[RFC PATCH 04/18] signal: Rename kernel_sigaction() to kthread_sigaction() and clean it up

@@ -241,13 +241,26 @@ extern void __set_current_blocked(const sigset_t *);
 extern int show_unhandled_signals;
 extern int sigsuspend(sigset_t *);
 
+typedef __signalfn_t *__kthread_sighandler_t;
+
+/* use the default signal handler for the kthread */
+#define KTHREAD_SIG_DFL ((__force __kthread_sighandler_t)SIG_DFL)
+/* ignore the signal in the kthread */
+#define KTHREAD_SIG_IGN	((__force __kthread_sighandler_t)SIG_IGN)
+
 struct sigaction {
 #ifndef __ARCH_HAS_IRIX_SIGACTION
-	__sighandler_t	sa_handler;
+	union {
+		__sighandler_t		sa_handler;
+		__kthread_sighandler_t	kthread_sa_handler;
+	};
 	unsigned long	sa_flags;
 #else
 	unsigned int	sa_flags;
-	__sighandler_t	sa_handler;
+	union {
+		__sighandler_t		sa_handler;
+		__kthread_sighandler_t	kthread_sa_handler;
+	};
 #endif
 #ifdef __ARCH_HAS_SA_RESTORER
 	__sigrestore_t sa_restorer;

@@ -280,7 +293,7 @@ struct ksignal {
 extern int get_signal(struct ksignal *ksig);
 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
 extern void exit_signals(struct task_struct *tsk);
-extern void kernel_sigaction(int, __sighandler_t);
+extern void kthread_sigaction(int, __kthread_sighandler_t);
 
 static inline void allow_signal(int sig)
 {

@@ -289,12 +302,12 @@ static inline void allow_signal(int sig)
 	 * know it'll be handled, so that they don't get converted to
 	 * SIGKILL or just silently dropped.
 	 */
-	kernel_sigaction(sig, (__force __sighandler_t)2);
+	kthread_sigaction(sig, (__kthread_sighandler_t)2);
 }
 
 static inline void disallow_signal(int sig)
 {
-	kernel_sigaction(sig, SIG_IGN);
+	kthread_sigaction(sig, KTHREAD_SIG_IGN);
 }
 
 extern struct kmem_cache *sighand_cachep;

@@ -273,7 +273,7 @@ static int wait_for_helper(void *data)
 	pid_t pid;
 
 	/* If SIGCLD is ignored sys_wait4 won't populate the status. */
-	kernel_sigaction(SIGCHLD, SIG_DFL);
+	kthread_sigaction(SIGCHLD, KTHREAD_SIG_DFL);
 	pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
 	if (pid < 0) {
 		sub_info->retval = pid;

@@ -3077,11 +3077,11 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo,
 /*
  * For kthreads only, must not be used if cloned with CLONE_SIGHAND
  */
-void kernel_sigaction(int sig, __sighandler_t action)
+void kthread_sigaction(int sig, __kthread_sighandler_t action)
 {
 	spin_lock_irq(&current->sighand->siglock);
-	current->sighand->action[sig - 1].sa.sa_handler = action;
-	if (action == SIG_IGN) {
+	current->sighand->action[sig - 1].sa.kthread_sa_handler = action;
+	if (action == KTHREAD_SIG_IGN) {
 		sigset_t mask;
 
 		sigemptyset(&mask);

@@ -3093,7 +3093,7 @@ void kernel_sigaction(int sig, __sighandler_t action)
 	}
 	spin_unlock_irq(&current->sighand->siglock);
 }
-EXPORT_SYMBOL(kernel_sigaction);
+EXPORT_SYMBOL(kthread_sigaction);
 
 int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 {