Re: [PATCH v2] vmalloc: Fix issues with flush flag

[Edgecombe, Rick P]

On Mon, 2019-05-20 at 15:48 -0700, David Miller wrote:
> From: "Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx>
> Date: Mon, 20 May 2019 22:17:49 +0000
> 
> > Thanks for testing. So I guess that suggests it's the TLB flush
> > causing
> > the problem on sparc and not any lazy purge deadlock. I had sent
> > Meelis
> > another test patch that just flushed the entire 0 to ULONG_MAX
> > range to
> > try to always the get the "flush all" logic and apprently it didn't
> > boot mostly either. It also showed that it's not getting stuck
> > anywhere
> > in the vm_remove_alias() function. Something just hangs later.
> 
> I wonder if an address is making it to the TLB flush routines which
> is
> not page aligned.
I think vmalloc should force PAGE_SIZE alignment, but will double check
nothing got screwed up.

> Or a TLB flush is being done before the callsites
> are patched properly for the given cpu type.
Any idea how I could log when this is done? It looks like it's done
really early in boot assembly. This behavior shouldn't happen until
modules or BPF are being freed.