[PATCH] x86: Don't require the vDSO for handling a.out signals

and in other strange binfmts. vDSO is not necessarily mapped there.

Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
index 8f4afcc..4f99e87 100644
--- a/arch/i386/kernel/signal.c
+++ b/arch/i386/kernel/signal.c
@@ -21,6 +21,7 @@
 #include <linux/suspend.h>
 #include <linux/ptrace.h>
 #include <linux/elf.h>
+#include <linux/binfmts.h>
 #include <asm/processor.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
@@ -349,7 +350,10 @@
 			goto give_sigsegv;
 	}
 
-	restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
+	if (current->binfmt->hasvdso)
+		restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
+	else
+		restorer = (void *)&frame->retcode;
 	if (ka->sa.sa_flags & SA_RESTORER)
 		restorer = ka->sa.sa_restorer;