Al, this is the current (and new) open_exec():
struct file *open_exec(const char *name)
{
struct dentry *dentry;
struct file *file;
lock_kernel();
dentry = lookup_dentry(name, NULL, LOOKUP_FOLLOW);
file = (struct file*) dentry;
if (!IS_ERR(dentry)) {
file = ERR_PTR(-EACCES);
if (dentry->d_inode && S_ISREG(dentry->d_inode->i_mode)) {
int err = permission(dentry->d_inode, MAY_EXEC);
file = ERR_PTR(err);
if (!err) {
file = dentry_open(dentry, O_RDONLY);
out:
unlock_kernel();
return file;
}
}
dput(dentry);
}
goto out;
}
The exit conditions from it are rather odd. It ends with a "goto out" to
the middle of the code, just so it can return an arg and unlock the kernel.
Also, it has a few too many nested if's. Ion and I rewrote it more cleanly
and clearly. Here's a small patch.
Erez.
*** linux-2.3-vanilla/fs/exec.c Fri Mar 24 12:34:59 2000
--- linux-2.3.bad/fs/exec.c Fri Mar 24 22:13:59 2000
***************
*** 319,343 ****
{
struct dentry *dentry;
struct file *file;
lock_kernel();
dentry = lookup_dentry(name, NULL, LOOKUP_FOLLOW);
! file = (struct file*) dentry;
! if (!IS_ERR(dentry)) {
file = ERR_PTR(-EACCES);
! if (dentry->d_inode && S_ISREG(dentry->d_inode->i_mode)) {
! int err = permission(dentry->d_inode, MAY_EXEC);
! file = ERR_PTR(err);
! if (!err) {
! file = dentry_open(dentry, O_RDONLY);
! out:
! unlock_kernel();
! return file;
! }
! }
! dput(dentry);
}
goto out;
}
int kernel_read(struct file *file, unsigned long offset,
--- 319,351 ----
{
struct dentry *dentry;
struct file *file;
+ int err;
lock_kernel();
dentry = lookup_dentry(name, NULL, LOOKUP_FOLLOW);
! if (IS_ERR(dentry)) {
! file = (struct file*) dentry;
! goto out;
! }
! if (!dentry->d_inode || !S_ISREG(dentry->d_inode->i_mode)) {
file = ERR_PTR(-EACCES);
! goto out_dput;
! }
!
! err = permission(dentry->d_inode, MAY_EXEC);
! if (err) {
! file = ERR_PTR(err);
! goto out_dput;
}
+
+ file = dentry_open(dentry, O_RDONLY);
goto out;
+
+ out_dput:
+ dput(dentry);
+ out:
+ unlock_kernel();
+ return file;
}
int kernel_read(struct file *file, unsigned long offset,
