Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1479519

Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory map by md5 value

Show all headers | View raw

On Tue 2016-08-30 13:54:44, Rafael J. Wysocki wrote:
> On Tuesday, August 30, 2016 04:35:05 PM joeyli wrote:
> > On Mon, Aug 29, 2016 at 03:41:23PM +0200, Borislav Petkov wrote:
> > > On Mon, Aug 29, 2016 at 09:15:00AM +0200, Pavel Machek wrote:
> > > > Sounds about as easy as hot unplugging arbitrary memory address. IOW
> > > > "not easy".
> > > 
> > > Regardless, forcibly panicking the system more is still the wrong
> > > approach IMO.
> > > 
> > > Instead, I'd try to issue a big fat warning that BIOS corrupts E820 and
> > > that the user should disable hibernation on that box and never ever
> > > enable it again.
> > > 
> > > After that, the kernel should *disable* hibernation for the current boot
> > > so any further hibernation runs don't even happen. Maybe even taint
> > > itself.
> > >
> > 
> > I support this idea to disable hibernation when kernel detected e820 layout
> > was changed by BIOS. If system resume luckily then kernel should warn to user
> > and refuse to hibernate again. User must to know that's better to reboot
> > system when he saw the warning message after lucky resume.
> > 
> > Not just BIOS doesn't fix e820 layout. There have some machines doesn't provide
> > _S4_ function, so the hibernation fallbacks to "shutdown" mode because "platform"
> > mode unavailable. In this situation, user is just lucky to run the hibernation.
> > Kernel should warn to user and disable hibernation when detected e820 layout
> > changed.
> 
> Well, please see my reply to Boris.
> 
> Pavel is right that running after detecting an e820 mismatch is generally risky,
> so why don't we shut down the system (but try to do that cleanly instead of
> causing it to panic right away) on an e820 mismatch?

I don't think that's good idea.

Anything involving userspace is risky at that point, and clean
shutdown means a _lot_ of userspace.

We know the filesystems are reasonably clean as we sync-ed
them; I believe right solution is to panic -- on-disk state is pretty
good and we don't want to do anything risky.

Best regards,

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH][v8] PM / hibernate: Verify the consistent of e820 memory map by md5 value Chen Yu <yu.c.chen@intel.com> - 2016-08-28 18:30 +0200
  Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-28 18:40 +0200
  Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Borislav Petkov <bp@alien8.de> - 2016-08-29 07:10 +0200
    Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-29 09:20 +0200
      Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Borislav Petkov <bp@alien8.de> - 2016-08-29 16:50 +0200
        Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value joeyli <jlee@suse.com> - 2016-08-30 10:40 +0200
          Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory map by md5 value "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-08-30 13:50 +0200
            Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-09-08 23:20 +0200
              Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Chen Yu <yu.c.chen@intel.com> - 2016-09-09 09:30 +0200
                Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-09-09 09:40 +0200
        Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory map by md5 value "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-08-30 13:50 +0200
    Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value "Rafael J. Wysocki" <rafael@kernel.org> - 2016-08-29 15:50 +0200
      Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-29 17:20 +0200
        Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory map by md5 value "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-08-30 14:00 +0200
          Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-30 22:00 +0200
            Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value "Rafael J. Wysocki" <rafael@kernel.org> - 2016-08-31 00:00 +0200
              Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-31 13:10 +0200
  Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory map by md5 value "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-08-31 02:30 +0200
    Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-31 13:10 +0200
      Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value Pavel Machek <pavel@ucw.cz> - 2016-08-31 13:50 +0200
        Re: [PATCH][v8] PM / hibernate: Verify the consistent of e820 memory  map by md5 value "Rafael J. Wysocki" <rafael@kernel.org> - 2016-08-31 14:00 +0200

csiph-web