Re: chmod from LSM

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sarnoldat_private

On Thu, May 22, 2003 at 09:17:24AM -0700, Michael Halcrow wrote:
> I've been trying to re-implement sys_chmod inside of my LSM, but I
> keep getting errno=14 every time I use __user_walk to get the dentry
> for my file.  This is the EFAULT error code, which indicates that one

Hopefully, your module is already working with a dentry or inode, in
which case the __user_walk() function is superfluous. (Given a pathname
_in userspace_, it copies the pathname to the kernel and then performs a
lookup on the name to find a dentry.)

If your pathname originates in the the kernel, then the copy operation
which normally works userspace-->kernelspace is now being asked to
perform kernelspace-->kernelspace. Since the path is already in the
kernel, you don't need that. :)

I hope this helps.

-- 
"In God we trust, all others we monitor."
 -- NSA, Intercept Operators's motto, 1970