Linux lhjmq-records 5.15.0-118-generic #128-Ubuntu SMP Fri Jul 5 09:28:59 UTC 2024 x86_64
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __IPC_NAMESPACE_H__
#define __IPC_NAMESPACE_H__
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
#include <linux/notifier.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/refcount.h>
#include <linux/rhashtable-types.h>
#include <linux/sysctl.h>
#include <linux/percpu_counter.h>
struct user_namespace;
struct ipc_ids {
int in_use;
unsigned short seq;
struct rw_semaphore rwsem;
struct idr ipcs_idr;
int max_idx;
int last_idx; /* For wrap around detection */
#ifdef CONFIG_CHECKPOINT_RESTORE
int next_id;
#endif
struct rhashtable key_ht;
};
struct ipc_namespace {
struct ipc_ids ids[3];
int sem_ctls[4];
int used_sems;
unsigned int msg_ctlmax;
unsigned int msg_ctlmnb;
unsigned int msg_ctlmni;
struct percpu_counter percpu_msg_bytes;
struct percpu_counter percpu_msg_hdrs;
size_t shm_ctlmax;
size_t shm_ctlall;
unsigned long shm_tot;
int shm_ctlmni;
/*
* Defines whether IPC_RMID is forced for _all_ shm segments regardless
* of shmctl()
*/
int shm_rmid_forced;
struct notifier_block ipcns_nb;
/* The kern_mount of the mqueuefs sb. We take a ref on it */
struct vfsmount *mq_mnt;
/* # queues in this ns, protected by mq_lock */
unsigned int mq_queues_count;
/* next fields are set through sysctl */
unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
unsigned int mq_msg_default;
unsigned int mq_msgsize_default;
struct ctl_table_set mq_set;
struct ctl_table_header *mq_sysctls;
struct ctl_table_set ipc_set;
struct ctl_table_header *ipc_sysctls;
/* user_ns which owns the ipc ns */
struct user_namespace *user_ns;
struct ucounts *ucounts;
struct llist_node mnt_llist;
struct ns_common ns;
} __randomize_layout;
extern struct ipc_namespace init_ipc_ns;
extern spinlock_t mq_lock;
#ifdef CONFIG_SYSVIPC
extern void shm_destroy_orphaned(struct ipc_namespace *ns);
#else /* CONFIG_SYSVIPC */
static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
#endif /* CONFIG_SYSVIPC */
#ifdef CONFIG_POSIX_MQUEUE
extern int mq_init_ns(struct ipc_namespace *ns);
/*
* POSIX Message Queue default values:
*
* MIN_*: Lowest value an admin can set the maximum unprivileged limit to
* DFLT_*MAX: Default values for the maximum unprivileged limits
* DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
* an attribute to the open call and the queue must be created
* HARD_*: Highest value the maximums can be set to. These are enforced
* on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
* suitably high)
*
* POSIX Requirements:
* Per app minimum openable message queues - 8. This does not map well
* to the fact that we limit the number of queues on a per namespace
* basis instead of a per app basis. So, make the default high enough
* that no given app should have a hard time opening 8 queues.
* Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
* Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
* we have run into a situation where running applications in the wild
* require this to be at least 5MB, and preferably 10MB, so I set the
* value to 16MB in hopes that this user is the worst of the bunch and
* the new maximum will handle anyone else. I may have to revisit this
* in the future.
*/
#define DFLT_QUEUESMAX 256
#define MIN_MSGMAX 1
#define DFLT_MSG 10U
#define DFLT_MSGMAX 10
#define HARD_MSGMAX 65536
#define MIN_MSGSIZEMAX 128
#define DFLT_MSGSIZE 8192U
#define DFLT_MSGSIZEMAX 8192
#define HARD_MSGSIZEMAX (16*1024*1024)
#else
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
#endif
extern struct ipc_namespace *get_ipc_ns_exported(struct ipc_namespace *ns);
extern struct ipc_namespace *show_init_ipc_ns(void);
#if defined(CONFIG_IPC_NS)
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
struct user_namespace *user_ns, struct ipc_namespace *ns);
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
if (ns)
refcount_inc(&ns->ns.count);
return ns;
}
static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
{
if (ns) {
if (refcount_inc_not_zero(&ns->ns.count))
return ns;
}
return NULL;
}
extern void put_ipc_ns(struct ipc_namespace *ns);
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
struct user_namespace *user_ns, struct ipc_namespace *ns)
{
if (flags & CLONE_NEWIPC)
return ERR_PTR(-EINVAL);
return ns;
}
static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
return ns;
}
static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
{
return ns;
}
static inline void put_ipc_ns(struct ipc_namespace *ns)
{
}
#endif
#ifdef CONFIG_POSIX_MQUEUE_SYSCTL
void retire_mq_sysctls(struct ipc_namespace *ns);
bool setup_mq_sysctls(struct ipc_namespace *ns);
#else /* CONFIG_POSIX_MQUEUE_SYSCTL */
static inline void retire_mq_sysctls(struct ipc_namespace *ns)
{
}
static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
{
return true;
}
#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
#ifdef CONFIG_SYSVIPC_SYSCTL
bool setup_ipc_sysctls(struct ipc_namespace *ns);
void retire_ipc_sysctls(struct ipc_namespace *ns);
#else /* CONFIG_SYSVIPC_SYSCTL */
static inline void retire_ipc_sysctls(struct ipc_namespace *ns)
{
}
static inline bool setup_ipc_sysctls(struct ipc_namespace *ns)
{
return true;
}
#endif /* CONFIG_SYSVIPC_SYSCTL */
#endif
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