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778c114477
linux/fs/proc/base.c
Eric W. Biederman 778c114477 [PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks 
Since 2.2 we have been doing a chroot check to see if it is appropriate to
return a read or follow one of these magic symlinks.  The chroot check was
asking a question about the visibility of files to the calling process and
it was actually checking the destination process, and not the files
themselves.  That test was clearly bogus.

In my first pass through I simply fixed the test to check the visibility of
the files themselves.  That naive approach to fixing the permissions was
too strict and resulted in cases where a task could not even see all of
it's file descriptors.

What has disturbed me about relaxing this check is that file descriptors
are per-process private things, and they are occasionaly used a user space
capability tokens.  Looking a little farther into the symlink path on /proc
I did find userid checks and a check for capability (CAP_DAC_OVERRIDE) so
there were permissions checking this.

But I was still concerned about privacy.  Besides /proc there is only one
other way to find out this kind of information, and that is ptrace.  ptrace
has been around for a long time and it has a well established security
model.

So after thinking about it I finally realized that the permission checks
that make sense are the permission checks applied to ptrace_attach.  The
checks are simple per process, and won't cause nasty surprises for people
coming from less capable unices.

Unfortunately there is one case that the current ptrace_attach test does
not cover: Zombies and kernel threads.  Single stepping those kinds of
processes is impossible.  Being able to see which file descriptors are open
on these tasks is important to lsof, fuser and friends.  So for these
special processes I made the rule you can't find out unless you have
CAP_SYS_PTRACE.

These proc permission checks should now conform to the principle of least
surprise.  As well as using much less code to implement :)

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:26 -07:00

2375 lines
56 KiB
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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.
*
*
* 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.
*/
#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/capability.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/rcupdate.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 <linux/poll.h>
#include "internal.h"
/* NOTE:
* Implementing inode permission operations in /proc is almost
* certainly an error. Permission checks need to happen during
* each system call not at open time. The reason is that most of
* what we wish to check for permissions in /proc varies at runtime.
*
* The classic example of a problem is opening file descriptors
* in /proc for a task before it execs a suid executable.
*/
/*
* 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_NUMA_MAPS,
PROC_TGID_MOUNTS,
PROC_TGID_MOUNTSTATS,
PROC_TGID_WCHAN,
#ifdef CONFIG_MMU
PROC_TGID_SMAPS,
#endif
#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,
PROC_TGID_ATTR_KEYCREATE,
#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,
PROC_TID_NUMA_MAPS,
PROC_TID_MOUNTS,
PROC_TID_MOUNTSTATS,
PROC_TID_WCHAN,
#ifdef CONFIG_MMU
PROC_TID_SMAPS,
#endif
#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,
PROC_TID_ATTR_KEYCREATE,
#endif
#ifdef CONFIG_AUDITSYSCALL
PROC_TID_LOGINUID,
#endif
PROC_TID_OOM_SCORE,
PROC_TID_OOM_ADJUST,
/* Add new entries before this */
PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */
};
/* Worst case buffer size needed for holding an integer. */
#define PROC_NUMBUF 10
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),
#ifdef CONFIG_NUMA
E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
#endif
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),
E(PROC_TGID_MOUNTSTATS, "mountstats", S_IFREG|S_IRUSR),
#ifdef CONFIG_MMU
E(PROC_TGID_SMAPS, "smaps", S_IFREG|S_IRUGO),
#endif
#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),
#ifdef CONFIG_NUMA
E(PROC_TID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
#endif
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_MMU
E(PROC_TID_SMAPS, "smaps", S_IFREG|S_IRUGO),
#endif
#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),
E(PROC_TGID_ATTR_KEYCREATE, "keycreate", 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),
E(PROC_TID_ATTR_KEYCREATE, "keycreate", 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 = get_proc_task(inode);
struct files_struct *files = NULL;
struct file *file;
int fd = proc_fd(inode);
if (task) {
files = get_files_struct(task);
put_task_struct(task);
}
if (files) {
/*
* We are not taking a ref to the file structure, so we must
* hold ->file_lock.
*/
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 struct fs_struct *get_fs_struct(struct task_struct *task)
{
struct fs_struct *fs;
task_lock(task);
fs = task->fs;
if(fs)
atomic_inc(&fs->count);
task_unlock(task);
return fs;
}
static int get_nr_threads(struct task_struct *tsk)
{
/* Must be called with the rcu_read_lock held */
unsigned long flags;
int count = 0;
if (lock_task_sighand(tsk, &flags)) {
count = atomic_read(&tsk->signal->count);
unlock_task_sighand(tsk, &flags);
}
return count;
}
static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
struct task_struct *task = get_proc_task(inode);
struct fs_struct *fs = NULL;
int result = -ENOENT;
if (task) {
fs = get_fs_struct(task);
put_task_struct(task);
}
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 task_struct *task = get_proc_task(inode);
struct fs_struct *fs = NULL;
int result = -ENOENT;
if (task) {
fs = get_fs_struct(task);
put_task_struct(task);
}
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 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 (!ptrace_may_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_fd_access_allowed(struct inode *inode)
{
struct task_struct *task;
int allowed = 0;
/* Allow access to a task's file descriptors if either we may
* use ptrace attach to the process and find out that
* information, or if the task cannot possibly be ptraced
* allow access if we have the proper capability.
*/
task = get_proc_task(inode);
if (task == current)
allowed = 1;
if (task && !allowed) {
int alive;
task_lock(task);
alive = !!task->mm;
task_unlock(task);
if (alive)
/* For a living task obey ptrace_may_attach */
allowed = ptrace_may_attach(task);
else
/* For a special task simply check the capability */
allowed = capable(CAP_SYS_PTRACE);
}
if (task)
put_task_struct(task);
return allowed;
}
extern struct seq_operations mounts_op;
struct proc_mounts {
struct seq_file m;
int event;
};
static int mounts_open(struct inode *inode, struct file *file)
{
struct task_struct *task = get_proc_task(inode);
struct namespace *namespace = NULL;
struct proc_mounts *p;
int ret = -EINVAL;
if (task) {
task_lock(task);
namespace = task->namespace;
if (namespace)
get_namespace(namespace);
task_unlock(task);
put_task_struct(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);
}
put_namespace(namespace);
}
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 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;
}
static struct file_operations proc_mounts_operations = {
.open = mounts_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
.poll = mounts_poll,
};
extern struct seq_operations mountstats_op;
static int mountstats_open(struct inode *inode, struct file *file)
{
int ret = seq_open(file, &mountstats_op);
if (!ret) {
struct seq_file *m = file->private_data;
struct namespace *namespace = NULL;
struct task_struct *task = get_proc_task(inode);
if (task) {
task_lock(task);
namespace = task->namespace;
if (namespace)
get_namespace(namespace);
task_unlock(task);
put_task_struct(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,
};
#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 = get_proc_task(inode);
length = -ESRCH;
if (!task)
goto out_no_task;
if (count > PROC_BLOCK_SIZE)
count = PROC_BLOCK_SIZE;
length = -ENOMEM;
if (!(page = __get_free_page(GFP_KERNEL)))
goto out;
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);
out:
put_task_struct(task);
out_no_task:
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 = get_proc_task(file->f_dentry->d_inode);
char *page;
unsigned long src = *ppos;
int ret = -ESRCH;
struct mm_struct *mm;
if (!task)
goto out_no_task;
if (!MAY_PTRACE(task) || !ptrace_may_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) || !ptrace_may_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:
put_task_struct(task);
out_no_task:
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 = get_proc_task(file->f_dentry->d_inode);
unsigned long dst = *ppos;
copied = -ESRCH;
if (!task)
goto out_no_task;
if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
goto out;
copied = -ENOMEM;
page = (char *)__get_free_page(GFP_USER);
if (!page)
goto out;
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);
out:
put_task_struct(task);
out_no_task:
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 = get_proc_task(file->f_dentry->d_inode);
char buffer[PROC_NUMBUF];
size_t len;
int oom_adjust;
loff_t __ppos = *ppos;
if (!task)
return -ESRCH;
oom_adjust = task->oomkilladj;
put_task_struct(task);
len = snprintf(buffer, sizeof(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;
char buffer[PROC_NUMBUF], *end;
int oom_adjust;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
return -EFAULT;
oom_adjust = simple_strtol(buffer, &end, 0);
if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
return -EINVAL;
if (*end == '\n')
end++;
task = get_proc_task(file->f_dentry->d_inode);
if (!task)
return -ESRCH;
task->oomkilladj = oom_adjust;
put_task_struct(task);
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,
};
#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 = get_proc_task(inode);
ssize_t length;
char tmpbuf[TMPBUFLEN];
if (!task)
return -ESRCH;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
audit_get_loginuid(task->audit_context));
put_task_struct(task);
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;
uid_t loginuid;
if (!capable(CAP_AUDIT_CONTROL))
return -EPERM;
if (current != pid_task(proc_pid(inode), PIDTYPE_PID))
return -EPERM;
if (count >= PAGE_SIZE)
count = PAGE_SIZE - 1;
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;
page[count] = '\0';
loginuid = simple_strtoul(page, &tmp, 10);
if (tmp == page) {
length = -EINVAL;
goto out_free_page;
}
length = audit_set_loginuid(current, loginuid);
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 = get_proc_task(file->f_dentry->d_inode);
char __buf[20];
loff_t __ppos = *ppos;
size_t len;
if (!tsk)
return -ESRCH;
/* no need to print the trailing zero, so use only len */
len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
put_task_struct(tsk);
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 = get_proc_task(file->f_dentry->d_inode);
char __buf[20], *end;
unsigned int seccomp_mode;
ssize_t result;
result = -ESRCH;
if (!tsk)
goto out_no_task;
/* can set it only once to be even more secure */
result = -EPERM;
if (unlikely(tsk->seccomp.mode))
goto out;
result = -EFAULT;
memset(__buf, 0, sizeof(__buf));
count = min(count, sizeof(__buf) - 1);
if (copy_from_user(__buf, buf, count))
goto out;
seccomp_mode = simple_strtoul(__buf, &end, 0);
if (*end == '\n')
end++;
result = -EINVAL;
if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
tsk->seccomp.mode = seccomp_mode;
set_tsk_thread_flag(tsk, TIF_SECCOMP);
} else
goto out;
result = -EIO;
if (unlikely(!(end - __buf)))
goto out;
result = end - __buf;
out:
put_task_struct(tsk);
out_no_task:
return result;
}
static struct file_operations proc_seccomp_operations = {
.read = seccomp_read,
.write = seccomp_write,
};
#endif /* CONFIG_SECCOMP */
static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
int error = -EACCES;
/* We don't need a base pointer in the /proc filesystem */
path_release(nd);
/* Are we allowed to snoop on the tasks file descriptors? */
if (!proc_fd_access_allowed(inode))
goto out;
error = PROC_I(inode)->op.proc_get_link(inode, &nd->dentry, &nd->mnt);
nd->last_type = LAST_BIND;
out:
return ERR_PTR(error);
}
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;
/* Are we allowed to snoop on the tasks file descriptors? */
if (!proc_fd_access_allowed(inode))
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
};
static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_dentry;
struct inode *inode = dentry->d_inode;
struct task_struct *p = get_proc_task(inode);
unsigned int fd, tid, ino;
int retval;
char buf[PROC_NUMBUF];
struct files_struct * files;
struct fdtable *fdt;
retval = -ENOENT;
if (!p)
goto out_no_task;
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 = parent_ino(dentry);
if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
goto out;
filp->f_pos++;
default:
files = get_files_struct(p);
if (!files)
goto out;
rcu_read_lock();
fdt = files_fdtable(files);
for (fd = filp->f_pos-2;
fd < fdt->max_fds;
fd++, filp->f_pos++) {
unsigned int i,j;
if (!fcheck_files(files, fd))
continue;
rcu_read_unlock();
j = PROC_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, PROC_NUMBUF-j, fd+2, ino, DT_LNK) < 0) {
rcu_read_lock();
break;
}
rcu_read_lock();
}
rcu_read_unlock();
put_files_struct(files);
}
out:
put_task_struct(p);
out_no_task:
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 task_struct *task = get_proc_task(inode);
struct pid_entry *p;
ino_t ino;
int ret;
ret = -ENOENT;
if (!task)
goto out;
ret = 0;
pid = task->pid;
put_task_struct(task);
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);
if(dumpable == 1)
return 1;
return 0;
}
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);
/*
* grab the reference to task.
*/
ei->pid = get_pid(task->pids[PIDTYPE_PID].pid);
if (!ei->pid)
goto out_unlock;
inode->i_uid = 0;
inode->i_gid = 0;
if (task_dumpable(task)) {
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.
*
* Before the /proc/pid/status file was created the only way to read
* the effective uid of a /process was to stat /proc/pid. Reading
* /proc/pid/status is slow enough that procps and other packages
* kept stating /proc/pid. To keep the rules in /proc simple I have
* made this apply to all per process world readable and executable
* directories.
*/
static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
if (task) {
if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
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);
put_task_struct(task);
return 1;
}
d_drop(dentry);
return 0;
}
static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
struct task_struct *task;
generic_fillattr(inode, stat);
rcu_read_lock();
stat->uid = 0;
stat->gid = 0;
task = pid_task(proc_pid(inode), PIDTYPE_PID);
if (task) {
if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
task_dumpable(task)) {
stat->uid = task->euid;
stat->gid = task->egid;
}
}
rcu_read_unlock();
return 0;
}
static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
int fd = proc_fd(inode);
struct files_struct *files;
if (task) {
files = get_files_struct(task);
if (files) {
rcu_read_lock();
if (fcheck_files(files, fd)) {
rcu_read_unlock();
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);
put_task_struct(task);
return 1;
}
rcu_read_unlock();
put_files_struct(files);
}
put_task_struct(task);
}
d_drop(dentry);
return 0;
}
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 !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
}
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,
};
/* 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 = get_proc_task(dir);
unsigned fd = name_to_int(dentry);
struct dentry *result = ERR_PTR(-ENOENT);
struct file * file;
struct files_struct * files;
struct inode *inode;
struct proc_inode *ei;
if (!task)
goto out_no_task;
if (fd == ~0U)
goto out;
inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
if (!inode)
goto out;
ei = PROC_I(inode);
ei->fd = fd;
files = get_files_struct(task);
if (!files)
goto out_unlock;
inode->i_mode = S_IFLNK;
/*
* We are not taking a ref to the file structure, so we must
* hold ->file_lock.
*/
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);
/* Close the race of the process dying before we return the dentry */
if (tid_fd_revalidate(dentry, NULL))
result = NULL;
out:
put_task_struct(task);
out_no_task:
return result;
out_unlock2:
spin_unlock(&files->file_lock);
put_files_struct(files);
out_unlock:
iput(inode);
goto out;
}
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 int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
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,
};
static struct inode_operations proc_task_inode_operations = {
.lookup = proc_task_lookup,
.getattr = proc_task_getattr,
};
#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 = get_proc_task(inode);
length = -ESRCH;
if (!task)
goto out_no_task;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
length = -ENOMEM;
if (!(page = __get_free_page(GFP_KERNEL)))
goto out;
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);
out:
put_task_struct(task);
out_no_task:
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 = get_proc_task(inode);
length = -ESRCH;
if (!task)
goto out_no_task;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
/* No partial writes. */
length = -EINVAL;
if (*ppos != 0)
goto out;
length = -ENOMEM;
page = (char*)__get_free_page(GFP_USER);
if (!page)
goto out;
length = -EFAULT;
if (copy_from_user(page, buf, count))
goto out_free;
length = security_setprocattr(task,
(char*)file->f_dentry->d_name.name,
(void*)page, count);
out_free:
free_page((unsigned long) page);
out:
put_task_struct(task);
out_no_task:
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
/* SMP-safe */
static struct dentry *proc_pident_lookup(struct inode *dir,
struct dentry *dentry,
struct pid_entry *ents)
{
struct inode *inode;
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
struct pid_entry *p;
struct proc_inode *ei;
error = ERR_PTR(-ENOENT);
inode = NULL;
if (!task)
goto out_no_task;
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 = ERR_PTR(-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:
inode->i_nlink = 2;
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;
#ifdef CONFIG_NUMA
case PROC_TID_NUMA_MAPS:
case PROC_TGID_NUMA_MAPS:
inode->i_fop = &proc_numa_maps_operations;
break;
#endif
case PROC_TID_MEM:
case PROC_TGID_MEM:
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_MMU
case PROC_TID_SMAPS:
case PROC_TGID_SMAPS:
inode->i_fop = &proc_smaps_operations;
break;
#endif
case PROC_TID_MOUNTSTATS:
case PROC_TGID_MOUNTSTATS:
inode->i_fop = &proc_mountstats_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:
case PROC_TID_ATTR_KEYCREATE:
case PROC_TGID_ATTR_KEYCREATE:
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);
error = ERR_PTR(-EINVAL);
goto out;
}
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
error = NULL;
out:
put_task_struct(task);
out_no_task:
return 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,
.getattr = pid_getattr,
};
static struct inode_operations proc_tid_base_inode_operations = {
.lookup = proc_tid_base_lookup,
.getattr = pid_getattr,
};
#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,
.getattr = pid_getattr,
};
static struct inode_operations proc_tid_attr_inode_operations = {
.lookup = proc_tid_attr_lookup,
.getattr = pid_getattr,
};
#endif
/*
* /proc/self:
*/
static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
int buflen)
{
char tmp[PROC_NUMBUF];
sprintf(tmp, "%d", current->tgid);
return vfs_readlink(dentry,buffer,buflen,tmp);
}
static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
{
char tmp[PROC_NUMBUF];
sprintf(tmp, "%d", current->tgid);
return ERR_PTR(vfs_follow_link(nd,tmp));
}
static struct inode_operations proc_self_inode_operations = {
.readlink = proc_self_readlink,
.follow_link = proc_self_follow_link,
};
/**
* proc_flush_task - Remove dcache entries for @task from the /proc dcache.
*
* @task: task that should be flushed.
*
* Looks in the dcache for
* /proc/@pid
* /proc/@tgid/task/@pid
* if either directory is present flushes it and all of it'ts children
* from the dcache.
*
* It is safe and reasonable to cache /proc entries for a task until
* that task exits. After that they just clog up the dcache with
* useless entries, possibly causing useful dcache entries to be
* flushed instead. This routine is proved to flush those useless
* dcache entries at process exit time.
*
* NOTE: This routine is just an optimization so it does not guarantee
* that no dcache entries will exist at process exit time it
* just makes it very unlikely that any will persist.
*/
void proc_flush_task(struct task_struct *task)
{
struct dentry *dentry, *leader, *dir;
char buf[PROC_NUMBUF];
struct qstr name;
name.name = buf;
name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
dentry = d_hash_and_lookup(proc_mnt->mnt_root, &name);
if (dentry) {
shrink_dcache_parent(dentry);
d_drop(dentry);
dput(dentry);
}
if (thread_group_leader(task))
goto out;
name.name = buf;
name.len = snprintf(buf, sizeof(buf), "%d", task->tgid);
leader = d_hash_and_lookup(proc_mnt->mnt_root, &name);
if (!leader)
goto out;
name.name = "task";
name.len = strlen(name.name);
dir = d_hash_and_lookup(leader, &name);
if (!dir)
goto out_put_leader;
name.name = buf;
name.len = snprintf(buf, sizeof(buf), "%d", task->pid);
dentry = d_hash_and_lookup(dir, &name);
if (dentry) {
shrink_dcache_parent(dentry);
d_drop(dentry);
dput(dentry);
}
dput(dir);
out_put_leader:
dput(leader);
out:
return;
}
/* SMP-safe */
struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
struct dentry *result = ERR_PTR(-ENOENT);
struct task_struct *task;
struct inode *inode;
struct proc_inode *ei;
unsigned tgid;
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;
rcu_read_lock();
task = find_task_by_pid(tgid);
if (task)
get_task_struct(task);
rcu_read_unlock();
if (!task)
goto out;
inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
if (!inode)
goto out_put_task;
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;
#ifdef CONFIG_SECURITY
inode->i_nlink = 5;
#else
inode->i_nlink = 4;
#endif
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
result = NULL;
out_put_task:
put_task_struct(task);
out:
return result;
}
/* SMP-safe */
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
struct dentry *result = ERR_PTR(-ENOENT);
struct task_struct *task;
struct task_struct *leader = get_proc_task(dir);
struct inode *inode;
unsigned tid;
if (!leader)
goto out_no_task;
tid = name_to_int(dentry);
if (tid == ~0U)
goto out;
rcu_read_lock();
task = find_task_by_pid(tid);
if (task)
get_task_struct(task);
rcu_read_unlock();
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;
#ifdef CONFIG_SECURITY
inode->i_nlink = 4;
#else
inode->i_nlink = 3;
#endif
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
result = NULL;
out_drop_task:
put_task_struct(task);
out:
put_task_struct(leader);
out_no_task:
return result;
}
/*
* Find the first tgid to return to user space.
*
* Usually this is just whatever follows &init_task, but if the users
* buffer was too small to hold the full list or there was a seek into
* the middle of the directory we have more work to do.
*
* In the case of a short read we start with find_task_by_pid.
*
* In the case of a seek we start with &init_task and walk nr
* threads past it.
*/
static struct task_struct *first_tgid(int tgid, unsigned int nr)
{
struct task_struct *pos;
rcu_read_lock();
if (tgid && nr) {
pos = find_task_by_pid(tgid);
if (pos && thread_group_leader(pos))
goto found;
}
/* If nr exceeds the number of processes get out quickly */
pos = NULL;
if (nr && nr >= nr_processes())
goto done;
/* If we haven't found our starting place yet start with
* the init_task and walk nr tasks forward.
*/
for (pos = next_task(&init_task); nr > 0; --nr) {
pos = next_task(pos);
if (pos == &init_task) {
pos = NULL;
goto done;
}
}
found:
get_task_struct(pos);
done:
rcu_read_unlock();
return pos;
}
/*
* Find the next task in the task list.
* Return NULL if we loop or there is any error.
*
* The reference to the input task_struct is released.
*/
static struct task_struct *next_tgid(struct task_struct *start)
{
struct task_struct *pos;
rcu_read_lock();
pos = start;
if (pid_alive(start))
pos = next_task(start);
if (pid_alive(pos) && (pos != &init_task)) {
get_task_struct(pos);
goto done;
}
pos = NULL;
done:
rcu_read_unlock();
put_task_struct(start);
return pos;
}
/* for the /proc/ directory itself, after non-process stuff has been done */
int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
char buf[PROC_NUMBUF];
unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY;
struct task_struct *task;
int 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++;
}
nr -= 1;
/* f_version caches the tgid value that the last readdir call couldn't
* return. lseek aka telldir automagically resets f_version to 0.
*/
tgid = filp->f_version;
filp->f_version = 0;
for (task = first_tgid(tgid, nr);
task;
task = next_tgid(task), filp->f_pos++) {
int len;
ino_t ino;
tgid = task->pid;
len = snprintf(buf, sizeof(buf), "%d", tgid);
ino = fake_ino(tgid, PROC_TGID_INO);
if (filldir(dirent, buf, len, 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;
put_task_struct(task);
break;
}
}
return 0;
}
/*
* Find the first tid of a thread group to return to user space.
*
* Usually this is just the thread group leader, but if the users
* buffer was too small or there was a seek into the middle of the
* directory we have more work todo.
*
* In the case of a short read we start with find_task_by_pid.
*
* In the case of a seek we start with the leader and walk nr
* threads past it.
*/
static struct task_struct *first_tid(struct task_struct *leader, int tid, int nr)
{
struct task_struct *pos = NULL;
read_lock(&tasklist_lock);
/* Attempt to start with the pid of a thread */
if (tid && (nr > 0)) {
pos = find_task_by_pid(tid);
if (pos && (pos->group_leader != leader))
pos = NULL;
if (pos)
nr = 0;
}
/* If nr exceeds the number of threads there is nothing todo */
if (nr) {
if (nr >= get_nr_threads(leader))
goto done;
}
/* If we haven't found our starting place yet start with the
* leader and walk nr threads forward.
*/
if (!pos && (nr >= 0))
pos = leader;
for (; pos && pid_alive(pos); pos = next_thread(pos)) {
if (--nr > 0)
continue;
get_task_struct(pos);
goto done;
}
pos = NULL;
done:
read_unlock(&tasklist_lock);
return pos;
}
/*
* Find the next thread in the thread list.
* Return NULL if there is an error or no next thread.
*
* The reference to the input task_struct is released.
*/
static struct task_struct *next_tid(struct task_struct *start)
{
struct task_struct *pos;
read_lock(&tasklist_lock);
pos = start;
if (pid_alive(start))
pos = next_thread(start);
if (pid_alive(pos) && (pos != start->group_leader))
get_task_struct(pos);
else
pos = NULL;
read_unlock(&tasklist_lock);
put_task_struct(start);
return pos;
}
/* for the /proc/TGID/task/ directories */
static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
char buf[PROC_NUMBUF];
struct dentry *dentry = filp->f_dentry;
struct inode *inode = dentry->d_inode;
struct task_struct *leader = get_proc_task(inode);
struct task_struct *task;
int retval = -ENOENT;
ino_t ino;
int tid;
unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
if (!leader)
goto out_no_task;
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 */
}
/* f_version caches the tgid value that the last readdir call couldn't
* return. lseek aka telldir automagically resets f_version to 0.
*/
tid = filp->f_version;
filp->f_version = 0;
for (task = first_tid(leader, tid, pos - 2);
task;
task = next_tid(task), pos++) {
int len;
tid = task->pid;
len = snprintf(buf, sizeof(buf), "%d", tid);
ino = fake_ino(tid, PROC_TID_INO);
if (filldir(dirent, buf, len, pos, ino, DT_DIR < 0)) {
/* returning this tgid failed, save it as the first
* pid for the next readir call */
filp->f_version = tid;
put_task_struct(task);
break;
}
}
out:
filp->f_pos = pos;
put_task_struct(leader);
out_no_task:
return retval;
}
static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
struct task_struct *p = get_proc_task(inode);
generic_fillattr(inode, stat);
if (p) {
rcu_read_lock();
stat->nlink += get_nr_threads(p);
rcu_read_unlock();
put_task_struct(p);
}
return 0;
}
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