/*
* Note that while the flag value (low two bits) for sys_open means:
* 00 - read-only
* 01 - write-only
* 10 - read-write
* 11 - special
* it is changed into
* 00 - no permissions needed
* 01 - read-permission
* 10 - write-permission
* 11 - read-write
* for the internal routines (ie open_namei()/follow_link() etc). 00 is
* used by symlinks.
*/
static struct file *do_filp_open(int dfd, const char *filename, int flags,
int mode)
{
int namei_flags, error;
struct nameidata nd;
namei_flags = flags;
if ((namei_flags+1) & O_ACCMODE)
namei_flags++;
error = open_namei(dfd, filename, namei_flags, mode, &nd);
if (!error){
/*
if(active_transaction() && !shadow(nd.dentry->d_inode)){
printk(KERN_ERR "Not shadow for file %s, %p\n", filename, &nd.dentry->d_inode);
printk(KERN_ERR "Dentry = %p, %p, %p\n", &nd.dentry, nd.dentry, shadow(nd.dentry));
OSA_MAGIC(OSA_BREAKSIM);
}
KSTM_BUG_ON(active_transaction() && !shadow(nd.dentry->d_inode));
*/
return nameidata_to_filp(&nd, flags);
}
return ERR_PTR(error);
}
/*
* Note that a shared library must be both readable and executable due to
* security reasons.
*
* Also note that we take the address to load from from the file itself.
*/
asmlinkage long sys_uselib(const char __user * library)
{
struct file * file;
struct nameidata nd;
const struct _inode *inode;
int error;
error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC);
if (error)
goto out;
error = -EACCES;
if (nd.mnt->mnt_flags & MNT_NOEXEC)
goto exit;
error = -EINVAL;
inode = d_get_inode_ro(nd.dentry);
if (!S_ISREG(inode->i_mode))
goto exit;
error = vfs_permission(inode, &nd, MAY_READ | MAY_EXEC);
if (error)
goto exit;
file = nameidata_to_filp(&nd, O_RDONLY);
error = PTR_ERR(file);
if (IS_ERR(file))
goto out;
error = -ENOEXEC;
if(file->f_op) {
struct linux_binfmt * fmt;
read_lock(&binfmt_lock);
for (fmt = formats ; fmt ; fmt = fmt->next) {
if (!fmt->load_shlib)
continue;
if (!try_module_get(fmt->module))
continue;
read_unlock(&binfmt_lock);
error = fmt->load_shlib(file);
read_lock(&binfmt_lock);
put_binfmt(fmt);
if (error != -ENOEXEC)
break;
}
read_unlock(&binfmt_lock);
}
fput(file);
out:
return error;
exit:
release_open_intent(&nd);
path_release(&nd);
goto out;
}
/*
* Note that while the flag value (low two bits) for sys_open means:
* 00 - read-only
* 01 - write-only
* 10 - read-write
* 11 - special
* it is changed into
* 00 - no permissions needed
* 01 - read-permission
* 10 - write-permission
* 11 - read-write
* for the internal routines (ie open_namei()/follow_link() etc). 00 is
* used by symlinks.
*/
static struct file *do_filp_open(int dfd, const char *filename, int flags,
int mode)
{
int namei_flags, error;
struct nameidata nd;
namei_flags = flags;
if ((namei_flags+1) & O_ACCMODE)
namei_flags++;
error = open_namei(dfd, filename, namei_flags, mode, &nd);
if (!error)
return nameidata_to_filp(&nd, flags);
return ERR_PTR(error);
}
