add file position info to proc
Add support for finding out the current file position, open flags and possibly other info in the future. These new entries are added: /proc/PID/fdinfo/FD /proc/PID/task/TID/fdinfo/FD For each fd the information is provided in the following format: pos: 1234 flags: 0100002 [bunk@stusta.de: make struct proc_fdinfo_file_operations static] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
c5141e6d64
commit
2793274298
132
fs/proc/base.c
132
fs/proc/base.c
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@ -1238,7 +1238,10 @@ out:
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return ~0U;
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}
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static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
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#define PROC_FDINFO_MAX 64
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static int proc_fd_info(struct inode *inode, struct dentry **dentry,
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struct vfsmount **mnt, char *info)
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{
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struct task_struct *task = get_proc_task(inode);
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struct files_struct *files = NULL;
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@ -1257,8 +1260,16 @@ static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsm
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spin_lock(&files->file_lock);
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file = fcheck_files(files, fd);
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if (file) {
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*mnt = mntget(file->f_path.mnt);
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*dentry = dget(file->f_path.dentry);
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if (mnt)
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*mnt = mntget(file->f_path.mnt);
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if (dentry)
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*dentry = dget(file->f_path.dentry);
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if (info)
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snprintf(info, PROC_FDINFO_MAX,
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"pos:\t%lli\n"
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"flags:\t0%o\n",
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(long long) file->f_pos,
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file->f_flags);
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spin_unlock(&files->file_lock);
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put_files_struct(files);
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return 0;
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@ -1269,6 +1280,12 @@ static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsm
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return -ENOENT;
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}
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static int proc_fd_link(struct inode *inode, struct dentry **dentry,
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struct vfsmount **mnt)
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{
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return proc_fd_info(inode, dentry, mnt, NULL);
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}
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static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
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{
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struct inode *inode = dentry->d_inode;
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@ -1364,7 +1381,9 @@ out_iput:
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goto out;
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}
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static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
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static struct dentry *proc_lookupfd_common(struct inode *dir,
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struct dentry *dentry,
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instantiate_t instantiate)
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{
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struct task_struct *task = get_proc_task(dir);
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unsigned fd = name_to_int(dentry);
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@ -1375,23 +1394,15 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
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if (fd == ~0U)
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goto out;
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result = proc_fd_instantiate(dir, dentry, task, &fd);
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result = instantiate(dir, dentry, task, &fd);
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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 result;
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}
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static int proc_fd_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
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struct task_struct *task, int fd)
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{
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char name[PROC_NUMBUF];
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int len = snprintf(name, sizeof(name), "%d", fd);
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return proc_fill_cache(filp, dirent, filldir, name, len,
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proc_fd_instantiate, task, &fd);
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}
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static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
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static int proc_readfd_common(struct file * filp, void * dirent,
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filldir_t filldir, instantiate_t instantiate)
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{
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struct dentry *dentry = filp->f_path.dentry;
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struct inode *inode = dentry->d_inode;
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@ -1427,12 +1438,17 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
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for (fd = filp->f_pos-2;
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fd < fdt->max_fds;
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fd++, filp->f_pos++) {
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char name[PROC_NUMBUF];
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int len;
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if (!fcheck_files(files, fd))
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continue;
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rcu_read_unlock();
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if (proc_fd_fill_cache(filp, dirent, filldir, p, fd) < 0) {
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len = snprintf(name, sizeof(name), "%d", fd);
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if (proc_fill_cache(filp, dirent, filldir,
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name, len, instantiate,
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p, &fd) < 0) {
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rcu_read_lock();
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break;
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}
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@ -1447,6 +1463,32 @@ out_no_task:
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return retval;
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}
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static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
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struct nameidata *nd)
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{
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return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
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}
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static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
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{
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return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
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}
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static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
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size_t len, loff_t *ppos)
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{
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char tmp[PROC_FDINFO_MAX];
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int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, NULL, tmp);
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if (!err)
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err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
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return err;
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}
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static const struct file_operations proc_fdinfo_file_operations = {
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.open = nonseekable_open,
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.read = proc_fdinfo_read,
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};
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static const struct file_operations proc_fd_operations = {
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.read = generic_read_dir,
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.readdir = proc_readfd,
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@ -1478,6 +1520,58 @@ static const struct inode_operations proc_fd_inode_operations = {
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.setattr = proc_setattr,
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};
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static struct dentry *proc_fdinfo_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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unsigned fd = *(unsigned *)ptr;
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struct inode *inode;
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struct proc_inode *ei;
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struct dentry *error = ERR_PTR(-ENOENT);
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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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ei->fd = fd;
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inode->i_mode = S_IFREG | S_IRUSR;
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inode->i_fop = &proc_fdinfo_file_operations;
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dentry->d_op = &tid_fd_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 (tid_fd_revalidate(dentry, NULL))
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error = NULL;
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out:
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return error;
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}
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static struct dentry *proc_lookupfdinfo(struct inode *dir,
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struct dentry *dentry,
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struct nameidata *nd)
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{
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return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
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}
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static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
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{
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return proc_readfd_common(filp, dirent, filldir,
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proc_fdinfo_instantiate);
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}
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static const struct file_operations proc_fdinfo_operations = {
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.read = generic_read_dir,
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.readdir = proc_readfdinfo,
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};
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/*
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* proc directories can do almost nothing..
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*/
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static const struct inode_operations proc_fdinfo_inode_operations = {
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.lookup = proc_lookupfdinfo,
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.setattr = proc_setattr,
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};
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static struct dentry *proc_pident_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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static const struct pid_entry tgid_base_stuff[] = {
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DIR("task", S_IRUGO|S_IXUGO, task),
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DIR("fd", S_IRUSR|S_IXUSR, fd),
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DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
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INF("environ", S_IRUSR, pid_environ),
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INF("auxv", S_IRUSR, pid_auxv),
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INF("status", S_IRUGO, pid_status),
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inode->i_op = &proc_tgid_base_inode_operations;
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inode->i_fop = &proc_tgid_base_operations;
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inode->i_flags|=S_IMMUTABLE;
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inode->i_nlink = 4;
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inode->i_nlink = 5;
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#ifdef CONFIG_SECURITY
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inode->i_nlink += 1;
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#endif
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*/
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static const struct pid_entry tid_base_stuff[] = {
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DIR("fd", S_IRUSR|S_IXUSR, fd),
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DIR("fdinfo", S_IRUSR|S_IXUSR, fdinfo),
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INF("environ", S_IRUSR, pid_environ),
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INF("auxv", S_IRUSR, pid_auxv),
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INF("status", S_IRUGO, pid_status),
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inode->i_op = &proc_tid_base_inode_operations;
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inode->i_fop = &proc_tid_base_operations;
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inode->i_flags|=S_IMMUTABLE;
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inode->i_nlink = 3;
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inode->i_nlink = 4;
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#ifdef CONFIG_SECURITY
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inode->i_nlink += 1;
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#endif
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