Re: [PATCH pstore-next v2 2/4] pstore: Allocate compression during late_initcall()

[Doug Anderson <dianders@chromium.org>]

Hi,

On Sun, May 5, 2019 at 6:16 AM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Fri, May 03, 2019 at 11:37:51AM -0700, Douglas Anderson wrote:
> > Hi,
> >
> > On Thu, Oct 18, 2018 at 11:56 AM Kees Cook <keescook@chromium.org> wrote:
> > >
> > > From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
> > >
> > > ramoops's call of pstore_register() was recently moved to run during
> > > late_initcall() because the crypto backend may not have been ready during
> > > postcore_initcall(). This meant early-boot crash dumps were not getting
> > > caught by pstore any more.
> > >
> > > Instead, lets allow calls to pstore_register() earlier, and once crypto
> > > is ready we can initialize the compression.
> > >
> > > Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
> > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > > Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
> > > Fixes: cb3bee0369bc ("pstore: Use crypto compress API")
> > > [kees: trivial rebase]
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > ---
> > >  fs/pstore/platform.c | 10 +++++++++-
> > >  fs/pstore/ram.c      |  2 +-
> > >  2 files changed, 10 insertions(+), 2 deletions(-)
> >
> > I'd propose that these three patches:
> >
> > 95047b0519c1 pstore: Refactor compression initialization
> > 416031653eb5 pstore: Allocate compression during late_initcall()
> > cb095afd4476 pstore: Centralize init/exit routines
> >
> > Get sent to linux-stable.  Specifically I'll mention that 4.19 needs
> > it.  IMO the regression of pstore not catching early boot crashes is
> > pretty serious IMO.
>
> So just those 3 commits and not this specific patch from Joel?

The middle commit ("pstore: Allocate compression during
late_initcall()") is ${SUBJECT} patch and the one with the "Fixes"
tag.

The first commit ("pstore: Centralize init/exit routines") is needed
to apply the middle commit.

I haven't done lots of analysis but the last commit ("pstore: Refactor
compression initialization") sure looks like it's important if you
have the middle commit.  Specifically the middle commit allocates the
compression earlier and the last commit says that it improves handling
of this situation.


Unless someone thinks otherwise, it seems best to apply all 3?


-Doug