OS-4514 [lx] SIGEV_THREAD_ID emulation needed

*** 988,997 ****
--- 988,1052 ----
                  }
  
                  return (0);
          }
  
+         case B_SIGEV_THREAD_ID: {
+                 /*
+                  * Emulate Linux's timer_create(2) SIGEV_THREAD_ID
+                  * notification method. This mechanism is only meant
+                  * for userland threading libraries such as glibc and
+                  * is documented as such. Therefore, assume this is
+                  * only ever invoked for the purpose of alerting a
+                  * Linux threading library. Assume that the tid is a
+                  * member of the caller's process and the signal
+                  * number is valid. See lx_sigev_thread_id() for the
+                  * userland side of this emulation.
+                  *
+                  * The return code from this function is not checked
+                  * by the caller since it executes in an asynchronous
+                  * context and there is nothing much to be done. If
+                  * this function does fail then it will manifest as
+                  * Linux threads waiting for a signal they will never
+                  * receive.
+                  *
+                  * arg1 -- Linux tid
+                  * arg2 -- Linux signal number
+                  * arg3 -- union sigval
+                  */
+ 
+                 int native_sig = lx_ltos_signo((int)arg2, 0);
+                 pid_t native_pid;
+                 int native_tid;
+                 sigqueue_t *sqp;
+ 
+                 if (native_sig == 0)
+                         return (EINVAL);
+ 
+                 lx_lpid_to_spair((pid_t)arg1, &native_pid, &native_tid);
+                 sqp = kmem_zalloc(sizeof (sigqueue_t), KM_SLEEP);
+                 mutex_enter(&curproc->p_lock);
+ 
+                 if ((t = idtot(curproc, native_tid)) == NULL) {
+                         mutex_exit(&curproc->p_lock);
+                         kmem_free(sqp, sizeof (sigqueue_t));
+                         return (ESRCH);
+                 }
+ 
+                 sqp->sq_info.si_signo = native_sig;
+                 sqp->sq_info.si_code = SI_TIMER;
+                 sqp->sq_info.si_pid = curproc->p_pid;
+                 sqp->sq_info.si_zoneid = getzoneid();
+                 sqp->sq_info.si_uid = crgetruid(CRED());
+                 sqp->sq_info.si_value.sival_ptr = (void *)arg3;
+                 sigaddqa(curproc, t, sqp);
+ 
+                 mutex_exit(&curproc->p_lock);
+ 
+                 return (0);
+         }
+ 
          case B_SET_AFFINITY_MASK:
          case B_GET_AFFINITY_MASK:
                  /*
                   * Retrieve or store the CPU affinity mask for the
                   * requested linux pid.