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![Christoph Hellwig](/assets/img/avatar_default.png)
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
253 lines
6.1 KiB
C
253 lines
6.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2007
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*
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* Author: Eric Biederman <ebiederm@xmision.com>
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*/
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#include <linux/module.h>
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#include <linux/ipc.h>
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#include <linux/nsproxy.h>
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#include <linux/sysctl.h>
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#include <linux/uaccess.h>
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#include <linux/ipc_namespace.h>
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#include <linux/msg.h>
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#include "util.h"
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static void *get_ipc(struct ctl_table *table)
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{
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char *which = table->data;
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struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
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which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
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return which;
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}
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#ifdef CONFIG_PROC_SYSCTL
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static int proc_ipc_dointvec(struct ctl_table *table, int write,
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void *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table ipc_table;
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memcpy(&ipc_table, table, sizeof(ipc_table));
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ipc_table.data = get_ipc(table);
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return proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
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}
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static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write,
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void *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table ipc_table;
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memcpy(&ipc_table, table, sizeof(ipc_table));
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ipc_table.data = get_ipc(table);
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return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
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}
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static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
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void *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ipc_namespace *ns = current->nsproxy->ipc_ns;
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int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
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if (err < 0)
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return err;
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if (ns->shm_rmid_forced)
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shm_destroy_orphaned(ns);
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return err;
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}
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static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
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void *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table ipc_table;
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memcpy(&ipc_table, table, sizeof(ipc_table));
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ipc_table.data = get_ipc(table);
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return proc_doulongvec_minmax(&ipc_table, write, buffer,
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lenp, ppos);
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}
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static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
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void *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table ipc_table;
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int dummy = 0;
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memcpy(&ipc_table, table, sizeof(ipc_table));
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ipc_table.data = &dummy;
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if (write)
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pr_info_once("writing to auto_msgmni has no effect");
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return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
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}
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static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
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void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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int ret, semmni;
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struct ipc_namespace *ns = current->nsproxy->ipc_ns;
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semmni = ns->sem_ctls[3];
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ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
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if (!ret)
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ret = sem_check_semmni(current->nsproxy->ipc_ns);
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/*
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* Reset the semmni value if an error happens.
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*/
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if (ret)
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ns->sem_ctls[3] = semmni;
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return ret;
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}
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#else
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#define proc_ipc_doulongvec_minmax NULL
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#define proc_ipc_dointvec NULL
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#define proc_ipc_dointvec_minmax NULL
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#define proc_ipc_dointvec_minmax_orphans NULL
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#define proc_ipc_auto_msgmni NULL
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#define proc_ipc_sem_dointvec NULL
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#endif
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int ipc_mni = IPCMNI;
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int ipc_mni_shift = IPCMNI_SHIFT;
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int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
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static struct ctl_table ipc_kern_table[] = {
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{
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.procname = "shmmax",
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.data = &init_ipc_ns.shm_ctlmax,
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.maxlen = sizeof(init_ipc_ns.shm_ctlmax),
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.mode = 0644,
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.proc_handler = proc_ipc_doulongvec_minmax,
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},
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{
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.procname = "shmall",
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.data = &init_ipc_ns.shm_ctlall,
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.maxlen = sizeof(init_ipc_ns.shm_ctlall),
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.mode = 0644,
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.proc_handler = proc_ipc_doulongvec_minmax,
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},
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{
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.procname = "shmmni",
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.data = &init_ipc_ns.shm_ctlmni,
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.maxlen = sizeof(init_ipc_ns.shm_ctlmni),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = &ipc_mni,
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},
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{
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.procname = "shm_rmid_forced",
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.data = &init_ipc_ns.shm_rmid_forced,
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.maxlen = sizeof(init_ipc_ns.shm_rmid_forced),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax_orphans,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_ONE,
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},
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{
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.procname = "msgmax",
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.data = &init_ipc_ns.msg_ctlmax,
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.maxlen = sizeof(init_ipc_ns.msg_ctlmax),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_INT_MAX,
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},
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{
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.procname = "msgmni",
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.data = &init_ipc_ns.msg_ctlmni,
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.maxlen = sizeof(init_ipc_ns.msg_ctlmni),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = &ipc_mni,
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},
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{
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.procname = "auto_msgmni",
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.data = NULL,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_ipc_auto_msgmni,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_ONE,
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},
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{
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.procname = "msgmnb",
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.data = &init_ipc_ns.msg_ctlmnb,
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.maxlen = sizeof(init_ipc_ns.msg_ctlmnb),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_INT_MAX,
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},
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{
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.procname = "sem",
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.data = &init_ipc_ns.sem_ctls,
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.maxlen = 4*sizeof(int),
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.mode = 0644,
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.proc_handler = proc_ipc_sem_dointvec,
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},
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#ifdef CONFIG_CHECKPOINT_RESTORE
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{
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.procname = "sem_next_id",
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.data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
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.maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_INT_MAX,
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},
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{
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.procname = "msg_next_id",
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.data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
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.maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_INT_MAX,
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},
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{
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.procname = "shm_next_id",
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.data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
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.maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
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.mode = 0644,
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.proc_handler = proc_ipc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_INT_MAX,
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},
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#endif
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{}
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};
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static struct ctl_table ipc_root_table[] = {
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{
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.procname = "kernel",
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.mode = 0555,
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.child = ipc_kern_table,
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},
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{}
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};
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static int __init ipc_sysctl_init(void)
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{
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register_sysctl_table(ipc_root_table);
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return 0;
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}
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device_initcall(ipc_sysctl_init);
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static int __init ipc_mni_extend(char *str)
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{
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ipc_mni = IPCMNI_EXTEND;
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ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
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ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE;
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pr_info("IPCMNI extended to %d.\n", ipc_mni);
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return 0;
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}
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early_param("ipcmni_extend", ipc_mni_extend);
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