Re: [PATCH v2 2/4] modules: Add new special vfree flags

From: Edgecombe, Rick P
Date: Thu Dec 13 2018 - 16:48:23 EST


On Thu, 2018-12-13 at 19:27 +0000, Nadav Amit wrote:
> > On Dec 13, 2018, at 11:02 AM, Edgecombe, Rick P <rick.p.edgecombe@xxxxxxxxx>
> > wrote:
> >
> > On Wed, 2018-12-12 at 23:40 +0000, Nadav Amit wrote:
> > > > On Dec 11, 2018, at 4:03 PM, Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> > > > wrote:
> > > >
> > > > Add new flags for handling freeing of special permissioned memory in
> > > > vmalloc,
> > > > and remove places where the handling was done in module.c.
> > > >
> > > > This will enable this flag for all architectures.
> > > >
> > > > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> > > > ---
> > > > kernel/module.c | 43 ++++++++++++-------------------------------
> > > > 1 file changed, 12 insertions(+), 31 deletions(-)
> > >
> > > I count on you for merging your patch-set with mine, since clearly they
> > > conflict.
> >
> > Yes, I can rebase on top of yours if you omit the changes around
> > module_memfree
> > for your next version. It should fit together pretty cleanly for BPF and
> > modules
> > I think. Not sure what you are planning for kprobes and ftrace.
>
> Are you asking after looking at the latest version of my patch-set?
>
> Kprobes is done and ack'd. ftrace needs to be broken into two separate
> changes (setting x after writing, and using text_poke interfaces), unless
> Steven ackâs them. The changes introduce some overhead (3x), but I think it
> is a reasonable slowdown for a debug feature.
>
> Can you have a look at the series Iâve sent and let me know which patches
> to drop? It would be best (for me) if the two series are fully merged.

Looking at v7, the only extra thing could be the tweaks to the existing lines in
kprobes free_insn_page be omitted, since those lines would just be removed in my
later changes.