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/*
* linux/fs/proc/base.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* proc base directory handling functions
*/
#include <asm/segment.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
static int proc_readbase(struct inode *, struct file *, struct dirent *, int);
static int proc_lookupbase(struct inode *,const char *,int,struct inode **);
static struct file_operations proc_base_operations = {
NULL, /* lseek - default */
NULL, /* read - bad */
NULL, /* write - bad */
proc_readbase, /* readdir */
NULL, /* select - default */
NULL, /* ioctl - default */
NULL, /* mmap */
NULL, /* no special open code */
NULL, /* no special release code */
NULL /* can't fsync */
};
/*
* proc directories can do almost nothing..
*/
struct inode_operations proc_base_inode_operations = {
&proc_base_operations, /* default base directory file-ops */
NULL, /* create */
proc_lookupbase, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
NULL, /* readlink */
NULL, /* follow_link */
NULL, /* bmap */
NULL, /* truncate */
NULL /* permission */
};
static struct proc_dir_entry base_dir[] = {
{ 1,2,".." },
{ 2,1,"." },
{ 3,3,"mem" },
{ 4,3,"cwd" },
{ 5,4,"root" },
{ 6,3,"exe" },
{ 7,2,"fd" },
{ 8,4,"mmap" },
{ 9,7,"environ" },
{ 10,7,"cmdline" },
{ 11,4,"stat" },
{ 12,5,"statm" },
{ 15,4,"maps" }
};
#define NR_BASE_DIRENTRY ((sizeof (base_dir))/(sizeof (base_dir[0])))
int proc_match(int len,const char * name,struct proc_dir_entry * de)
{
register int same __asm__("ax");
if (!de || !de->low_ino)
return 0;
/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
if (!len && (de->name[0]=='.') && (de->name[1]=='\0'))
return 1;
if (de->namelen != len)
return 0;
__asm__("cld\n\t"
"repe ; cmpsb\n\t"
"setz %%al"
:"=a" (same)
:"0" (0),"S" ((long) name),"D" ((long) de->name),"c" (len)
:"cx","di","si");
return same;
}
static int proc_lookupbase(struct inode * dir,const char * name, int len,
struct inode ** result)
{
unsigned int pid, ino;
int i;
*result = NULL;
if (!dir)
return -ENOENT;
if (!S_ISDIR(dir->i_mode)) {
iput(dir);
return -ENOENT;
}
ino = dir->i_ino;
pid = ino >> 16;
i = NR_BASE_DIRENTRY;
while (i-- > 0 && !proc_match(len,name,base_dir+i))
/* nothing */;
if (i < 0) {
iput(dir);
return -ENOENT;
}
if (base_dir[i].low_ino == 1)
ino = 1;
else
ino = (pid << 16) + base_dir[i].low_ino;
for (i = 0 ; i < NR_TASKS ; i++)
if (task[i] && task[i]->pid == pid)
break;
if (!pid || i >= NR_TASKS) {
iput(dir);
return -ENOENT;
}
if (!(*result = iget(dir->i_sb,ino))) {
iput(dir);
return -ENOENT;
}
iput(dir);
return 0;
}
static int proc_readbase(struct inode * inode, struct file * filp,
struct dirent * dirent, int count)
{
struct proc_dir_entry * de;
unsigned int pid, ino;
int i,j;
if (!inode || !S_ISDIR(inode->i_mode))
return -EBADF;
ino = inode->i_ino;
pid = ino >> 16;
for (i = 0 ; i < NR_TASKS ; i++)
if (task[i] && task[i]->pid == pid)
break;
if (!pid || i >= NR_TASKS)
return 0;
if (((unsigned) filp->f_pos) < NR_BASE_DIRENTRY) {
de = base_dir + filp->f_pos;
filp->f_pos++;
i = de->namelen;
ino = de->low_ino;
if (ino != 1)
ino |= (pid << 16);
put_fs_long(ino, &dirent->d_ino);
put_fs_word(i,&dirent->d_reclen);
put_fs_byte(0,i+dirent->d_name);
j = i;
while (i--)
put_fs_byte(de->name[i], i+dirent->d_name);
return j;
}
return 0;
}