OS-7125 Need mitigation of L1TF (CVE-2018-3646)
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

*** 73,83 ****
--- 73,88 ----
  #include <sys/schedctl.h>
  #include <sys/waitq.h>
  #include <sys/cpucaps.h>
  #include <sys/kiconv.h>
  #include <sys/ctype.h>
+ #include <sys/ht.h>
  
+ #ifndef STACK_GROWTH_DOWN
+ #error Stacks do not grow downward; 3b2 zombie attack detected!
+ #endif
+ 
  struct kmem_cache *thread_cache;        /* cache of free threads */
  struct kmem_cache *lwp_cache;           /* cache of free lwps */
  struct kmem_cache *turnstile_cache;     /* cache of free turnstiles */
  
  /*
*** 514,525 ****
           * is ready to run.
           */
          if (CPU->cpu_part == &cp_default)
                  t->t_cpu = CPU;
          else
!                 t->t_cpu = disp_lowpri_cpu(cp_default.cp_cpulist, t->t_lpl,
!                     t->t_pri, NULL);
  
          t->t_disp_queue = t->t_cpu->cpu_disp;
          kpreempt_enable();
  
          /*
--- 519,530 ----
           * is ready to run.
           */
          if (CPU->cpu_part == &cp_default)
                  t->t_cpu = CPU;
          else
!                 t->t_cpu = disp_lowpri_cpu(cp_default.cp_cpulist, t,
!                     t->t_pri);
  
          t->t_disp_queue = t->t_cpu->cpu_disp;
          kpreempt_enable();
  
          /*
*** 1324,1333 ****
--- 1329,1340 ----
          ASSERT(t->t_intr != NULL);
  
          itp = t->t_intr;                /* interrupted thread */
          t->t_intr = NULL;               /* clear interrupt ptr */
  
+         ht_end_intr();
+ 
          /*
           * Get state from interrupt thread for the one
           * it interrupted.
           */