diff --git a/arch/sim/src/nuttx-names.dat b/arch/sim/src/nuttx-names.dat
index 759743be534..f1373f1d9c1 100644
--- a/arch/sim/src/nuttx-names.dat
+++ b/arch/sim/src/nuttx-names.dat
@@ -62,7 +62,10 @@ pthread_mutex_init NXpthread_mutex_init
 pthread_mutex_lock NXpthread_mutex_lock
 pthread_mutex_unlock NXpthread_mutex_unlock
 pthread_setspecific NXpthread_setspecific
+pthread_setcancelstate NXpthread_setcancelstate
+pthread_setcanceltype NXpthread_setcanceltype
 pthread_sigmask NXpthread_sigmask
+pthread_testcancel NXpthread_testcancel
 pthread_yield  NXpthread_yield
 ptsname        NXptsname
 ptsname_r      NXptsname_r
diff --git a/sched/init/os_smpstart.c b/sched/init/os_smpstart.c
index ba8afac2ded..17316e5b616 100644
--- a/sched/init/os_smpstart.c
+++ b/sched/init/os_smpstart.c
@@ -218,6 +218,13 @@ int os_smp_start(void)
        */
 
       up_initial_state(tcb);
+
+      /* Set the task flags to indicate that this is a kernel thread and that
+       * this task is locked to this CPU.
+       */
+
+      tcb->flags = (TCB_FLAG_TTYPE_KERNEL | TCB_FLAG_NONCANCELABLE | TCB_FLAG_CPU_LOCKED);
+      tcb->cpu   = cpu;
     }
 
   /* Then start all of the other CPUs after we have completed the memory
diff --git a/sched/init/os_start.c b/sched/init/os_start.c
index 17e1f40cde9..5b8236b56ac 100644
--- a/sched/init/os_start.c
+++ b/sched/init/os_start.c
@@ -470,10 +470,11 @@ void os_start(void)
        */
 
 #ifdef CONFIG_SMP
-      g_idletcb[cpu].cmn.flags = (TCB_FLAG_TTYPE_KERNEL | TCB_FLAG_CPU_LOCKED);
+      g_idletcb[cpu].cmn.flags = (TCB_FLAG_TTYPE_KERNEL TCB_FLAG_NONCANCELABLE |
+                                  TCB_FLAG_CPU_LOCKED);
       g_idletcb[cpu].cmn.cpu   = cpu;
 #else
-      g_idletcb[cpu].cmn.flags = TCB_FLAG_TTYPE_KERNEL;
+      g_idletcb[cpu].cmn.flags = (TCB_FLAG_TTYPE_KERNEL | TCB_FLAG_NONCANCELABLE);
 #endif
 
 #ifdef CONFIG_SMP
diff --git a/sched/pthread/pthread_testcancel.c b/sched/pthread/pthread_testcancel.c
index 0e6186dec2e..c58d9344e10 100644
--- a/sched/pthread/pthread_testcancel.c
+++ b/sched/pthread/pthread_testcancel.c
@@ -42,6 +42,8 @@
 #include <pthread.h>
 #include <errno.h>
 
+#include <nuttx/pthread.h>
+
 #include "sched/sched.h"
 
 /****************************************************************************
@@ -60,7 +62,6 @@
 
 void pthread_testcancel(void)
 {
-#ifdef CONFIG_CANCELLATION_POINTS
-#  warning Missing Logic
-#endif
+  enter_cancellation_point();
+  leave_cancellation_point();
 }
diff --git a/sched/sched/sched_wait.c b/sched/sched/sched_wait.c
index d1547e07cfa..6a50403d54e 100644
--- a/sched/sched/sched_wait.c
+++ b/sched/sched/sched_wait.c
@@ -44,6 +44,7 @@
 #include <errno.h>
 
 #include <nuttx/sched.h>
+#include <nuttx/pthread.h>
 
 #include "sched/sched.h"
 
@@ -84,4 +85,3 @@ pid_t wait(FAR int *stat_loc)
 }
 
 #endif /* CONFIG_SCHED_WAITPID && CONFIG_SCHED_HAVE_PARENT */
-
diff --git a/sched/sched/sched_waitid.c b/sched/sched/sched_waitid.c
index f4e48d5f649..3fb3a329a21 100644
--- a/sched/sched/sched_waitid.c
+++ b/sched/sched/sched_waitid.c
@@ -164,6 +164,10 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
   int errcode;
   int ret;
 
+  /* waitid() is a cancellation point */
+
+  enter_cancellation_point();
+
   /* MISSING LOGIC:   If WNOHANG is provided in the options, then this function
    * should returned immediately.  However, there is no mechanism available now
    * know if the thread has child:  The children remember their parents (if
@@ -404,12 +408,14 @@ int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options)
         }
     }
 
+  leave_cancellation_point();
   sched_unlock();
   return OK;
 
 errout_with_errno:
   set_errno(errcode);
 errout:
+  leave_cancellation_point();
   sched_unlock();
   return ERROR;
 }
diff --git a/sched/sched/sched_waitpid.c b/sched/sched/sched_waitpid.c
index a3ef50674f1..d386d153087 100644
--- a/sched/sched/sched_waitpid.c
+++ b/sched/sched/sched_waitpid.c
@@ -45,6 +45,7 @@
 #include <errno.h>
 
 #include <nuttx/sched.h>
+#include <nuttx/pthread.h>
 
 #include "sched/sched.h"
 #include "group/group.h"
@@ -185,12 +186,17 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options)
 
   DEBUGASSERT(stat_loc);
 
+  /* waitpid() is a cancellation point */
+
+  enter_cancellation_point();
+
   /* None of the options are supported */
 
 #ifdef CONFIG_DEBUG_FEATURES
   if (options != 0)
     {
       set_errno(ENOSYS);
+      leave_cancellation_point();
       return ERROR;
     }
 #endif
@@ -268,12 +274,14 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options)
 
   /* On success, return the PID */
 
+  leave_cancellation_point();
   sched_unlock();
   return pid;
 
 errout_with_errno:
   set_errno(errcode);
 errout:
+  leave_cancellation_point();
   sched_unlock();
   return ERROR;
 }
@@ -307,12 +315,17 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options)
 
   DEBUGASSERT(stat_loc);
 
+  /* waitpid() is a cancellation point */
+
+  enter_cancellation_point();
+
   /* None of the options are supported */
 
 #ifdef CONFIG_DEBUG_FEATURES
   if (options != 0)
     {
       set_errno(ENOSYS);
+      leave_cancellation_point();
       return ERROR;
     }
 #endif
@@ -528,6 +541,7 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options)
         }
     }
 
+  leave_cancellation_point();
   sched_unlock();
   return (int)pid;
 
@@ -535,6 +549,7 @@ errout_with_errno:
   set_errno(errcode);
 
 errout_with_lock:
+  leave_cancellation_point();
   sched_unlock();
   return ERROR;
 }
diff --git a/sched/semaphore/sem_wait.c b/sched/semaphore/sem_wait.c
index da855bc70c0..d0b6c8661a3 100644
--- a/sched/semaphore/sem_wait.c
+++ b/sched/semaphore/sem_wait.c
@@ -86,6 +86,10 @@ int sem_wait(FAR sem_t *sem)
 
   DEBUGASSERT(sem != NULL && up_interrupt_context() == false);
 
+  /* sem_wait is a cancellation point */
+
+  enter_cancellation_point();
+
   /* Make sure we were supplied with a valid semaphore. */
 
   if (sem != NULL)
@@ -196,5 +200,6 @@ int sem_wait(FAR sem_t *sem)
       set_errno(EINVAL);
     }
 
+  leave_cancellation_point();
   return ret;
 }