cvs commit: src/sys/kern kern_proc.c

[Robert Watson]

rwatson     2004-08-14 17:15:16 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             kern_proc.c 
  Log:
  Cause pfind() not to return processes in the PRS_NEW state.  As a result,
  threads consuming the result of pfind() will not need to check for a NULL
  credential pointer or other signs of an incompletely created process.
  However, this also means that pfind() cannot be used to test for the
  existence or find such a process.  Annotate pfind() to indicate that this
  is the case.  A review of curent consumers seems to indicate that this is
  not a problem for any of them.  This closes a number of race conditions
  that could result in NULL pointer dereferences and related failure modes.
  Other related races continue to exist, especially during iteration of the
  allproc list without due caution.
  
  Discussed with: tjr, green
  
  Revision  Changes    Path
  1.215     +8 -1      src/sys/kern/kern_proc.c