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/* $Id: linux32.c,v 1.4 2000/02/29 20:49:15 ulfc Exp $
*
* Conversion between 32-bit and 64-bit native system calls.
*
* Copyright (C) 2000 Silicon Graphics, Inc.
* Written by Ulf Carlsson (ulfc@engr.sgi.com)
* sys32_execve from ia64/ia32 code, Feb 2000, Kanoj Sarcar (kanoj@sgi.com)
*/
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/highuid.h>
#include <asm/uaccess.h>
#include <asm/mman.h>
/*
* Revalidate the inode. This is required for proper NFS attribute caching.
*/
static __inline__ int
do_revalidate(struct dentry *dentry)
{
struct inode * inode = dentry->d_inode;
if (inode->i_op && inode->i_op->revalidate)
return inode->i_op->revalidate(dentry);
return 0;
}
static int cp_new_stat32(struct inode * inode, struct stat32 * statbuf)
{
struct stat32 tmp;
unsigned int blocks, indirect;
memset(&tmp, 0, sizeof(tmp));
tmp.st_dev = kdev_t_to_nr(inode->i_dev);
tmp.st_ino = inode->i_ino;
tmp.st_mode = inode->i_mode;
tmp.st_nlink = inode->i_nlink;
SET_STAT_UID(tmp, inode->i_uid);
SET_STAT_GID(tmp, inode->i_gid);
tmp.st_rdev = kdev_t_to_nr(inode->i_rdev);
tmp.st_size = inode->i_size;
tmp.st_atime = inode->i_atime;
tmp.st_mtime = inode->i_mtime;
tmp.st_ctime = inode->i_ctime;
/*
* st_blocks and st_blksize are approximated with a simple algorithm if
* they aren't supported directly by the filesystem. The minix and msdos
* filesystems don't keep track of blocks, so they would either have to
* be counted explicitly (by delving into the file itself), or by using
* this simple algorithm to get a reasonable (although not 100% accurate)
* value.
*/
/*
* Use minix fs values for the number of direct and indirect blocks. The
* count is now exact for the minix fs except that it counts zero blocks.
* Everything is in units of BLOCK_SIZE until the assignment to
* tmp.st_blksize.
*/
#define D_B 7
#define I_B (BLOCK_SIZE / sizeof(unsigned short))
if (!inode->i_blksize) {
blocks = (tmp.st_size + BLOCK_SIZE - 1) / BLOCK_SIZE;
if (blocks > D_B) {
indirect = (blocks - D_B + I_B - 1) / I_B;
blocks += indirect;
if (indirect > 1) {
indirect = (indirect - 1 + I_B - 1) / I_B;
blocks += indirect;
if (indirect > 1)
blocks++;
}
}
tmp.st_blocks = (BLOCK_SIZE / 512) * blocks;
tmp.st_blksize = BLOCK_SIZE;
} else {
tmp.st_blocks = inode->i_blocks;
tmp.st_blksize = inode->i_blksize;
}
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
asmlinkage int sys32_newstat(char * filename, struct stat32 *statbuf)
{
struct dentry * dentry;
int error;
lock_kernel();
dentry = namei(filename);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
error = do_revalidate(dentry);
if (!error)
error = cp_new_stat32(dentry->d_inode, statbuf);
dput(dentry);
}
unlock_kernel();
return error;
}
asmlinkage int sys32_newlstat(char *filename, struct stat32 * statbuf)
{
struct dentry * dentry;
int error;
lock_kernel();
dentry = lnamei(filename);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
error = do_revalidate(dentry);
if (!error)
error = cp_new_stat32(dentry->d_inode, statbuf);
dput(dentry);
}
unlock_kernel();
return error;
}
asmlinkage int sys32_newfstat(unsigned int fd, struct stat32 * statbuf)
{
struct file * f;
int err = -EBADF;
lock_kernel();
f = fget(fd);
if (f) {
struct dentry * dentry = f->f_dentry;
err = do_revalidate(dentry);
if (!err)
err = cp_new_stat32(dentry->d_inode, statbuf);
fput(f);
}
unlock_kernel();
return err;
}
asmlinkage int sys_mmap2(void) {return 0;}
asmlinkage int sys_truncate64(const char *path, unsigned long high,
unsigned long low)
{
if ((int)high < 0)
return -EINVAL;
return sys_truncate(path, (high << 32) | low);
}
asmlinkage int sys_ftruncate64(unsigned int fd, unsigned long high,
unsigned long low)
{
if ((int)high < 0)
return -EINVAL;
return sys_ftruncate(fd, (high << 32) | low);
}
asmlinkage int sys_stat64(char * filename, struct stat *statbuf)
{
return sys_newstat(filename, statbuf);
}
asmlinkage int sys_lstat64(char * filename, struct stat *statbuf)
{
return sys_newlstat(filename, statbuf);
}
asmlinkage int sys_fstat64(unsigned int fd, struct stat *statbuf)
{
return sys_fstat(fd, statbuf);
}
static int
nargs(unsigned int arg, char **ap)
{
char *ptr;
int n, err;
n = 0;
for (; ptr; ) {
if ((err = get_user(ptr, (int *)arg)))
return(err);
if (ap)
*ap++ = ptr;
arg += sizeof(unsigned int);
n++;
}
return(n - 1);
}
asmlinkage long
sys32_execve(abi64_no_regargs, struct pt_regs regs)
{
extern asmlinkage int sys_execve(abi64_no_regargs, struct pt_regs regs);
extern asmlinkage long sys_munmap(unsigned long addr, size_t len);
unsigned int argv = (unsigned int)regs.regs[5];
unsigned int envp = (unsigned int)regs.regs[6];
char **av, **ae;
int na, ne, r, len;
na = nargs(argv, NULL);
ne = nargs(envp, NULL);
len = (na + ne + 2) * sizeof(*av);
/*
* kmalloc won't work because the `sys_exec' code will attempt
* to do a `get_user' on the arg list and `get_user' will fail
* on a kernel address (simplifies `get_user'). Instead we
* do an mmap to get a user address. Note that since a successful
* `execve' frees all current memory we only have to do an
* `munmap' if the `execve' failes.
*/
down(¤t->mm->mmap_sem);
lock_kernel();
av = do_mmap_pgoff(0, NULL, len,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0);
unlock_kernel();
up(¤t->mm->mmap_sem);
if (IS_ERR(av))
return(av);
ae = av + na + 1;
av[na] = (char *)0;
ae[ne] = (char *)0;
(void)nargs(argv, av);
(void)nargs(envp, ae);
regs.regs[5] = av;
regs.regs[6] = ae;
r = sys_execve(__dummy0,__dummy0,__dummy0,__dummy0,__dummy0,__dummy0,__dummy0,__dummy0, regs);
if (IS_ERR(r))
sys_munmap(av, len);
return(r);
}
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