Re: [PATCH v2 1/4] android: binder: Don't get mm from task

From: Greg Kroah-Hartman
Date: Wed Oct 25 2017 - 04:59:36 EST


On Tue, Oct 24, 2017 at 11:36:48AM -0700, Arve Hjønnevåg wrote:
> On Tue, Oct 24, 2017 at 12:28 AM, Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > On Mon, Oct 23, 2017 at 11:18:52AM -0700, Arve Hjønnevåg wrote:
> >> On Sat, Oct 21, 2017 at 1:15 AM, Greg Kroah-Hartman
> >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >> > On Fri, Oct 20, 2017 at 08:58:58PM -0400, Sherry Yang wrote:
> >> >> Use binder_alloc struct's mm_struct rather than getting
> >> >> a reference to the mm struct through get_task_mm to
> >> >> avoid a potential deadlock between lru lock, task lock and
> >> >> dentry lock, since a thread can be holding the task lock
> >> >> and the dentry lock while trying to acquire the lru lock.
> >> >>
> >> >> Acked-by: Arve Hjønnevåg <arve@xxxxxxxxxxx>
> >> >> Signed-off-by: Sherry Yang <sherryy@xxxxxxxxxxx>
> >> >> ---
> >> >> drivers/android/binder_alloc.c | 22 +++++++++-------------
> >> >> drivers/android/binder_alloc.h | 1 -
> >> >> 2 files changed, 9 insertions(+), 14 deletions(-)
> >> >
> >> > I've applied these first 2 patches, but patches 3 and 4 I have already
> >> > applied to my char-misc-next tree, right?
> >> >
> >> > thanks,
> >> >
> >> > greg k-h
> >>
> >> I would expect you got a merge conflict from one of those. Using patch
> >> 3 and 4 in from this patchset should avoid that conflict if your
> >> eventual 4.15 branch is not based on your current char-misc-next
> >> branch.
> >
> > I've resolved the merge conflict so my char-misc-next branch should be
> > all caught up now. It would be wonderful if you could verify this.
> >
> > thanks,
> >
> > greg k-h
>
> I have not tested your branch directly, but the relevant code in
> char-misc-next is now identical to the code I tested.

Wonderful, thanks for verifying.

greg k-h