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