1. 05 3月, 2009 6 次提交
  2. 04 3月, 2009 9 次提交
  3. 03 3月, 2009 24 次提交
  4. 02 3月, 2009 1 次提交
    • P
      x86 mmiotrace: fix race with release_kmmio_fault_page() · 340430c5
      Pekka Paalanen 提交于
      There was a theoretical possibility to a race between arming a page in
      post_kmmio_handler() and disarming the page in
      release_kmmio_fault_page():
      
      cpu0                             cpu1
      ------------------------------------------------------------------
      mmiotrace shutdown
      enter release_kmmio_fault_page
                                       fault on the page
                                       disarm the page
      disarm the page
                                       handle the MMIO access
                                       re-arm the page
      put the page on release list
      remove_kmmio_fault_pages()
                                       fault on the page
                                       page not known to mmiotrace
                                       fall back to do_page_fault()
                                       *KABOOM*
      
      (This scenario also shows the double disarm case which is allowed.)
      
      Fixed by acquiring kmmio_lock in post_kmmio_handler() and checking
      if the page is being released from mmiotrace.
      Signed-off-by: NPekka Paalanen <pq@iki.fi>
      Cc: Stuart Bennett <stuart@freedesktop.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      340430c5