Re: [PATCH] Documentation/livepatch: remove the limitation for schedule() patching

From	Miroslav Benes <mbenes@suse.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH] Documentation/livepatch: remove the limitation for schedule() patching
Date	2017-01-10 11:40 +0100
Message-ID	<sY20q-aM-23@gated-at.bofh.it> (permalink)
References	<sWE9Q-3lM-17@gated-at.bofh.it> <sWIds-6kw-27@gated-at.bofh.it> <sXHIl-4hX-11@gated-at.bofh.it> <sXJAu-5tx-35@gated-at.bofh.it>
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On Mon, 9 Jan 2017, Josh Poimboeuf wrote:

> On Mon, Jan 09, 2017 at 01:50:19PM +0100, Miroslav Benes wrote:
> > There is still one thing which I don't understand. Why __schedule() 
> > (patched or the original) is not on the stack. The actual "sleep" 
> > should happen in __switch_to_asm() which is C function now. And there is a 
> > call to __switch_to_asm() in __schedule(). __schedule() thus should be on 
> > the stack, shouldn't it? What am I missing? __switch_to_asm() pushes %rbp 
> > on the stack...
> 
> Ah, this is an unwinder bug.  get_frame_pointer() needs to be fixed so
> that for an inactive task it returns a pointer to inactive_task_frame.bp
> rather than the value of inactive_task_frame.bp itself.  Will fix it.

And it works with the fix. Thanks.

Miroslav

Thread

[PATCH] Documentation/livepatch: remove the limitation for schedule() patching Miroslav Benes <mbenes@suse.cz> - 2017-01-06 16:00 +0100
  Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Petr Mladek <pmladek@suse.com> - 2017-01-06 16:10 +0100
    Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Miroslav Benes <mbenes@suse.cz> - 2017-01-06 16:20 +0100
  Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Josh Poimboeuf <jpoimboe@redhat.com> - 2017-01-06 20:20 +0100
    Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Miroslav Benes <mbenes@suse.cz> - 2017-01-09 14:00 +0100
      Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Josh Poimboeuf <jpoimboe@redhat.com> - 2017-01-09 16:00 +0100
        Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Miroslav Benes <mbenes@suse.cz> - 2017-01-10 11:40 +0100
  Re: [PATCH] Documentation/livepatch: remove the limitation for  schedule() patching Jiri Kosina <jikos@kernel.org> - 2017-01-11 02:40 +0100

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