Re: d_lookup: Unable to handle kernel paging request

From: Al Viro
Date: Tue Jun 18 2019 - 14:53:28 EST

On Tue, Jun 18, 2019 at 07:35:48PM +0100, Al Viro wrote:

> So far it looks like something is buggering a forward reference
> in hash chain in a fairly specific way - the values seen had been
> 00000000010000000 and
> 00008800010000000. Does that smell like anything from arm64-specific
> data structures (PTE, etc.)?

make that 0000000001000000 and 0000880001000000 resp. Tests in the
patch are correct, just mistyped it here...

> Alternatively, we might've gone off rails a step (or more) before,
> with the previous iteration going through bogus, but at least mapped
> address - the one that has never been a dentry in the first place.