From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42164 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915AbeCPPiM (ORCPT ); Fri, 16 Mar 2018 11:38:12 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Piggin , Michael Ellerman , Sasha Levin Subject: [PATCH 4.14 094/109] powerpc/64: Dont trace irqs-off at interrupt return to soft-disabled context Date: Fri, 16 Mar 2018 16:24:03 +0100 Message-Id: <20180316152335.018699164@linuxfoundation.org> In-Reply-To: <20180316152329.844663293@linuxfoundation.org> References: <20180316152329.844663293@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Piggin [ Upstream commit acb1feab320e38588fccc568e3767761f494976f ] When an interrupt is returning to a soft-disabled context (which can happen for non-maskable interrupts or synchronous interrupts), it goes through the motions of soft-disabling again, including calling TRACE_DISABLE_INTS (i.e., trace_hardirqs_off()). This is not necessary, because we must already be soft-disabled in the interrupt context, it also may be causing crashes in the irq tracing code to re-enter as an nmi. Replace it with a warning to ensure that soft-interrupts are still disabled. Fixes: 7c0482e3d055 ("powerpc/irq: Fix another case of lazy IRQ state getting out of sync") Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/entry_64.S | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -939,9 +939,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) beq 1f rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS stb r7,PACAIRQHAPPENED(r13) -1: li r0,0 - stb r0,PACASOFTIRQEN(r13); - TRACE_DISABLE_INTS +1: +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_BUG) + /* The interrupt should not have soft enabled. */ + lbz r7,PACASOFTIRQEN(r13) +1: tdnei r7,0 + EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING +#endif b .Ldo_restore /*