base.c 48.4 KB
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Linus Torvalds 已提交
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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.
 */

#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>
#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>
#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>
#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,
	PROC_TGID_MOUNTS,
	PROC_TGID_WCHAN,
#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,
#endif
#ifdef CONFIG_AUDITSYSCALL
	PROC_TGID_LOGINUID,
#endif
	PROC_TGID_FD_DIR,
	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,
	PROC_TID_MOUNTS,
	PROC_TID_WCHAN,
#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,
#endif
#ifdef CONFIG_AUDITSYSCALL
	PROC_TID_LOGINUID,
#endif
	PROC_TID_FD_DIR = 0x8000,	/* 0x8000-0xffff */
	PROC_TID_OOM_SCORE,
	PROC_TID_OOM_ADJUST,
};

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),
	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),
#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),
	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),
#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),
	{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),
	{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) {
		spin_lock(&files->file_lock);
		file = fcheck_files(files, fd);
		if (file) {
			*mnt = mntget(file->f_vfsmnt);
			*dentry = dget(file->f_dentry);
			spin_unlock(&files->file_lock);
			put_files_struct(files);
			return 0;
		}
		spin_unlock(&files->file_lock);
		put_files_struct(files);
	}
	return -ENOENT;
}

static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
	struct fs_struct *fs;
	int result = -ENOENT;
	task_lock(proc_task(inode));
	fs = proc_task(inode)->fs;
	if(fs)
		atomic_inc(&fs->count);
	task_unlock(proc_task(inode));
	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)
{
	struct fs_struct *fs;
	int result = -ENOENT;
	task_lock(proc_task(inode));
	fs = proc_task(inode)->fs;
	if(fs)
		atomic_inc(&fs->count);
	task_unlock(proc_task(inode));
	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;
}

#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 may_ptrace_attach(struct task_struct *task)
{
	int retval = 0;

	task_lock(task);

	if (!task->mm)
		goto out;
	if (((current->uid != task->euid) ||
	     (current->uid != task->suid) ||
	     (current->uid != task->uid) ||
	     (current->gid != task->egid) ||
	     (current->gid != task->sgid) ||
	     (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE))
		goto out;
	rmb();
A
Alan Cox 已提交
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	if (task->mm->dumpable != 1 && !capable(CAP_SYS_PTRACE))
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Linus Torvalds 已提交
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		goto out;
	if (security_ptrace(current, task))
		goto out;

	retval = 1;
out:
	task_unlock(task);
	return retval;
}

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);
		if (!may_ptrace_attach(task))
			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 */

static int proc_check_root(struct inode *inode)
{
	struct dentry *de, *base, *root;
	struct vfsmount *our_vfsmnt, *vfsmnt, *mnt;
	int res = 0;

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

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

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

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

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);
}

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,
};

extern struct seq_operations mounts_op;
static int mounts_open(struct inode *inode, struct file *file)
{
	struct task_struct *task = proc_task(inode);
	int ret = seq_open(file, &mounts_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 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);
}

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

#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;

	if (!MAY_PTRACE(task) || !may_ptrace_attach(task))
		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);
		if (!retval || !MAY_PTRACE(task) || !may_ptrace_attach(task)) {
			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;

	if (!MAY_PTRACE(task) || !may_ptrace_attach(task))
		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);
754
	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;

	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_free_page;

	loginuid = simple_strtoul(page, &tmp, 10);
	if (tmp == page) {
		length = -EINVAL;
		goto out_free_page;

	}
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Steve Grubb 已提交
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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 */

893
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:
910
	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;

	lock_kernel();

	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:
	unlock_kernel();
	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)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct task_struct *p = proc_task(inode);
	unsigned int fd, tid, ino;
	int retval;
	char buf[NUMBUF];
	struct files_struct * files;

	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:
			ino = fake_ino(tid, PROC_TID_INO);
			if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
				goto out;
			filp->f_pos++;
		default:
			files = get_files_struct(p);
			if (!files)
				goto out;
			spin_lock(&files->file_lock);
			for (fd = filp->f_pos-2;
			     fd < files->max_fds;
			     fd++, filp->f_pos++) {
				unsigned int i,j;

				if (!fcheck_files(files, fd))
					continue;
				spin_unlock(&files->file_lock);

				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) {
					spin_lock(&files->file_lock);
					break;
				}
				spin_lock(&files->file_lock);
			}
			spin_unlock(&files->file_lock);
			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);
A
Alan Cox 已提交
1116 1117 1118
	if(dumpable == 1)
		return 1;
	return 0;
L
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1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423
}


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);
	ei->task = NULL;
	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;
	if (ino == PROC_TGID_INO || ino == PROC_TID_INO || task_dumpable(task)) {
		inode->i_uid = task->euid;
		inode->i_gid = task->egid;
	}
	security_task_to_inode(task, inode);

out:
	return inode;

out_unlock:
	ei->pde = NULL;
	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)) {
		if (proc_type(inode) == PROC_TGID_INO || proc_type(inode) == PROC_TID_INO || 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;
	}
	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) {
		spin_lock(&files->file_lock);
		if (fcheck_files(files, fd)) {
			spin_unlock(&files->file_lock);
			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;
		}
		spin_unlock(&files->file_lock);
		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;
	spin_lock(&files->file_lock);
	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;
	spin_unlock(&files->file_lock);
	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:
	spin_unlock(&files->file_lock);
	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,
	.permission	= proc_permission,
};

#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

1424 1425
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:
1465
			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;
		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;
#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:
			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);
}

1695
static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
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{
	char tmp[30];
	sprintf(tmp, "%d", current->tgid);
1699
	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,
};

/**
1708
 * proc_pid_unhash -  Unhash /proc/@pid entry from the dcache.
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1709 1710
 * @p: task that should be flushed.
 *
1711
 * Drops the /proc/@pid dcache entry from the hash chains.
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1712
 *
1713 1714
 * 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;
}

/**
1746
 * proc_pid_flush - recover memory used by stale /proc/@pid/x entries
1747
 * @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;
1808 1809 1810 1811 1812
#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;
1867 1868 1869 1870 1871
#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;
1950 1951
		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);
2051
	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;
}