linux-kernel - Re: Splat during resume

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Message-ID: <20170325215012.v5vywew7pfi3qk5f@pd.tnic>
Date:   Sat, 25 Mar 2017 22:50:12 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Cc:     lkml <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Andy Lutomirski <luto@...nel.org>,
        Arnd Bergmann <arnd@...db.de>, Brian Gerst <brgerst@...il.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Denys Vlasenko <dvlasenk@...hat.com>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>,
        Peter Zijlstra <peterz@...radead.org>,
        linux-arch@...r.kernel.org, linux-mm@...ck.org,
        x86-ml <x86@...nel.org>
Subject: Re: Splat during resume

On Sat, Mar 25, 2017 at 10:46:15PM +0100, Borislav Petkov wrote:
> On Sat, Mar 25, 2017 at 07:58:55PM +0100, Borislav Petkov wrote:
> > Hey Rafael,
> > 
> > have you seen this already (partial splat photo attached)? Happens
> > during resume from s2d. Judging by the timestamps, this looks like the
> > resume kernel before we switch to the original, boot one but I could be
> > mistaken.
> > 
> > This is -rc3+tip/master.
> > 
> > I can't catch a full splat because this is a laptop and it doesn't have
> > serial. netconsole is helping me for shit so we'd need some guess work.
> > 
> > So I'm open to suggestions.
> > 
> > Please don't say "bisect" yet ;-)))
> 
> No need, I found it. Reverting
> 
>   ea3b5e60ce80 ("x86/mm/ident_map: Add 5-level paging support")
> 
> makes the machine suspend and resume just fine again. Lemme add people to CC.

So I see rIP pointing to ident_pmd_init() and the stack trace has
load_image_and_restore() so if I try to connect the dots, I get:

load_image_and_restore
|-> hibernation_restore
 |-> resume_target_kernel
  |-> swsusp_arch_resume
   |-> set_up_temporary_mappings
    |-> kernel_ident_mapping_init
     |-> ... ident_pmd_init

I'll let you folks make sense of what's going on.

Thanks.

-- 
Regards/Gruss,
    Boris.

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