8634 epoll fails to wake on certain edge-triggered conditions
8635 epoll should not emit POLLNVAL
8636 recursive epoll should emit EPOLLRDNORM
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>

*** 22,32 ****
  /*        All Rights Reserved   */
  
  
  /*
   * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
!  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
   */
  
  #include <sys/types.h>
  #include <sys/sysmacros.h>
  #include <sys/param.h>
--- 22,32 ----
  /*        All Rights Reserved   */
  
  
  /*
   * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
!  * Copyright 2017 Joyent, Inc.
   */
  
  #include <sys/types.h>
  #include <sys/sysmacros.h>
  #include <sys/param.h>
*** 8172,8186 ****
   * Note: POLLRDDATA assumes that synch streams only return messages with
   * an M_DATA attached (i.e. not messages consisting of only
   * an M_PROTO/M_PCPROTO part).
   */
  int
! strpoll(
!         struct stdata *stp,
!         short events_arg,
!         int anyyet,
!         short *reventsp,
          struct pollhead **phpp)
  {
          int events = (ushort_t)events_arg;
          int retevents = 0;
          mblk_t *mp;
--- 8172,8182 ----
   * Note: POLLRDDATA assumes that synch streams only return messages with
   * an M_DATA attached (i.e. not messages consisting of only
   * an M_PROTO/M_PCPROTO part).
   */
  int
! strpoll(struct stdata *stp, short events_arg, int anyyet, short *reventsp,
      struct pollhead **phpp)
  {
          int events = (ushort_t)events_arg;
          int retevents = 0;
          mblk_t *mp;
*** 8314,8325 ****
                                  retevents |= normevents;
                          else
                                  retevents |= (events & (POLLIN | POLLRDBAND));
                          break;
                  }
!                 if (! (retevents & normevents) &&
!                     (stp->sd_wakeq & RSLEEP)) {
                          /*
                           * Sync stream barrier read queue has data.
                           */
                          retevents |= normevents;
                  }
--- 8310,8320 ----
                                  retevents |= normevents;
                          else
                                  retevents |= (events & (POLLIN | POLLRDBAND));
                          break;
                  }
!                 if (!(retevents & normevents) && (stp->sd_wakeq & RSLEEP)) {
                          /*
                           * Sync stream barrier read queue has data.
                           */
                          retevents |= normevents;
                  }
*** 8326,8348 ****
                  /* Treat eof as normal data */
                  if (sd_flags & STREOF)
                          retevents |= normevents;
          }
  
-         *reventsp = (short)retevents;
-         if (retevents && !(events & POLLET)) {
-                 if (headlocked)
-                         mutex_exit(&stp->sd_lock);
-                 return (0);
-         }
- 
          /*
!          * If poll() has not found any events yet, set up event cell
!          * to wake up the poll if a requested event occurs on this
!          * stream.  Check for collisions with outstanding poll requests.
           */
!         if (!anyyet) {
                  *phpp = &stp->sd_pollist;
                  if (headlocked == 0) {
                          if (polllock(&stp->sd_pollist, &stp->sd_lock) != 0) {
                                  *reventsp = POLLNVAL;
                                  return (0);
--- 8321,8335 ----
                  /* Treat eof as normal data */
                  if (sd_flags & STREOF)
                          retevents |= normevents;
          }
  
          /*
!          * Pass back a pollhead if no events are pending or if edge-triggering
!          * has been configured on this resource.
           */
!         if ((retevents == 0 && !anyyet) || (events & POLLET)) {
                  *phpp = &stp->sd_pollist;
                  if (headlocked == 0) {
                          if (polllock(&stp->sd_pollist, &stp->sd_lock) != 0) {
                                  *reventsp = POLLNVAL;
                                  return (0);
*** 8349,8358 ****
--- 8336,8347 ----
                          }
                          headlocked = 1;
                  }
                  stp->sd_rput_opt |= SR_POLLIN;
          }
+ 
+         *reventsp = (short)retevents;
          if (headlocked)
                  mutex_exit(&stp->sd_lock);
          return (0);
  }