Re: [PATCH 01/12] uprobes: split THPs before trying replace them

[Andrew Morton]

On Wed, 25 Jan 2017 01:22:17 +0300 "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote:

> On Tue, Jan 24, 2017 at 01:28:49PM -0800, Andrew Morton wrote:
> > On Tue, 24 Jan 2017 19:28:13 +0300 "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
> > 
> > > For THPs page_check_address() always fails. It's better to split them
> > > first before trying to replace.
> > 
> > So what does this mean.  uprobes simply fails to work when trying to
> > place a probe into a THP memory region?
> 
> Looks like we can end up with endless retry loop in uprobe_write_opcode().
> 
> > How come nobody noticed (and reported) this when using the feature?
> 
> I guess it's not often used for anon memory.

OK,  can we please include discussion of these things in the changelog?