1. 03 Aug, 2009 1 commit
  2. 31 Jul, 2009 1 commit
    • Pallipadi, Venkatesh's avatar
      x86, pat: Fix set_memory_wc related corruption · bdc6340f
      Pallipadi, Venkatesh authored
      Changeset 3869c4aa
      that went in after 2.6.30-rc1 was a seemingly small change to _set_memory_wc()
      to make it complaint with SDM requirements. But, introduced a nasty bug, which
      can result in crash and/or strange corruptions when set_memory_wc is used.
      One such crash reported here
      http://lkml.org/lkml/2009/7/30/94
      
      Actually, that changeset introduced two bugs.
      * change_page_attr_set() takes &addr as first argument and can the addr value
        might have changed on return, even for single page change_page_attr_set()
        call. That will make the second change_page_attr_set() in this routine
        operate on unrelated addr, that can eventually cause strange corruptions
        and bad page state crash.
      * The second change_page_attr_set() call, before setting _PAGE_CACHE_WC, should
        clear the earlier _PAGE_CACHE_UC_MINUS, as otherwise cache attribute will not
        be WC (will be UC instead).
      
      The patch below fixes both these problems. Sending a single patch to fix both
      the problems, as the change is to the same line of code. The change to have a
      addr_copy is not very clean. But, it is simpler than making more changes
      through various routines in pageattr.c.
      
      A huge thanks to Jerome for reporting this problem and providing a simple test
      case that helped us root cause the problem.
      Reported-by: default avatarJerome Glisse <glisse@freedesktop.org>
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
      LKML-Reference: <20090730214319.GA1889@linux-os.sc.intel.com>
      Acked-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      bdc6340f
  3. 27 Jul, 2009 32 commits
  4. 26 Jul, 2009 6 commits