6474 getupeercred causes spurious event port wakeups on FIFOs

*** 1125,1134 ****
--- 1125,1149 ----
          return ((VTOF(vp)->fn_flag & FIFOFAST) ?
              fifo_fastioctl(vp, cmd, arg, mode, cr, rvalp) :
              fifo_strioctl(vp, cmd, arg, mode, cr, rvalp));
  }
  
+ static inline int
+ fifo_ioctl_getpeercred(fifonode_t *fnp, intptr_t arg, int mode)
+ {
+         k_peercred_t *kp = (k_peercred_t *)arg;
+ 
+         if (mode == FKIOCTL && fnp->fn_pcredp != NULL) {
+                 crhold(fnp->fn_pcredp);
+                 kp->pc_cr = fnp->fn_pcredp;
+                 kp->pc_cpid = fnp->fn_cpid;
+                 return (0);
+         } else {
+                 return (ENOTSUP);
+         }
+ }
+ 
  static int
  fifo_fastioctl(vnode_t *vp, int cmd, intptr_t arg, int mode, cred_t *cr,
      int *rvalp)
  {
          fifonode_t      *fnp            = VTOF(vp);
*** 1344,1353 ****
--- 1359,1372 ----
          case I_FLUSHBAND:
                  error = 0;
                  *rvalp = 0;
                  break;
  
+         case _I_GETPEERCRED:
+                 error = fifo_ioctl_getpeercred(fnp, arg, mode);
+                 break;
+ 
          /*
           * invalid calls for stream head or fifos
           */
  
          case I_POP:             /* shouldn't happen */
*** 1391,1411 ****
  {
          fifonode_t      *fnp = VTOF(vp);
          int             error;
          fifolock_t      *fn_lock;
  
!         if (cmd == _I_GETPEERCRED) {
!                 if (mode == FKIOCTL && fnp->fn_pcredp != NULL) {
!                         k_peercred_t *kp = (k_peercred_t *)arg;
!                         crhold(fnp->fn_pcredp);
!                         kp->pc_cr = fnp->fn_pcredp;
!                         kp->pc_cpid = fnp->fn_cpid;
!                         return (0);
!                 } else {
!                         return (ENOTSUP);
!                 }
!         }
  
          error = strioctl(vp, cmd, arg, mode, U_TO_K, cr, rvalp);
  
          switch (cmd) {
          /*
--- 1410,1421 ----
  {
          fifonode_t      *fnp = VTOF(vp);
          int             error;
          fifolock_t      *fn_lock;
  
!         if (cmd == _I_GETPEERCRED)
!                 return (fifo_ioctl_getpeercred(fnp, arg, mode));
  
          error = strioctl(vp, cmd, arg, mode, U_TO_K, cr, rvalp);
  
          switch (cmd) {
          /*