um: simplify set_handler()

For one thing, we always block the same signals (IRQ ones - IO, WINCH, VTALRM),
so there's no need to pass sa_mask elements in arguments.  For another, the
flags depend only on whether it's an IRQ signal or not (we add SA_RESTART
for them).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

4 files changed, 19 insertions, 27 deletions

diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index 2e2663a8e910..598ca825ea9f 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -225,7 +225,7 @@ extern char *get_umid(void);
 extern void timer_init(void);
 extern void set_sigstack(void *sig_stack, int size);
 extern void remove_sigstack(void);
-extern void set_handler(int sig, void (*handler)(int), int flags, ...);
+extern void set_handler(int sig, void (*handler)(int));
 extern int change_sig(int signal, int on);
 extern void block_signals(void);
 extern void unblock_signals(void);
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index c1a8fa74ebb9..075ae920143d 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -235,20 +235,13 @@ out:
 
 void init_new_thread_signals(void)
 {
-        set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK,
-                    SIGIO, SIGWINCH, SIGVTALRM, -1);
-        set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK,
-                    SIGIO, SIGWINCH, SIGVTALRM, -1);
-        set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK,
-                    SIGIO, SIGWINCH, SIGVTALRM, -1);
-        set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK,
-                    SIGIO, SIGWINCH, SIGVTALRM, -1);
-        set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK,
-                    SIGIO, SIGWINCH, SIGVTALRM, -1);
+        set_handler(SIGSEGV, (__sighandler_t) sig_handler);
+        set_handler(SIGTRAP, (__sighandler_t) sig_handler);
+        set_handler(SIGFPE, (__sighandler_t) sig_handler);
+        set_handler(SIGILL, (__sighandler_t) sig_handler);
+        set_handler(SIGBUS, (__sighandler_t) sig_handler);
         signal(SIGHUP, SIG_IGN);
-
-        set_handler(SIGIO, (__sighandler_t) sig_handler,
-                    SA_ONSTACK | SA_RESTART, SIGIO, SIGWINCH, SIGVTALRM, -1);
+        set_handler(SIGIO, (__sighandler_t) sig_handler);
         signal(SIGWINCH, SIG_IGN);
         signal(SIGTERM, SIG_DFL);
 }
diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 75c3e9c9cabb..f248fb2ab58c 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -111,8 +111,7 @@ void alarm_handler(int sig, struct sigcontext *sc)
 
 void timer_init(void)
 {
-        set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
-                    SA_ONSTACK | SA_RESTART, SIGIO, SIGWINCH, -1);
+        set_handler(SIGVTALRM, (__sighandler_t) alarm_handler);
 }
 
 void set_sigstack(void *sig_stack, int size)
@@ -174,27 +173,28 @@ static void hard_handler(int sig, siginfo_t *info, void *p)
         handle_signal(sig, (struct sigcontext *) &uc->uc_mcontext);
 }
 
-void set_handler(int sig, void (*handler)(int), int flags, ...)
+void set_handler(int sig, void (*handler)(int))
 {
         struct sigaction action;
-        va_list ap;
+        int flags = SA_SIGINFO | SA_ONSTACK;
         sigset_t sig_mask;
-        int mask;
 
         handlers[sig] = (void (*)(int, struct sigcontext *)) handler;
         action.sa_sigaction = hard_handler;
 
+        /* block irq ones */
         sigemptyset(&action.sa_mask);
-
-        va_start(ap, flags);
-        while ((mask = va_arg(ap, int)) != -1)
-                sigaddset(&action.sa_mask, mask);
-        va_end(ap);
+        sigaddset(&action.sa_mask, SIGVTALRM);
+        sigaddset(&action.sa_mask, SIGIO);
+        sigaddset(&action.sa_mask, SIGWINCH);
 
         if (sig == SIGSEGV)
                 flags |= SA_NODEFER;
 
-        action.sa_flags = flags | SA_SIGINFO;
+        if (sigismember(&action.sa_mask, sig))
+                flags |= SA_RESTART; /* if it's an irq signal */
+
+        action.sa_flags = flags;
         action.sa_restorer = NULL;
         if (sigaction(sig, &action, NULL) < 0)
                 panic("sigaction failed - errno = %d\n", errno);
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 20b34dcb0906..31743f1d1195 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -659,8 +659,7 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
 {
         int n;
 
-        set_handler(SIGWINCH, (__sighandler_t) sig_handler,
-                    SA_ONSTACK | SA_RESTART, SIGIO, SIGVTALRM, -1);
+        set_handler(SIGWINCH, (__sighandler_t) sig_handler);
 
         /*
          * Can't use UML_SETJMP or UML_LONGJMP here because they save