--- zzzz-none-000/linux-2.6.19.2/arch/powerpc/kernel/signal_32.c	2007-01-10 19:10:37.000000000 +0000
+++ davinci-8020-5505/linux-2.6.19.2/arch/powerpc/kernel/signal_32.c	2007-01-19 14:42:56.000000000 +0000
@@ -759,7 +759,7 @@
 
 	/* Save user registers on the stack */
 	frame = &rt_sf->uc.uc_mcontext;
-	if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
+	if (vdso32_rt_sigtramp && current->mm->context.vdso_base != ~0UL) {
 		if (save_user_regs(regs, frame, 0))
 			goto badframe;
 		regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp;