cvs commit: src/sys/dev/sound/pcm sndstat.c

[Don Lewis]

truckman    2004-09-10 09:37:06 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/sound/pcm    sndstat.c 
  Log:
  Convert sndstat_lock from a mutex to an sx lock.  sndstat_read()
  holds sndstat_lock across a call to uiomove(), which is not legal
  to do with a  mutex because of the possibility that the data transfer
  could sleep because of a page fault.  It is not possible to just
  unlock the mutex for the uiomove() call without introducing another
  locking mechanism to prevent the body of sndstat_read() from being
  re-entered.  Converting sndstat_lock to an sx lock is the least
  complicated change.
  
  This is a candidate for RELENG_5.
  
  LOR:            030
  MFC after:      4 days
  
  Revision  Changes    Path
  1.18      +29 -26    src/sys/dev/sound/pcm/sndstat.c