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  1. 22 12月, 2008 35 次提交
  3. 21 12月, 2008 3 次提交
  5. 20 12月, 2008 2 次提交
    • D
      x86: fix resume (S2R) broken by Intel microcode module, on A110L · 280a9ca5
      由 Dmitry Adamushko 提交于 
      Impact: fix deadlock

This is in response to the following bug report:

Bug-Entry       : http://bugzilla.kernel.org/show_bug.cgi?id=12100
Subject         : resume (S2R) broken by Intel microcode module, on A110L
Submitter       : Andreas Mohr <andi@lisas.de>
Date            : 2008-11-25 08:48 (19 days old)
Handled-By      : Dmitry Adamushko <dmitry.adamushko@gmail.com>

[ The deadlock scenario has been discovered by Andreas Mohr ]

I think I might have a logical explanation why the system:

  (http://bugzilla.kernel.org/show_bug.cgi?id=12100)

might hang upon resuming, OTOH it should have likely hanged each and every time.

(1) possible deadlock in microcode_resume_cpu() if either 'if' section is
taken;

(2) now, I don't see it in spec. and can't experimentally verify it (newer
ucodes don't seem to be available for my Core2duo)... but logically-wise, I'd
think that when read upon resuming, the 'microcode revision' (MSR 0x8B) should
be back to its original one (we need to reload ucode anyway so it doesn't seem
logical if a cpu doesn't drop the version)... if so, the comparison with
memcmp() for the full 'struct cpu_signature' is wrong... and that's how one of
the aforementioned 'if' sections might have been triggered - leading to a
deadlock.

Obviously, in my tests I simulated loading/resuming with the ucode of the same
version (just to see that the file is loaded/re-loaded upon resuming) so this
issue has never popped up.

I'd appreciate if someone with an appropriate system might give a try to the
2nd patch (titled "fix a comparison && deadlock...").

In any case, the deadlock situation is a must-have fix.
Reported-by: NAndreas Mohr <andi@lisas.de>
Signed-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com>
Tested-by: NAndreas Mohr <andi@lisas.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      280a9ca5
    • J
      fs/9p: change simple_strtol to simple_strtoul · f1d9e458
      由 Julia Lawall 提交于 
      Since v9ses->uid is unsigned, it would seem better to use simple_strtoul that
simple_strtol.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r2@
long e;
position p;
@@

e = simple_strtol@p(...)

@@
position p != r2.p;
type T;
T e;
@@

e =
- simple_strtol@p
+ simple_strtoul
  (...)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
      f1d9e458