base.c 54.0 KB
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/*
 *  linux/fs/proc/base.c
 *
 *  Copyright (C) 1991, 1992 Linus Torvalds
 *
 *  proc base directory handling functions
 *
 *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
 *  Instead of using magical inumbers to determine the kind of object
 *  we allocate and fill in-core inodes upon lookup. They don't even
 *  go into icache. We cache the reference to task_struct upon lookup too.
 *  Eventually it should become a filesystem in its own. We don't use the
 *  rest of procfs anymore.
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 *
 *
 *  Changelog:
 *  17-Jan-2005
 *  Allan Bezerra
 *  Bruna Moreira <bruna.moreira@indt.org.br>
 *  Edjard Mota <edjard.mota@indt.org.br>
 *  Ilias Biris <ilias.biris@indt.org.br>
 *  Mauricio Lin <mauricio.lin@indt.org.br>
 *
 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
 *
 *  A new process specific entry (smaps) included in /proc. It shows the
 *  size of rss for each memory area. The maps entry lacks information
 *  about physical memory size (rss) for each mapped file, i.e.,
 *  rss information for executables and library files.
 *  This additional information is useful for any tools that need to know
 *  about physical memory consumption for a process specific library.
 *
 *  Changelog:
 *  21-Feb-2005
 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
 *  Pud inclusion in the page table walking.
 *
 *  ChangeLog:
 *  10-Mar-2005
 *  10LE Instituto Nokia de Tecnologia - INdT:
 *  A better way to walks through the page table as suggested by Hugh Dickins.
 *
 *  Simo Piiroinen <simo.piiroinen@nokia.com>:
 *  Smaps information related to shared, private, clean and dirty pages.
 *
 *  Paul Mundt <paul.mundt@nokia.com>:
 *  Overall revision about smaps.
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 */

#include <asm/uaccess.h>

#include <linux/config.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
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#include <linux/capability.h>
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#include <linux/file.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/namei.h>
#include <linux/namespace.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
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#include <linux/rcupdate.h>
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#include <linux/kallsyms.h>
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/ptrace.h>
#include <linux/seccomp.h>
#include <linux/cpuset.h>
#include <linux/audit.h>
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#include <linux/poll.h>
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#include "internal.h"

/*
 * For hysterical raisins we keep the same inumbers as in the old procfs.
 * Feel free to change the macro below - just keep the range distinct from
 * inumbers of the rest of procfs (currently those are in 0x0000--0xffff).
 * As soon as we'll get a separate superblock we will be able to forget
 * about magical ranges too.
 */

#define fake_ino(pid,ino) (((pid)<<16)|(ino))

enum pid_directory_inos {
	PROC_TGID_INO = 2,
	PROC_TGID_TASK,
	PROC_TGID_STATUS,
	PROC_TGID_MEM,
#ifdef CONFIG_SECCOMP
	PROC_TGID_SECCOMP,
#endif
	PROC_TGID_CWD,
	PROC_TGID_ROOT,
	PROC_TGID_EXE,
	PROC_TGID_FD,
	PROC_TGID_ENVIRON,
	PROC_TGID_AUXV,
	PROC_TGID_CMDLINE,
	PROC_TGID_STAT,
	PROC_TGID_STATM,
	PROC_TGID_MAPS,
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	PROC_TGID_NUMA_MAPS,
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	PROC_TGID_MOUNTS,
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	PROC_TGID_MOUNTSTATS,
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	PROC_TGID_WCHAN,
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#ifdef CONFIG_MMU
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	PROC_TGID_SMAPS,
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#endif
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#ifdef CONFIG_SCHEDSTATS
	PROC_TGID_SCHEDSTAT,
#endif
#ifdef CONFIG_CPUSETS
	PROC_TGID_CPUSET,
#endif
#ifdef CONFIG_SECURITY
	PROC_TGID_ATTR,
	PROC_TGID_ATTR_CURRENT,
	PROC_TGID_ATTR_PREV,
	PROC_TGID_ATTR_EXEC,
	PROC_TGID_ATTR_FSCREATE,
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	PROC_TGID_ATTR_KEYCREATE,
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#endif
#ifdef CONFIG_AUDITSYSCALL
	PROC_TGID_LOGINUID,
#endif
	PROC_TGID_OOM_SCORE,
	PROC_TGID_OOM_ADJUST,
	PROC_TID_INO,
	PROC_TID_STATUS,
	PROC_TID_MEM,
#ifdef CONFIG_SECCOMP
	PROC_TID_SECCOMP,
#endif
	PROC_TID_CWD,
	PROC_TID_ROOT,
	PROC_TID_EXE,
	PROC_TID_FD,
	PROC_TID_ENVIRON,
	PROC_TID_AUXV,
	PROC_TID_CMDLINE,
	PROC_TID_STAT,
	PROC_TID_STATM,
	PROC_TID_MAPS,
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	PROC_TID_NUMA_MAPS,
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	PROC_TID_MOUNTS,
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	PROC_TID_MOUNTSTATS,
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	PROC_TID_WCHAN,
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#ifdef CONFIG_MMU
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	PROC_TID_SMAPS,
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#endif
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#ifdef CONFIG_SCHEDSTATS
	PROC_TID_SCHEDSTAT,
#endif
#ifdef CONFIG_CPUSETS
	PROC_TID_CPUSET,
#endif
#ifdef CONFIG_SECURITY
	PROC_TID_ATTR,
	PROC_TID_ATTR_CURRENT,
	PROC_TID_ATTR_PREV,
	PROC_TID_ATTR_EXEC,
	PROC_TID_ATTR_FSCREATE,
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	PROC_TID_ATTR_KEYCREATE,
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#endif
#ifdef CONFIG_AUDITSYSCALL
	PROC_TID_LOGINUID,
#endif
	PROC_TID_OOM_SCORE,
	PROC_TID_OOM_ADJUST,
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	/* Add new entries before this */
	PROC_TID_FD_DIR = 0x8000,	/* 0x8000-0xffff */
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};

struct pid_entry {
	int type;
	int len;
	char *name;
	mode_t mode;
};

#define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}

static struct pid_entry tgid_base_stuff[] = {
	E(PROC_TGID_TASK,      "task",    S_IFDIR|S_IRUGO|S_IXUGO),
	E(PROC_TGID_FD,        "fd",      S_IFDIR|S_IRUSR|S_IXUSR),
	E(PROC_TGID_ENVIRON,   "environ", S_IFREG|S_IRUSR),
	E(PROC_TGID_AUXV,      "auxv",	  S_IFREG|S_IRUSR),
	E(PROC_TGID_STATUS,    "status",  S_IFREG|S_IRUGO),
	E(PROC_TGID_CMDLINE,   "cmdline", S_IFREG|S_IRUGO),
	E(PROC_TGID_STAT,      "stat",    S_IFREG|S_IRUGO),
	E(PROC_TGID_STATM,     "statm",   S_IFREG|S_IRUGO),
	E(PROC_TGID_MAPS,      "maps",    S_IFREG|S_IRUGO),
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#ifdef CONFIG_NUMA
	E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
#endif
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	E(PROC_TGID_MEM,       "mem",     S_IFREG|S_IRUSR|S_IWUSR),
#ifdef CONFIG_SECCOMP
	E(PROC_TGID_SECCOMP,   "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
#endif
	E(PROC_TGID_CWD,       "cwd",     S_IFLNK|S_IRWXUGO),
	E(PROC_TGID_ROOT,      "root",    S_IFLNK|S_IRWXUGO),
	E(PROC_TGID_EXE,       "exe",     S_IFLNK|S_IRWXUGO),
	E(PROC_TGID_MOUNTS,    "mounts",  S_IFREG|S_IRUGO),
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	E(PROC_TGID_MOUNTSTATS, "mountstats", S_IFREG|S_IRUSR),
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#ifdef CONFIG_MMU
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	E(PROC_TGID_SMAPS,     "smaps",   S_IFREG|S_IRUGO),
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#endif
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#ifdef CONFIG_SECURITY
	E(PROC_TGID_ATTR,      "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
#endif
#ifdef CONFIG_KALLSYMS
	E(PROC_TGID_WCHAN,     "wchan",   S_IFREG|S_IRUGO),
#endif
#ifdef CONFIG_SCHEDSTATS
	E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
#endif
#ifdef CONFIG_CPUSETS
	E(PROC_TGID_CPUSET,    "cpuset",  S_IFREG|S_IRUGO),
#endif
	E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
	E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
#ifdef CONFIG_AUDITSYSCALL
	E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
#endif
	{0,0,NULL,0}
};
static struct pid_entry tid_base_stuff[] = {
	E(PROC_TID_FD,         "fd",      S_IFDIR|S_IRUSR|S_IXUSR),
	E(PROC_TID_ENVIRON,    "environ", S_IFREG|S_IRUSR),
	E(PROC_TID_AUXV,       "auxv",	  S_IFREG|S_IRUSR),
	E(PROC_TID_STATUS,     "status",  S_IFREG|S_IRUGO),
	E(PROC_TID_CMDLINE,    "cmdline", S_IFREG|S_IRUGO),
	E(PROC_TID_STAT,       "stat",    S_IFREG|S_IRUGO),
	E(PROC_TID_STATM,      "statm",   S_IFREG|S_IRUGO),
	E(PROC_TID_MAPS,       "maps",    S_IFREG|S_IRUGO),
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#ifdef CONFIG_NUMA
	E(PROC_TID_NUMA_MAPS,  "numa_maps",    S_IFREG|S_IRUGO),
#endif
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	E(PROC_TID_MEM,        "mem",     S_IFREG|S_IRUSR|S_IWUSR),
#ifdef CONFIG_SECCOMP
	E(PROC_TID_SECCOMP,    "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
#endif
	E(PROC_TID_CWD,        "cwd",     S_IFLNK|S_IRWXUGO),
	E(PROC_TID_ROOT,       "root",    S_IFLNK|S_IRWXUGO),
	E(PROC_TID_EXE,        "exe",     S_IFLNK|S_IRWXUGO),
	E(PROC_TID_MOUNTS,     "mounts",  S_IFREG|S_IRUGO),
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#ifdef CONFIG_MMU
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	E(PROC_TID_SMAPS,      "smaps",   S_IFREG|S_IRUGO),
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#endif
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#ifdef CONFIG_SECURITY
	E(PROC_TID_ATTR,       "attr",    S_IFDIR|S_IRUGO|S_IXUGO),
#endif
#ifdef CONFIG_KALLSYMS
	E(PROC_TID_WCHAN,      "wchan",   S_IFREG|S_IRUGO),
#endif
#ifdef CONFIG_SCHEDSTATS
	E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
#endif
#ifdef CONFIG_CPUSETS
	E(PROC_TID_CPUSET,     "cpuset",  S_IFREG|S_IRUGO),
#endif
	E(PROC_TID_OOM_SCORE,  "oom_score",S_IFREG|S_IRUGO),
	E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
#ifdef CONFIG_AUDITSYSCALL
	E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
#endif
	{0,0,NULL,0}
};

#ifdef CONFIG_SECURITY
static struct pid_entry tgid_attr_stuff[] = {
	E(PROC_TGID_ATTR_CURRENT,  "current",  S_IFREG|S_IRUGO|S_IWUGO),
	E(PROC_TGID_ATTR_PREV,     "prev",     S_IFREG|S_IRUGO),
	E(PROC_TGID_ATTR_EXEC,     "exec",     S_IFREG|S_IRUGO|S_IWUGO),
	E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
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	E(PROC_TGID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
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	{0,0,NULL,0}
};
static struct pid_entry tid_attr_stuff[] = {
	E(PROC_TID_ATTR_CURRENT,   "current",  S_IFREG|S_IRUGO|S_IWUGO),
	E(PROC_TID_ATTR_PREV,      "prev",     S_IFREG|S_IRUGO),
	E(PROC_TID_ATTR_EXEC,      "exec",     S_IFREG|S_IRUGO|S_IWUGO),
	E(PROC_TID_ATTR_FSCREATE,  "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
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	E(PROC_TID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
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	{0,0,NULL,0}
};
#endif

#undef E

static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
	struct task_struct *task = proc_task(inode);
	struct files_struct *files;
	struct file *file;
	int fd = proc_type(inode) - PROC_TID_FD_DIR;

	files = get_files_struct(task);
	if (files) {
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		/*
		 * We are not taking a ref to the file structure, so we must
		 * hold ->file_lock.
		 */
		spin_lock(&files->file_lock);
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		file = fcheck_files(files, fd);
		if (file) {
			*mnt = mntget(file->f_vfsmnt);
			*dentry = dget(file->f_dentry);
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			spin_unlock(&files->file_lock);
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			put_files_struct(files);
			return 0;
		}
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		spin_unlock(&files->file_lock);
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		put_files_struct(files);
	}
	return -ENOENT;
}

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static struct fs_struct *get_fs_struct(struct task_struct *task)
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{
	struct fs_struct *fs;
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	task_lock(task);
	fs = task->fs;
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	if(fs)
		atomic_inc(&fs->count);
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	task_unlock(task);
	return fs;
}

static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
	struct fs_struct *fs = get_fs_struct(proc_task(inode));
	int result = -ENOENT;
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	if (fs) {
		read_lock(&fs->lock);
		*mnt = mntget(fs->pwdmnt);
		*dentry = dget(fs->pwd);
		read_unlock(&fs->lock);
		result = 0;
		put_fs_struct(fs);
	}
	return result;
}

static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
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	struct fs_struct *fs = get_fs_struct(proc_task(inode));
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	int result = -ENOENT;
	if (fs) {
		read_lock(&fs->lock);
		*mnt = mntget(fs->rootmnt);
		*dentry = dget(fs->root);
		read_unlock(&fs->lock);
		result = 0;
		put_fs_struct(fs);
	}
	return result;
}

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/* Same as proc_root_link, but this addionally tries to get fs from other
 * threads in the group */
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static int proc_task_root_link(struct inode *inode, struct dentry **dentry,
				struct vfsmount **mnt)
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{
	struct fs_struct *fs;
	int result = -ENOENT;
	struct task_struct *leader = proc_task(inode);

	task_lock(leader);
	fs = leader->fs;
	if (fs) {
		atomic_inc(&fs->count);
		task_unlock(leader);
	} else {
		/* Try to get fs from other threads */
		task_unlock(leader);
		read_lock(&tasklist_lock);
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		if (pid_alive(leader)) {
			struct task_struct *task = leader;

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			while ((task = next_thread(task)) != leader) {
				task_lock(task);
				fs = task->fs;
				if (fs) {
					atomic_inc(&fs->count);
					task_unlock(task);
					break;
				}
				task_unlock(task);
			}
		}
		read_unlock(&tasklist_lock);
	}

	if (fs) {
		read_lock(&fs->lock);
		*mnt = mntget(fs->rootmnt);
		*dentry = dget(fs->root);
		read_unlock(&fs->lock);
		result = 0;
		put_fs_struct(fs);
	}
	return result;
}


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#define MAY_PTRACE(task) \
	(task == current || \
	(task->parent == current && \
	(task->ptrace & PT_PTRACED) && \
	 (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
	 security_ptrace(current,task) == 0))

static int proc_pid_environ(struct task_struct *task, char * buffer)
{
	int res = 0;
	struct mm_struct *mm = get_task_mm(task);
	if (mm) {
		unsigned int len = mm->env_end - mm->env_start;
		if (len > PAGE_SIZE)
			len = PAGE_SIZE;
		res = access_process_vm(task, mm->env_start, buffer, len, 0);
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		if (!ptrace_may_attach(task))
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			res = -ESRCH;
		mmput(mm);
	}
	return res;
}

static int proc_pid_cmdline(struct task_struct *task, char * buffer)
{
	int res = 0;
	unsigned int len;
	struct mm_struct *mm = get_task_mm(task);
	if (!mm)
		goto out;
	if (!mm->arg_end)
		goto out_mm;	/* Shh! No looking before we're done */

 	len = mm->arg_end - mm->arg_start;
 
	if (len > PAGE_SIZE)
		len = PAGE_SIZE;
 
	res = access_process_vm(task, mm->arg_start, buffer, len, 0);

	// If the nul at the end of args has been overwritten, then
	// assume application is using setproctitle(3).
	if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
		len = strnlen(buffer, res);
		if (len < res) {
		    res = len;
		} else {
			len = mm->env_end - mm->env_start;
			if (len > PAGE_SIZE - res)
				len = PAGE_SIZE - res;
			res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
			res = strnlen(buffer, res);
		}
	}
out_mm:
	mmput(mm);
out:
	return res;
}

static int proc_pid_auxv(struct task_struct *task, char *buffer)
{
	int res = 0;
	struct mm_struct *mm = get_task_mm(task);
	if (mm) {
		unsigned int nwords = 0;
		do
			nwords += 2;
		while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
		res = nwords * sizeof(mm->saved_auxv[0]);
		if (res > PAGE_SIZE)
			res = PAGE_SIZE;
		memcpy(buffer, mm->saved_auxv, res);
		mmput(mm);
	}
	return res;
}


#ifdef CONFIG_KALLSYMS
/*
 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 * Returns the resolved symbol.  If that fails, simply return the address.
 */
static int proc_pid_wchan(struct task_struct *task, char *buffer)
{
	char *modname;
	const char *sym_name;
	unsigned long wchan, size, offset;
	char namebuf[KSYM_NAME_LEN+1];

	wchan = get_wchan(task);

	sym_name = kallsyms_lookup(wchan, &size, &offset, &modname, namebuf);
	if (sym_name)
		return sprintf(buffer, "%s", sym_name);
	return sprintf(buffer, "%lu", wchan);
}
#endif /* CONFIG_KALLSYMS */

#ifdef CONFIG_SCHEDSTATS
/*
 * Provides /proc/PID/schedstat
 */
static int proc_pid_schedstat(struct task_struct *task, char *buffer)
{
	return sprintf(buffer, "%lu %lu %lu\n",
			task->sched_info.cpu_time,
			task->sched_info.run_delay,
			task->sched_info.pcnt);
}
#endif

/* The badness from the OOM killer */
unsigned long badness(struct task_struct *p, unsigned long uptime);
static int proc_oom_score(struct task_struct *task, char *buffer)
{
	unsigned long points;
	struct timespec uptime;

	do_posix_clock_monotonic_gettime(&uptime);
	points = badness(task, uptime.tv_sec);
	return sprintf(buffer, "%lu\n", points);
}

/************************************************************************/
/*                       Here the fs part begins                        */
/************************************************************************/

/* permission checks */

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/* If the process being read is separated by chroot from the reading process,
 * don't let the reader access the threads.
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 *
 * note: this does dput(root) and mntput(vfsmnt) on exit.
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 */
static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
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{
550 551
	struct dentry *de, *base;
	struct vfsmount *our_vfsmnt, *mnt;
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	int res = 0;
553

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	read_lock(&current->fs->lock);
	our_vfsmnt = mntget(current->fs->rootmnt);
	base = dget(current->fs->root);
	read_unlock(&current->fs->lock);

	spin_lock(&vfsmount_lock);
	de = root;
	mnt = vfsmnt;

563 564
	while (mnt != our_vfsmnt) {
		if (mnt == mnt->mnt_parent)
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			goto out;
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		de = mnt->mnt_mountpoint;
		mnt = mnt->mnt_parent;
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	}

	if (!is_subdir(de, base))
		goto out;
	spin_unlock(&vfsmount_lock);

exit:
	dput(base);
	mntput(our_vfsmnt);
	dput(root);
578
	mntput(vfsmnt);
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	return res;
out:
	spin_unlock(&vfsmount_lock);
	res = -EACCES;
	goto exit;
}

586 587 588 589 590 591 592 593 594 595
static int proc_check_root(struct inode *inode)
{
	struct dentry *root;
	struct vfsmount *vfsmnt;

	if (proc_root_link(inode, &root, &vfsmnt)) /* Ewww... */
		return -ENOENT;
	return proc_check_chroot(root, vfsmnt);
}

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static int proc_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	if (generic_permission(inode, mask, NULL) != 0)
		return -EACCES;
	return proc_check_root(inode);
}

603 604 605 606 607 608 609 610 611 612 613 614 615 616
static int proc_task_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	struct dentry *root;
	struct vfsmount *vfsmnt;

	if (generic_permission(inode, mask, NULL) != 0)
		return -EACCES;

	if (proc_task_root_link(inode, &root, &vfsmnt))
		return -ENOENT;

	return proc_check_chroot(root, vfsmnt);
}

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extern struct seq_operations proc_pid_maps_op;
static int maps_open(struct inode *inode, struct file *file)
{
	struct task_struct *task = proc_task(inode);
	int ret = seq_open(file, &proc_pid_maps_op);
	if (!ret) {
		struct seq_file *m = file->private_data;
		m->private = task;
	}
	return ret;
}

static struct file_operations proc_maps_operations = {
	.open		= maps_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656
#ifdef CONFIG_NUMA
extern struct seq_operations proc_pid_numa_maps_op;
static int numa_maps_open(struct inode *inode, struct file *file)
{
	struct task_struct *task = proc_task(inode);
	int ret = seq_open(file, &proc_pid_numa_maps_op);
	if (!ret) {
		struct seq_file *m = file->private_data;
		m->private = task;
	}
	return ret;
}

static struct file_operations proc_numa_maps_operations = {
	.open		= numa_maps_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};
#endif

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#ifdef CONFIG_MMU
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extern struct seq_operations proc_pid_smaps_op;
static int smaps_open(struct inode *inode, struct file *file)
{
	struct task_struct *task = proc_task(inode);
	int ret = seq_open(file, &proc_pid_smaps_op);
	if (!ret) {
		struct seq_file *m = file->private_data;
		m->private = task;
	}
	return ret;
}

static struct file_operations proc_smaps_operations = {
	.open		= smaps_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};
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#endif
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extern struct seq_operations mounts_op;
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struct proc_mounts {
	struct seq_file m;
	int event;
};

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static int mounts_open(struct inode *inode, struct file *file)
{
	struct task_struct *task = proc_task(inode);
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	struct namespace *namespace;
	struct proc_mounts *p;
	int ret = -EINVAL;
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	task_lock(task);
	namespace = task->namespace;
	if (namespace)
		get_namespace(namespace);
	task_unlock(task);

	if (namespace) {
		ret = -ENOMEM;
		p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
		if (p) {
			file->private_data = &p->m;
			ret = seq_open(file, &mounts_op);
			if (!ret) {
				p->m.private = namespace;
				p->event = namespace->event;
				return 0;
			}
			kfree(p);
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		}
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		put_namespace(namespace);
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	}
	return ret;
}

static int mounts_release(struct inode *inode, struct file *file)
{
	struct seq_file *m = file->private_data;
	struct namespace *namespace = m->private;
	put_namespace(namespace);
	return seq_release(inode, file);
}

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static unsigned mounts_poll(struct file *file, poll_table *wait)
{
	struct proc_mounts *p = file->private_data;
	struct namespace *ns = p->m.private;
	unsigned res = 0;

	poll_wait(file, &ns->poll, wait);

	spin_lock(&vfsmount_lock);
	if (p->event != ns->event) {
		p->event = ns->event;
		res = POLLERR;
	}
	spin_unlock(&vfsmount_lock);

	return res;
}

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static struct file_operations proc_mounts_operations = {
	.open		= mounts_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= mounts_release,
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	.poll		= mounts_poll,
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};

749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780
extern struct seq_operations mountstats_op;
static int mountstats_open(struct inode *inode, struct file *file)
{
	struct task_struct *task = proc_task(inode);
	int ret = seq_open(file, &mountstats_op);

	if (!ret) {
		struct seq_file *m = file->private_data;
		struct namespace *namespace;
		task_lock(task);
		namespace = task->namespace;
		if (namespace)
			get_namespace(namespace);
		task_unlock(task);

		if (namespace)
			m->private = namespace;
		else {
			seq_release(inode, file);
			ret = -EINVAL;
		}
	}
	return ret;
}

static struct file_operations proc_mountstats_operations = {
	.open		= mountstats_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= mounts_release,
};

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#define PROC_BLOCK_SIZE	(3*1024)		/* 4K page size but our output routines use some slack for overruns */

static ssize_t proc_info_read(struct file * file, char __user * buf,
			  size_t count, loff_t *ppos)
{
	struct inode * inode = file->f_dentry->d_inode;
	unsigned long page;
	ssize_t length;
	struct task_struct *task = proc_task(inode);

	if (count > PROC_BLOCK_SIZE)
		count = PROC_BLOCK_SIZE;
	if (!(page = __get_free_page(GFP_KERNEL)))
		return -ENOMEM;

	length = PROC_I(inode)->op.proc_read(task, (char*)page);

	if (length >= 0)
		length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
	free_page(page);
	return length;
}

static struct file_operations proc_info_file_operations = {
	.read		= proc_info_read,
};

static int mem_open(struct inode* inode, struct file* file)
{
	file->private_data = (void*)((long)current->self_exec_id);
	return 0;
}

static ssize_t mem_read(struct file * file, char __user * buf,
			size_t count, loff_t *ppos)
{
	struct task_struct *task = proc_task(file->f_dentry->d_inode);
	char *page;
	unsigned long src = *ppos;
	int ret = -ESRCH;
	struct mm_struct *mm;

823
	if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
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		goto out;

	ret = -ENOMEM;
	page = (char *)__get_free_page(GFP_USER);
	if (!page)
		goto out;

	ret = 0;
 
	mm = get_task_mm(task);
	if (!mm)
		goto out_free;

	ret = -EIO;
 
	if (file->private_data != (void*)((long)current->self_exec_id))
		goto out_put;

	ret = 0;
 
	while (count > 0) {
		int this_len, retval;

		this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
		retval = access_process_vm(task, src, page, this_len, 0);
849
		if (!retval || !MAY_PTRACE(task) || !ptrace_may_attach(task)) {
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			if (!ret)
				ret = -EIO;
			break;
		}

		if (copy_to_user(buf, page, retval)) {
			ret = -EFAULT;
			break;
		}
 
		ret += retval;
		src += retval;
		buf += retval;
		count -= retval;
	}
	*ppos = src;

out_put:
	mmput(mm);
out_free:
	free_page((unsigned long) page);
out:
	return ret;
}

#define mem_write NULL

#ifndef mem_write
/* This is a security hazard */
static ssize_t mem_write(struct file * file, const char * buf,
			 size_t count, loff_t *ppos)
{
	int copied = 0;
	char *page;
	struct task_struct *task = proc_task(file->f_dentry->d_inode);
	unsigned long dst = *ppos;

887
	if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
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		return -ESRCH;

	page = (char *)__get_free_page(GFP_USER);
	if (!page)
		return -ENOMEM;

	while (count > 0) {
		int this_len, retval;

		this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
		if (copy_from_user(page, buf, this_len)) {
			copied = -EFAULT;
			break;
		}
		retval = access_process_vm(task, dst, page, this_len, 1);
		if (!retval) {
			if (!copied)
				copied = -EIO;
			break;
		}
		copied += retval;
		buf += retval;
		dst += retval;
		count -= retval;			
	}
	*ppos = dst;
	free_page((unsigned long) page);
	return copied;
}
#endif

static loff_t mem_lseek(struct file * file, loff_t offset, int orig)
{
	switch (orig) {
	case 0:
		file->f_pos = offset;
		break;
	case 1:
		file->f_pos += offset;
		break;
	default:
		return -EINVAL;
	}
	force_successful_syscall_return();
	return file->f_pos;
}

static struct file_operations proc_mem_operations = {
	.llseek		= mem_lseek,
	.read		= mem_read,
	.write		= mem_write,
	.open		= mem_open,
};

static ssize_t oom_adjust_read(struct file *file, char __user *buf,
				size_t count, loff_t *ppos)
{
	struct task_struct *task = proc_task(file->f_dentry->d_inode);
	char buffer[8];
	size_t len;
	int oom_adjust = task->oomkilladj;
	loff_t __ppos = *ppos;

	len = sprintf(buffer, "%i\n", oom_adjust);
	if (__ppos >= len)
		return 0;
	if (count > len-__ppos)
		count = len-__ppos;
	if (copy_to_user(buf, buffer + __ppos, count))
		return -EFAULT;
	*ppos = __ppos + count;
	return count;
}

static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
				size_t count, loff_t *ppos)
{
	struct task_struct *task = proc_task(file->f_dentry->d_inode);
	char buffer[8], *end;
	int oom_adjust;

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;
	memset(buffer, 0, 8);
	if (count > 6)
		count = 6;
	if (copy_from_user(buffer, buf, count))
		return -EFAULT;
	oom_adjust = simple_strtol(buffer, &end, 0);
977
	if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
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		return -EINVAL;
	if (*end == '\n')
		end++;
	task->oomkilladj = oom_adjust;
	if (end - buffer == 0)
		return -EIO;
	return end - buffer;
}

static struct file_operations proc_oom_adjust_operations = {
	.read		= oom_adjust_read,
	.write		= oom_adjust_write,
};

static struct inode_operations proc_mem_inode_operations = {
	.permission	= proc_permission,
};

#ifdef CONFIG_AUDITSYSCALL
#define TMPBUFLEN 21
static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
	struct inode * inode = file->f_dentry->d_inode;
	struct task_struct *task = proc_task(inode);
	ssize_t length;
	char tmpbuf[TMPBUFLEN];

	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
				audit_get_loginuid(task->audit_context));
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
				   size_t count, loff_t *ppos)
{
	struct inode * inode = file->f_dentry->d_inode;
	char *page, *tmp;
	ssize_t length;
	struct task_struct *task = proc_task(inode);
	uid_t loginuid;

	if (!capable(CAP_AUDIT_CONTROL))
		return -EPERM;

	if (current != task)
		return -EPERM;

1026 1027
	if (count >= PAGE_SIZE)
		count = PAGE_SIZE - 1;
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	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}
	page = (char*)__get_free_page(GFP_USER);
	if (!page)
		return -ENOMEM;
	length = -EFAULT;
	if (copy_from_user(page, buf, count))
		goto out_free_page;

1040
	page[count] = '\0';
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	loginuid = simple_strtoul(page, &tmp, 10);
	if (tmp == page) {
		length = -EINVAL;
		goto out_free_page;

	}
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	length = audit_set_loginuid(task, loginuid);
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	if (likely(length == 0))
		length = count;

out_free_page:
	free_page((unsigned long) page);
	return length;
}

static struct file_operations proc_loginuid_operations = {
	.read		= proc_loginuid_read,
	.write		= proc_loginuid_write,
};
#endif

#ifdef CONFIG_SECCOMP
static ssize_t seccomp_read(struct file *file, char __user *buf,
			    size_t count, loff_t *ppos)
{
	struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
	char __buf[20];
	loff_t __ppos = *ppos;
	size_t len;

	/* no need to print the trailing zero, so use only len */
	len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
	if (__ppos >= len)
		return 0;
	if (count > len - __ppos)
		count = len - __ppos;
	if (copy_to_user(buf, __buf + __ppos, count))
		return -EFAULT;
	*ppos = __ppos + count;
	return count;
}

static ssize_t seccomp_write(struct file *file, const char __user *buf,
			     size_t count, loff_t *ppos)
{
	struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
	char __buf[20], *end;
	unsigned int seccomp_mode;

	/* can set it only once to be even more secure */
	if (unlikely(tsk->seccomp.mode))
		return -EPERM;

	memset(__buf, 0, sizeof(__buf));
	count = min(count, sizeof(__buf) - 1);
	if (copy_from_user(__buf, buf, count))
		return -EFAULT;
	seccomp_mode = simple_strtoul(__buf, &end, 0);
	if (*end == '\n')
		end++;
	if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
		tsk->seccomp.mode = seccomp_mode;
		set_tsk_thread_flag(tsk, TIF_SECCOMP);
	} else
		return -EINVAL;
	if (unlikely(!(end - __buf)))
		return -EIO;
	return end - __buf;
}

static struct file_operations proc_seccomp_operations = {
	.read		= seccomp_read,
	.write		= seccomp_write,
};
#endif /* CONFIG_SECCOMP */

1117
static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
	struct inode *inode = dentry->d_inode;
	int error = -EACCES;

	/* We don't need a base pointer in the /proc filesystem */
	path_release(nd);

	if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
		goto out;
	error = proc_check_root(inode);
	if (error)
		goto out;

	error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
	nd->last_type = LAST_BIND;
out:
1134
	return ERR_PTR(error);
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}

static int do_proc_readlink(struct dentry *dentry, struct vfsmount *mnt,
			    char __user *buffer, int buflen)
{
	struct inode * inode;
	char *tmp = (char*)__get_free_page(GFP_KERNEL), *path;
	int len;

	if (!tmp)
		return -ENOMEM;
		
	inode = dentry->d_inode;
	path = d_path(dentry, mnt, tmp, PAGE_SIZE);
	len = PTR_ERR(path);
	if (IS_ERR(path))
		goto out;
	len = tmp + PAGE_SIZE - 1 - path;

	if (len > buflen)
		len = buflen;
	if (copy_to_user(buffer, path, len))
		len = -EFAULT;
 out:
	free_page((unsigned long)tmp);
	return len;
}

static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
{
	int error = -EACCES;
	struct inode *inode = dentry->d_inode;
	struct dentry *de;
	struct vfsmount *mnt = NULL;


	if (current->fsuid != inode->i_uid && !capable(CAP_DAC_OVERRIDE))
		goto out;
	error = proc_check_root(inode);
	if (error)
		goto out;

	error = PROC_I(inode)->op.proc_get_link(inode, &de, &mnt);
	if (error)
		goto out;

	error = do_proc_readlink(de, mnt, buffer, buflen);
	dput(de);
	mntput(mnt);
out:
	return error;
}

static struct inode_operations proc_pid_link_inode_operations = {
	.readlink	= proc_pid_readlink,
	.follow_link	= proc_pid_follow_link
};

#define NUMBUF 10

static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
{
1197 1198
	struct dentry *dentry = filp->f_dentry;
	struct inode *inode = dentry->d_inode;
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	struct task_struct *p = proc_task(inode);
	unsigned int fd, tid, ino;
	int retval;
	char buf[NUMBUF];
	struct files_struct * files;
1204
	struct fdtable *fdt;
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	retval = -ENOENT;
	if (!pid_alive(p))
		goto out;
	retval = 0;
	tid = p->pid;

	fd = filp->f_pos;
	switch (fd) {
		case 0:
			if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
				goto out;
			filp->f_pos++;
		case 1:
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			ino = parent_ino(dentry);
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			if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
				goto out;
			filp->f_pos++;
		default:
			files = get_files_struct(p);
			if (!files)
				goto out;
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			rcu_read_lock();
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			fdt = files_fdtable(files);
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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++) {
				unsigned int i,j;

				if (!fcheck_files(files, fd))
					continue;
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				rcu_read_unlock();
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				j = NUMBUF;
				i = fd;
				do {
					j--;
					buf[j] = '0' + (i % 10);
					i /= 10;
				} while (i);

				ino = fake_ino(tid, PROC_TID_FD_DIR + fd);
				if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
1248
					rcu_read_lock();
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					break;
				}
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				rcu_read_lock();
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			}
1253
			rcu_read_unlock();
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			put_files_struct(files);
	}
out:
	return retval;
}

static int proc_pident_readdir(struct file *filp,
		void *dirent, filldir_t filldir,
		struct pid_entry *ents, unsigned int nents)
{
	int i;
	int pid;
	struct dentry *dentry = filp->f_dentry;
	struct inode *inode = dentry->d_inode;
	struct pid_entry *p;
	ino_t ino;
	int ret;

	ret = -ENOENT;
	if (!pid_alive(proc_task(inode)))
		goto out;

	ret = 0;
	pid = proc_task(inode)->pid;
	i = filp->f_pos;
	switch (i) {
	case 0:
		ino = inode->i_ino;
		if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
			goto out;
		i++;
		filp->f_pos++;
		/* fall through */
	case 1:
		ino = parent_ino(dentry);
		if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
			goto out;
		i++;
		filp->f_pos++;
		/* fall through */
	default:
		i -= 2;
		if (i >= nents) {
			ret = 1;
			goto out;
		}
		p = ents + i;
		while (p->name) {
			if (filldir(dirent, p->name, p->len, filp->f_pos,
				    fake_ino(pid, p->type), p->mode >> 12) < 0)
				goto out;
			filp->f_pos++;
			p++;
		}
	}

	ret = 1;
out:
	return ret;
}

static int proc_tgid_base_readdir(struct file * filp,
			     void * dirent, filldir_t filldir)
{
	return proc_pident_readdir(filp,dirent,filldir,
				   tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
}

static int proc_tid_base_readdir(struct file * filp,
			     void * dirent, filldir_t filldir)
{
	return proc_pident_readdir(filp,dirent,filldir,
				   tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
}

/* building an inode */

static int task_dumpable(struct task_struct *task)
{
	int dumpable = 0;
	struct mm_struct *mm;

	task_lock(task);
	mm = task->mm;
	if (mm)
		dumpable = mm->dumpable;
	task_unlock(task);
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	if(dumpable == 1)
		return 1;
	return 0;
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}


static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task, int ino)
{
	struct inode * inode;
	struct proc_inode *ei;

	/* We need a new inode */
	
	inode = new_inode(sb);
	if (!inode)
		goto out;

	/* Common stuff */
	ei = PROC_I(inode);
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_ino = fake_ino(task->pid, ino);

	if (!pid_alive(task))
		goto out_unlock;

	/*
	 * grab the reference to task.
	 */
	get_task_struct(task);
	ei->task = task;
	ei->type = ino;
	inode->i_uid = 0;
	inode->i_gid = 0;
1374
	if (task_dumpable(task)) {
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		inode->i_uid = task->euid;
		inode->i_gid = task->egid;
	}
	security_task_to_inode(task, inode);

out:
	return inode;

out_unlock:
	iput(inode);
	return NULL;
}

/* dentry stuff */

/*
 *	Exceptional case: normally we are not allowed to unhash a busy
 * directory. In this case, however, we can do it - no aliasing problems
 * due to the way we treat inodes.
 *
 * Rewrite the inode's ownerships here because the owning task may have
 * performed a setuid(), etc.
 */
static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
{
	struct inode *inode = dentry->d_inode;
	struct task_struct *task = proc_task(inode);
	if (pid_alive(task)) {
1403
		if (task_dumpable(task)) {
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			inode->i_uid = task->euid;
			inode->i_gid = task->egid;
		} else {
			inode->i_uid = 0;
			inode->i_gid = 0;
		}
		security_task_to_inode(task, inode);
		return 1;
	}
	d_drop(dentry);
	return 0;
}

static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
{
	struct inode *inode = dentry->d_inode;
	struct task_struct *task = proc_task(inode);
	int fd = proc_type(inode) - PROC_TID_FD_DIR;
	struct files_struct *files;

	files = get_files_struct(task);
	if (files) {
1426
		rcu_read_lock();
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		if (fcheck_files(files, fd)) {
1428
			rcu_read_unlock();
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			put_files_struct(files);
			if (task_dumpable(task)) {
				inode->i_uid = task->euid;
				inode->i_gid = task->egid;
			} else {
				inode->i_uid = 0;
				inode->i_gid = 0;
			}
			security_task_to_inode(task, inode);
			return 1;
		}
1440
		rcu_read_unlock();
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		put_files_struct(files);
	}
	d_drop(dentry);
	return 0;
}

static void pid_base_iput(struct dentry *dentry, struct inode *inode)
{
	struct task_struct *task = proc_task(inode);
	spin_lock(&task->proc_lock);
	if (task->proc_dentry == dentry)
		task->proc_dentry = NULL;
	spin_unlock(&task->proc_lock);
	iput(inode);
}

static int pid_delete_dentry(struct dentry * dentry)
{
	/* Is the task we represent dead?
	 * If so, then don't put the dentry on the lru list,
	 * kill it immediately.
	 */
	return !pid_alive(proc_task(dentry->d_inode));
}

static struct dentry_operations tid_fd_dentry_operations =
{
	.d_revalidate	= tid_fd_revalidate,
	.d_delete	= pid_delete_dentry,
};

static struct dentry_operations pid_dentry_operations =
{
	.d_revalidate	= pid_revalidate,
	.d_delete	= pid_delete_dentry,
};

static struct dentry_operations pid_base_dentry_operations =
{
	.d_revalidate	= pid_revalidate,
	.d_iput		= pid_base_iput,
	.d_delete	= pid_delete_dentry,
};

/* Lookups */

static unsigned name_to_int(struct dentry *dentry)
{
	const char *name = dentry->d_name.name;
	int len = dentry->d_name.len;
	unsigned n = 0;

	if (len > 1 && *name == '0')
		goto out;
	while (len-- > 0) {
		unsigned c = *name++ - '0';
		if (c > 9)
			goto out;
		if (n >= (~0U-9)/10)
			goto out;
		n *= 10;
		n += c;
	}
	return n;
out:
	return ~0U;
}

/* SMP-safe */
static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
{
	struct task_struct *task = proc_task(dir);
	unsigned fd = name_to_int(dentry);
	struct file * file;
	struct files_struct * files;
	struct inode *inode;
	struct proc_inode *ei;

	if (fd == ~0U)
		goto out;
	if (!pid_alive(task))
		goto out;

	inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
	if (!inode)
		goto out;
	ei = PROC_I(inode);
	files = get_files_struct(task);
	if (!files)
		goto out_unlock;
	inode->i_mode = S_IFLNK;
1532 1533 1534 1535 1536 1537

	/*
	 * We are not taking a ref to the file structure, so we must
	 * hold ->file_lock.
	 */
	spin_lock(&files->file_lock);
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	file = fcheck_files(files, fd);
	if (!file)
		goto out_unlock2;
	if (file->f_mode & 1)
		inode->i_mode |= S_IRUSR | S_IXUSR;
	if (file->f_mode & 2)
		inode->i_mode |= S_IWUSR | S_IXUSR;
1545
	spin_unlock(&files->file_lock);
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	put_files_struct(files);
	inode->i_op = &proc_pid_link_inode_operations;
	inode->i_size = 64;
	ei->op.proc_get_link = proc_fd_link;
	dentry->d_op = &tid_fd_dentry_operations;
	d_add(dentry, inode);
	return NULL;

out_unlock2:
1555
	spin_unlock(&files->file_lock);
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	put_files_struct(files);
out_unlock:
	iput(inode);
out:
	return ERR_PTR(-ENOENT);
}

static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir);
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd);

static struct file_operations proc_fd_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_readfd,
};

static struct file_operations proc_task_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_task_readdir,
};

/*
 * proc directories can do almost nothing..
 */
static struct inode_operations proc_fd_inode_operations = {
	.lookup		= proc_lookupfd,
	.permission	= proc_permission,
};

static struct inode_operations proc_task_inode_operations = {
	.lookup		= proc_task_lookup,
1586
	.permission	= proc_task_permission,
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};

#ifdef CONFIG_SECURITY
static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
	struct inode * inode = file->f_dentry->d_inode;
	unsigned long page;
	ssize_t length;
	struct task_struct *task = proc_task(inode);

	if (count > PAGE_SIZE)
		count = PAGE_SIZE;
	if (!(page = __get_free_page(GFP_KERNEL)))
		return -ENOMEM;

	length = security_getprocattr(task, 
				      (char*)file->f_dentry->d_name.name, 
				      (void*)page, count);
	if (length >= 0)
		length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
	free_page(page);
	return length;
}

static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
				   size_t count, loff_t *ppos)
{ 
	struct inode * inode = file->f_dentry->d_inode;
	char *page; 
	ssize_t length; 
	struct task_struct *task = proc_task(inode); 

	if (count > PAGE_SIZE) 
		count = PAGE_SIZE; 
	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}
	page = (char*)__get_free_page(GFP_USER); 
	if (!page) 
		return -ENOMEM;
	length = -EFAULT; 
	if (copy_from_user(page, buf, count)) 
		goto out;

	length = security_setprocattr(task, 
				      (char*)file->f_dentry->d_name.name, 
				      (void*)page, count);
out:
	free_page((unsigned long) page);
	return length;
} 

static struct file_operations proc_pid_attr_operations = {
	.read		= proc_pid_attr_read,
	.write		= proc_pid_attr_write,
};

static struct file_operations proc_tid_attr_operations;
static struct inode_operations proc_tid_attr_inode_operations;
static struct file_operations proc_tgid_attr_operations;
static struct inode_operations proc_tgid_attr_inode_operations;
#endif

1652 1653
static int get_tid_list(int index, unsigned int *tids, struct inode *dir);

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/* SMP-safe */
static struct dentry *proc_pident_lookup(struct inode *dir, 
					 struct dentry *dentry,
					 struct pid_entry *ents)
{
	struct inode *inode;
	int error;
	struct task_struct *task = proc_task(dir);
	struct pid_entry *p;
	struct proc_inode *ei;

	error = -ENOENT;
	inode = NULL;

	if (!pid_alive(task))
		goto out;

	for (p = ents; p->name; p++) {
		if (p->len != dentry->d_name.len)
			continue;
		if (!memcmp(dentry->d_name.name, p->name, p->len))
			break;
	}
	if (!p->name)
		goto out;

	error = -EINVAL;
	inode = proc_pid_make_inode(dir->i_sb, task, p->type);
	if (!inode)
		goto out;

	ei = PROC_I(inode);
	inode->i_mode = p->mode;
	/*
	 * Yes, it does not scale. And it should not. Don't add
	 * new entries into /proc/<tgid>/ without very good reasons.
	 */
	switch(p->type) {
		case PROC_TGID_TASK:
1693
			inode->i_nlink = 2 + get_tid_list(2, NULL, dir);
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			inode->i_op = &proc_task_inode_operations;
			inode->i_fop = &proc_task_operations;
			break;
		case PROC_TID_FD:
		case PROC_TGID_FD:
			inode->i_nlink = 2;
			inode->i_op = &proc_fd_inode_operations;
			inode->i_fop = &proc_fd_operations;
			break;
		case PROC_TID_EXE:
		case PROC_TGID_EXE:
			inode->i_op = &proc_pid_link_inode_operations;
			ei->op.proc_get_link = proc_exe_link;
			break;
		case PROC_TID_CWD:
		case PROC_TGID_CWD:
			inode->i_op = &proc_pid_link_inode_operations;
			ei->op.proc_get_link = proc_cwd_link;
			break;
		case PROC_TID_ROOT:
		case PROC_TGID_ROOT:
			inode->i_op = &proc_pid_link_inode_operations;
			ei->op.proc_get_link = proc_root_link;
			break;
		case PROC_TID_ENVIRON:
		case PROC_TGID_ENVIRON:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_environ;
			break;
		case PROC_TID_AUXV:
		case PROC_TGID_AUXV:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_auxv;
			break;
		case PROC_TID_STATUS:
		case PROC_TGID_STATUS:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_status;
			break;
		case PROC_TID_STAT:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_tid_stat;
			break;
		case PROC_TGID_STAT:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_tgid_stat;
			break;
		case PROC_TID_CMDLINE:
		case PROC_TGID_CMDLINE:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_cmdline;
			break;
		case PROC_TID_STATM:
		case PROC_TGID_STATM:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_statm;
			break;
		case PROC_TID_MAPS:
		case PROC_TGID_MAPS:
			inode->i_fop = &proc_maps_operations;
			break;
1755 1756 1757 1758 1759 1760
#ifdef CONFIG_NUMA
		case PROC_TID_NUMA_MAPS:
		case PROC_TGID_NUMA_MAPS:
			inode->i_fop = &proc_numa_maps_operations;
			break;
#endif
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		case PROC_TID_MEM:
		case PROC_TGID_MEM:
			inode->i_op = &proc_mem_inode_operations;
			inode->i_fop = &proc_mem_operations;
			break;
#ifdef CONFIG_SECCOMP
		case PROC_TID_SECCOMP:
		case PROC_TGID_SECCOMP:
			inode->i_fop = &proc_seccomp_operations;
			break;
#endif /* CONFIG_SECCOMP */
		case PROC_TID_MOUNTS:
		case PROC_TGID_MOUNTS:
			inode->i_fop = &proc_mounts_operations;
			break;
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#ifdef CONFIG_MMU
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		case PROC_TID_SMAPS:
		case PROC_TGID_SMAPS:
			inode->i_fop = &proc_smaps_operations;
			break;
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#endif
1782 1783 1784 1785
		case PROC_TID_MOUNTSTATS:
		case PROC_TGID_MOUNTSTATS:
			inode->i_fop = &proc_mountstats_operations;
			break;
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#ifdef CONFIG_SECURITY
		case PROC_TID_ATTR:
			inode->i_nlink = 2;
			inode->i_op = &proc_tid_attr_inode_operations;
			inode->i_fop = &proc_tid_attr_operations;
			break;
		case PROC_TGID_ATTR:
			inode->i_nlink = 2;
			inode->i_op = &proc_tgid_attr_inode_operations;
			inode->i_fop = &proc_tgid_attr_operations;
			break;
		case PROC_TID_ATTR_CURRENT:
		case PROC_TGID_ATTR_CURRENT:
		case PROC_TID_ATTR_PREV:
		case PROC_TGID_ATTR_PREV:
		case PROC_TID_ATTR_EXEC:
		case PROC_TGID_ATTR_EXEC:
		case PROC_TID_ATTR_FSCREATE:
		case PROC_TGID_ATTR_FSCREATE:
1805 1806
		case PROC_TID_ATTR_KEYCREATE:
		case PROC_TGID_ATTR_KEYCREATE:
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			inode->i_fop = &proc_pid_attr_operations;
			break;
#endif
#ifdef CONFIG_KALLSYMS
		case PROC_TID_WCHAN:
		case PROC_TGID_WCHAN:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_wchan;
			break;
#endif
#ifdef CONFIG_SCHEDSTATS
		case PROC_TID_SCHEDSTAT:
		case PROC_TGID_SCHEDSTAT:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_pid_schedstat;
			break;
#endif
#ifdef CONFIG_CPUSETS
		case PROC_TID_CPUSET:
		case PROC_TGID_CPUSET:
			inode->i_fop = &proc_cpuset_operations;
			break;
#endif
		case PROC_TID_OOM_SCORE:
		case PROC_TGID_OOM_SCORE:
			inode->i_fop = &proc_info_file_operations;
			ei->op.proc_read = proc_oom_score;
			break;
		case PROC_TID_OOM_ADJUST:
		case PROC_TGID_OOM_ADJUST:
			inode->i_fop = &proc_oom_adjust_operations;
			break;
#ifdef CONFIG_AUDITSYSCALL
		case PROC_TID_LOGINUID:
		case PROC_TGID_LOGINUID:
			inode->i_fop = &proc_loginuid_operations;
			break;
#endif
		default:
			printk("procfs: impossible type (%d)",p->type);
			iput(inode);
			return ERR_PTR(-EINVAL);
	}
	dentry->d_op = &pid_dentry_operations;
	d_add(dentry, inode);
	return NULL;

out:
	return ERR_PTR(error);
}

static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
	return proc_pident_lookup(dir, dentry, tgid_base_stuff);
}

static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
	return proc_pident_lookup(dir, dentry, tid_base_stuff);
}

static struct file_operations proc_tgid_base_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_tgid_base_readdir,
};

static struct file_operations proc_tid_base_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_tid_base_readdir,
};

static struct inode_operations proc_tgid_base_inode_operations = {
	.lookup		= proc_tgid_base_lookup,
};

static struct inode_operations proc_tid_base_inode_operations = {
	.lookup		= proc_tid_base_lookup,
};

#ifdef CONFIG_SECURITY
static int proc_tgid_attr_readdir(struct file * filp,
			     void * dirent, filldir_t filldir)
{
	return proc_pident_readdir(filp,dirent,filldir,
				   tgid_attr_stuff,ARRAY_SIZE(tgid_attr_stuff));
}

static int proc_tid_attr_readdir(struct file * filp,
			     void * dirent, filldir_t filldir)
{
	return proc_pident_readdir(filp,dirent,filldir,
				   tid_attr_stuff,ARRAY_SIZE(tid_attr_stuff));
}

static struct file_operations proc_tgid_attr_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_tgid_attr_readdir,
};

static struct file_operations proc_tid_attr_operations = {
	.read		= generic_read_dir,
	.readdir	= proc_tid_attr_readdir,
};

static struct dentry *proc_tgid_attr_lookup(struct inode *dir,
				struct dentry *dentry, struct nameidata *nd)
{
	return proc_pident_lookup(dir, dentry, tgid_attr_stuff);
}

static struct dentry *proc_tid_attr_lookup(struct inode *dir,
				struct dentry *dentry, struct nameidata *nd)
{
	return proc_pident_lookup(dir, dentry, tid_attr_stuff);
}

static struct inode_operations proc_tgid_attr_inode_operations = {
	.lookup		= proc_tgid_attr_lookup,
};

static struct inode_operations proc_tid_attr_inode_operations = {
	.lookup		= proc_tid_attr_lookup,
};
#endif

/*
 * /proc/self:
 */
static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
			      int buflen)
{
	char tmp[30];
	sprintf(tmp, "%d", current->tgid);
	return vfs_readlink(dentry,buffer,buflen,tmp);
}

1941
static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
	char tmp[30];
	sprintf(tmp, "%d", current->tgid);
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	return ERR_PTR(vfs_follow_link(nd,tmp));
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}	

static struct inode_operations proc_self_inode_operations = {
	.readlink	= proc_self_readlink,
	.follow_link	= proc_self_follow_link,
};

/**
1954
 * proc_pid_unhash -  Unhash /proc/@pid entry from the dcache.
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 * @p: task that should be flushed.
 *
1957
 * Drops the /proc/@pid dcache entry from the hash chains.
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 *
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 * Dropping /proc/@pid entries and detach_pid must be synchroneous,
 * otherwise e.g. /proc/@pid/exe might point to the wrong executable,
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 * if the pid value is immediately reused. This is enforced by
 * - caller must acquire spin_lock(p->proc_lock)
 * - must be called before detach_pid()
 * - proc_pid_lookup acquires proc_lock, and checks that
 *   the target is not dead by looking at the attach count
 *   of PIDTYPE_PID.
 */

struct dentry *proc_pid_unhash(struct task_struct *p)
{
	struct dentry *proc_dentry;

	proc_dentry = p->proc_dentry;
	if (proc_dentry != NULL) {

		spin_lock(&dcache_lock);
		spin_lock(&proc_dentry->d_lock);
		if (!d_unhashed(proc_dentry)) {
			dget_locked(proc_dentry);
			__d_drop(proc_dentry);
			spin_unlock(&proc_dentry->d_lock);
		} else {
			spin_unlock(&proc_dentry->d_lock);
			proc_dentry = NULL;
		}
		spin_unlock(&dcache_lock);
	}
	return proc_dentry;
}

/**
1992
 * proc_pid_flush - recover memory used by stale /proc/@pid/x entries
1993
 * @proc_dentry: directoy to prune.
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 *
 * Shrink the /proc directory that was used by the just killed thread.
 */
	
void proc_pid_flush(struct dentry *proc_dentry)
{
	might_sleep();
	if(proc_dentry != NULL) {
		shrink_dcache_parent(proc_dentry);
		dput(proc_dentry);
	}
}

/* SMP-safe */
struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
	struct task_struct *task;
	struct inode *inode;
	struct proc_inode *ei;
	unsigned tgid;
	int died;

	if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) {
		inode = new_inode(dir->i_sb);
		if (!inode)
			return ERR_PTR(-ENOMEM);
		ei = PROC_I(inode);
		inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
		inode->i_ino = fake_ino(0, PROC_TGID_INO);
		ei->pde = NULL;
		inode->i_mode = S_IFLNK|S_IRWXUGO;
		inode->i_uid = inode->i_gid = 0;
		inode->i_size = 64;
		inode->i_op = &proc_self_inode_operations;
		d_add(dentry, inode);
		return NULL;
	}
	tgid = name_to_int(dentry);
	if (tgid == ~0U)
		goto out;

	read_lock(&tasklist_lock);
	task = find_task_by_pid(tgid);
	if (task)
		get_task_struct(task);
	read_unlock(&tasklist_lock);
	if (!task)
		goto out;

	inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);


	if (!inode) {
		put_task_struct(task);
		goto out;
	}
	inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
	inode->i_op = &proc_tgid_base_inode_operations;
	inode->i_fop = &proc_tgid_base_operations;
	inode->i_flags|=S_IMMUTABLE;
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#ifdef CONFIG_SECURITY
	inode->i_nlink = 5;
#else
	inode->i_nlink = 4;
#endif
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	dentry->d_op = &pid_base_dentry_operations;

	died = 0;
	d_add(dentry, inode);
	spin_lock(&task->proc_lock);
	task->proc_dentry = dentry;
	if (!pid_alive(task)) {
		dentry = proc_pid_unhash(task);
		died = 1;
	}
	spin_unlock(&task->proc_lock);

	put_task_struct(task);
	if (died) {
		proc_pid_flush(dentry);
		goto out;
	}
	return NULL;
out:
	return ERR_PTR(-ENOENT);
}

/* SMP-safe */
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
	struct task_struct *task;
	struct task_struct *leader = proc_task(dir);
	struct inode *inode;
	unsigned tid;

	tid = name_to_int(dentry);
	if (tid == ~0U)
		goto out;

	read_lock(&tasklist_lock);
	task = find_task_by_pid(tid);
	if (task)
		get_task_struct(task);
	read_unlock(&tasklist_lock);
	if (!task)
		goto out;
	if (leader->tgid != task->tgid)
		goto out_drop_task;

	inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);


	if (!inode)
		goto out_drop_task;
	inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
	inode->i_op = &proc_tid_base_inode_operations;
	inode->i_fop = &proc_tid_base_operations;
	inode->i_flags|=S_IMMUTABLE;
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#ifdef CONFIG_SECURITY
	inode->i_nlink = 4;
#else
	inode->i_nlink = 3;
#endif
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	dentry->d_op = &pid_base_dentry_operations;

	d_add(dentry, inode);

	put_task_struct(task);
	return NULL;
out_drop_task:
	put_task_struct(task);
out:
	return ERR_PTR(-ENOENT);
}

#define PROC_NUMBUF 10
#define PROC_MAXPIDS 20

/*
 * Get a few tgid's to return for filldir - we need to hold the
 * tasklist lock while doing this, and we must release it before
 * we actually do the filldir itself, so we use a temp buffer..
 */
static int get_tgid_list(int index, unsigned long version, unsigned int *tgids)
{
	struct task_struct *p;
	int nr_tgids = 0;

	index--;
	read_lock(&tasklist_lock);
	p = NULL;
	if (version) {
		p = find_task_by_pid(version);
		if (p && !thread_group_leader(p))
			p = NULL;
	}

	if (p)
		index = 0;
	else
		p = next_task(&init_task);

	for ( ; p != &init_task; p = next_task(p)) {
		int tgid = p->pid;
		if (!pid_alive(p))
			continue;
		if (--index >= 0)
			continue;
		tgids[nr_tgids] = tgid;
		nr_tgids++;
		if (nr_tgids >= PROC_MAXPIDS)
			break;
	}
	read_unlock(&tasklist_lock);
	return nr_tgids;
}

/*
 * Get a few tid's to return for filldir - we need to hold the
 * tasklist lock while doing this, and we must release it before
 * we actually do the filldir itself, so we use a temp buffer..
 */
static int get_tid_list(int index, unsigned int *tids, struct inode *dir)
{
	struct task_struct *leader_task = proc_task(dir);
	struct task_struct *task = leader_task;
	int nr_tids = 0;

	index -= 2;
	read_lock(&tasklist_lock);
	/*
	 * The starting point task (leader_task) might be an already
	 * unlinked task, which cannot be used to access the task-list
	 * via next_thread().
	 */
	if (pid_alive(task)) do {
		int tid = task->pid;

		if (--index >= 0)
			continue;
2196 2197
		if (tids != NULL)
			tids[nr_tids] = tid;
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		nr_tids++;
		if (nr_tids >= PROC_MAXPIDS)
			break;
	} while ((task = next_thread(task)) != leader_task);
	read_unlock(&tasklist_lock);
	return nr_tids;
}

/* for the /proc/ directory itself, after non-process stuff has been done */
int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
	unsigned int tgid_array[PROC_MAXPIDS];
	char buf[PROC_NUMBUF];
	unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
	unsigned int nr_tgids, i;
	int next_tgid;

	if (!nr) {
		ino_t ino = fake_ino(0,PROC_TGID_INO);
		if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0)
			return 0;
		filp->f_pos++;
		nr++;
	}

	/* f_version caches the tgid value that the last readdir call couldn't
	 * return. lseek aka telldir automagically resets f_version to 0.
	 */
	next_tgid = filp->f_version;
	filp->f_version = 0;
	for (;;) {
		nr_tgids = get_tgid_list(nr, next_tgid, tgid_array);
		if (!nr_tgids) {
			/* no more entries ! */
			break;
		}
		next_tgid = 0;

		/* do not use the last found pid, reserve it for next_tgid */
		if (nr_tgids == PROC_MAXPIDS) {
			nr_tgids--;
			next_tgid = tgid_array[nr_tgids];
		}

		for (i=0;i<nr_tgids;i++) {
			int tgid = tgid_array[i];
			ino_t ino = fake_ino(tgid,PROC_TGID_INO);
			unsigned long j = PROC_NUMBUF;

			do
				buf[--j] = '0' + (tgid % 10);
			while ((tgid /= 10) != 0);

			if (filldir(dirent, buf+j, PROC_NUMBUF-j, filp->f_pos, ino, DT_DIR) < 0) {
				/* returning this tgid failed, save it as the first
				 * pid for the next readir call */
				filp->f_version = tgid_array[i];
				goto out;
			}
			filp->f_pos++;
			nr++;
		}
	}
out:
	return 0;
}

/* for the /proc/TGID/task/ directories */
static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
	unsigned int tid_array[PROC_MAXPIDS];
	char buf[PROC_NUMBUF];
	unsigned int nr_tids, i;
	struct dentry *dentry = filp->f_dentry;
	struct inode *inode = dentry->d_inode;
	int retval = -ENOENT;
	ino_t ino;
	unsigned long pos = filp->f_pos;  /* avoiding "long long" filp->f_pos */

	if (!pid_alive(proc_task(inode)))
		goto out;
	retval = 0;

	switch (pos) {
	case 0:
		ino = inode->i_ino;
		if (filldir(dirent, ".", 1, pos, ino, DT_DIR) < 0)
			goto out;
		pos++;
		/* fall through */
	case 1:
		ino = parent_ino(dentry);
		if (filldir(dirent, "..", 2, pos, ino, DT_DIR) < 0)
			goto out;
		pos++;
		/* fall through */
	}

	nr_tids = get_tid_list(pos, tid_array, inode);
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	inode->i_nlink = pos + nr_tids;
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	for (i = 0; i < nr_tids; i++) {
		unsigned long j = PROC_NUMBUF;
		int tid = tid_array[i];

		ino = fake_ino(tid,PROC_TID_INO);

		do
			buf[--j] = '0' + (tid % 10);
		while ((tid /= 10) != 0);

		if (filldir(dirent, buf+j, PROC_NUMBUF-j, pos, ino, DT_DIR) < 0)
			break;
		pos++;
	}
out:
	filp->f_pos = pos;
	return retval;
}