Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in schedule and __might_sleep

From	Linus Torvalds <torvalds@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in schedule and __might_sleep
Date	2016-05-24 04:20 +0200
Message-ID	<rCa6S-5we-11@gated-at.bofh.it> (permalink)
References	(4 earlier) <oojqi-1qw-7@gated-at.bofh.it> <r7oz7-6aX-1@gated-at.bofh.it> <rC9kt-4VI-1@gated-at.bofh.it> <rC9DQ-51L-3@gated-at.bofh.it> <rCa6S-5we-9@gated-at.bofh.it>
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On Mon, May 23, 2016 at 7:09 PM, Andy Lutomirski <luto@amacapital.net> wrote:
>
> What about this silly fix?  (Pardon the probable whitespace damage.)

That looks fine to me, and has a reason for it.

That said, I'm not convinced about the preempt_enable/preempt_disable
excuse: that would be horribly buggy anyway, and has nothing to do
with IST's. Why protect against random insane bugs?

So the "3*" certainly doesn't hurt, but and I won't argue more against
it, but it looks pretty magical and made-up. Might as well just
add/subtract one. You can never protect against people who
intentionally write buggy code, and if it's protecting against
unintentional buggy code I don't see why the IST case is so special
when it's just a tiny fraction of code..

              Linus

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Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in  schedule and __might_sleep Andy Lutomirski <luto@amacapital.net> - 2016-05-24 03:30 +0200
  Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in  schedule and __might_sleep Linus Torvalds <torvalds@linux-foundation.org> - 2016-05-24 03:50 +0200
    Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in  schedule and __might_sleep Andy Lutomirski <luto@amacapital.net> - 2016-05-24 04:20 +0200
      Re: [PATCH v3 3/3] sched, x86: Check that we're on the right stack in  schedule and __might_sleep Linus Torvalds <torvalds@linux-foundation.org> - 2016-05-24 04:20 +0200

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