* Implemented sigaltstack() and set_signal_stack(), thus closing bug #1401.

* On exec() the new function thread_reset_for_exec() is called which clears the signals
  and cancels an eventually set alarm. Both things weren't done before...
* Some minor cleanups.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21989 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/libroot/posix/signal/Jamfile

@@ -6,7 +6,9 @@ MergeObject posix_signal.o :
 	kill.c
 	raise.c
 	send_signal.c
+	set_signal_stack.c
 	sigaction.c
+	sigaltstack.c
 	signal.c
 	sigpending.c
 	sigprocmask.c

src/system/libroot/posix/signal/set_signal_stack.c

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2007, Axel Dörfler, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <errno.h>
+#include <signal.h>
+
+#include <syscalls.h>
+
+
+void
+set_signal_stack(void *ptr, size_t size)
+{
+	stack_t alternateStack;
+	status_t status;
+
+	alternateStack.ss_sp = ptr;
+	alternateStack.ss_size = size;
+	alternateStack.ss_flags = 0;
+
+	status = _kern_set_signal_stack(&alternateStack, NULL);
+	if (status < B_OK)
+		errno = status;
+}
+
+

src/system/libroot/posix/signal/sigaltstack.c

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2007, Axel Dörfler, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <errno.h>
+#include <signal.h>
+
+#include <syscalls.h>
+
+
+int
+sigaltstack(const stack_t *alternateStack, stack_t *oldAlternateStack)
+{
+	status_t status =_kern_set_signal_stack(alternateStack, oldAlternateStack);
+	if (status < B_OK) {
+		errno = status;
+		return -1;
+	}
+
+	return 0;
+}