipc/util.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ipc/util.h')
-rw-r--r--ipc/util.h293
1 files changed, 293 insertions, 0 deletions
diff --git a/ipc/util.h b/ipc/util.h
new file mode 100644
index 000000000..b2906e366
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+++ b/ipc/util.h
@@ -0,0 +1,293 @@
+/* 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>
+
+/*
+ * 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_SYSCTL
+extern 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_MQUEUE
+extern void mq_clear_sbinfo(struct ipc_namespace *ns);
+extern void mq_put_mnt(struct ipc_namespace *ns);
+#else
+static inline void mq_clear_sbinfo(struct ipc_namespace *ns) { }
+static inline void mq_put_mnt(struct ipc_namespace *ns) { }
+#endif
+
+#ifdef CONFIG_SYSVIPC
+void 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);
+#else
+static 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_FS
+void __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_VERSION
+int 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