Xtensa: Provide an architecture specific sigaction and sa_restorer function in libc to avoid having to place executable code on stack.

Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 59 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/xtensa/sigaction.c b/libc/sysdeps/linux/xtensa/sigaction.c
new file mode 100644
index 000000000..5ef40c36e
--- /dev/null
+++ b/libc/sysdeps/linux/xtensa/sigaction.c
@@ -0,0 +1,59 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * sigaction() for Xtensa uClibc
+ *
+ * Copyright (C) 2007, 2008 Tensilica Inc.
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ */ 
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/syscall.h>
+#include <string.h>
+#include <bits/kernel_sigaction.h>
+
+#define SA_RESTORER	0x04000000	
+
+extern void __default_sa_restorer (void);
+
+libc_hidden_proto(memcpy)
+
+int __libc_sigaction (int signum, const struct sigaction *act, 
+					  struct sigaction *oldact)
+{
+	struct kernel_sigaction kact, koldact;
+	int result;
+
+	if (act) {
+		kact.k_sa_handler = act->sa_handler;
+		memcpy(&kact.sa_mask, &act->sa_mask, sizeof (kact.sa_mask));
+		kact.sa_flags = act->sa_flags;
+
+		if (kact.sa_flags & SA_RESTORER) {
+			kact.sa_restorer = act->sa_restorer;
+		} else {
+			kact.sa_restorer = __default_sa_restorer;
+			kact.sa_flags |= SA_RESTORER;
+		}
+	}
+
+	result = __syscall_rt_sigaction(signum, act ? __ptrvalue (&kact) : NULL,
+									oldact ? __ptrvalue (&koldact) : NULL,
+									_NSIG / 8);
+
+	if (oldact && result >= 0) {
+		oldact->sa_handler = koldact.k_sa_handler;
+		memcpy(&oldact->sa_mask, &koldact.sa_mask, sizeof(oldact->sa_mask));
+		oldact->sa_flags = koldact.sa_flags;
+		oldact->sa_restorer = koldact.sa_restorer;
+	}
+
+	return result;
+}
+
+#ifndef LIBC_SIGACTION
+libc_hidden_proto (sigaction)
+weak_alias (__libc_sigaction, sigaction)
+libc_hidden_weak (sigaction)
+#endif