cvs commit: src/sys/kern tty.c

[Konstantin Belousov]

kib         2008-05-23 16:46:27 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             tty.c 
  Log:
  The dev_refthread() in the tty_gettp() may fail, because Giant is taken
  in the giant_trick routines after the dev_refthread increments the
  si_threadcount. Remove assert, do not perform dev_relthread() for failed
  dev_refthread(), and handle failure in the tty_gettp() callers (cdevsw
  tty methods).
  
  Before kern_conf.c 1.210 and 1.211, the kernel usually paniced in the
  giant_trick routines dereferencing NULL cdevsw, not taking this fault.
  
  Reported by:    Vince Hoffman <jhary unsane co uk>
  Debugging help and tested by:   pho
  Reviewed by:    jhb
  MFC after:      1 week
  
  Revision  Changes    Path
  1.279     +6 -5      src/sys/kern/tty.c