Re: [PATCH] efibc: avoid stack overflow warning

From	Matt Fleming <matt@codeblueprint.co.uk>
Newsgroups	linux.kernel
Subject	Re: [PATCH] efibc: avoid stack overflow warning
Date	2016-05-01 00:50 +0200
Message-ID	<rtLS1-7cr-1@gated-at.bofh.it> (permalink)
References	<rtkIa-1vq-7@gated-at.bofh.it> <rtJwS-5qf-11@gated-at.bofh.it> <rtLIm-78D-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Sun, 01 May, at 12:34:29AM, Arnd Bergmann wrote:
> 
> The sys_restart() system call takes a mutex before calling kernel_restart()
> or kernel_poweroff().
> 
> I've had a closer look now and found that there are a few other
> callers of kernel_restart, so I guess if you restart using sysctl
> at the exact same time as calling /sbin/reboot, things may break.
 
Right. Or if the dm-verify-target driver saw an error.

> It's not something we'd have to worry about in practice, but it does
> make my patch incorrect. Should we come up with a different way to
> do it?

Jeremy proposed a patch to dynamically allocate the memory, which I
think is the correct way to go given that our (reasonable) assumptions
about reboot notifier concurrency are not guaranteed,

  https://lkml.kernel.org/r/87h9eked24.fsf@jcompost-MOBL1.tl.intel.com

Thread

[PATCH] efibc: avoid stack overflow warning Arnd Bergmann <arnd@arndb.de> - 2016-04-29 19:50 +0200
  Re: [PATCH] efibc: avoid stack overflow warning Matt Fleming <matt@codeblueprint.co.uk> - 2016-04-30 22:20 +0200
    Re: [PATCH] efibc: avoid stack overflow warning Arnd Bergmann <arnd@arndb.de> - 2016-05-01 00:40 +0200
      Re: [PATCH] efibc: avoid stack overflow warning Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-01 00:50 +0200
        Re: [PATCH] efibc: avoid stack overflow warning Arnd Bergmann <arnd@arndb.de> - 2016-05-01 01:30 +0200
          Re: [PATCH] efibc: avoid stack overflow warning Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-01 15:20 +0200

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