diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index cfb8fd76afb4..c43cc26bde5d 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1800,7 +1800,7 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 		tm_reclaim_current(0);
 #endif
 
-	memset(regs->gpr, 0, sizeof(regs->gpr));
+	memset(&regs->gpr[1], 0, sizeof(regs->gpr) - sizeof(regs->gpr[0]));
 	regs->ctr = 0;
 	regs->link = 0;
 	regs->xer = 0;