mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-13 21:16:53 +07:00
5d826c847b
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
298 lines
6.4 KiB
C
298 lines
6.4 KiB
C
#include <linux/proc_fs.h>
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#include <linux/nsproxy.h>
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#include <linux/sched.h>
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#include <linux/ptrace.h>
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#include <linux/fs_struct.h>
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#include <linux/mount.h>
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#include <linux/path.h>
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#include <linux/namei.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <net/net_namespace.h>
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#include <linux/ipc_namespace.h>
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#include <linux/pid_namespace.h>
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#include <linux/user_namespace.h>
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#include "internal.h"
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static const struct proc_ns_operations *ns_entries[] = {
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#ifdef CONFIG_NET_NS
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&netns_operations,
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#endif
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#ifdef CONFIG_UTS_NS
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&utsns_operations,
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#endif
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#ifdef CONFIG_IPC_NS
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&ipcns_operations,
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#endif
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#ifdef CONFIG_PID_NS
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&pidns_operations,
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#endif
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#ifdef CONFIG_USER_NS
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&userns_operations,
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#endif
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&mntns_operations,
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};
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static const struct file_operations ns_file_operations = {
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.llseek = no_llseek,
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};
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static const struct inode_operations ns_inode_operations = {
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.setattr = proc_setattr,
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};
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static char *ns_dname(struct dentry *dentry, char *buffer, int buflen)
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{
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struct inode *inode = dentry->d_inode;
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const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns.ns_ops;
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return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
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ns_ops->name, inode->i_ino);
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}
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const struct dentry_operations ns_dentry_operations =
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{
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.d_delete = always_delete_dentry,
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.d_dname = ns_dname,
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};
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static struct dentry *proc_ns_get_dentry(struct super_block *sb,
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struct task_struct *task, const struct proc_ns_operations *ns_ops)
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{
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struct dentry *dentry, *result;
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struct inode *inode;
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struct proc_inode *ei;
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struct qstr qname = { .name = "", };
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void *ns;
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ns = ns_ops->get(task);
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if (!ns)
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return ERR_PTR(-ENOENT);
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dentry = d_alloc_pseudo(sb, &qname);
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if (!dentry) {
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ns_ops->put(ns);
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return ERR_PTR(-ENOMEM);
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}
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inode = iget_locked(sb, ns_ops->inum(ns));
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if (!inode) {
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dput(dentry);
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ns_ops->put(ns);
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return ERR_PTR(-ENOMEM);
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}
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ei = PROC_I(inode);
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if (inode->i_state & I_NEW) {
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inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
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inode->i_op = &ns_inode_operations;
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inode->i_mode = S_IFREG | S_IRUGO;
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inode->i_fop = &ns_file_operations;
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ei->ns.ns_ops = ns_ops;
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ei->ns.ns = ns;
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unlock_new_inode(inode);
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} else {
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ns_ops->put(ns);
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}
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d_set_d_op(dentry, &ns_dentry_operations);
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result = d_instantiate_unique(dentry, inode);
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if (result) {
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dput(dentry);
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dentry = result;
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}
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return dentry;
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}
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static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
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struct inode *inode = dentry->d_inode;
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struct super_block *sb = inode->i_sb;
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struct proc_inode *ei = PROC_I(inode);
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struct task_struct *task;
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struct path ns_path;
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void *error = ERR_PTR(-EACCES);
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task = get_proc_task(inode);
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if (!task)
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goto out;
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if (!ptrace_may_access(task, PTRACE_MODE_READ))
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goto out_put_task;
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ns_path.dentry = proc_ns_get_dentry(sb, task, ei->ns.ns_ops);
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if (IS_ERR(ns_path.dentry)) {
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error = ERR_CAST(ns_path.dentry);
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goto out_put_task;
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}
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ns_path.mnt = mntget(nd->path.mnt);
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nd_jump_link(nd, &ns_path);
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error = NULL;
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out_put_task:
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put_task_struct(task);
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out:
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return error;
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}
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static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
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{
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struct inode *inode = dentry->d_inode;
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struct proc_inode *ei = PROC_I(inode);
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const struct proc_ns_operations *ns_ops = ei->ns.ns_ops;
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struct task_struct *task;
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void *ns;
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char name[50];
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int res = -EACCES;
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task = get_proc_task(inode);
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if (!task)
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goto out;
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if (!ptrace_may_access(task, PTRACE_MODE_READ))
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goto out_put_task;
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res = -ENOENT;
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ns = ns_ops->get(task);
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if (!ns)
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goto out_put_task;
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snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
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res = readlink_copy(buffer, buflen, name);
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ns_ops->put(ns);
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out_put_task:
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put_task_struct(task);
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out:
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return res;
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}
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static const struct inode_operations proc_ns_link_inode_operations = {
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.readlink = proc_ns_readlink,
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.follow_link = proc_ns_follow_link,
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.setattr = proc_setattr,
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};
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static int proc_ns_instantiate(struct inode *dir,
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struct dentry *dentry, struct task_struct *task, const void *ptr)
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{
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const struct proc_ns_operations *ns_ops = ptr;
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struct inode *inode;
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struct proc_inode *ei;
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inode = proc_pid_make_inode(dir->i_sb, task);
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if (!inode)
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goto out;
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ei = PROC_I(inode);
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inode->i_mode = S_IFLNK|S_IRWXUGO;
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inode->i_op = &proc_ns_link_inode_operations;
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ei->ns.ns_ops = ns_ops;
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d_set_d_op(dentry, &pid_dentry_operations);
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d_add(dentry, inode);
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/* Close the race of the process dying before we return the dentry */
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if (pid_revalidate(dentry, 0))
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return 0;
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out:
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return -ENOENT;
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}
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static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
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{
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struct task_struct *task = get_proc_task(file_inode(file));
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const struct proc_ns_operations **entry, **last;
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if (!task)
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return -ENOENT;
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if (!dir_emit_dots(file, ctx))
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goto out;
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if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
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goto out;
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entry = ns_entries + (ctx->pos - 2);
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last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
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while (entry <= last) {
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const struct proc_ns_operations *ops = *entry;
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if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
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proc_ns_instantiate, task, ops))
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break;
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ctx->pos++;
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entry++;
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}
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out:
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put_task_struct(task);
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return 0;
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}
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const struct file_operations proc_ns_dir_operations = {
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.read = generic_read_dir,
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.iterate = proc_ns_dir_readdir,
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};
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static struct dentry *proc_ns_dir_lookup(struct inode *dir,
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struct dentry *dentry, unsigned int flags)
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{
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int error;
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struct task_struct *task = get_proc_task(dir);
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const struct proc_ns_operations **entry, **last;
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unsigned int len = dentry->d_name.len;
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error = -ENOENT;
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if (!task)
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goto out_no_task;
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last = &ns_entries[ARRAY_SIZE(ns_entries)];
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for (entry = ns_entries; entry < last; entry++) {
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if (strlen((*entry)->name) != len)
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continue;
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if (!memcmp(dentry->d_name.name, (*entry)->name, len))
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break;
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}
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if (entry == last)
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goto out;
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error = proc_ns_instantiate(dir, dentry, task, *entry);
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out:
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put_task_struct(task);
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out_no_task:
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return ERR_PTR(error);
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}
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const struct inode_operations proc_ns_dir_inode_operations = {
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.lookup = proc_ns_dir_lookup,
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.getattr = pid_getattr,
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.setattr = proc_setattr,
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};
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struct file *proc_ns_fget(int fd)
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{
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struct file *file;
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file = fget(fd);
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if (!file)
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return ERR_PTR(-EBADF);
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if (file->f_op != &ns_file_operations)
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goto out_invalid;
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return file;
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out_invalid:
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fput(file);
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return ERR_PTR(-EINVAL);
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}
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struct proc_ns *get_proc_ns(struct inode *inode)
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{
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return &PROC_I(inode)->ns;
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}
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bool proc_ns_inode(struct inode *inode)
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{
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return inode->i_fop == &ns_file_operations;
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}
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