[PATCH v3 10/12] um: remove force_flush_all from fork_handler

[Johannes Berg]

On Wed, 2024-07-03 at 12:08 +0200, Benjamin Berg wrote:
> On Wed, 2024-07-03 at 11:45 +0200, Johannes Berg wrote:
> > On Fri, 2024-05-24 at 23:37 +0200, benjamin at sipsolutions.net wrote:
> > > From: Benjamin Berg <benjamin.berg at intel.com>
> > > 
> > > There should be no need for this.
> > 
> > "should" ;-)
> 
> Hmm, I would have expected the previous patch is what breaks it.

Ouch, you're right, I replied to the wrong patch - bisected to the
previous one indeed.

> > This breaks things if glibc enables rseq. That might even be already
> > broken in the sense that it might corrupt memory that's put at the same
> > place the rseq was installed? But it at least it appears to still work
> > without this patch...
> 
> Then it would make sense to me as the previous force_flush_all would
> have only unmapped up to TASK_SIZE. While this now uses STUB_START
> which clears more memory as TASK_SIZE has some alignment.

Right.

johannes