1. 24 Dec, 2008 1 commit
    • Ingo Molnar's avatar
      x86: disable X86_PTRACE_BTS · 40f15ad8
      Ingo Molnar authored
      there's a new ptrace arch level feature in .28:
        config X86_PTRACE_BTS
        bool "Branch Trace Store"
      it has broken fork() handling: the old DS area gets copied over into
      a new task without clearing it.
      Fixes exist but they came too late:
        c5dee617: x86, bts: memory accounting
        bf53de90: x86, bts: add fork and exit handling
      and are queued up for v2.6.29. This shows that the facility is still not
      tested well enough to release into a stable kernel - disable it for now and
      reactivate in .29. In .29 the hardware-branch-tracer will use the DS/BTS
      facilities too - hopefully resulting in better code.
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
  2. 20 Dec, 2008 1 commit
    • Dmitry Adamushko's avatar
      x86: fix resume (S2R) broken by Intel microcode module, on A110L · 280a9ca5
      Dmitry Adamushko authored
      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:
      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
      (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
      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: default avatarAndreas Mohr <andi@lisas.de>
      Signed-off-by: default avatarDmitry Adamushko <dmitry.adamushko@gmail.com>
      Tested-by: default avatarAndreas Mohr <andi@lisas.de>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
  3. 18 Dec, 2008 2 commits
  4. 17 Dec, 2008 2 commits
  5. 16 Dec, 2008 23 commits
  6. 15 Dec, 2008 8 commits
  7. 14 Dec, 2008 3 commits