11927 Log, or optionally panic, on zero-length kmem allocations
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Jason King <jason.brian.king@gmail.com>

*** 98,107 ****
         garbage. This random garbage may include secure kernel data. Therefore,
         uninitialized kernel memory should be handled carefully. For example,
         never copyout(9F) a potentially uninitialized buffer.
  
  NOTES
!        kmem_alloc(0, flag) always returns NULL.  kmem_free(NULL, 0) is legal.
  
  
  
!                                October 22, 2014                 KMEM_ALLOC(9F)
--- 98,110 ----
         garbage. This random garbage may include secure kernel data. Therefore,
         uninitialized kernel memory should be handled carefully. For example,
         never copyout(9F) a potentially uninitialized buffer.
  
  NOTES
!        kmem_alloc(0, flag) always returns NULL, but if KM_SLEEP is set, this
!        behavior is considered to be deprecated; the system may be configured
!        to explicitly panic in this case in lieu of returning NULL.
!        kmem_free(NULL, 0) is legal, however.
  
  
  
!                                November 20, 2019                KMEM_ALLOC(9F)