sched/cancelpt: Fix MISRA C 2012 Rule 10.4 violations

Fix violations of MISRA C:2012 Rule 10.4 (operand of unsigned and signed)
in cancellation point handling code.

Changed all CANCEL_FLAG_* macro definitions and their usage to use unsigned
literals (1u instead of 1) to ensure consistent unsigned arithmetic when
performing bitwise operations. This eliminates mixed signed/unsigned operand
violations in:

- CANCEL_FLAG_NONCANCELABLE
- CANCEL_FLAG_CANCEL_ASYNC
- CANCEL_FLAG_CANCEL_PENDING

The changes affect cancellation point entry/exit logic, cancellation state
management, and cancellation type handling across both kernel and libc
implementations.

Signed-off-by: fangxinyong <fangxinyong@xiaomi.com>

include/nuttx/cancelpt.h

@@ -63,9 +63,9 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-#define CANCEL_FLAG_NONCANCELABLE   (1 << 0) /* Pthread is non-cancelable */
+#define CANCEL_FLAG_NONCANCELABLE   (1u << 0) /* Pthread is non-cancelable */
-#define CANCEL_FLAG_CANCEL_ASYNC    (1 << 1) /* Async (vs deferred) cancellation type */
+#define CANCEL_FLAG_CANCEL_ASYNC    (1u << 1) /* Async (vs deferred) cancellation type */
-#define CANCEL_FLAG_CANCEL_PENDING  (1 << 2) /* Pthread cancel is pending */
+#define CANCEL_FLAG_CANCEL_PENDING  (1u << 2) /* Pthread cancel is pending */
 
 /****************************************************************************
  * Public Function Prototypes

libs/libc/sched/task_cancelpt.c

@@ -106,13 +106,13 @@ bool enter_cancellation_point(void)
    * nesting level.
    */
 
-  if (((tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) == 0 &&
+  if (((tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) == 0u &&
-       (tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) == 0) ||
+       (tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) == 0u) ||
       tls->tl_cpcount > 0)
     {
       /* Check if there is a pending cancellation */
 
-      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0)
+      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0u)
         {
           /* Yes... return true (if we don't exit here) */
 
@@ -194,7 +194,7 @@ void leave_cancellation_point(void)
            * the type of the thread.
            */
 
-          if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0)
+          if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0u)
             {
 #ifndef CONFIG_DISABLE_PTHREAD
               pthread_exit(PTHREAD_CANCELED);
@@ -245,13 +245,13 @@ bool check_cancellation_point(void)
    * cancellation and will true if there is a pending cancellation.
    */
 
-  if (((tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) == 0 &&
+  if (((tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) == 0u &&
-       (tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) == 0) ||
+       (tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) == 0u) ||
       tls->tl_cpcount > 0)
     {
       /* Check if there is a pending cancellation.  If so, return true. */
 
-      ret = ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0);
+      ret = ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0u);
     }
 
   return ret;

libs/libc/sched/task_setcancelstate.c

@@ -71,7 +71,7 @@ int task_setcancelstate(int state, FAR int *oldstate)
 
   if (oldstate != NULL)
     {
-      if ((tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) != 0)
+      if ((tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) != 0u)
         {
           *oldstate = TASK_CANCEL_DISABLE;
         }
@@ -91,12 +91,12 @@ int task_setcancelstate(int state, FAR int *oldstate)
 
       /* Check if a cancellation was pending */
 
-      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0)
+      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0u)
         {
 #ifdef CONFIG_CANCELLATION_POINTS
           /* If we are using deferred cancellation? */
 
-          if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) != 0)
+          if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) != 0u)
 #endif
             {
               /* No.. We are using asynchronous cancellation.  If the

libs/libc/sched/task_setcanceltype.c

@@ -63,7 +63,7 @@ int task_setcanceltype(int type, FAR int *oldtype)
 
   if (oldtype != NULL)
     {
-      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) != 0)
+      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) != 0u)
         {
           *oldtype = TASK_CANCEL_ASYNCHRONOUS;
         }
@@ -86,8 +86,8 @@ int task_setcanceltype(int type, FAR int *oldtype)
        * cancellation is pending, then exit now.
        */
 
-      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0 &&
+      if ((tls->tl_cpstate & CANCEL_FLAG_CANCEL_PENDING) != 0u &&
-          (tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) == 0)
+          (tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) == 0u)
         {
           tls->tl_cpstate &= ~CANCEL_FLAG_CANCEL_PENDING;
 

sched/task/task_cancelpt.c

@@ -109,7 +109,7 @@ bool nxnotify_cancellation(FAR struct tcb_s *tcb)
   /* Check to see if this task has the non-cancelable bit set. */
 
   if ((tcb->flags & TCB_FLAG_FORCED_CANCEL) == 0 &&
-      (tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) != 0)
+      (tls->tl_cpstate & CANCEL_FLAG_NONCANCELABLE) != 0u)
     {
       /* Then we cannot cancel the thread now.  Here is how this is
        * supposed to work:
@@ -131,7 +131,7 @@ bool nxnotify_cancellation(FAR struct tcb_s *tcb)
 #ifdef CONFIG_CANCELLATION_POINTS
   /* Check if this task supports deferred cancellation */
 
-  if (!ret && (tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) == 0)
+  if (!ret && (tls->tl_cpstate & CANCEL_FLAG_CANCEL_ASYNC) == 0u)
     {
       /* Then we cannot cancel the task asynchronously. */