diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index e477c9d0498b..8a1b001d0b11 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -605,6 +605,13 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 	regs->ccr = 0;
 	regs->gpr[1] = sp;
 
+	/*
+	 * We have just cleared all the nonvolatile GPRs, so make
+	 * FULL_REGS(regs) return true.  This is necessary to allow
+	 * ptrace to examine the thread immediately after exec.
+	 */
+	regs->trap &= ~1UL;
+
 #ifdef CONFIG_PPC32
 	regs->mq = 0;
 	regs->nip = start;