[PATCH] uml: remove SIGPROF from change_signals

From: Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
      Jeff Dike <jdike@addtoit.com>

Since local_irq_save() and local_irq_disable() should match (apart from saving
the flags), get/set_signals must match [un]block_signals, i.e. 
change_signals; since get/set_signals don't enable/disable SIGPROF (and this
behaviour is safe as explained in the comment the patch adds, since the
profiling code does not interact with the kernel code), not even
change_signals must toggle it.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/kernel/signal_user.c

@@ -57,6 +57,10 @@ int change_sig(int signal, int on)
 	return(!sigismember(&old, signal));
 }
 
+/* Both here and in set/get_signal we don't touch SIGPROF, because we must not
+ * disable profiling; it's safe because the profiling code does not interact
+ * with the kernel code at all.*/
+
 static void change_signals(int type)
 {
 	sigset_t mask;
@@ -65,7 +69,6 @@ static void change_signals(int type)
 	sigaddset(&mask, SIGVTALRM);
 	sigaddset(&mask, SIGALRM);
 	sigaddset(&mask, SIGIO);
-	sigaddset(&mask, SIGPROF);
 	if(sigprocmask(type, &mask, NULL) < 0)
 		panic("Failed to change signal mask - errno = %d", errno);
 }