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linux/fs/proc/base.c

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48 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.
*/
#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();
if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE))
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);
if ((oom_adjust < -16 || oom_adjust > 15) && oom_adjust != OOM_DISABLE)
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;
}
length = audit_set_loginuid(task, 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 = 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 */
static int 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);
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:
return 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;
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);
return dumpable;
}
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
static int get_tid_list(int index, unsigned int *tids, struct inode *dir);
/* 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:
inode->i_nlink = 2 + get_tid_list(2, NULL, dir);
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);
}
static int proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
{
char tmp[30];
sprintf(tmp, "%d", current->tgid);
return vfs_follow_link(nd,tmp);
}
static struct inode_operations proc_self_inode_operations = {
.readlink = proc_self_readlink,
.follow_link = proc_self_follow_link,
};
/**
* proc_pid_unhash - Unhash /proc/@pid entry from the dcache.
* @p: task that should be flushed.
*
* Drops the /proc/@pid dcache entry from the hash chains.
*
* Dropping /proc/@pid entries and detach_pid must be synchroneous,
* otherwise e.g. /proc/@pid/exe might point to the wrong executable,
* 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;
}
/**
* proc_pid_flush - recover memory used by stale /proc/@pid/x entries
* @proc_dentry: directoy to prune.
*
* 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;
#ifdef CONFIG_SECURITY
inode->i_nlink = 5;
#else
inode->i_nlink = 4;
#endif
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;
#ifdef CONFIG_SECURITY
inode->i_nlink = 4;
#else
inode->i_nlink = 3;
#endif
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;
if (tids != NULL)
tids[nr_tids] = tid;
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);
inode->i_nlink = pos + nr_tids;
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;
}
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