https://github.com/torvalds/linux
Tip revision: 9ebcfadb0610322ac537dd7aa5d9cbc2b2894c68 authored by Linus Torvalds on 28 June 2020, 22:00:24 UTC
Linux 5.8-rc3
Linux 5.8-rc3
Tip revision: 9ebcfad
ipc_sysctl.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2007
*
* Author: Eric Biederman <ebiederm@xmision.com>
*/
#include <linux/module.h>
#include <linux/ipc.h>
#include <linux/nsproxy.h>
#include <linux/sysctl.h>
#include <linux/uaccess.h>
#include <linux/ipc_namespace.h>
#include <linux/msg.h>
#include "util.h"
static void *get_ipc(struct ctl_table *table)
{
char *which = table->data;
struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
return which;
}
#ifdef CONFIG_PROC_SYSCTL
static int proc_ipc_dointvec(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = get_ipc(table);
return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
}
static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = get_ipc(table);
return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
}
static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct ipc_namespace *ns = current->nsproxy->ipc_ns;
int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (err < 0)
return err;
if (ns->shm_rmid_forced)
shm_destroy_orphaned(ns);
return err;
}
static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = get_ipc(table);
return proc_doulongvec_minmax(&ipc_table, write, buffer,
lenp, ppos);
}
static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
int dummy = 0;
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = &dummy;
if (write)
pr_info_once("writing to auto_msgmni has no effect");
return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
}
static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
int ret, semmni;
struct ipc_namespace *ns = current->nsproxy->ipc_ns;
semmni = ns->sem_ctls[3];
ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
if (!ret)
ret = sem_check_semmni(current->nsproxy->ipc_ns);
/*
* Reset the semmni value if an error happens.
*/
if (ret)
ns->sem_ctls[3] = semmni;
return ret;
}
#else
#define proc_ipc_doulongvec_minmax NULL
#define proc_ipc_dointvec NULL
#define proc_ipc_dointvec_minmax NULL
#define proc_ipc_dointvec_minmax_orphans NULL
#define proc_ipc_auto_msgmni NULL
#define proc_ipc_sem_dointvec NULL
#endif
int ipc_mni = IPCMNI;
int ipc_mni_shift = IPCMNI_SHIFT;
int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
static struct ctl_table ipc_kern_table[] = {
{
.procname = "shmmax",
.data = &init_ipc_ns.shm_ctlmax,
.maxlen = sizeof(init_ipc_ns.shm_ctlmax),
.mode = 0644,
.proc_handler = proc_ipc_doulongvec_minmax,
},
{
.procname = "shmall",
.data = &init_ipc_ns.shm_ctlall,
.maxlen = sizeof(init_ipc_ns.shm_ctlall),
.mode = 0644,
.proc_handler = proc_ipc_doulongvec_minmax,
},
{
.procname = "shmmni",
.data = &init_ipc_ns.shm_ctlmni,
.maxlen = sizeof(init_ipc_ns.shm_ctlmni),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &ipc_mni,
},
{
.procname = "shm_rmid_forced",
.data = &init_ipc_ns.shm_rmid_forced,
.maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax_orphans,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "msgmax",
.data = &init_ipc_ns.msg_ctlmax,
.maxlen = sizeof(init_ipc_ns.msg_ctlmax),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "msgmni",
.data = &init_ipc_ns.msg_ctlmni,
.maxlen = sizeof(init_ipc_ns.msg_ctlmni),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = &ipc_mni,
},
{
.procname = "auto_msgmni",
.data = NULL,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_ipc_auto_msgmni,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "msgmnb",
.data = &init_ipc_ns.msg_ctlmnb,
.maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "sem",
.data = &init_ipc_ns.sem_ctls,
.maxlen = 4*sizeof(int),
.mode = 0644,
.proc_handler = proc_ipc_sem_dointvec,
},
#ifdef CONFIG_CHECKPOINT_RESTORE
{
.procname = "sem_next_id",
.data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
.maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "msg_next_id",
.data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
.maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
{
.procname = "shm_next_id",
.data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
.maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
.mode = 0644,
.proc_handler = proc_ipc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
#endif
{}
};
static struct ctl_table ipc_root_table[] = {
{
.procname = "kernel",
.mode = 0555,
.child = ipc_kern_table,
},
{}
};
static int __init ipc_sysctl_init(void)
{
register_sysctl_table(ipc_root_table);
return 0;
}
device_initcall(ipc_sysctl_init);
static int __init ipc_mni_extend(char *str)
{
ipc_mni = IPCMNI_EXTEND;
ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE;
pr_info("IPCMNI extended to %d.\n", ipc_mni);
return 0;
}
early_param("ipcmni_extend", ipc_mni_extend);